summaryrefslogtreecommitdiff
path: root/components/addons/src/AddonRepository.jsm
blob: a857a5530eac21a52a828ae6d206455b1999180a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

"use strict";

const Cc = Components.classes;
const Ci = Components.interfaces;
const Cu = Components.utils;
const Cr = Components.results;

Components.utils.import("resource://gre/modules/Services.jsm");
Components.utils.import("resource://gre/modules/AddonManager.jsm");
Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");

XPCOMUtils.defineLazyModuleGetter(this, "NetUtil",
                                  "resource://gre/modules/NetUtil.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "OS",
                                  "resource://gre/modules/osfile.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "DeferredSave",
                                  "resource://gre/modules/DeferredSave.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "AddonRepository_SQLiteMigrator",
                                  "resource://gre/modules/addons/AddonRepository_SQLiteMigrator.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "Promise",
                                  "resource://gre/modules/Promise.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "Task",
                                  "resource://gre/modules/Task.jsm");


this.EXPORTED_SYMBOLS = [ "AddonRepository" ];

const PREF_GETADDONS_CACHE_ENABLED       = "extensions.getAddons.cache.enabled";
const PREF_GETADDONS_CACHE_TYPES         = "extensions.getAddons.cache.types";
const PREF_GETADDONS_CACHE_ID_ENABLED    = "extensions.%ID%.getAddons.cache.enabled"
const PREF_GETADDONS_BROWSEADDONS        = "extensions.getAddons.browseAddons";
const PREF_GETADDONS_BYIDS               = "extensions.getAddons.get.url";
const PREF_GETADDONS_BYIDS_PERFORMANCE   = "extensions.getAddons.getWithPerformance.url";
const PREF_GETADDONS_BROWSERECOMMENDED   = "extensions.getAddons.recommended.browseURL";
const PREF_GETADDONS_GETRECOMMENDED      = "extensions.getAddons.recommended.url";
const PREF_GETADDONS_BROWSESEARCHRESULTS = "extensions.getAddons.search.browseURL";
const PREF_GETADDONS_GETSEARCHRESULTS    = "extensions.getAddons.search.url";
const PREF_GETADDONS_DB_SCHEMA           = "extensions.getAddons.databaseSchema"

const PREF_METADATA_LASTUPDATE           = "extensions.getAddons.cache.lastUpdate";
const PREF_METADATA_UPDATETHRESHOLD_SEC  = "extensions.getAddons.cache.updateThreshold";
const DEFAULT_METADATA_UPDATETHRESHOLD_SEC = 172800;  // two days

const XMLURI_PARSE_ERROR  = "http://www.mozilla.org/newlayout/xml/parsererror.xml";

const API_VERSION = "1.5";
const DEFAULT_CACHE_TYPES = "extension,theme,locale,dictionary";

const KEY_PROFILEDIR        = "ProfD";
const FILE_DATABASE         = "addons.json";
const DB_SCHEMA             = 5;
const DB_MIN_JSON_SCHEMA    = 5;
const DB_BATCH_TIMEOUT_MS   = 50;

const BLANK_DB = function() {
  return {
    addons: new Map(),
    schema: DB_SCHEMA
  };
}

const TOOLKIT_ID     = "toolkit@mozilla.org";
Cu.import("resource://gre/modules/Log.jsm");
const LOGGER_ID = "addons.repository";

// Create a new logger for use by the Addons Repository
// (Requires AddonManager.jsm)
var logger = Log.repository.getLogger(LOGGER_ID);

// A map between XML keys to AddonSearchResult keys for string values
// that require no extra parsing from XML
const STRING_KEY_MAP = {
  name:               "name",
  version:            "version",
  homepage:           "homepageURL",
  support:            "supportURL"
};

// A map between XML keys to AddonSearchResult keys for string values
// that require parsing from HTML
const HTML_KEY_MAP = {
  summary:            "description",
  description:        "fullDescription",
  developer_comments: "developerComments",
  eula:               "eula"
};

// A map between XML keys to AddonSearchResult keys for integer values
// that require no extra parsing from XML
const INTEGER_KEY_MAP = {
  total_downloads:  "totalDownloads",
  weekly_downloads: "weeklyDownloads",
  daily_users:      "dailyUsers"
};

// Wrap the XHR factory so that tests can override with a mock
var XHRequest = Components.Constructor("@mozilla.org/xmlextras/xmlhttprequest;1",
                                       "nsIXMLHttpRequest");

function convertHTMLToPlainText(html) {
  if (!html)
    return html;
  var converter = Cc["@mozilla.org/widget/htmlformatconverter;1"].
                  createInstance(Ci.nsIFormatConverter);

  var input = Cc["@mozilla.org/supports-string;1"].
              createInstance(Ci.nsISupportsString);
  input.data = html.replace(/\n/g, "<br>");

  var output = {};
  converter.convert("text/html", input, input.data.length, "text/unicode",
                    output, {});

  if (output.value instanceof Ci.nsISupportsString)
    return output.value.data.replace(/\r\n/g, "\n");
  return html;
}

function getAddonsToCache(aIds, aCallback) {
  try {
    var types = Services.prefs.getCharPref(PREF_GETADDONS_CACHE_TYPES);
  }
  catch (e) { }
  if (!types)
    types = DEFAULT_CACHE_TYPES;

  types = types.split(",");

  AddonManager.getAddonsByIDs(aIds, function getAddonsToCache_getAddonsByIDs(aAddons) {
    let enabledIds = [];
    for (var i = 0; i < aIds.length; i++) {
      var preference = PREF_GETADDONS_CACHE_ID_ENABLED.replace("%ID%", aIds[i]);
      try {
        if (!Services.prefs.getBoolPref(preference))
          continue;
      } catch(e) {
        // If the preference doesn't exist caching is enabled by default
      }

      // The add-ons manager may not know about this ID yet if it is a pending
      // install. In that case we'll just cache it regardless
      if (aAddons[i] && (types.indexOf(aAddons[i].type) == -1))
        continue;

      enabledIds.push(aIds[i]);
    }

    aCallback(enabledIds);
  });
}

function AddonSearchResult(aId) {
  this.id = aId;
  this.icons = {};
  this._unsupportedProperties = {};
}

AddonSearchResult.prototype = {
  /**
   * The ID of the add-on
   */
  id: null,

  /**
   * The add-on type (e.g. "extension" or "theme")
   */
  type: null,

  /**
   * The name of the add-on
   */
  name: null,

  /**
   * The version of the add-on
   */
  version: null,

  /**
   * The creator of the add-on
   */
  creator: null,

  /**
   * The developers of the add-on
   */
  developers: null,

  /**
   * A short description of the add-on
   */
  description: null,

  /**
   * The full description of the add-on
   */
  fullDescription: null,

  /**
   * The developer comments for the add-on. This includes any information
   * that may be helpful to end users that isn't necessarily applicable to
   * the add-on description (e.g. known major bugs)
   */
  developerComments: null,

  /**
   * The end-user licensing agreement (EULA) of the add-on
   */
  eula: null,

  /**
   * The url of the add-on's icon
   */
  get iconURL() {
    return this.icons && this.icons[32];
  },

   /**
   * The URLs of the add-on's icons, as an object with icon size as key
   */
  icons: null,

  /**
   * An array of screenshot urls for the add-on
   */
  screenshots: null,

  /**
   * The homepage for the add-on
   */
  homepageURL: null,

  /**
   * The homepage for the add-on
   */
  learnmoreURL: null,

  /**
   * The support URL for the add-on
   */
  supportURL: null,

  /**
   * The contribution url of the add-on
   */
  contributionURL: null,

  /**
   * The suggested contribution amount
   */
  contributionAmount: null,

  /**
   * The URL to visit in order to purchase the add-on
   */
  purchaseURL: null,

