<?php
/**
 * List Session Files API
 * Scans uploads/sessions/ directory and returns all available files
 * Used for importing backend files to projects
 */

// Suppress HTML error output
error_reporting(E_ALL);
ini_set('display_errors', 0);
ini_set('log_errors', 1);

header('Content-Type: application/json');
header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: GET, POST, OPTIONS');
header('Access-Control-Allow-Headers: Content-Type');

// Handle OPTIONS preflight
if ($_SERVER['REQUEST_METHOD'] === 'OPTIONS') {
    http_response_code(200);
    exit;
}

try {
    $uploadsDir = __DIR__ . '/uploads/sessions';

    // Check if directory exists
    if (!is_dir($uploadsDir)) {
        echo json_encode([
            'success' => true,
            'sessions' => [],
            'message' => 'No sessions directory found'
        ]);
        exit;
    }

    $sessions = [];
    $sessionDirs = glob($uploadsDir . '/*', GLOB_ONLYDIR);

    foreach ($sessionDirs as $sessionPath) {
        $sessionId = basename($sessionPath);
        $imagesDir = $sessionPath . '/images';
        $videosDir = $sessionPath . '/videos';

        $sessionData = [
            'session_id' => $sessionId,
            'images' => [],
            'videos' => []
        ];

        // Scan images directory
        if (is_dir($imagesDir)) {
            $imageFiles = glob($imagesDir . '/*.{jpg,jpeg,png,webp}', GLOB_BRACE);

            foreach ($imageFiles as $imagePath) {
                $filename = basename($imagePath);
                $metaPath = $imagePath . '.meta';

                // Get file stats
                $fileSize = filesize($imagePath);
                $createdAt = filectime($imagePath);
                $expiresAt = $createdAt + (24 * 3600); // 24 hours from creation

                // Read metadata if available
                $mimeType = 'image/jpeg';
                if (file_exists($metaPath)) {
                    $metaContent = file_get_contents($metaPath);
                    $meta = json_decode($metaContent, true);
                    if ($meta && isset($meta['mime_type'])) {
                        $mimeType = $meta['mime_type'];
                    }
                }

                $sessionData['images'][] = [
                    'filename' => $filename,
                    'path' => 'sessions/' . $sessionId . '/images/' . $filename,
                    'created_at' => $createdAt,
                    'expires_at' => $expiresAt,
                    'time_remaining' => max(0, $expiresAt - time()),
                    'mime_type' => $mimeType,
                    'size_kb' => round($fileSize / 1024, 2),
                    'size_bytes' => $fileSize
                ];
            }
        }

        // Scan videos directory
        if (is_dir($videosDir)) {
            $videoFiles = glob($videosDir . '/*.{mp4,webm,mov}', GLOB_BRACE);

            foreach ($videoFiles as $videoPath) {
                $filename = basename($videoPath);
                $metaPath = $videoPath . '.meta';

                // Get file stats
                $fileSize = filesize($videoPath);
                $createdAt = filectime($videoPath);
                $expiresAt = $createdAt + (24 * 3600);

                // Read metadata if available
                $mimeType = 'video/mp4';
                if (file_exists($metaPath)) {
                    $metaContent = file_get_contents($metaPath);
                    $meta = json_decode($metaContent, true);
                    if ($meta && isset($meta['mime_type'])) {
                        $mimeType = $meta['mime_type'];
                    }
                }

                $sessionData['videos'][] = [
                    'filename' => $filename,
                    'path' => 'sessions/' . $sessionId . '/videos/' . $filename,
                    'created_at' => $createdAt,
                    'expires_at' => $expiresAt,
                    'time_remaining' => max(0, $expiresAt - time()),
                    'mime_type' => $mimeType,
                    'size_kb' => round($fileSize / 1024, 2),
                    'size_mb' => round($fileSize / (1024 * 1024), 2),
                    'size_bytes' => $fileSize
                ];
            }
        }

        // Only include sessions that have files
        if (count($sessionData['images']) > 0 || count($sessionData['videos']) > 0) {
            $sessions[] = $sessionData;
        }
    }

    // Sort sessions by most recent file
    usort($sessions, function($a, $b) {
        $aMax = 0;
        $bMax = 0;

        foreach ($a['images'] as $img) {
            $aMax = max($aMax, $img['created_at']);
        }
        foreach ($a['videos'] as $vid) {
            $aMax = max($aMax, $vid['created_at']);
        }

        foreach ($b['images'] as $img) {
            $bMax = max($bMax, $img['created_at']);
        }
        foreach ($b['videos'] as $vid) {
            $bMax = max($bMax, $vid['created_at']);
        }

        return $bMax - $aMax; // Descending order (newest first)
    });

    echo json_encode([
        'success' => true,
        'sessions' => $sessions,
        'total_sessions' => count($sessions),
        'total_files' => array_reduce($sessions, function($carry, $session) {
            return $carry + count($session['images']) + count($session['videos']);
        }, 0)
    ], JSON_PRETTY_PRINT);

} catch (Exception $e) {
    error_log("Error in list_session_files.php: " . $e->getMessage());
    http_response_code(500);
    echo json_encode([
        'success' => false,
        'error' => 'Failed to list session files',
        'message' => $e->getMessage()
    ]);
}