<?php

/**
 * db_prefs.php
 *
 * This contains functions for manipulating user preferences
 * stored in a database, accessed though the Pear DB layer.
 *
 * Database:
 *
 * The preferences table should have three columns:
 *    user       char  \  primary
 *    prefkey    char  /  key
 *    prefval    blob
 *
 *   CREATE TABLE userprefs (user CHAR(128) NOT NULL DEFAULT '',
 *                           prefkey CHAR(64) NOT NULL DEFAULT '',
 *                           prefval BLOB NOT NULL DEFAULT '',
 *                           primary key (user,prefkey));
 *
 * Configuration of databasename, username and password is done
 * by using conf.pl or the administrator plugin
 *
 * @copyright 1999-2015 The SquirrelMail Project Team
 * @license http://opensource.org/licenses/gpl-license.php GNU Public License
 * @version $Id: db_prefs.php 14512 2015-06-21 10:07:38Z pdontthink $
 * @package squirrelmail
 * @subpackage prefs
 * @since 1.1.3
 */

/** Unknown database */
define('SMDB_UNKNOWN', 0);
/** MySQL */
define('SMDB_MYSQL', 1);
/** PostgreSQL */
define('SMDB_PGSQL', 2);

if (!include_once('DB.php')) {
    // same error also in abook_database.php
    require_once(SM_PATH . 'functions/display_messages.php');
    $error  = _("Could not include PEAR database functions required for the database backend.") . "<br />\n";
    $error .= sprintf(_("Is PEAR installed, and is the include path set correctly to find %s?"),
                        '<tt>DB.php</tt>') . "<br />\n";
    $error .= _("Please contact your system administrator and report this error.");
    error_box($error, $color);
    exit;
}

global $prefs_are_cached, $prefs_cache;

/**
 * @ignore
 */
function cachePrefValues($username) {
    global $prefs_are_cached, $prefs_cache;

    sqgetGlobalVar('prefs_are_cached', $prefs_are_cached, SQ_SESSION );
    if ($prefs_are_cached) {
        sqgetGlobalVar('prefs_cache', $prefs_cache, SQ_SESSION );
        return;
    }

    sqsession_unregister('prefs_cache');
    sqsession_unregister('prefs_are_cached');

    $db = new dbPrefs;
    if(isset($db->error)) {
        printf( _("Preference database error (%s). Exiting abnormally"),
              $db->error);
        exit;
    }

    $db->fillPrefsCache($username);
    if (isset($db->error)) {
        printf( _("Preference database error (%s). Exiting abnormally"),
              $db->error);
        exit;
    }

    $prefs_are_cached = true;

    sqsession_register($prefs_cache, 'prefs_cache');
    sqsession_register($prefs_are_cached, 'prefs_are_cached');
}

/**
 * Completely undocumented class - someone document it!
 * @package squirrelmail
 */
class dbPrefs {
    var $table = 'userprefs';
    var $user_field = 'user';
    var $key_field = 'prefkey';
    var $val_field = 'prefval';

    var $dbh   = NULL;
    var $error = NULL;
    var $db_type = SMDB_UNKNOWN;

    var $default = Array('theme_default' => 0,
                         'include_self_reply_all' => 0,
                         'do_not_reply_to_self' => 1,
                         'show_html_default' => '0');

    function open() {
        global $prefs_dsn, $prefs_table;
        global $prefs_user_field, $prefs_key_field, $prefs_val_field;

        if(isset($this->dbh)) {
            return true;
        }

        if (preg_match('/^mysql/', $prefs_dsn)) {
            $this->db_type = SMDB_MYSQL;
        } elseif (preg_match('/^pgsql/', $prefs_dsn)) {
            $this->db_type = SMDB_PGSQL;
        }

        if (!empty($prefs_table)) {
            $this->table = $prefs_table;
        }
        if (!empty($prefs_user_field)) {
            $this->user_field = $prefs_user_field;
        }

