<?php 
class Gateway extends MY_Controller {
  function __construct()
  {
    return parent::__construct();
  }
  function email_config() {
    header('Content-Type: application/json');

    $sql = "SELECT 
        M_EmailConfigSender,
        M_EmailConfigUsername,
        M_EmailConfigPassword,
        M_EmailConfigServer,
        M_EmailConfigMaxRetry
      FROM m_emailconfig
      LIMIT 1";
    $query = $this->db->query($sql);
    if ($query === false) {
      echo json_encode(array('status' => 'ERR', 'message' => 'Failed to fetch email config', 'config' => array()));
      return;
    }

    $row = $query->row_array();
    echo json_encode(array('status' => 'OK', 'message' => 'Email config fetched', 'config' => empty($row) ? array() : $row));
    return;
  }
  function get_order($limit) {
    header('Content-Type: application/json');

    $limit = (int) $limit;
    if ($limit < 1) {
      $limit = 1;
    }

    $rows = array();
    $this->db->trans_begin();

    $selectSql = "SELECT * 
      FROM t_send_email 
      WHERE T_SendEmailStatus = 'S' 
      ORDER BY T_SendEmailID ASC 
      LIMIT {$limit} 
      FOR UPDATE";
    $query = $this->db->query($selectSql);

    if ($query === false) {
      $this->db->trans_rollback();
      echo json_encode(array('status' => 'ERR', 'message' => 'Failed to fetch sending queue', 'data' => array()));
      return;
    }

    $rows = $query->result_array();

    $remaining = $limit - count($rows);
    if ($remaining > 0) {
      $selectRetrySql = "SELECT * 
        FROM t_send_email 
        WHERE T_SendEmailStatus = 'E' 
          AND T_SendEmailCount <= 5
        ORDER BY T_SendEmailID ASC 
        LIMIT {$remaining} 
        FOR UPDATE";
      $retryQuery = $this->db->query($selectRetrySql);

      if ($retryQuery === false) {
        $this->db->trans_rollback();
        echo json_encode(array('status' => 'ERR', 'message' => 'Failed to fetch retry queue', 'data' => array()));
        return;
      }

      $retryRows = $retryQuery->result_array();
      if (!empty($retryRows)) {
        $rows = array_merge($rows, $retryRows);
      }
    }

    if (!empty($rows)) {
      $ids = array();
      foreach ($rows as $row) {
        $ids[] = (int) $row['T_SendEmailID'];
      }

      $updateSql = "UPDATE t_send_email 
        SET T_SendEmailStatus = 'P',
            T_SendEmailLastUpdated = NOW()
        WHERE T_SendEmailID IN (" . implode(',', $ids) . ")";
      $updated = $this->db->query($updateSql);

      if ($updated === false) {
        $this->db->trans_rollback();
        echo json_encode(array('status' => 'ERR', 'message' => 'Failed to update queue status', 'data' => array()));
        return;
      }
    }

    if ($this->db->trans_status() === false) {
      $this->db->trans_rollback();
      echo json_encode(array('status' => 'ERR', 'message' => 'Transaction failed', 'data' => array()));
      return;
    }

    $this->db->trans_commit();
    echo json_encode(array('status' => 'OK', 'message' => 'Data fetched', 'data' => $rows, 'total' => count($rows)));
    return;
  } 
  function update() {
    header('Content-Type: application/json');

    $raw = file_get_contents('php://input');
    $payload = json_decode($raw, true);
    if (!is_array($payload)) {
      echo json_encode(array('status' => 'ERR', 'message' => 'Invalid JSON payload'));
      return;
    }

    $id = isset($payload['id']) ? (int) $payload['id'] : 0;
    $status = isset($payload['status']) ? strtoupper(trim($payload['status'])) : '';
    $message = isset($payload['message']) ? $payload['message'] : '';

    if ($id < 1) {
      echo json_encode(array('status' => 'ERR', 'message' => 'Invalid id'));
      return;
    }

    if ($status !== 'OK' && $status !== 'ERR') {
      echo json_encode(array('status' => 'ERR', 'message' => 'Invalid status'));
      return;
    }

    $escapedMessage = $this->db->escape($message);
    $setSql = "T_SendEmailResponse = {$escapedMessage}, T_SendEmailLastUpdated = NOW()";
    if ($status === 'OK') {
      $setSql .= ", T_SendEmailStatus = 'R', T_SendEmailReceived = NOW()";
    } else {
      $setSql .= ", T_SendEmailStatus = 'E', T_SendEmailCount = T_SendEmailCount + 1";
    }

    $this->db->trans_begin();
    $sql = "UPDATE t_send_email SET {$setSql} WHERE T_SendEmailID = {$id}";
    $updated = $this->db->query($sql);

    if ($updated === false || $this->db->trans_status() === false) {
      $this->db->trans_rollback();
      echo json_encode(array('status' => 'ERR', 'message' => 'Failed to update data'));
      return;
    }

    $this->db->trans_commit();
    echo json_encode(array('status' => 'OK', 'message' => 'Data updated', 'id' => $id, 'result_status' => $status));
    return;
  }
}