<?php
session_start();
require_once 'config/db.php';
require_once 'includes/functions.php';

check_login();

$action = $_REQUEST['action'] ?? '';

if ($action === 'create' && $_SERVER['REQUEST_METHOD'] === 'POST') {
    $topic = trim($_POST['topic']);
    $meet_date = $_POST['meet_date'];
    $start_time = $_POST['start_time'];
    $end_time = $_POST['end_time'];
    
    // Google Calendar API Integration
    $meet_link = "";
    $google_event_id = null;
    
    $refresh_token = get_setting($pdo_sys, 'google_refresh_token');
    $client_id = get_setting($pdo_sys, 'google_client_id');
    $client_secret = get_setting($pdo_sys, 'google_client_secret');
    
    if (!empty($refresh_token) && !empty($client_id) && !empty($client_secret) && file_exists('vendor/autoload.php')) {
        require_once 'vendor/autoload.php';
        
        try {
            $client = new Google\Client();
            $client->setClientId($client_id);
            $client->setClientSecret($client_secret);
            $client->refreshToken($refresh_token);
            
            $service = new Google\Service\Calendar($client);
            
            // Prepare DateTime RFC3339
            $startDateTime = date('c', strtotime("$meet_date $start_time"));
            $endDateTime = date('c', strtotime("$meet_date $end_time"));
            
            $event = new Google\Service\Calendar\Event(array(
              'summary' => $topic,
              'description' => 'จองห้องประชุมออนไลน์ผ่านระบบ',
              'start' => array(
                'dateTime' => $startDateTime,
                'timeZone' => 'Asia/Bangkok',
              ),
              'end' => array(
                'dateTime' => $endDateTime,
                'timeZone' => 'Asia/Bangkok',
              ),
              'conferenceData' => array(
                'createRequest' => array(
                  'requestId' => uniqid(),
                  'conferenceSolutionKey' => array(
                    'type' => 'hangoutsMeet'
                  )
                )
              )
            ));

            $calendarId = 'primary';
            $optParams = array('conferenceDataVersion' => 1);
            
            $createdEvent = $service->events->insert($calendarId, $event, $optParams);
            $google_event_id = $createdEvent->getId();
            
            if ($createdEvent->getConferenceData()) {
                $entryPoints = $createdEvent->getConferenceData()->getEntryPoints();
                foreach ($entryPoints as $entryPoint) {
                    if ($entryPoint->getEntryPointType() === 'video') {
                        $meet_link = $entryPoint->getUri();
                        break;
                    }
                }
            }
        } catch (Exception $e) {
            // Log error but we might still insert empty link or fallback
            error_log("Google API Error: " . $e->getMessage());
        }
    }
    
    // Fallback if API fails or not connected
    if (empty($meet_link)) {
        function generateRandomString($length = 3) {
            return substr(str_shuffle(str_repeat($x='abcdefghijklmnopqrstuvwxyz', ceil($length/strlen($x)) )),1,$length);
        }
        $meet_link = "https://meet.google.com/" . generateRandomString(3) . "-" . generateRandomString(4) . "-" . generateRandomString(3) . " (Mock)";
    }

    $sql = "INSERT INTO meet_requests (topic, meet_date, start_time, end_time, meet_link, google_event_id, created_by) 
            VALUES (:topic, :meet_date, :start_time, :end_time, :link, :event_id, :created_by)";
    
    try {
        $stmt = $pdo_sys->prepare($sql);
        $stmt->execute([
            'topic' => $topic,
            'meet_date' => $meet_date,
            'start_time' => $start_time,
            'end_time' => $end_time,
            'link' => $meet_link,
            'event_id' => $google_event_id,
            'created_by' => $_SESSION['fullname']
        ]);

        add_log($pdo_sys, $_SESSION['cid'], $_SESSION['fullname'], 'Create Request', "Created meet request: $topic");

        header("location: requests.php?msg=success");
        exit;
    } catch (PDOException $e) {
        die("Error: " . $e->getMessage());
    }
} elseif ($action === 'edit' && $_SERVER['REQUEST_METHOD'] === 'POST') {
    $id = $_POST['id'] ?? 0;
    $topic = trim($_POST['topic']);
    $meet_date = $_POST['meet_date'];
    $start_time = $_POST['start_time'];
    $end_time = $_POST['end_time'];
    
    if ($id) {
        try {
            // Check for Google Event ID and permissions
            $stmt_old = $pdo_sys->prepare("SELECT google_event_id, created_by FROM meet_requests WHERE id = :id");
            $stmt_old->execute(['id' => $id]);
            $old_req = $stmt_old->fetch();
            
