/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * 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/. */

#include "nsPlacesTables.h"

#ifndef __nsPlacesTriggers_h__
#define __nsPlacesTriggers_h__

/**
 * Exclude these visit types:
 *  0 - invalid
 *  4 - EMBED
 *  7 - DOWNLOAD
 *  8 - FRAMED_LINK
 *  9 - RELOAD
 **/
#define EXCLUDED_VISIT_TYPES "0, 4, 7, 8, 9"

/**
 * This triggers update visit_count and last_visit_date based on historyvisits
 * table changes.
 */
#define CREATE_HISTORYVISITS_AFTERINSERT_TRIGGER NS_LITERAL_CSTRING( \
  "CREATE TEMP TRIGGER moz_historyvisits_afterinsert_v2_trigger " \
  "AFTER INSERT ON moz_historyvisits FOR EACH ROW " \
  "BEGIN " \
    "SELECT store_last_inserted_id('moz_historyvisits', NEW.id); " \
    "UPDATE moz_places SET " \
      "visit_count = visit_count + (SELECT NEW.visit_type NOT IN (" EXCLUDED_VISIT_TYPES ")), "\
      "last_visit_date = MAX(IFNULL(last_visit_date, 0), NEW.visit_date) " \
    "WHERE id = NEW.place_id;" \
  "END" \
)

#define CREATE_HISTORYVISITS_AFTERDELETE_TRIGGER NS_LITERAL_CSTRING( \
  "CREATE TEMP TRIGGER moz_historyvisits_afterdelete_v2_trigger " \
  "AFTER DELETE ON moz_historyvisits FOR EACH ROW " \
  "BEGIN " \
    "UPDATE moz_places SET " \
      "visit_count = visit_count - (SELECT OLD.visit_type NOT IN (" EXCLUDED_VISIT_TYPES ")), "\
      "last_visit_date = (SELECT visit_date FROM moz_historyvisits " \
                         "WHERE place_id = OLD.place_id " \
                         "ORDER BY visit_date DESC LIMIT 1) " \
    "WHERE id = OLD.place_id;" \
  "END" \
)

/**
 * A predicate matching pages on rev_host, based on a given host value.
 * 'host' may be either the moz_hosts.host column or an alias representing an
 * equivalent value.
 */
#define HOST_TO_REVHOST_PREDICATE \
  "rev_host = get_unreversed_host(host || '.') || '.' " \
  "OR rev_host = get_unreversed_host(host || '.') || '.www.'"

/**
 * Select the best prefix for a host, based on existing pages registered for it.
 * Prefixes have a priority, from the top to the bottom, so that secure pages
 * have higher priority, and more generically "www." prefixed hosts come before
 * unprefixed ones.
 * Given a host, examine associated pages and:
 *  - if all of the typed pages start with https://www. return https://www.
 *  - if all of the typed pages start with https:// return https://
 *  - if all of the typed pages start with ftp: return ftp://
 *  - if all of the typed pages start with www. return www.
 *  - otherwise don't use any prefix
 */
#define HOSTS_PREFIX_PRIORITY_FRAGMENT \
  "SELECT CASE " \
    "WHEN 1 = ( " \
      "SELECT min(substr(url,1,12) = 'https://www.') FROM moz_places h " \
      "WHERE (" HOST_TO_REVHOST_PREDICATE ") AND +h.typed = 1 " \
    ") THEN 'https://www.' " \
    "WHEN 1 = ( " \
      "SELECT min(substr(url,1,8) = 'https://') FROM moz_places h " \
      "WHERE (" HOST_TO_REVHOST_PREDICATE ") AND +h.typed = 1 " \
    ") THEN 'https://' " \
    "WHEN 1 = ( " \
      "SELECT min(substr(url,1,4) = 'ftp:') FROM moz_places h " \
      "WHERE (" HOST_TO_REVHOST_PREDICATE ") AND +h.typed = 1 " \
    ") THEN 'ftp://' " \
    "WHEN 1 = ( " \
      "SELECT min(substr(url,1,11) = 'http://www.') FROM moz_places h " \
      "WHERE (" HOST_TO_REVHOST_PREDICATE ") AND +h.typed = 1 " \
    ") THEN 'www.' " \
  "END "

