<?php

namespace MailPoet\Config;

use MailPoet\Models\Setting;
use MailPoet\Util\Url;

class Changelog {
  function init() {
    $doing_ajax = (bool)(defined('DOING_AJAX') && DOING_AJAX);

    // don't run any check when it's an ajax request
    if($doing_ajax) {
      return;
    }

    // don't run any check when we're not on our pages
    if(
      !(isset($_GET['page']))
      or
      (isset($_GET['page']) && strpos($_GET['page'], 'mailpoet') !== 0)
    ) {
      return;
    }

    add_action(
      'admin_init',
      array($this, 'check')
    );
  }

  function check() {
    $version = Setting::getValue('version', null);
    $redirect_url = null;

    $mp2_migrator = new MP2Migrator();
    if(!in_array($_GET['page'], array('mailpoet-migration', 'mailpoet-settings')) && $mp2_migrator->isMigrationStartedAndNotCompleted()) {
      // Force the redirection if the migration has started but is not completed
      $redirect_url = admin_url('admin.php?page=mailpoet-migration');
    } else {
      if($version === null) {
        // new install
        if($mp2_migrator->isMigrationNeeded()) {
          // Migration from MP2
          $redirect_url = admin_url('admin.php?page=mailpoet-migration');
        } else {
          $redirect_url = admin_url('admin.php?page=mailpoet-welcome');
        }
      } else if($version !== Env::$version) {
        // update
        $redirect_url = admin_url('admin.php?page=mailpoet-update');
      }
    }

    if($redirect_url !== null) {
      // save version number
      Setting::setValue('version', Env::$version);

      Url::redirectWithReferer($redirect_url);
    }
  }
}