<?php

//vim: ts=2 sw=2

include_once "db.php";

  class Migration {

    public static function instance() {

      static $inst = NULL;

      if ($inst === NULL) {

        $inst = new Migration();

      }

      return $inst;

    }

    private function __construct() {

    }

    public function run() {

      $db = DBConn::instance()->db();

      $user_version = intval($db->query("PRAGMA user_version")->fetchColumn());

      $this->applyMigrations($db, $user_version);

      $this->applyDataFixes($db);

    }

    protected function getMigrationFiles($user_version) {

      $result = array();

      $glob_pattern = build_file_path(cptBaseDir(), 'app', 'migrations', '*.php');

      $migrations = glob($glob_pattern);

      if (!is_array($migrations))

        return $result;

      foreach( $migrations as $mig ) {

        $parts = array();

        if (preg_match('/\/migrations\/([0-9]+)_[^\/]*.php$/', $mig, $parts)) {

          $order = intval($parts[1]);

          if ($order < $user_version)

            continue;

          $result[$order] = $mig;

        }

      }

      return $result;

    }

    protected function applyMigrations($db, $user_version) {

      $migrations = $this->getMigrationFiles($user_version);

      if (empty($migrations))

        return;

      ksort($migrations, SORT_NUMERIC);

      error_log('current user_version: ' . $user_version);

      error_log('find ' . count($migrations) . ' new db migrations, start to apply ...');

      $db->beginTransaction();

      foreach($migrations as $order => $path) {

        error_log('apply db migration: ' . $path . ' ...');

        include($path);

        $user_version = $order;

      }

      $user_version += 1;

      error_log('update $user_version to ' . $user_version);

      $db->query('PRAGMA user_version = ' . $user_version);

      $db->commit();

      error_log('db migration done.');

    }

    protected function applyDataFixes($db) {

      if (!$db)

        return;

      $flag_file = build_file_path(cptBaseDir(), 'RESET_ADMIN_PASSWORD');

      if (!file_exists($flag_file))

        return;

      error_log("start to reset password of 'admin' ...");

      $db->beginTransaction();

      $db->exec(<<<EOD

        UPDATE users SET salt = 'hNsq25IWKmRfSCOu', checksum = 'dc7b9f203aa5cf1bca33d5fc126cd783f98590e9' WHERE name = 'admin';

EOD

      );

      unlink($flag_file)

      $db->commit();

      error_log("password reset is done");

    }

  }

?>