  /**
   * The numerical cost of the add-on in some currency, for sorting purposes
   * only
   */
  purchaseAmount: null,

  /**
   * The display cost of the add-on, for display purposes only
   */
  purchaseDisplayAmount: null,

  /**
   * The rating of the add-on, 0-5
   */
  averageRating: null,

  /**
   * The number of reviews for this add-on
   */
  reviewCount: null,

  /**
   * The URL to the list of reviews for this add-on
   */
  reviewURL: null,

  /**
   * The total number of times the add-on was downloaded
   */
  totalDownloads: null,

  /**
   * The number of times the add-on was downloaded the current week
   */
  weeklyDownloads: null,

  /**
   * The number of daily users for the add-on
   */
  dailyUsers: null,

  /**
   * AddonInstall object generated from the add-on XPI url
   */
  install: null,

  /**
   * nsIURI storing where this add-on was installed from
   */
  sourceURI: null,

  /**
   * The status of the add-on in the repository (e.g. 4 = "Public")
   */
  repositoryStatus: null,

  /**
   * The size of the add-on's files in bytes. For an add-on that have not yet
   * been downloaded this may be an estimated value.
   */
  size: null,

  /**
   * The Date that the add-on was most recently updated
   */
  updateDate: null,

  /**
   * True or false depending on whether the add-on is compatible with the
   * current version of the application
   */
  isCompatible: true,

  /**
   * True or false depending on whether the add-on is compatible with the
   * current platform
   */
  isPlatformCompatible: true,

  /**
   * Array of AddonCompatibilityOverride objects, that describe overrides for
   * compatibility with an application versions.
   **/
  compatibilityOverrides: null,

  /**
   * True if the add-on has a secure means of updating
   */
  providesUpdatesSecurely: true,

  /**
   * The current blocklist state of the add-on
   */
  blocklistState: Ci.nsIBlocklistService.STATE_NOT_BLOCKED,

  /**
   * True if this add-on cannot be used in the application based on version
   * compatibility, dependencies and blocklisting
   */
  appDisabled: false,

  /**
   * True if the user wants this add-on to be disabled
   */
  userDisabled: false,

  /**
   * Indicates what scope the add-on is installed in, per profile, user,
   * system or application
   */
  scope: AddonManager.SCOPE_PROFILE,

  /**
   * True if the add-on is currently functional
   */
  isActive: true,

  /**
   * A bitfield holding all of the current operations that are waiting to be
   * performed for this add-on
   */
  pendingOperations: AddonManager.PENDING_NONE,

  /**
   * A bitfield holding all the the operations that can be performed on
   * this add-on
   */
  permissions: 0,

  /**
   * Tests whether this add-on is known to be compatible with a
   * particular application and platform version.
   *
   * @param  appVersion
   *         An application version to test against
   * @param  platformVersion
   *         A platform version to test against
   * @return Boolean representing if the add-on is compatible
   */
  isCompatibleWith: function ASR_isCompatibleWith(aAppVerison, aPlatformVersion) {
    return true;
  },

  /**
   * Starts an update check for this add-on. This will perform
   * asynchronously and deliver results to the given listener.
   *
   * @param  aListener
   *         An UpdateListener for the update process
   * @param  aReason
   *         A reason code for performing the update
   * @param  aAppVersion
   *         An application version to check for updates for
   * @param  aPlatformVersion
   *         A platform version to check for updates for
   */
  findUpdates: function ASR_findUpdates(aListener, aReason, aAppVersion, aPlatformVersion) {
    if ("onNoCompatibilityUpdateAvailable" in aListener)
      aListener.onNoCompatibilityUpdateAvailable(this);
    if ("onNoUpdateAvailable" in aListener)
      aListener.onNoUpdateAvailable(this);
    if ("onUpdateFinished" in aListener)
      aListener.onUpdateFinished(this);
  },

  toJSON: function() {
    let json = {};

    for (let [property, value] of Iterator(this)) {
      if (property.startsWith("_") ||
          typeof(value) === "function")
        continue;

      try {
        switch (property) {
          case "sourceURI":
            json.sourceURI = value ? value.spec : "";
            break;

          case "updateDate":
            json.updateDate = value ? value.getTime() : "";
            break;

          default:
            json[property] = value;
        }
      } catch (ex) {
        logger.warn("Error writing property value for " + property);
      }
    }

    for (let [property, value] of Iterator(this._unsupportedProperties)) {
      if (!property.startsWith("_"))
        json[property] = value;
    }

    return json;
  }
}

/**
 * The add-on repository is a source of add-ons that can be installed. It can
 * be searched in three ways. The first takes a list of IDs and returns a
 * list of the corresponding add-ons. The second returns a list of add-ons that
 * come highly recommended. This list should change frequently. The third is to
 * search for specific search terms entered by the user. Searches are
 * asynchronous and results should be passed to the provided callback object
 * when complete. The results passed to the callback should only include add-ons
 * that are compatible with the current application and are not already
 * installed.
 */
this.AddonRepository = {
  /**
   * Whether caching is currently enabled
   */
  get cacheEnabled() {
    // Act as though caching is disabled if there was an unrecoverable error
    // openning the database.
    if (!AddonDatabase.databaseOk) {
      logger.warn("Cache is disabled because database is not OK");
      return false;
    }

    let preference = PREF_GETADDONS_CACHE_ENABLED;
    return Services.prefs.getBoolPref(preference, false);
  },

  // A cache of the add-ons stored in the database
  _addons: null,

  // Whether a search is currently in progress
  _searching: false,

  // XHR associated with the current request
  _request: null,

  /*
   * Addon search results callback object that contains two functions
   *
   * searchSucceeded - Called when a search has suceeded.
   *
   * @param  aAddons
   *         An array of the add-on results. In the case of searching for
   *         specific terms the ordering of results may be determined by
   *         the search provider.
   * @param  aAddonCount
   *         The length of aAddons
   * @param  aTotalResults
   *         The total results actually available in the repository
   *
   *
   * searchFailed - Called when an error occurred when performing a search.
   */
  _callback: null,

  // Maximum number of results to return
  _maxResults: null,

  /**
   * Shut down AddonRepository
   * return: promise{integer} resolves with the result of flushing
   *         the AddonRepository database
   */
  shutdown: function AddonRepo_shutdown() {
    this.cancelSearch();

    this._addons = null;
    return AddonDatabase.shutdown(false);
  },

  metadataAge: function() {
    let now = Math.round(Date.now() / 1000);
    let lastUpdate = Services.prefs.getIntPref(PREF_METADATA_LASTUPDATE, 0);

    // Handle clock jumps
    if (now < lastUpdate) {
      return now;
    }
    return now - lastUpdate;
  },

  isMetadataStale: function AddonRepo_isMetadataStale() {
    let threshold = Services.prefs.getIntPref(PREF_METADATA_UPDATETHRESHOLD_SEC,
                                              DEFAULT_METADATA_UPDATETHRESHOLD_SEC);
    return (this.metadataAge() > threshold);
  },