        // the default user field is "user", which in PostgreSQL
        // is an identifier and causes errors if not escaped
        //
        if ($this->db_type == SMDB_PGSQL) {
           $this->user_field = '"' . $this->user_field . '"';
        }

        if (!empty($prefs_key_field)) {
            $this->key_field = $prefs_key_field;
        }
        if (!empty($prefs_val_field)) {
            $this->val_field = $prefs_val_field;
        }
        $dbh = DB::connect($prefs_dsn, true);

        if(DB::isError($dbh)) {
            $this->error = DB::errorMessage($dbh);
            return false;
        }

        $this->dbh = $dbh;
        return true;
    }

    function failQuery($res = NULL) {
        if($res == NULL) {
            printf(_("Preference database error (%s). Exiting abnormally"),
                  $this->error);
        } else {
            printf(_("Preference database error (%s). Exiting abnormally"),
                  DB::errorMessage($res));
        }
        exit;
    }


    function getKey($user, $key, $default = '') {
        global $prefs_cache;

        $result = NULL;
        $result = do_hook_function('get_pref_override', array($user, $key, $default));
// FIXME: ideally, we'd have a better way to determine if the return value from the hook above should be respected, even if it is NULL, but this is as good as it gets for now... previously the test was more weak: if (!$result)
        if (is_null($result)) {
            cachePrefValues($user);

            if (isset($prefs_cache[$key])) {
                $result = $prefs_cache[$key];
            } else {
//FIXME: is there justification for having these TWO hooks so close together?  who uses these?
                $result = do_hook_function('get_pref', array($user, $key));
//FIXME: testing below for !$result means that a plugin cannot fetch its own pref value of 0, '0', '', FALSE, or anything else that evaluates to boolean FALSE.
                if (!$result) {
                    if (isset($this->default[$key])) {
                        $result = $this->default[$key];
                    } else {
                        $result = $default;
                    }
                }
            }
        }
        return $result;
    }

    function deleteKey($user, $key) {
        global $prefs_cache;

        if (!$this->open()) {
            return false;
        }
        $query = sprintf("DELETE FROM %s WHERE %s='%s' AND %s='%s'",
                         $this->table,
                         $this->user_field,
                         $this->dbh->quoteString($user),
                         $this->key_field,
                         $this->dbh->quoteString($key));

        $res = $this->dbh->simpleQuery($query);
        if(DB::isError($res)) {
            $this->failQuery($res);
        }

        unset($prefs_cache[$key]);

        return true;
    }

    function setKey($user, $key, $value) {
        if (!$this->open()) {
            return false;
        }
        if ($this->db_type == SMDB_MYSQL) {
            $query = sprintf("REPLACE INTO %s (%s, %s, %s) ".
                             "VALUES('%s','%s','%s')",
                             $this->table,
                             $this->user_field,
                             $this->key_field,
                             $this->val_field,
                             $this->dbh->quoteString($user),
                             $this->dbh->quoteString($key),
                             $this->dbh->quoteString($value));

            $res = $this->dbh->simpleQuery($query);
            if(DB::isError($res)) {
                $this->failQuery($res);
            }
        } elseif ($this->db_type == SMDB_PGSQL) {
            $this->dbh->simpleQuery("BEGIN TRANSACTION");
            $query = sprintf("DELETE FROM %s WHERE %s='%s' AND %s='%s'",
                             $this->table,
                             $this->user_field,
                             $this->dbh->quoteString($user),
                             $this->key_field,
                             $this->dbh->quoteString($key));
            $res = $this->dbh->simpleQuery($query);
            if (DB::isError($res)) {
                $this->dbh->simpleQuery("ROLLBACK TRANSACTION");
                $this->failQuery($res);
            }
            $query = sprintf("INSERT INTO %s (%s, %s, %s) VALUES ('%s', '%s', '%s')",
                             $this->table,
                             $this->user_field,
                             $this->key_field,
                             $this->val_field,
                             $this->dbh->quoteString($user),
                             $this->dbh->quoteString($key),
                             $this->dbh->quoteString($value));
            $res = $this->dbh->simpleQuery($query);
            if (DB::isError($res)) {
                $this->dbh->simpleQuery("ROLLBACK TRANSACTION");
                $this->failQuery($res);
            }
            $this->dbh->simpleQuery("COMMIT TRANSACTION");
        } else {
            $query = sprintf("DELETE FROM %s WHERE %s='%s' AND %s='%s'",
                             $this->table,
                             $this->user_field,
                             $this->dbh->quoteString($user),
                             $this->key_field,
                             $this->dbh->quoteString($key));
            $res = $this->dbh->simpleQuery($query);
            if (DB::isError($res)) {
                $this->failQuery($res);
            }
            $query = sprintf("INSERT INTO %s (%s, %s, %s) VALUES ('%s', '%s', '%s')",
                             $this->table,
                             $this->user_field,
                             $this->key_field,
                             $this->val_field,
                             $this->dbh->quoteString($user),
                             $this->dbh->quoteString($key),
                             $this->dbh->quoteString($value));
            $res = $this->dbh->simpleQuery($query);
            if (DB::isError($res)) {
                $this->failQuery($res);
            }
        }