/**
 * These triggers update the hostnames table whenever moz_places changes.
 */
#define CREATE_PLACES_AFTERINSERT_TRIGGER NS_LITERAL_CSTRING( \
  "CREATE TEMP TRIGGER moz_places_afterinsert_trigger " \
  "AFTER INSERT ON moz_places FOR EACH ROW " \
  "BEGIN " \
    "SELECT store_last_inserted_id('moz_places', NEW.id); " \
    "INSERT OR REPLACE INTO moz_hosts (id, host, frecency, typed, prefix) " \
    "SELECT " \
        "(SELECT id FROM moz_hosts WHERE host = fixup_url(get_unreversed_host(NEW.rev_host))), " \
        "fixup_url(get_unreversed_host(NEW.rev_host)), " \
        "MAX(IFNULL((SELECT frecency FROM moz_hosts WHERE host = fixup_url(get_unreversed_host(NEW.rev_host))), -1), NEW.frecency), " \
        "MAX(IFNULL((SELECT typed FROM moz_hosts WHERE host = fixup_url(get_unreversed_host(NEW.rev_host))), 0), NEW.typed), " \
        "(" HOSTS_PREFIX_PRIORITY_FRAGMENT \
         "FROM ( " \
            "SELECT fixup_url(get_unreversed_host(NEW.rev_host)) AS host " \
          ") AS match " \
        ") " \
    " WHERE LENGTH(NEW.rev_host) > 1; " \
  "END" \
)

// This is a hack to workaround the lack of FOR EACH STATEMENT in Sqlite, until
// bug 871908 can be fixed properly.
// We store the modified hosts in a temp table, and after every DELETE FROM
// moz_places, we issue a DELETE FROM moz_updatehosts_temp.  The AFTER DELETE
// trigger will then take care of updating the moz_hosts table.
// Note this way we lose atomicity, crashing between the 2 queries may break the
// hosts table coherency. So it's better to run those DELETE queries in a single
// transaction.
// Regardless, this is still better than hanging the browser for several minutes
// on a fast machine.
#define CREATE_PLACES_AFTERDELETE_TRIGGER NS_LITERAL_CSTRING( \
  "CREATE TEMP TRIGGER moz_places_afterdelete_trigger " \
  "AFTER DELETE ON moz_places FOR EACH ROW " \
  "BEGIN " \
    "INSERT OR IGNORE INTO moz_updatehosts_temp (host)" \
    "VALUES (fixup_url(get_unreversed_host(OLD.rev_host)));" \
  "END" \
)

#define CREATE_UPDATEHOSTS_AFTERDELETE_TRIGGER NS_LITERAL_CSTRING( \
  "CREATE TEMP TRIGGER moz_updatehosts_afterdelete_trigger " \
  "AFTER DELETE ON moz_updatehosts_temp FOR EACH ROW " \
  "BEGIN " \
    "DELETE FROM moz_hosts " \
    "WHERE host = OLD.host " \
      "AND NOT EXISTS(" \
        "SELECT 1 FROM moz_places " \
          "WHERE rev_host = get_unreversed_host(host || '.') || '.' " \
             "OR rev_host = get_unreversed_host(host || '.') || '.www.' " \
      "); " \
    "UPDATE moz_hosts " \
    "SET prefix = (" HOSTS_PREFIX_PRIORITY_FRAGMENT ") " \
    "WHERE host = OLD.host; " \
  "END" \
)

// For performance reasons the host frecency is updated only when the page
// frecency changes by a meaningful percentage.  This is because the frecency
// decay algorithm requires to update all the frecencies at once, causing a
// too high overhead, while leaving the ordering unchanged.
#define CREATE_PLACES_AFTERUPDATE_FRECENCY_TRIGGER NS_LITERAL_CSTRING( \
  "CREATE TEMP TRIGGER moz_places_afterupdate_frecency_trigger " \
  "AFTER UPDATE OF frecency ON moz_places FOR EACH ROW " \
  "WHEN NEW.frecency >= 0 " \
    "AND ABS(" \
      "IFNULL((NEW.frecency - OLD.frecency) / CAST(NEW.frecency AS REAL), " \
             "(NEW.frecency - OLD.frecency))" \
    ") > .05 " \
  "BEGIN " \
    "UPDATE moz_hosts " \
    "SET frecency = (SELECT MAX(frecency) FROM moz_places " \
                    "WHERE rev_host = get_unreversed_host(host || '.') || '.' " \
                       "OR rev_host = get_unreversed_host(host || '.') || '.www.') " \
    "WHERE host = fixup_url(get_unreversed_host(NEW.rev_host)); " \
  "END" \
)

