<?php
error_reporting(E_ALL);
ini_set('display_errors', 1);
file_put_contents('logs/debug.log', "Callback script started\n", FILE_APPEND);

session_start();


require_once 'google-config.php';

function log_error($message) {
    $log_file = 'logs/google_auth.log';
    $timestamp = date('Y-m-d H:i:s');
    // Ensure the log directory exists
    if (!is_dir(dirname($log_file))) {
        mkdir(dirname($log_file), 0775, true);
    }
    file_put_contents($log_file, "[$timestamp] $message\n", FILE_APPEND);
}

if (isset($_GET['code'])) {
    $code = $_GET['code'];

    $token_url = 'https://oauth2.googleapis.com/token';
    $token_params = [
        'code' => $code,
        'client_id' => GOOGLE_CLIENT_ID,
        'client_secret' => GOOGLE_CLIENT_SECRET,
        'redirect_uri' => GOOGLE_REDIRECT_URI,
        'grant_type' => 'authorization_code'
    ];

    $ch = curl_init($token_url);
    curl_setopt($ch, CURLOPT_POST, true);
    curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($token_params));
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

    $response = curl_exec($ch);
    $http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    $curl_error = curl_error($ch);
    curl_close($ch);

    if ($curl_error) {
        log_error("cURL Error: " . $curl_error);
        echo "An error occurred. Please try again later. (Code: 1)";
        exit();
    }

    if ($http_code == 200) {
        $token_data = json_decode($response, true);

        if (json_last_error() !== JSON_ERROR_NONE) {
            log_error("Failed to decode JSON response: " . $response);
            echo "An error occurred. Please try again later. (Code: 2)";
            exit();
        }

        // Ensure the db directory exists
        if (!is_dir(dirname('db/google_tokens.json'))) {
            mkdir(dirname('db/google_tokens.json'), 0775, true);
        }

        if (file_put_contents('db/google_tokens.json', json_encode($token_data)) === false) {
            log_error("Failed to write tokens to db/google_tokens.json");
            echo "An error occurred. Please try again later. (Code: 3)";
            exit();
        }

        $_SESSION['google_access_token'] = $token_data['access_token'];

        header('Location: dashboard.php');
        exit();

    } else {
        log_error("Error fetching access token. HTTP Code: " . $http_code . ", Response: " . $response);
        echo "An error occurred while trying to connect to Google. Please check your credentials in setup.php and try again.";
    }
} else {
    log_error("Authorization code not found in callback.");
    echo "Authorization code not found.";
}