        return true;
    }

    function fillPrefsCache($user) {
        global $prefs_cache;

        if (!$this->open()) {
            return;
        }

        $prefs_cache = array();
        $query = sprintf("SELECT %s as prefkey, %s as prefval FROM %s ".
                         "WHERE %s = '%s'",
                         $this->key_field,
                         $this->val_field,
                         $this->table,
                         $this->user_field,
                         $this->dbh->quoteString($user));
        $res = $this->dbh->query($query);
        if (DB::isError($res)) {
            $this->failQuery($res);
        }

        while ($row = $res->fetchRow(DB_FETCHMODE_ASSOC)) {
            $prefs_cache[$row['prefkey']] = $row['prefval'];
        }
    }

} /* end class dbPrefs */


/**
 * returns the value for the pref $string
 * @ignore
 */
function getPref($data_dir, $username, $string, $default = '') {
    $db = new dbPrefs;
    if(isset($db->error)) {
        printf( _("Preference database error (%s). Exiting abnormally"),
              $db->error);
        exit;
    }

    return $db->getKey($username, $string, $default);
}

/**
 * Remove the pref $string
 * @ignore
 */
function removePref($data_dir, $username, $string) {
    global $prefs_cache;
    $db = new dbPrefs;
    if(isset($db->error)) {
        $db->failQuery();
    }

    $db->deleteKey($username, $string);

    if (isset($prefs_cache[$string])) {
        unset($prefs_cache[$string]);
    }

    sqsession_register($prefs_cache , 'prefs_cache');
    return;
}

/**
 * sets the pref, $string, to $set_to
 * @ignore
 */
function setPref($data_dir, $username, $string, $set_to) {
    global $prefs_cache;

    if (isset($prefs_cache[$string]) && ($prefs_cache[$string] == $set_to)) {
        return;
    }

    if ($set_to === '') {
        removePref($data_dir, $username, $string);
        return;
    }

    $db = new dbPrefs;
    if(isset($db->error)) {
        $db->failQuery();
    }

    $db->setKey($username, $string, $set_to);
    $prefs_cache[$string] = $set_to;
    assert_options(ASSERT_ACTIVE, 1);
    assert_options(ASSERT_BAIL, 1);
    assert ('$set_to == $prefs_cache[$string]');
    sqsession_register($prefs_cache , 'prefs_cache');
    return;
}

/**
 * This checks if the prefs are available
 * @ignore
 */
function checkForPrefs($data_dir, $username) {
    $db = new dbPrefs;
    if(isset($db->error)) {
        $db->failQuery();
    }
}

/**
 * Writes the Signature
 * @ignore
 */
function setSig($data_dir, $username, $number, $string) {
    if ($number == "g") {
        $key = '___signature___';
    } else {
        $key = sprintf('___sig%s___', $number);
    }
    setPref($data_dir, $username, $key, $string);
    return;
}

/**
 * Gets the signature
 * @ignore
 */
function getSig($data_dir, $username, $number) {
    if ($number == "g") {
        $key = '___signature___';
    } else {
        $key = sprintf('___sig%d___', $number);
    }
    return getPref($data_dir, $username, $key);
}