  /**
   * Asynchronously get a cached add-on by id. The add-on (or null if the
   * add-on is not found) is passed to the specified callback. If caching is
   * disabled, null is passed to the specified callback.
   *
   * @param  aId
   *         The id of the add-on to get
   * @param  aCallback
   *         The callback to pass the result back to
   */
  getCachedAddonByID: Task.async(function* (aId, aCallback) {
    if (!aId || !this.cacheEnabled) {
      aCallback(null);
      return;
    }

    function getAddon(aAddons) {
      aCallback(aAddons.get(aId) || null);
    }

    if (this._addons == null) {
      AddonDatabase.retrieveStoredData().then(aAddons => {
        this._addons = aAddons;
        getAddon(aAddons);
      });

      return;
    }

    getAddon(this._addons);
  }),

  /**
   * Asynchronously repopulate cache so it only contains the add-ons
   * corresponding to the specified ids. If caching is disabled,
   * the cache is completely removed.
   *
   * @param  aTimeout
   *         (Optional) timeout in milliseconds to abandon the XHR request
   *         if we have not received a response from the server.
   * @return Promise{null}
   *         Resolves when the metadata ping is complete
   */
  repopulateCache: function(aTimeout) {
    return this._repopulateCacheInternal(false, aTimeout);
  },

  /*
   * Clear and delete the AddonRepository database
   * @return Promise{null} resolves when the database is deleted
   */
  _clearCache: function () {
    this._addons = null;
    return AddonDatabase.delete().then(() =>
      new Promise((resolve, reject) =>
        AddonManagerPrivate.updateAddonRepositoryData(resolve))
    );
  },

  _repopulateCacheInternal: Task.async(function* (aSendPerformance, aTimeout) {
    let allAddons = yield new Promise((resolve, reject) =>
      AddonManager.getAllAddons(resolve));

    // Completely remove cache if caching is not enabled
    if (!this.cacheEnabled) {
      logger.debug("Clearing cache because it is disabled");
      return this._clearCache();
    }

    // Tycho: let ids = [a.id for (a of allAddons)];
    let ids = [];
    for (let a of allAddons) {
      ids.push(a.id);
    }
    
    logger.debug("Repopulate add-on cache with " + ids.toSource());

    let self = this;
    let addonsToCache = yield new Promise((resolve, reject) =>
      getAddonsToCache(ids, resolve));

    // Completely remove cache if there are no add-ons to cache
    if (addonsToCache.length == 0) {
      logger.debug("Clearing cache because 0 add-ons were requested");
      return this._clearCache();
    }

    yield new Promise((resolve, reject) =>
      self._beginGetAddons(addonsToCache, {
        searchSucceeded: function repopulateCacheInternal_searchSucceeded(aAddons) {
          self._addons = new Map();
          for (let addon of aAddons) {
            self._addons.set(addon.id, addon);
          }
          AddonDatabase.repopulate(aAddons, resolve);
        },
        searchFailed: function repopulateCacheInternal_searchFailed() {
          logger.warn("Search failed when repopulating cache");
          resolve();
        }
      }, aSendPerformance, aTimeout));

    // Always call AddonManager updateAddonRepositoryData after we refill the cache
    yield new Promise((resolve, reject) =>
      AddonManagerPrivate.updateAddonRepositoryData(resolve));
  }),

  /**
   * Asynchronously add add-ons to the cache corresponding to the specified
   * ids. If caching is disabled, the cache is unchanged and the callback is
   * immediately called if it is defined.
   *
   * @param  aIds
   *         The array of add-on ids to add to the cache
   * @param  aCallback
   *         The optional callback to call once complete
   */
  cacheAddons: function AddonRepo_cacheAddons(aIds, aCallback) {
    logger.debug("cacheAddons: enabled " + this.cacheEnabled + " IDs " + aIds.toSource());
    if (!this.cacheEnabled) {
      if (aCallback)
        aCallback();
      return;
    }

    let self = this;
    getAddonsToCache(aIds, function cacheAddons_getAddonsToCache(aAddons) {
      // If there are no add-ons to cache, act as if caching is disabled
      if (aAddons.length == 0) {
        if (aCallback)
          aCallback();
        return;
      }

      self.getAddonsByIDs(aAddons, {
        searchSucceeded: function cacheAddons_searchSucceeded(aAddons) {
          for (let addon of aAddons) {
            self._addons.set(addon.id, addon);
          }
          AddonDatabase.insertAddons(aAddons, aCallback);
        },
        searchFailed: function cacheAddons_searchFailed() {
          logger.warn("Search failed when adding add-ons to cache");
          if (aCallback)
            aCallback();
        }
      });
    });
  },

  /**
   * The homepage for visiting this repository. If the corresponding preference
   * is not defined, defaults to about:blank.
   */
  get homepageURL() {
    let url = this._formatURLPref(PREF_GETADDONS_BROWSEADDONS, {});
    return (url != null) ? url : "about:blank";
  },

  /**
   * Returns whether this instance is currently performing a search. New
   * searches will not be performed while this is the case.
   */
  get isSearching() {
    return this._searching;
  },

  /**
   * The url that can be visited to see recommended add-ons in this repository.
   * If the corresponding preference is not defined, defaults to about:blank.
   */
  getRecommendedURL: function AddonRepo_getRecommendedURL() {
    let url = this._formatURLPref(PREF_GETADDONS_BROWSERECOMMENDED, {});
    return (url != null) ? url : "about:blank";
  },

  /**
   * Retrieves the url that can be visited to see search results for the given
   * terms. If the corresponding preference is not defined, defaults to
   * about:blank.
   *
   * @param  aSearchTerms
   *         Search terms used to search the repository
   */
  getSearchURL: function AddonRepo_getSearchURL(aSearchTerms) {
    let url = this._formatURLPref(PREF_GETADDONS_BROWSESEARCHRESULTS, {
      TERMS : encodeURIComponent(aSearchTerms)
    });
    return (url != null) ? url : "about:blank";
  },

  /**
   * Cancels the search in progress. If there is no search in progress this
   * does nothing.
   */
  cancelSearch: function AddonRepo_cancelSearch() {
    this._searching = false;
    if (this._request) {
      this._request.abort();
      this._request = null;
    }
    this._callback = null;
  },

  /**
   * Begins a search for add-ons in this repository by ID. Results will be
   * passed to the given callback.
   *
   * @param  aIDs
   *         The array of ids to search for
   * @param  aCallback
   *         The callback to pass results to
   */
  getAddonsByIDs: function AddonRepo_getAddonsByIDs(aIDs, aCallback) {
    return this._beginGetAddons(aIDs, aCallback, false);
  },

  /**
   * Begins a search of add-ons, potentially sending performance data.
   *
   * @param  aIDs
   *         Array of ids to search for.
   * @param  aCallback
   *         Function to pass results to.
   * @param  aSendPerformance
   *         Boolean indicating whether to send performance data with the
   *         request.
   * @param  aTimeout
   *         (Optional) timeout in milliseconds to abandon the XHR request
   *         if we have not received a response from the server.
   */
  _beginGetAddons: function(aIDs, aCallback, aSendPerformance, aTimeout) {
    let ids = aIDs.slice(0);

    let params = {
      API_VERSION : API_VERSION,
      IDS : ids.map(encodeURIComponent).join(',')
    };

    let pref = PREF_GETADDONS_BYIDS;

    if (aSendPerformance) {
      let type = Services.prefs.getPrefType(PREF_GETADDONS_BYIDS_PERFORMANCE);
      if (type == Services.prefs.PREF_STRING) {
        pref = PREF_GETADDONS_BYIDS_PERFORMANCE;

        let startupInfo = Cc["@mozilla.org/toolkit/app-startup;1"].
                          getService(Ci.nsIAppStartup).
                          getStartupInfo();

        params.TIME_MAIN = "";
        params.TIME_FIRST_PAINT = "";
        params.TIME_SESSION_RESTORED = "";
        if (startupInfo.process) {
          if (startupInfo.main) {
            params.TIME_MAIN = startupInfo.main - startupInfo.process;
          }
          if (startupInfo.firstPaint) {
            params.TIME_FIRST_PAINT = startupInfo.firstPaint -
                                      startupInfo.process;
          }
          if (startupInfo.sessionRestored) {
            params.TIME_SESSION_RESTORED = startupInfo.sessionRestored -
                                           startupInfo.process;
          }
        }
      }
    }

    let url = this._formatURLPref(pref, params);

    let self = this;
    function handleResults(aElements, aTotalResults, aCompatData) {
      // Don't use this._parseAddons() so that, for example,
      // incompatible add-ons are not filtered out
      let results = [];
      for (let i = 0; i < aElements.length && results.length < self._maxResults; i++) {
        let result = self._parseAddon(aElements[i], null, aCompatData);
        if (result == null)
          continue;