            if (!$old_req || ($_SESSION['role'] !== 'superadmin' && $old_req['created_by'] !== $_SESSION['fullname'])) {
                die("คุณไม่มีสิทธิ์แก้ไขรายการนี้");
            }
            
            if (!empty($old_req['google_event_id'])) {
                $refresh_token = get_setting($pdo_sys, 'google_refresh_token');
                $client_id = get_setting($pdo_sys, 'google_client_id');
                $client_secret = get_setting($pdo_sys, 'google_client_secret');
                if (!empty($refresh_token) && file_exists('vendor/autoload.php')) {
                    require_once 'vendor/autoload.php';
                    try {
                        $client = new Google\Client();
                        $client->setClientId($client_id);
                        $client->setClientSecret($client_secret);
                        $client->refreshToken($refresh_token);
                        $service = new Google\Service\Calendar($client);
                        
                        $event = $service->events->get('primary', $old_req['google_event_id']);
                        $event->setSummary($topic);
                        
                        $startDateTime = date('c', strtotime("$meet_date $start_time"));
                        $endDateTime = date('c', strtotime("$meet_date $end_time"));
                        
                        $start = new Google\Service\Calendar\EventDateTime();
                        $start->setDateTime($startDateTime);
                        $start->setTimeZone('Asia/Bangkok');
                        $event->setStart($start);
                        
                        $end = new Google\Service\Calendar\EventDateTime();
                        $end->setDateTime($endDateTime);
                        $end->setTimeZone('Asia/Bangkok');
                        $event->setEnd($end);
                        
                        $optParams = array('conferenceDataVersion' => 1);
                        $service->events->update('primary', $old_req['google_event_id'], $event, $optParams);
                    } catch (Exception $e) {
                        error_log("Google API Update Error: " . $e->getMessage());
                    }
                }
            }

            $sql = "UPDATE meet_requests SET topic = :topic, meet_date = :meet_date, start_time = :start_time, end_time = :end_time WHERE id = :id";
            $stmt = $pdo_sys->prepare($sql);
            $stmt->execute([
                'topic' => $topic,
                'meet_date' => $meet_date,
                'start_time' => $start_time,
                'end_time' => $end_time,
                'id' => $id
            ]);
            
            add_log($pdo_sys, $_SESSION['cid'], $_SESSION['fullname'], 'Edit Request', "Edited meet request ID: $id ($topic)");
            
            header("location: requests.php?msg=success");
            exit;
        } catch (PDOException $e) {
            die("Error: " . $e->getMessage());
        }
    }
} elseif ($action === 'delete') {
    $id = $_GET['id'] ?? 0;
    
    if ($id) {
        try {
            // Get info for log, Google Event ID, and check permissions
            $stmt = $pdo_sys->prepare("SELECT topic, google_event_id, created_by FROM meet_requests WHERE id = :id");
            $stmt->execute(['id' => $id]);
            $row = $stmt->fetch();
            
            if (!$row || ($_SESSION['role'] !== 'superadmin' && $row['created_by'] !== $_SESSION['fullname'])) {
                die("คุณไม่มีสิทธิ์ลบรายการนี้");
            }
            
            $topic = $row['topic'];
            
            if (!empty($row['google_event_id'])) {
                    $refresh_token = get_setting($pdo_sys, 'google_refresh_token');
                    $client_id = get_setting($pdo_sys, 'google_client_id');
                    $client_secret = get_setting($pdo_sys, 'google_client_secret');
                    if (!empty($refresh_token) && file_exists('vendor/autoload.php')) {
                        require_once 'vendor/autoload.php';
                        try {
                            $client = new Google\Client();
                            $client->setClientId($client_id);
                            $client->setClientSecret($client_secret);
                            $client->refreshToken($refresh_token);
                            $service = new Google\Service\Calendar($client);
                            
                            $service->events->delete('primary', $row['google_event_id']);
                        } catch (Exception $e) {
                            error_log("Google API Delete Error: " . $e->getMessage());
                        }
                }
            }

            $delStmt = $pdo_sys->prepare("DELETE FROM meet_requests WHERE id = :id");
            $delStmt->execute(['id' => $id]);

            add_log($pdo_sys, $_SESSION['cid'], $_SESSION['fullname'], 'Delete Request', "Deleted meet request ID: $id ($topic)");

            header("location: requests.php?msg=success");
            exit;
        } catch (PDOException $e) {
            die("Error: " . $e->getMessage());
        }
    }
}

header("location: requests.php");
exit;
?>