<?php

/**

 * @file

 * Install functions for PostgreSQL embedded database engine.

 */

// PostgreSQL specific install functions

class DatabaseTasks_pgsql extends DatabaseTasks {

  protected $pdoDriver = 'pgsql';

  public function __construct() {

    $this->tasks[] = array(

      'function' => 'checkEncoding',

      'arguments' => array(),

    );

    $this->tasks[] = array(

      'function' => 'checkPHPVersion',

      'arguments' => array(),

    );

    $this->tasks[] = array(

      'function' => 'checkBinaryOutput',

      'arguments' => array(),

    );

    $this->tasks[] = array(

      'function' => 'initializeDatabase',

      'arguments' => array(),

    );

  }

  public function name() {

    return st('PostgreSQL');

  }

  public function minimumVersion() {

    return '8.3';

  }

  /**

   * Check encoding is UTF8.

   */

  protected function checkEncoding() {

    try {

      if (db_query('SHOW server_encoding')->fetchField() == 'UTF8') {

        $this->pass(st('Database is encoded in UTF-8'));

      }

      else {

        $replacements = array(

          '%encoding' => 'UTF8',

          '%driver' => $this->name(),

          '!link' => '<a href="INSTALL.pgsql.txt">INSTALL.pgsql.txt</a>'

        );

        $text  = 'The %driver database must use %encoding encoding to work with Drupal.';

        $text .= 'Recreate the database with %encoding encoding. See !link for more details.';

        $this->fail(st($text, $replacements));

      }

    }

    catch (Exception $e) {

      $this->fail(st('Drupal could not determine the encoding of the database was set to UTF-8'));

    }

  }

  /**

   * Check PHP version.

   *

   * There are two bugs in PDO_pgsql affecting Drupal:

   *

   * - in versions < 5.2.7, PDO_pgsql refuses to insert an empty string into

   *   a NOT NULL BLOB column. See: http://bugs.php.net/bug.php?id=46249

   * - in versions < 5.2.11 and < 5.3.1 that prevents inserting integer values

   *   into numeric columns that exceed the PHP_INT_MAX value.

   *   See: http://bugs.php.net/bug.php?id=48924

   */

  function checkPHPVersion() {

    if (!version_compare(PHP_VERSION, '5.2.11', '>=') || (version_compare(PHP_VERSION, '5.3.0', '>=') && !version_compare(PHP_VERSION, '5.3.1', '>='))) {

      $this->fail(st('The version of PHP you are using has known issues with PostgreSQL. You need to upgrade PHP to 5.2.11, 5.3.1 or greater.'));

    };

  }

  /**

   * Check Binary Output.

   *

   * Unserializing does not work on Postgresql 9 when bytea_output is 'hex'.

   */

  function checkBinaryOutput() {

    // PostgreSQL < 9 doesn't support bytea_output, so verify we are running

    // at least PostgreSQL 9.

    $database_connection = Database::getConnection();

    if (version_compare($database_connection->version(), '9') >= 0) {

      if (!$this->checkBinaryOutputSuccess()) {

        // First try to alter the database. If it fails, raise an error telling

        // the user to do it themselves.

        $connection_options = $database_connection->getConnectionOptions();

        // It is safe to include the database name directly here, because this

        // code is only called when a connection to the database is already

        // established, thus the database name is guaranteed to be a correct

        // value.

        $query = "ALTER DATABASE \"" . $connection_options['database'] . "\" SET bytea_output = 'escape';";

        try {

          db_query($query);

        }

        catch (Exception $e) {

          // Ignore possible errors when the user doesn't have the necessary

          // privileges to ALTER the database.

        }

        // Close the database connection so that the configuration parameter

        // is applied to the current connection.

        db_close();

        // Recheck, if it fails, finally just rely on the end user to do the

        // right thing.

        if (!$this->checkBinaryOutputSuccess()) {

          $replacements = array(

            '%setting' => 'bytea_output',

            '%current_value' => 'hex',

            '%needed_value' => 'escape',

            '!query' => "<code>" . $query . "</code>",

          );

          $this->fail(st("The %setting setting is currently set to '%current_value', but needs to be '%needed_value'. Change this by running the following query: !query", $replacements));

        }

      }

    }

  }

  /**

   * Verify that a binary data roundtrip returns the original string.

   */

  protected function checkBinaryOutputSuccess() {

    $bytea_output = db_query("SELECT 'encoding'::bytea AS output")->fetchField();

    return ($bytea_output == 'encoding');

  }

  /**

   * Make PostgreSQL Drupal friendly.

   */

  function initializeDatabase() {

    // We create some functions using global names instead of prefixing them

    // like we do with table names. This is so that we don't double up if more

    // than one instance of Drupal is running on a single database. We therefore

    // avoid trying to create them again in that case.

    try {

      // Create functions.

      db_query('CREATE OR REPLACE FUNCTION "greatest"(numeric, numeric) RETURNS numeric AS

        \'SELECT CASE WHEN (($1 > $2) OR ($2 IS NULL)) THEN $1 ELSE $2 END;\'

        LANGUAGE \'sql\''

      );

      db_query('CREATE OR REPLACE FUNCTION "greatest"(numeric, numeric, numeric) RETURNS numeric AS

        \'SELECT greatest($1, greatest($2, $3));\'

        LANGUAGE \'sql\''

      );

      // Don't use {} around pg_proc table.

      if (!db_query("SELECT COUNT(*) FROM pg_proc WHERE proname = 'rand'")->fetchField()) {

        db_query('CREATE OR REPLACE FUNCTION "rand"() RETURNS float AS

          \'SELECT random();\'

          LANGUAGE \'sql\''

        );

      }

      db_query('CREATE OR REPLACE FUNCTION "substring_index"(text, text, integer) RETURNS text AS

        \'SELECT array_to_string((string_to_array($1, $2)) [1:$3], $2);\'

        LANGUAGE \'sql\''

      );

      // Using || to concatenate in Drupal is not recommended because there are

      // database drivers for Drupal that do not support the syntax, however

      // they do support CONCAT(item1, item2) which we can replicate in

      // PostgreSQL. PostgreSQL requires the function to be defined for each

      // different argument variation the function can handle.

      db_query('CREATE OR REPLACE FUNCTION "concat"(anynonarray, anynonarray) RETURNS text AS

        \'SELECT CAST($1 AS text) || CAST($2 AS text);\'

        LANGUAGE \'sql\'

      ');

      db_query('CREATE OR REPLACE FUNCTION "concat"(text, anynonarray) RETURNS text AS

        \'SELECT $1 || CAST($2 AS text);\'

        LANGUAGE \'sql\'

      ');

      db_query('CREATE OR REPLACE FUNCTION "concat"(anynonarray, text) RETURNS text AS

        \'SELECT CAST($1 AS text) || $2;\'

        LANGUAGE \'sql\'

      ');

      db_query('CREATE OR REPLACE FUNCTION "concat"(text, text) RETURNS text AS

        \'SELECT $1 || $2;\'

        LANGUAGE \'sql\'

      ');

      $this->pass(st('PostgreSQL has initialized itself.'));

    }

    catch (Exception $e) {

      $this->fail(st('Drupal could not be correctly setup with the existing database. Revise any errors.'));

    }

  }

}