        // Ignore add-on if it wasn't actually requested
        let idIndex = ids.indexOf(result.addon.id);
        if (idIndex == -1)
          continue;

        // Ignore add-on if the add-on manager doesn't know about its type:
        if (!(result.addon.type in AddonManager.addonTypes)) {
          continue;
        }

        results.push(result);
        // Ignore this add-on from now on
        ids.splice(idIndex, 1);
      }

      // Include any compatibility overrides for addons not hosted by the
      // remote repository.
      for each (let addonCompat in aCompatData) {
        if (addonCompat.hosted)
          continue;

        let addon = new AddonSearchResult(addonCompat.id);
        // Compatibility overrides can only be for extensions.
        addon.type = "extension";
        addon.compatibilityOverrides = addonCompat.compatRanges;
        let result = {
          addon: addon,
          xpiURL: null,
          xpiHash: null
        };
        results.push(result);
      }

      // aTotalResults irrelevant
      self._reportSuccess(results, -1);
    }

    this._beginSearch(url, ids.length, aCallback, handleResults, aTimeout);
  },

  /**
   * Performs the daily background update check.
   *
   * This API both searches for the add-on IDs specified and sends performance
   * data. It is meant to be called as part of the daily update ping. It should
   * not be used for any other purpose. Use repopulateCache instead.
   *
   * @return Promise{null} Resolves when the metadata update is complete.
   */
  backgroundUpdateCheck: function () {
    return this._repopulateCacheInternal(true);
  },

  /**
   * Begins a search for recommended add-ons in this repository. Results will
   * be passed to the given callback.
   *
   * @param  aMaxResults
   *         The maximum number of results to return
   * @param  aCallback
   *         The callback to pass results to
   */
  retrieveRecommendedAddons: function AddonRepo_retrieveRecommendedAddons(aMaxResults, aCallback) {
    let url = this._formatURLPref(PREF_GETADDONS_GETRECOMMENDED, {
      API_VERSION : API_VERSION,

      // Get twice as many results to account for potential filtering
      MAX_RESULTS : 2 * aMaxResults
    });

    let self = this;
    function handleResults(aElements, aTotalResults) {
      self._getLocalAddonIds(function retrieveRecommendedAddons_getLocalAddonIds(aLocalAddonIds) {
        // aTotalResults irrelevant
        self._parseAddons(aElements, -1, aLocalAddonIds);
      });
    }

    this._beginSearch(url, aMaxResults, aCallback, handleResults);
  },

  /**
   * Begins a search for add-ons in this repository. Results will be passed to
   * the given callback.
   *
   * @param  aSearchTerms
   *         The terms to search for
   * @param  aMaxResults
   *         The maximum number of results to return
   * @param  aCallback
   *         The callback to pass results to
   */
  searchAddons: function AddonRepo_searchAddons(aSearchTerms, aMaxResults, aCallback) {
    let compatMode = "normal";
    if (!AddonManager.checkCompatibility)
      compatMode = "ignore";
    else if (AddonManager.strictCompatibility)
      compatMode = "strict";

    let substitutions = {
      API_VERSION : API_VERSION,
      TERMS : encodeURIComponent(aSearchTerms),
      // Get twice as many results to account for potential filtering
      MAX_RESULTS : 2 * aMaxResults,
      COMPATIBILITY_MODE : compatMode,
    };

    let url = this._formatURLPref(PREF_GETADDONS_GETSEARCHRESULTS, substitutions);

    let self = this;
    function handleResults(aElements, aTotalResults) {
      self._getLocalAddonIds(function searchAddons_getLocalAddonIds(aLocalAddonIds) {
        self._parseAddons(aElements, aTotalResults, aLocalAddonIds);
      });
    }

    this._beginSearch(url, aMaxResults, aCallback, handleResults);
  },

  // Posts results to the callback
  _reportSuccess: function AddonRepo_reportSuccess(aResults, aTotalResults) {
    this._searching = false;
    this._request = null;
    // The callback may want to trigger a new search so clear references early
    // Tycho: let addons = [result.addon for each(result in aResults)];
    let addons = [];
    for each(let result in aResults) {
      addons.push(result.addon);
    }
    
    let callback = this._callback;
    this._callback = null;
    callback.searchSucceeded(addons, addons.length, aTotalResults);
  },

  // Notifies the callback of a failure
  _reportFailure: function AddonRepo_reportFailure() {
    this._searching = false;
    this._request = null;
    // The callback may want to trigger a new search so clear references early
    let callback = this._callback;
    this._callback = null;
    callback.searchFailed();
  },

  // Get descendant by unique tag name. Returns null if not unique tag name.
  _getUniqueDescendant: function AddonRepo_getUniqueDescendant(aElement, aTagName) {
    let elementsList = aElement.getElementsByTagName(aTagName);
    return (elementsList.length == 1) ? elementsList[0] : null;
  },

  // Get direct descendant by unique tag name.
  // Returns null if not unique tag name.
  _getUniqueDirectDescendant: function AddonRepo_getUniqueDirectDescendant(aElement, aTagName) {
    let elementsList = Array.filter(aElement.children,
                                    function arrayFiltering(aChild) aChild.tagName == aTagName);
    return (elementsList.length == 1) ? elementsList[0] : null;
  },

  // Parse out trimmed text content. Returns null if text content empty.
  _getTextContent: function AddonRepo_getTextContent(aElement) {
    let textContent = aElement.textContent.trim();
    return (textContent.length > 0) ? textContent : null;
  },

  // Parse out trimmed text content of a descendant with the specified tag name
  // Returns null if the parsing unsuccessful.
  _getDescendantTextContent: function AddonRepo_getDescendantTextContent(aElement, aTagName) {
    let descendant = this._getUniqueDescendant(aElement, aTagName);
    return (descendant != null) ? this._getTextContent(descendant) : null;
  },

  // Parse out trimmed text content of a direct descendant with the specified
  // tag name.
  // Returns null if the parsing unsuccessful.
  _getDirectDescendantTextContent: function AddonRepo_getDirectDescendantTextContent(aElement, aTagName) {
    let descendant = this._getUniqueDirectDescendant(aElement, aTagName);
    return (descendant != null) ? this._getTextContent(descendant) : null;
  },