#define CREATE_PLACES_AFTERUPDATE_TYPED_TRIGGER NS_LITERAL_CSTRING( \
  "CREATE TEMP TRIGGER moz_places_afterupdate_typed_trigger " \
  "AFTER UPDATE OF typed ON moz_places FOR EACH ROW " \
  "WHEN NEW.typed = 1 " \
  "BEGIN " \
    "UPDATE moz_hosts " \
    "SET typed = 1 " \
    "WHERE host = fixup_url(get_unreversed_host(NEW.rev_host)); " \
  "END" \
)

/**
 * This trigger removes a row from moz_openpages_temp when open_count reaches 0.
 *
 * @note this should be kept up-to-date with the definition in
 *       nsPlacesAutoComplete.js
 */
#define CREATE_REMOVEOPENPAGE_CLEANUP_TRIGGER NS_LITERAL_CSTRING( \
  "CREATE TEMPORARY TRIGGER moz_openpages_temp_afterupdate_trigger " \
  "AFTER UPDATE OF open_count ON moz_openpages_temp FOR EACH ROW " \
  "WHEN NEW.open_count = 0 " \
  "BEGIN " \
    "DELETE FROM moz_openpages_temp " \
    "WHERE url = NEW.url;" \
  "END" \
)

#define CREATE_BOOKMARKS_FOREIGNCOUNT_AFTERDELETE_TRIGGER NS_LITERAL_CSTRING( \
  "CREATE TEMP TRIGGER moz_bookmarks_foreign_count_afterdelete_trigger " \
  "AFTER DELETE ON moz_bookmarks FOR EACH ROW " \
  "BEGIN " \
    "UPDATE moz_places " \
    "SET foreign_count = foreign_count - 1 " \
    "WHERE id = OLD.fk;" \
  "END" \
)

#define CREATE_BOOKMARKS_FOREIGNCOUNT_AFTERINSERT_TRIGGER NS_LITERAL_CSTRING( \
  "CREATE TEMP TRIGGER moz_bookmarks_foreign_count_afterinsert_trigger " \
  "AFTER INSERT ON moz_bookmarks FOR EACH ROW " \
  "BEGIN " \
    "SELECT store_last_inserted_id('moz_bookmarks', NEW.id); " \
    "UPDATE moz_places " \
    "SET foreign_count = foreign_count + 1 " \
    "WHERE id = NEW.fk;" \
  "END" \
)

#define CREATE_BOOKMARKS_FOREIGNCOUNT_AFTERUPDATE_TRIGGER NS_LITERAL_CSTRING( \
  "CREATE TEMP TRIGGER moz_bookmarks_foreign_count_afterupdate_trigger " \
  "AFTER UPDATE OF fk ON moz_bookmarks FOR EACH ROW " \
  "BEGIN " \
    "UPDATE moz_places " \
    "SET foreign_count = foreign_count + 1 " \
    "WHERE id = NEW.fk;" \
    "UPDATE moz_places " \
    "SET foreign_count = foreign_count - 1 " \
    "WHERE id = OLD.fk;" \
  "END" \
)

#define CREATE_KEYWORDS_FOREIGNCOUNT_AFTERDELETE_TRIGGER NS_LITERAL_CSTRING( \
  "CREATE TEMP TRIGGER moz_keywords_foreign_count_afterdelete_trigger " \
  "AFTER DELETE ON moz_keywords FOR EACH ROW " \
  "BEGIN " \
    "UPDATE moz_places " \
    "SET foreign_count = foreign_count - 1 " \
    "WHERE id = OLD.place_id;" \
  "END" \
)

#define CREATE_KEYWORDS_FOREIGNCOUNT_AFTERINSERT_TRIGGER NS_LITERAL_CSTRING( \
  "CREATE TEMP TRIGGER moz_keyords_foreign_count_afterinsert_trigger " \
  "AFTER INSERT ON moz_keywords FOR EACH ROW " \
  "BEGIN " \
    "UPDATE moz_places " \
    "SET foreign_count = foreign_count + 1 " \
    "WHERE id = NEW.place_id;" \
  "END" \
)

#define CREATE_KEYWORDS_FOREIGNCOUNT_AFTERUPDATE_TRIGGER NS_LITERAL_CSTRING( \
  "CREATE TEMP TRIGGER moz_keywords_foreign_count_afterupdate_trigger " \
  "AFTER UPDATE OF place_id ON moz_keywords FOR EACH ROW " \
  "BEGIN " \
    "UPDATE moz_places " \
    "SET foreign_count = foreign_count + 1 " \
    "WHERE id = NEW.place_id; " \
    "UPDATE moz_places " \
    "SET foreign_count = foreign_count - 1 " \
    "WHERE id = OLD.place_id; " \
  "END" \
)

#endif // __nsPlacesTriggers_h__