<?php

namespace App\Libraries;

use Google\Client;
use Google\Service\Calendar;
use Google\Service\Calendar\Event;

class GoogleCalendarService
{
    protected $client;
    protected $service;

    public function __construct()
    {
        $appName = getenv('GOOGLE_OAUTH_APP_NAME');
        $clientID = getenv('GOOGLE_OAUTH_CLIENT_ID');
        $clientSecret = getenv('GOOGLE_OAUTH_CLIENT_SECRET');
        $redirectUri = getenv('GOOGLE_OAUTH_REDIRECT_URI');
        $scopes = getenv('GOOGLE_OAUTH_SCOPES');

        $scopesArray = explode(',', $scopes);

        $this->client = new Client();
        $this->client->setApplicationName($appName);
        $this->client->setClientId($clientID);
        $this->client->setClientSecret($clientSecret);
        $this->client->setRedirectUri($redirectUri);
        $this->client->addScope($scopesArray);
        $this->client->setPrompt('consent');
        $this->client->setAccessType('offline');

        $accessToken = session()->get('access_token');
        $refreshToken = session()->get('refresh_token'); // Session-la irunthu refresh token-a edukkurom

        if ($accessToken) {
            $this->client->setAccessToken($accessToken);

            if ($this->client->isAccessTokenExpired()) {
                if ($refreshToken) {
                    // Ippo session-la iruntha refresh token-a vechu puthu access token vaangurom
                    $newToken = $this->client->fetchAccessTokenWithRefreshToken($refreshToken);

                    // Romba mukkiyam: Puthu token-la refresh token thirumba varaathu, 
                    // so pazhaya refresh token-aiye namma retain pannanum.
                    if (!isset($newToken['refresh_token'])) {
                        $newToken['refresh_token'] = $refreshToken;
                    }

                    session()->set('access_token', $newToken);
                    $this->client->setAccessToken($newToken);
                } else {
                    // Refresh token illana, user marubadiyum login panna sollanum
                    return redirect()->to('/google-login');
                }
            }
        }
    }

    public function isReady()
    {   
        return $token = session()->get('access_token') && !$this->client->isAccessTokenExpired();
    }

    public function createEventForOrganizerOnly(array $data)
    {
        $this->service = new Calendar($this->client);

        // Date kuda '10:00' add panrathu safe
       $meeting_start = preg_match('/^\d{4}-\d{2}-\d{2}$/', $data['meeting_date']) ? $data['meeting_date'] . ' 10:00:00' : $data['meeting_date'];

        $event = new Event([
            'summary'     => $data['summary'],
            'description' => $data['description'] ?? '',
            'start' => [
                'dateTime' => date('c', strtotime($meeting_start)), // Ippo 10 AM-nu fix aagidum
                'timeZone' => 'Asia/Kolkata',
            ],
            'end' => [
                'dateTime' => date('c', strtotime($meeting_start . ' +30 minutes')),
                'timeZone' => 'Asia/Kolkata',
            ],
            'reminders' => [
                'useDefault' => false,
                'overrides' => [
                    ['method' => 'email', 'minutes' => 1440], // Munthuna naal 10 AM
                    ['method' => 'popup', 'minutes' => 60],   // Event annaki 9 AM
                ],
            ],
        ]);

        return $this->service->events->insert('primary', $event);
    }

    public function createEvent(array $data)
    {
        $this->service = new Calendar($this->client);
        $responses = [];

        try {

            $meetingStartRaw = (preg_match('/^\d{4}-\d{2}-\d{2}$/', $data['meeting_date'])) 
                ? $data['meeting_date'] . ' 10:00:00' 
                : $data['meeting_date'];

            $startTime = date('c', strtotime($meetingStartRaw));
            $endTime = date('c', strtotime(date('Y-m-d', strtotime($meetingStartRaw)) . ' 23:59:59'));

            // 2. Prepare Attendees
            $attendees = [];
            if (!empty($data['emails']) && is_array($data['emails'])) {
                foreach ($data['emails'] as $email) {
                    $attendees[] = ['email' => $email];
                }
            }

            // 3. Define the Event
            $event = new Event([
                'summary'     => $data['summary'],
                'description' => $data['description'] ?? '',
                'start'       => ['dateTime' => $startTime, 'timeZone' => 'Asia/Kolkata'],
                'end'         => ['dateTime' => $endTime,   'timeZone' => 'Asia/Kolkata'],
                'attendees'   => $attendees,
                'reminders'   => [
                    'useDefault' => false,
                    'overrides'  => [
                        ['method' => 'email', 'minutes' => 1440],
                        ['method' => 'popup', 'minutes' => 60],
                    ],
                ],
            ]);

            $optParams = ['sendUpdates' => 'all'];

            $calendarId = 'primary'; 
            $result = $this->service->events->insert($calendarId, $event, $optParams);
            
            $responses['status'] = 'success';
            $responses['event_id'] = $result->getId();
            $responses['raw_response'] = $result;

        } catch (\Exception $e) {

            $error_data = [
                'error' => $e->getMessage(),
                'data'  => $data,
                'trace' => $e->getTraceAsString()
            ];

            // Log only on failure
            log_message('error', 'Google Calendar Event Creation Failed' . json_encode($error_data ?? []));

            $responses['status'] = 'error';
            $responses['message'] = $e->getMessage();
            $responses['error_data'] = $error_data;
        }

        return $responses;
    }

    public function createStaffEvent(array $data)
    {
        $results = [];

        $meetingStartRaw = (preg_match('/^\d{4}-\d{2}-\d{2}$/', $data['meeting_date'])) 
            ? $data['meeting_date'] . ' 10:00:00' 
            : $data['meeting_date'];

        $startTime = date('c', strtotime($meetingStartRaw));
        $endTime = date('c', strtotime(date('Y-m-d', strtotime($meetingStartRaw)) . ' 23:59:59'));


        // Event Object create panrom (Common for all staff)
        $event = new Event([
            'summary'     => $data['summary'],
            'description' => $data['description'] ?? '',
            'start'       => ['dateTime' => $startTime, 'timeZone' => 'Asia/Kolkata'],
            'end'         => ['dateTime' => $endTime,   'timeZone' => 'Asia/Kolkata'],
            'reminders' => [
                'useDefault' => false,
                'overrides' => [
                    ['method' => 'email', 'minutes' => 1440],
                    ['method' => 'popup', 'minutes' => 60],
                ],
            ],
        ]);

        // Loop through each staff email in the array
        foreach ($data['emails'] as $email) {
            try {

                $this->client->setSubject($email);

                $staffService = new Calendar($this->client);

                $results[$email] = $staffService->events->insert('primary', $event);

            } catch (\Exception $e) {
                $results[$email] = 'Error: ' . $e->getMessage();
            }
        }

        return $results;
    }
}