  /*
   * Creates an AddonSearchResult by parsing an <addon> element
   *
   * @param  aElement
   *         The <addon> element to parse
   * @param  aSkip
   *         Object containing ids and sourceURIs of add-ons to skip.
   * @param  aCompatData
   *         Array of parsed addon_compatibility elements to accosiate with the
   *         resulting AddonSearchResult. Optional.
   * @return Result object containing the parsed AddonSearchResult, xpiURL and
   *         xpiHash if the parsing was successful. Otherwise returns null.
   */
  _parseAddon: function AddonRepo_parseAddon(aElement, aSkip, aCompatData) {
    let skipIDs = (aSkip && aSkip.ids) ? aSkip.ids : [];
    let skipSourceURIs = (aSkip && aSkip.sourceURIs) ? aSkip.sourceURIs : [];

    let guid = this._getDescendantTextContent(aElement, "guid");
    if (guid == null || skipIDs.indexOf(guid) != -1)
      return null;

    let addon = new AddonSearchResult(guid);
    let result = {
      addon: addon,
      xpiURL: null,
      xpiHash: null
    };

    if (aCompatData && guid in aCompatData)
      addon.compatibilityOverrides = aCompatData[guid].compatRanges;

    let self = this;
    for (let node = aElement.firstChild; node; node = node.nextSibling) {
      if (!(node instanceof Ci.nsIDOMElement))
        continue;

      let localName = node.localName;

      // Handle case where the wanted string value is located in text content
      // but only if the content is not empty
      if (localName in STRING_KEY_MAP) {
        addon[STRING_KEY_MAP[localName]] = this._getTextContent(node) || addon[STRING_KEY_MAP[localName]];
        continue;
      }

      // Handle case where the wanted string value is html located in text content
      if (localName in HTML_KEY_MAP) {
        addon[HTML_KEY_MAP[localName]] = convertHTMLToPlainText(this._getTextContent(node));
        continue;
      }

      // Handle case where the wanted integer value is located in text content
      if (localName in INTEGER_KEY_MAP) {
        let value = parseInt(this._getTextContent(node));
        if (value >= 0)
          addon[INTEGER_KEY_MAP[localName]] = value;
        continue;
      }

      // Handle cases that aren't as simple as grabbing the text content
      switch (localName) {
        case "type":
          // Map AMO's type id to corresponding string
          // https://github.com/mozilla/olympia/blob/master/apps/constants/base.py#L127
          // These definitions need to be updated whenever AMO adds a new type.
          let id = parseInt(node.getAttribute("id"));
          switch (id) {
            case 1:
              addon.type = "extension";
              break;
            case 2:
              addon.type = "theme";
              break;
            case 3:
              addon.type = "dictionary";
              break;
            case 4:
              addon.type = "search";
              break;
            case 5:
            case 6:
              addon.type = "locale";
              break;
            case 7:
              addon.type = "plugin";
              break;
            case 8:
              addon.type = "api";
              break;
            case 9:
              addon.type = "lightweight-theme";
              break;
            case 11:
              addon.type = "webapp";
              break;
            default:
              logger.info("Unknown type id " + id + " found when parsing response for GUID " + guid);
          }
          break;
        case "authors":
          let authorNodes = node.getElementsByTagName("author");
          for (let authorNode of authorNodes) {
            let name = self._getDescendantTextContent(authorNode, "name");
            let link = self._getDescendantTextContent(authorNode, "link");
            if (name == null || link == null)
              continue;

            let author = new AddonManagerPrivate.AddonAuthor(name, link);
            if (addon.creator == null)
              addon.creator = author;
            else {
              if (addon.developers == null)
                addon.developers = [];

              addon.developers.push(author);
            }
          }
          break;
        case "previews":
          let previewNodes = node.getElementsByTagName("preview");
          for (let previewNode of previewNodes) {
            let full = self._getUniqueDescendant(previewNode, "full");
            if (full == null)
              continue;

            let fullURL = self._getTextContent(full);
            let fullWidth = full.getAttribute("width");
            let fullHeight = full.getAttribute("height");

            let thumbnailURL, thumbnailWidth, thumbnailHeight;
            let thumbnail = self._getUniqueDescendant(previewNode, "thumbnail");
            if (thumbnail) {
              thumbnailURL = self._getTextContent(thumbnail);
              thumbnailWidth = thumbnail.getAttribute("width");
              thumbnailHeight = thumbnail.getAttribute("height");
            }
            let caption = self._getDescendantTextContent(previewNode, "caption");
            let screenshot = new AddonManagerPrivate.AddonScreenshot(fullURL, fullWidth, fullHeight,
                                                                     thumbnailURL, thumbnailWidth,
                                                                     thumbnailHeight, caption);

            if (addon.screenshots == null)
              addon.screenshots = [];

            if (previewNode.getAttribute("primary") == 1)
              addon.screenshots.unshift(screenshot);
            else
              addon.screenshots.push(screenshot);
          }
          break;
        case "learnmore":
          addon.learnmoreURL = this._getTextContent(node);
          addon.homepageURL = addon.homepageURL || addon.learnmoreURL;
          break;
        case "contribution_data":
          let meetDevelopers = this._getDescendantTextContent(node, "meet_developers");
          let suggestedAmount = this._getDescendantTextContent(node, "suggested_amount");
          if (meetDevelopers != null) {
            addon.contributionURL = meetDevelopers;
            addon.contributionAmount = suggestedAmount;
          }
          break
        case "payment_data":
          let link = this._getDescendantTextContent(node, "link");
          let amountTag = this._getUniqueDescendant(node, "amount");
          let amount = parseFloat(amountTag.getAttribute("amount"));
          let displayAmount = this._getTextContent(amountTag);
          if (link != null && amount != null && displayAmount != null) {
            addon.purchaseURL = link;
            addon.purchaseAmount = amount;
            addon.purchaseDisplayAmount = displayAmount;
          }
          break
        case "rating":
          let averageRating = parseInt(this._getTextContent(node));
          if (averageRating >= 0)
            addon.averageRating = Math.min(5, averageRating);
          break;
        case "reviews":
          let url = this._getTextContent(node);
          let num = parseInt(node.getAttribute("num"));
          if (url != null && num >= 0) {
            addon.reviewURL = url;
            addon.reviewCount = num;
          }
          break;
        case "status":
          let repositoryStatus = parseInt(node.getAttribute("id"));
          if (!isNaN(repositoryStatus))
            addon.repositoryStatus = repositoryStatus;
          break;
        case "all_compatible_os":
          let nodes = node.getElementsByTagName("os");
          addon.isPlatformCompatible = Array.some(nodes, function parseAddon_platformCompatFilter(aNode) {
            let text = aNode.textContent.toLowerCase().trim();
            return text == "all" || text == Services.appinfo.OS.toLowerCase();
          });
          break;
        case "install":
          // No os attribute means the xpi is compatible with any os
          if (node.hasAttribute("os")) {
            let os = node.getAttribute("os").trim().toLowerCase();
            // If the os is not ALL and not the current OS then ignore this xpi
            if (os != "all" && os != Services.appinfo.OS.toLowerCase())
              break;
          }

          let xpiURL = this._getTextContent(node);
          if (xpiURL == null)
            break;

          if (skipSourceURIs.indexOf(xpiURL) != -1)
            return null;

          result.xpiURL = xpiURL;
          addon.sourceURI = NetUtil.newURI(xpiURL);

          let size = parseInt(node.getAttribute("size"));
          addon.size = (size >= 0) ? size : null;

          let xpiHash = node.getAttribute("hash");
          if (xpiHash != null)
            xpiHash = xpiHash.trim();
          result.xpiHash = xpiHash ? xpiHash : null;
          break;
        case "last_updated":
          let epoch = parseInt(node.getAttribute("epoch"));
          if (!isNaN(epoch))
            addon.updateDate = new Date(1000 * epoch);
          break;
        case "icon":
          addon.icons[node.getAttribute("size")] = this._getTextContent(node);
          break;
      }
    }

