<?php

namespace App\RSpade\Core\Bootstrap;

use Exception;
use RuntimeException;
use App\RSpade\Core\Locks\RsxLocks;

/**
 * RsxBootstrap - Early initialization for the RSpade framework
 *
 * This class handles critical early initialization tasks that must occur
 * before the manifest or other systems are loaded. Most importantly, it
 * acquires the global application read lock that ensures we can coordinate
 * with other processes for exclusive operations like manifest rebuilding.
 */
class RsxBootstrap
{
    /**
     * The global application lock token
     * @var string|null
     */
    private static ?string $application_lock_token = null;

    /**
     * Whether bootstrap has been initialized
     * @var bool
     */
    private static bool $initialized = false;

    /**
     * Initialize the RSpade framework
     *
     * This MUST be called as early as possible in the application lifecycle,
     * ideally in the bootstrap/app.php file right after Laravel boots.
     *
     * Acquires a global READ lock for the application that can be upgraded
     * to WRITE when exclusive operations like manifest rebuilding are needed.
     *
     * @return void
     */
    public static function initialize(): void
    {
        if (self::$initialized) {
            return;
        }

        // Acquire global application read lock
        // This ensures we can coordinate with other processes
        self::__acquire_application_lock();

        // Register shutdown handler to release lock
        register_shutdown_function([self::class, 'shutdown']);

        self::$initialized = true;
    }

    /**
     * Acquire the global application lock
     *
     * All PHP processes acquire a READ lock by default.
     * Artisan commands and always_write_lock mode use WRITE lock.
     * This can be upgraded to WRITE for exclusive operations.
     *
     * @return void
     */
    private static function __acquire_application_lock(): void
    {
        $always_write = config('rsx.locking.always_write_lock', false);

        // Detect artisan commands by checking if running from CLI and the script name contains 'artisan'
        $is_artisan = php_sapi_name() === 'cli' &&
                      isset($_SERVER['argv'][0]) &&
                      strpos($_SERVER['argv'][0], 'artisan') !== false;

        // Determine lock type
        // Artisan commands always get write lock
        // Or if always_write_lock is enabled
        $lock_type = ($is_artisan || $always_write) ? RsxLocks::WRITE_LOCK : RsxLocks::READ_LOCK;

        // Issue warning if always_write_lock is enabled in production CLI mode
        if ($always_write && php_sapi_name() === 'cli' && app()->environment('production')) {
            fwrite(STDERR, "\033[33mWARNING: RSX_ALWAYS_WRITE_LOCK is enabled in production. " .
                          'ALL requests are serialized with exclusive write lock. ' .
                          "This severely impacts performance and should only be used for critical operations.\033[0m\n");
        }

        console_debug('CONCURRENCY', "Acquiring global application '" . ($lock_type == RsxLocks::WRITE_LOCK ? 'WRITE' : 'READ') . "'lock");

        try {
            self::$application_lock_token = RsxLocks::get_lock(
                RsxLocks::SERVER_LOCK,
                RsxLocks::LOCK_APPLICATION,
                $lock_type,
                config('rsx.locking.timeout', 30)
            );
        } catch (Exception $e) {
            // If we can't acquire the lock, the application cannot proceed
            shouldnt_happen(
                "Failed to acquire application {$lock_type} lock: " . $e->getMessage() . "\n" .
                'This likely means another process has an exclusive lock.'
            );
        }

        console_debug('CONCURRENCY', 'Global application lock acquired');

        // Check if log rotation is needed (development mode only)
        // TODO: cant log rotate before getting build key
        // We logrotate somewhere else, dont we?
        // if (env('APP_ENV') !== 'production') {
        //     $current_hash = Manifest::get_build_key();
        //     $version_file = storage_path('rsx-tmp/log_version');
        //     $should_rotate = false;

        //     // Ensure directory exists
        //     $dir = dirname($version_file);
        //     if (!is_dir($dir)) {
        //         @mkdir($dir, 0755, true);
        //     }

        //     // Check if version file exists and compare hash
        //     if (file_exists($version_file)) {
        //         $stored_hash = trim(file_get_contents($version_file));
        //         if ($stored_hash !== $current_hash) {
        //             $should_rotate = true;
        //         }
        //     } else {
        //         // File doesn't exist, first run
        //         $should_rotate = true;
        //     }

        //     // Rotate logs if needed
        //     if ($should_rotate) {
        //         Debugger::logrotate();

        //         // Update version file with new hash
        //         file_put_contents($version_file, $current_hash);
        //     }
        // }
    }

    /**
     * Upgrade the application lock to exclusive write mode
     *
     * Used when performing operations that require exclusive access,
     * such as manifest rebuilding or bundle compilation.
     *
     * @return string New lock token after upgrade
     * @throws RuntimeException if upgrade fails
     */
    public static function upgrade_to_write_lock(): string
    {
        if (!self::$application_lock_token) {
            shouldnt_happen('Cannot upgrade lock - no application lock held');
        }

        try {
            $new_token = RsxLocks::upgrade_lock(
                self::$application_lock_token,
                config('rsx.locking.timeout', 30)
            );

            self::$application_lock_token = $new_token;

            return $new_token;
        } catch (Exception $e) {
            throw new RuntimeException(
                'Failed to upgrade application lock to write mode: ' . $e->getMessage()
            );
        }
    }

    /**
     * Get the current application lock token
     *
     * @return string|null
     */
    public static function get_application_lock_token(): ?string
    {
        return self::$application_lock_token;
    }

    /**
     * Check if we hold the application lock
     *
     * @return bool
     */
    public static function has_application_lock(): bool
    {
        return self::$application_lock_token !== null;
    }

    /**
     * Shutdown handler - releases locks
     *
     * @return void
     */
    public static function shutdown(): void
    {
        if (self::$application_lock_token) {
            try {
                RsxLocks::release_lock(self::$application_lock_token);
            } catch (Exception $e) {
                // Ignore errors during shutdown
            } finally {
                self::$application_lock_token = null;
            }
        }
    }

    /**
     * Force release of application lock (emergency use only)
     *
     * @return void
     */
    public static function force_release(): void
    {
        if (self::$application_lock_token) {
            RsxLocks::release_lock(self::$application_lock_token);
            self::$application_lock_token = null;
        }
    }

    /**
     * Temporarily release application lock for testing
     * Used by rsx:debug to prevent lock contention with Playwright
     *
     * @return void
     */
    public static function temporarily_release_lock(): void
    {
        if (self::$application_lock_token) {
            RsxLocks::release_lock(self::$application_lock_token);
            self::$application_lock_token = null;
        }
    }
}