    return result;
  },

  _parseAddons: function AddonRepo_parseAddons(aElements, aTotalResults, aSkip) {
    let self = this;
    let results = [];

    function isSameApplication(aAppNode) {
      if (self._getTextContent(aAppNode) == Services.appinfo.ID) {
        return true;
      }
      return false;
    }

    for (let i = 0; i < aElements.length && results.length < this._maxResults; i++) {
      let element = aElements[i];

      let tags = this._getUniqueDescendant(element, "compatible_applications");
      if (tags == null)
        continue;

      let applications = tags.getElementsByTagName("appID");
      let compatible = Array.some(applications, function parseAddons_applicationsCompatFilter(aAppNode) {
        if (!isSameApplication(aAppNode))
          return false;

        let parent = aAppNode.parentNode;
        let minVersion = self._getDescendantTextContent(parent, "min_version");
        let maxVersion = self._getDescendantTextContent(parent, "max_version");
        if (minVersion == null || maxVersion == null)
          return false;

        let currentVersion = Services.appinfo.version;
        return (Services.vc.compare(minVersion, currentVersion) <= 0 &&
                ((!AddonManager.strictCompatibility) ||
                 Services.vc.compare(currentVersion, maxVersion) <= 0));
      });

      // Ignore add-ons not compatible with this Application
      if (!compatible) {
        if (AddonManager.checkCompatibility)
          continue;

        if (!Array.some(applications, isSameApplication))
          continue;
      }

      // Add-on meets all requirements, so parse out data.
      // Don't pass in compatiblity override data, because that's only returned
      // in GUID searches, which don't use _parseAddons().
      let result = this._parseAddon(element, aSkip);
      if (result == null)
        continue;

      // Ignore add-on missing a required attribute
      let requiredAttributes = ["id", "name", "version", "type", "creator"];
      if (requiredAttributes.some(function parseAddons_attributeFilter(aAttribute) !result.addon[aAttribute]))
        continue;

      // Ignore add-on with a type AddonManager doesn't understand:
      if (!(result.addon.type in AddonManager.addonTypes))
        continue;

      // Add only if the add-on is compatible with the platform
      if (!result.addon.isPlatformCompatible)
        continue;

      // Add only if there was an xpi compatible with this OS or there was a
      // way to purchase the add-on
      if (!result.xpiURL && !result.addon.purchaseURL)
        continue;

      result.addon.isCompatible = compatible;

      results.push(result);
      // Ignore this add-on from now on by adding it to the skip array
      aSkip.ids.push(result.addon.id);
    }

    // Immediately report success if no AddonInstall instances to create
    let pendingResults = results.length;
    if (pendingResults == 0) {
      this._reportSuccess(results, aTotalResults);
      return;
    }

    // Create an AddonInstall for each result
    results.forEach(function(aResult) {
      let addon = aResult.addon;
      let callback = function addonInstallCallback(aInstall) {
        addon.install = aInstall;
        pendingResults--;
        if (pendingResults == 0)
          self._reportSuccess(results, aTotalResults);
      }

      if (aResult.xpiURL) {
        AddonManager.getInstallForURL(aResult.xpiURL, callback,
                                      "application/x-xpinstall", aResult.xpiHash,
                                      addon.name, addon.icons, addon.version);
      }
      else {
        callback(null);
      }
    });
  },

  // Parses addon_compatibility nodes, that describe compatibility overrides.
  _parseAddonCompatElement: function AddonRepo_parseAddonCompatElement(aResultObj, aElement) {
    let guid = this._getDescendantTextContent(aElement, "guid");
    if (!guid) {
        logger.debug("Compatibility override is missing guid.");
      return;
    }

    let compat = {id: guid};
    compat.hosted = aElement.getAttribute("hosted") != "false";

    function findMatchingAppRange(aNodes) {
      let toolkitAppRange = null;
      for (let node of aNodes) {
        let appID = this._getDescendantTextContent(node, "appID");
        if (appID != Services.appinfo.ID && appID != TOOLKIT_ID)
          continue;

        let minVersion = this._getDescendantTextContent(node, "min_version");
        let maxVersion = this._getDescendantTextContent(node, "max_version");
        if (minVersion == null || maxVersion == null)
          continue;

        let appRange = { appID: appID,
                         appMinVersion: minVersion,
                         appMaxVersion: maxVersion };

        // Only use Toolkit app ranges if no ranges match the application ID.
        if (appID == TOOLKIT_ID)
          toolkitAppRange = appRange;
        else
          return appRange;
      }
      return toolkitAppRange;
    }

    function parseRangeNode(aNode) {
      let type = aNode.getAttribute("type");
      // Only "incompatible" (blacklisting) is supported for now.
      if (type != "incompatible") {
        logger.debug("Compatibility override of unsupported type found.");
        return null;
      }

      let override = new AddonManagerPrivate.AddonCompatibilityOverride(type);

      override.minVersion = this._getDirectDescendantTextContent(aNode, "min_version");
      override.maxVersion = this._getDirectDescendantTextContent(aNode, "max_version");

      if (!override.minVersion) {
        logger.debug("Compatibility override is missing min_version.");
        return null;
      }
      if (!override.maxVersion) {
        logger.debug("Compatibility override is missing max_version.");
        return null;
      }

      let appRanges = aNode.querySelectorAll("compatible_applications > application");
      let appRange = findMatchingAppRange.bind(this)(appRanges);
      if (!appRange) {
        logger.debug("Compatibility override is missing a valid application range.");
        return null;
      }

      override.appID = appRange.appID;
      override.appMinVersion = appRange.appMinVersion;
      override.appMaxVersion = appRange.appMaxVersion;

      return override;
    }

    let rangeNodes = aElement.querySelectorAll("version_ranges > version_range");
    compat.compatRanges = Array.map(rangeNodes, parseRangeNode.bind(this))
                               .filter(function compatRangesFilter(aItem) !!aItem);
    if (compat.compatRanges.length == 0)
      return;

    aResultObj[compat.id] = compat;
  },

  // Parses addon_compatibility elements.
  _parseAddonCompatData: function AddonRepo_parseAddonCompatData(aElements) {
    let compatData = {};
    Array.forEach(aElements, this._parseAddonCompatElement.bind(this, compatData));
    return compatData;
  },

  // Begins a new search if one isn't currently executing
  _beginSearch: function(aURI, aMaxResults, aCallback, aHandleResults, aTimeout) {
    if (this._searching || aURI == null || aMaxResults <= 0) {
      logger.warn("AddonRepository search failed: searching " + this._searching + " aURI " + aURI +
                  " aMaxResults " + aMaxResults);
      aCallback.searchFailed();
      return;
    }

    this._searching = true;
    this._callback = aCallback;
    this._maxResults = aMaxResults;

    logger.debug("Requesting " + aURI);

    this._request = new XHRequest();
    this._request.mozBackgroundRequest = true;
    this._request.open("GET", aURI, true);
    this._request.overrideMimeType("text/xml");
    if (aTimeout) {
      this._request.timeout = aTimeout;
    }

    this._request.addEventListener("error", aEvent => this._reportFailure(), false);
    this._request.addEventListener("timeout", aEvent => this._reportFailure(), false);
    this._request.addEventListener("load", aEvent => {
      logger.debug("Got metadata search load event");
      let request = aEvent.target;
      let responseXML = request.responseXML;

      if (!responseXML || responseXML.documentElement.namespaceURI == XMLURI_PARSE_ERROR ||
          (request.status != 200 && request.status != 0)) {
        this._reportFailure();
        return;
      }

      let documentElement = responseXML.documentElement;
      let elements = documentElement.getElementsByTagName("addon");
      let totalResults = elements.length;
      let parsedTotalResults = parseInt(documentElement.getAttribute("total_results"));
      // Parsed value of total results only makes sense if >= elements.length
      if (parsedTotalResults >= totalResults)
        totalResults = parsedTotalResults;

      let compatElements = documentElement.getElementsByTagName("addon_compatibility");
      let compatData = this._parseAddonCompatData(compatElements);

      aHandleResults(elements, totalResults, compatData);
    }, false);
    this._request.send(null);
  },

  // Gets the id's of local add-ons, and the sourceURI's of local installs,
  // passing the results to aCallback
  _getLocalAddonIds: function AddonRepo_getLocalAddonIds(aCallback) {
    let self = this;
    let localAddonIds = {ids: null, sourceURIs: null};

    AddonManager.getAllAddons(function getLocalAddonIds_getAllAddons(aAddons) {
      // Tycho: localAddonIds.ids = [a.id for each (a in aAddons)];
      localAddonIds.ids = [];
      
      for each(let a in aAddons) {
        localAddonIds.ids.push(a.id);
      }
      
      if (localAddonIds.sourceURIs)
        aCallback(localAddonIds);
    });

    AddonManager.getAllInstalls(function getLocalAddonIds_getAllInstalls(aInstalls) {
      localAddonIds.sourceURIs = [];
      aInstalls.forEach(function(aInstall) {
        if (aInstall.state != AddonManager.STATE_AVAILABLE)
          localAddonIds.sourceURIs.push(aInstall.sourceURI.spec);
      });

      if (localAddonIds.ids)
        aCallback(localAddonIds);
    });
  },

  // Create url from preference, returning null if preference does not exist
  _formatURLPref: function AddonRepo_formatURLPref(aPreference, aSubstitutions) {
    let url = Services.prefs.getCharPref(aPreference, "");
    if (!url) {
      logger.warn("_formatURLPref: Couldn't get pref: " + aPreference);
      return null;
    }

    url = url.replace(/%([A-Z_]+)%/g, function urlSubstitution(aMatch, aKey) {
      return (aKey in aSubstitutions) ? aSubstitutions[aKey] : aMatch;
    });

    return Services.urlFormatter.formatURL(url);
  },

  // Find a AddonCompatibilityOverride that matches a given aAddonVersion and
  // application/platform version.
  findMatchingCompatOverride: function AddonRepo_findMatchingCompatOverride(aAddonVersion,
                                                                     aCompatOverrides,
                                                                     aAppVersion,
                                                                     aPlatformVersion) {
    for (let override of aCompatOverrides) {

      let appVersion = null;
      if (override.appID == TOOLKIT_ID)
        appVersion = aPlatformVersion || Services.appinfo.runtimeVersion;
      else
        appVersion = aAppVersion || Services.appinfo.version;

      if (Services.vc.compare(override.minVersion, aAddonVersion) <= 0 &&
          Services.vc.compare(aAddonVersion, override.maxVersion) <= 0 &&
          Services.vc.compare(override.appMinVersion, appVersion) <= 0 &&
          Services.vc.compare(appVersion, override.appMaxVersion) <= 0) {
        return override;
      }
    }
    return null;
  },

  flush: function() {
    return AddonDatabase.flush();
  }
};

var AddonDatabase = {
  // false if there was an unrecoverable error opening the database
  databaseOk: true,

  connectionPromise: null,
  // the in-memory database
  DB: BLANK_DB(),

  /**
   * A getter to retrieve the path to the DB
   */
  get jsonFile() {
    return OS.Path.join(OS.Constants.Path.profileDir, FILE_DATABASE);
 },

  /**
   * Asynchronously opens a new connection to the database file.
   *
   * @return {Promise} a promise that resolves to the database.
   */
  openConnection: function() {
    if (!this.connectionPromise) {
     this.connectionPromise = Task.spawn(function*() {
       this.DB = BLANK_DB();

       let inputDB, schema;

       try {
         let data = yield OS.File.read(this.jsonFile, { encoding: "utf-8"})
         inputDB = JSON.parse(data);

         if (!inputDB.hasOwnProperty("addons") ||
             !Array.isArray(inputDB.addons)) {
           throw new Error("No addons array.");
         }

         if (!inputDB.hasOwnProperty("schema")) {
           throw new Error("No schema specified.");
         }

         schema = parseInt(inputDB.schema, 10);

         if (!Number.isInteger(schema) ||
             schema < DB_MIN_JSON_SCHEMA) {
           throw new Error("Invalid schema value.");
         }
       } catch (e if e instanceof OS.File.Error && e.becauseNoSuchFile) {
         logger.debug("No " + FILE_DATABASE + " found.");

         // Create a blank addons.json file
         this._saveDBToDisk();

         let dbSchema = Services.prefs.getIntPref(PREF_GETADDONS_DB_SCHEMA, 0);

         if (dbSchema < DB_MIN_JSON_SCHEMA) {
           let results = yield new Promise((resolve, reject) => {
             AddonRepository_SQLiteMigrator.migrate(resolve);
           });

           if (results.length) {
             yield this._insertAddons(results);
           }

           Services.prefs.setIntPref(PREF_GETADDONS_DB_SCHEMA, DB_SCHEMA);
         }

         return this.DB;
       } catch (e) {
         logger.error("Malformed " + FILE_DATABASE + ": " + e);
         this.databaseOk = false;

         return this.DB;
       }

       Services.prefs.setIntPref(PREF_GETADDONS_DB_SCHEMA, DB_SCHEMA);

       // We use _insertAddon manually instead of calling
       // insertAddons to avoid the write to disk which would
       // be a waste since this is the data that was just read.
       for (let addon of inputDB.addons) {
         this._insertAddon(addon);
       }

       return this.DB;
     }.bind(this));
    }

    return this.connectionPromise;
  },

  /**
   * A lazy getter for the database connection.
   */
  get connection() {
    return this.openConnection();
  },

  /**
   * Asynchronously shuts down the database connection and releases all
   * cached objects
   *
   * @param  aCallback
   *         An optional callback to call once complete
   * @param  aSkipFlush
   *         An optional boolean to skip flushing data to disk. Useful
   *         when the database is going to be deleted afterwards.
   */
  shutdown: function AD_shutdown(aSkipFlush) {
    this.databaseOk = true;

    if (!this.connectionPromise) {
      return Promise.resolve();
    }

    this.connectionPromise = null;

    if (aSkipFlush) {
      return Promise.resolve();
    } else {
      return this.Writer.flush();
    }
  },

  /**
   * Asynchronously deletes the database, shutting down the connection
   * first if initialized
   *
   * @param  aCallback
   *         An optional callback to call once complete
   * @return Promise{null} resolves when the database has been deleted
   */
  delete: function AD_delete(aCallback) {
    this.DB = BLANK_DB();

    this._deleting = this.Writer.flush()
      .then(null, () => {})
      // shutdown(true) never rejects
      .then(() => this.shutdown(true))
      .then(() => OS.File.remove(this.jsonFile, {}))
      .then(null, error => logger.error("Unable to delete Addon Repository file " +
                                 this.jsonFile, error))
      .then(() => this._deleting = null)
      .then(aCallback);
    return this._deleting;
  },

  toJSON: function AD_toJSON() {
    let json = {
      schema: this.DB.schema,
      addons: []
    }

    for (let [, value] of this.DB.addons)
      json.addons.push(value);

    return json;
  },

  /*
   * This is a deferred task writer that is used
   * to batch operations done within 50ms of each
   * other and thus generating only one write to disk
   */
  get Writer() {
    delete this.Writer;
    this.Writer = new DeferredSave(
      this.jsonFile,
      () => { return JSON.stringify(this); },
      DB_BATCH_TIMEOUT_MS
    );
    return this.Writer;
  },

  /**
   * Flush any pending I/O on the addons.json file
   * @return: Promise{null}
   *          Resolves when the pending I/O (writing out or deleting
   *          addons.json) completes
   */
  flush: function() {
    if (this._deleting) {
      return this._deleting;
    }
    return this.Writer.flush();
  },

  /**
   * Asynchronously retrieve all add-ons from the database
   * @return: Promise{Map}
   *          Resolves when the add-ons are retrieved from the database
   */
  retrieveStoredData: function (){
    return this.openConnection().then(db => db.addons);
  },

  /**
   * Asynchronously repopulates the database so it only contains the
   * specified add-ons
   *
   * @param  aAddons
   *         The array of add-ons to repopulate the database with
   * @param  aCallback
   *         An optional callback to call once complete
   */
  repopulate: function AD_repopulate(aAddons, aCallback) {
    this.DB.addons.clear();
    this.insertAddons(aAddons, function repopulate_insertAddons() {
      let now = Math.round(Date.now() / 1000);
      logger.debug("Cache repopulated, setting " + PREF_METADATA_LASTUPDATE + " to " + now);
      Services.prefs.setIntPref(PREF_METADATA_LASTUPDATE, now);
      if (aCallback)
        aCallback();
    });
  },

  /**
   * Asynchronously inserts an array of add-ons into the database
   *
   * @param  aAddons
   *         The array of add-ons to insert
   * @param  aCallback
   *         An optional callback to call once complete
   */
  insertAddons: Task.async(function* (aAddons, aCallback) {
    yield this.openConnection();
    yield this._insertAddons(aAddons, aCallback);
  }),

  _insertAddons: Task.async(function* (aAddons, aCallback) {
    for (let addon of aAddons) {
      this._insertAddon(addon);
    }

    yield this._saveDBToDisk();
    aCallback && aCallback();
  }),

  /**
   * Inserts an individual add-on into the database. If the add-on already
   * exists in the database (by id), then the specified add-on will not be
   * inserted.
   *
   * @param  aAddon
   *         The add-on to insert into the database
   * @param  aCallback
   *         The callback to call once complete
   */
  _insertAddon: function AD__insertAddon(aAddon) {
    let newAddon = this._parseAddon(aAddon);
    if (!newAddon ||
        !newAddon.id ||
        this.DB.addons.has(newAddon.id))
      return;

    this.DB.addons.set(newAddon.id, newAddon);
  },

  /*
   * Creates an AddonSearchResult by parsing an object structure
   * retrieved from the DB JSON representation.
   *
   * @param  aObj
   *         The object to parse
   * @return Returns an AddonSearchResult object.
   */
  _parseAddon: function (aObj) {
    if (aObj instanceof AddonSearchResult)
      return aObj;

    let id = aObj.id;
    if (!aObj.id)
      return null;

    let addon = new AddonSearchResult(id);

    for (let [expectedProperty,] of Iterator(AddonSearchResult.prototype)) {
      if (!(expectedProperty in aObj) ||
          typeof(aObj[expectedProperty]) === "function")
        continue;

      let value = aObj[expectedProperty];

      try {
        switch (expectedProperty) {
          case "sourceURI":
            addon.sourceURI = value ? NetUtil.newURI(value) :  null;
            break;

          case "creator":
            addon.creator = value
                            ? this._makeDeveloper(value)
                            : null;
            break;

          case "updateDate":
            addon.updateDate = value ? new Date(value) : null;
            break;

          case "developers":
            if (!addon.developers) addon.developers = [];
            for (let developer of value) {
              addon.developers.push(this._makeDeveloper(developer));
            }
            break;

          case "screenshots":
            if (!addon.screenshots) addon.screenshots = [];
            for (let screenshot of value) {
              addon.screenshots.push(this._makeScreenshot(screenshot));
            }
            break;

          case "compatibilityOverrides":
            if (!addon.compatibilityOverrides) addon.compatibilityOverrides = [];
            for (let override of value) {
              addon.compatibilityOverrides.push(
                this._makeCompatOverride(override)
              );
            }
            break;

          case "icons":
            if (!addon.icons) addon.icons = {};
            for (let [size, url] of Iterator(aObj.icons)) {
              addon.icons[size] = url;
            }
            break;

          case "iconURL":
            break;

          default:
            addon[expectedProperty] = value;
        }
      } catch (ex) {
        logger.warn("Error in parsing property value for " + expectedProperty + " | " + ex);
      }

      // delete property from obj to indicate we've already
      // handled it. The remaining public properties will
      // be stored separately and just passed through to
      // be written back to the DB.
      delete aObj[expectedProperty];
    }

    // Copy remaining properties to a separate object
    // to prevent accidental access on downgraded versions.
    // The properties will be merged in the same object
    // prior to being written back through toJSON.
    for (let remainingProperty of Object.keys(aObj)) {
      switch (typeof(aObj[remainingProperty])) {
        case "boolean":
        case "number":
        case "string":
        case "object":
          // these types are accepted
          break;
        default:
          continue;
      }

      if (!remainingProperty.startsWith("_"))
        addon._unsupportedProperties[remainingProperty] =
          aObj[remainingProperty];
    }

    return addon;
  },

  /**
   * Write the in-memory DB to disk, after waiting for
   * the DB_BATCH_TIMEOUT_MS timeout.
   *
   * @return Promise A promise that resolves after the
   *                 write to disk has completed.
   */
  _saveDBToDisk: function() {
    return this.Writer.saveChanges().then(
      null,
      e => logger.error("SaveDBToDisk failed", e));
  },

  /**
   * Make a developer object from a vanilla
   * JS object from the JSON database
   *
   * @param  aObj
   *         The JS object to use
   * @return The created developer
   */
  _makeDeveloper: function (aObj) {
    let name = aObj.name;
    let url = aObj.url;
    return new AddonManagerPrivate.AddonAuthor(name, url);
  },

  /**
   * Make a screenshot object from a vanilla
   * JS object from the JSON database
   *
   * @param  aObj
   *         The JS object to use
   * @return The created screenshot
   */
  _makeScreenshot: function (aObj) {
    let url = aObj.url;
    let width = aObj.width;
    let height = aObj.height;
    let thumbnailURL = aObj.thumbnailURL;
    let thumbnailWidth = aObj.thumbnailWidth;
    let thumbnailHeight = aObj.thumbnailHeight;
    let caption = aObj.caption;
    return new AddonManagerPrivate.AddonScreenshot(url, width, height, thumbnailURL,
                                                   thumbnailWidth, thumbnailHeight, caption);
  },

  /**
   * Make a CompatibilityOverride from a vanilla
   * JS object from the JSON database
   *
   * @param  aObj
   *         The JS object to use
   * @return The created CompatibilityOverride
   */
  _makeCompatOverride: function (aObj) {
    let type = aObj.type;
    let minVersion = aObj.minVersion;
    let maxVersion = aObj.maxVersion;
    let appID = aObj.appID;
    let appMinVersion = aObj.appMinVersion;
    let appMaxVersion = aObj.appMaxVersion;
    return new AddonManagerPrivate.AddonCompatibilityOverride(type,
                                                              minVersion,
                                                              maxVersion,
                                                              appID,
                                                              appMinVersion,
                                                              appMaxVersion);
  },
};