<?php
/**
 * Playlists API
 * 
 * GET /api/playlists.php?id=X - Get playlist details
 * GET /api/playlists.php?user_id=X - Get user's playlists
 * POST /api/playlists.php - Create playlist
 * PUT /api/playlists.php?id=X - Update playlist
 * DELETE /api/playlists.php?id=X - Delete playlist
 * 
 * POST /api/playlists.php?id=X&action=add_video - Add video to playlist
 * POST /api/playlists.php?id=X&action=remove_video - Remove video from playlist
 * POST /api/playlists.php?id=X&action=reorder - Reorder videos
 * POST /api/playlists.php?id=X&action=follow - Follow playlist
 * POST /api/playlists.php?id=X&action=unfollow - Unfollow playlist
 * POST /api/playlists.php?id=X&action=add_collaborator - Add collaborator
 * POST /api/playlists.php?id=X&action=remove_collaborator - Remove collaborator
 */

require_once dirname(__DIR__) . '/f_core/config.boot.php';
require_once dirname(__DIR__) . '/f_core/f_classes/class.playlists.php';

header('Content-Type: application/json');

session_start();
$current_user_id = $_SESSION['user_id'] ?? null;
$playlists = new VPlaylists();

$method = $_SERVER['REQUEST_METHOD'];

// GET - Retrieve playlist(s)
if ($method === 'GET') {
    if (isset($_GET['id'])) {
        // Get single playlist
        $playlist = $playlists->get($_GET['id'], $current_user_id);
        
        if (!$playlist) {
            http_response_code(404);
            echo json_encode(['success' => false, 'error' => 'Playlist not found']);
            exit;
        }
        
        // Get items
        $shuffle = isset($_GET['shuffle']) && $_GET['shuffle'] === 'true';
        $items = $playlists->getItems($_GET['id'], $shuffle);
        $playlist['items'] = $items;
        
        echo json_encode(['success' => true, 'data' => $playlist]);
        
    } elseif (isset($_GET['user_id'])) {
        // Get user's playlists
        $include_private = $current_user_id && $current_user_id == $_GET['user_id'];
        $user_playlists = $playlists->getUserPlaylists($_GET['user_id'], $include_private);
        
        echo json_encode(['success' => true, 'data' => $user_playlists]);
        
    } else {
        http_response_code(400);
        echo json_encode(['success' => false, 'error' => 'Missing playlist or user ID']);
    }
}

// POST - Create or perform actions
elseif ($method === 'POST') {
    if (!$current_user_id) {
        http_response_code(401);
        echo json_encode(['success' => false, 'error' => 'Authentication required']);
        exit;
    }
    
    $input = json_decode(file_get_contents('php://input'), true) ?: $_POST;
    $action = $_GET['action'] ?? $input['action'] ?? 'create';
    
    if ($action === 'create') {
        // Create new playlist
        $title = $input['title'] ?? '';
        $description = $input['description'] ?? '';
        $privacy = $input['privacy'] ?? 'public';
        $is_collaborative = isset($input['is_collaborative']) && $input['is_collaborative'];
        
        if (empty($title)) {
            http_response_code(400);
            echo json_encode(['success' => false, 'error' => 'Title is required']);
            exit;
        }
        
        $playlist_id = $playlists->create($current_user_id, $title, $description, $privacy, $is_collaborative);
        
        if ($playlist_id) {
            echo json_encode(['success' => true, 'playlist_id' => $playlist_id]);
        } else {
            http_response_code(500);
            echo json_encode(['success' => false, 'error' => 'Failed to create playlist']);
        }
        
    } elseif ($action === 'add_video') {
        $playlist_id = $_GET['id'] ?? $input['playlist_id'];
        $video_id = $input['video_id'] ?? null;
        
        if (!$playlist_id || !$video_id) {
            http_response_code(400);
            echo json_encode(['success' => false, 'error' => 'Playlist ID and video ID required']);
            exit;
        }
        
        $result = $playlists->addVideo($playlist_id, $video_id, $current_user_id);
        echo json_encode(['success' => (bool)$result]);
        
    } elseif ($action === 'remove_video') {
        $playlist_id = $_GET['id'] ?? $input['playlist_id'];
        $video_id = $input['video_id'] ?? null;
        
        if (!$playlist_id || !$video_id) {
            http_response_code(400);
            echo json_encode(['success' => false, 'error' => 'Playlist ID and video ID required']);
            exit;
        }
        
        $result = $playlists->removeVideo($playlist_id, $video_id, $current_user_id);
        echo json_encode(['success' => (bool)$result]);
        
    } elseif ($action === 'reorder') {
        $playlist_id = $_GET['id'] ?? $input['playlist_id'];
        $item_positions = $input['positions'] ?? null;
        
        if (!$playlist_id) {
            http_response_code(400);
            echo json_encode(['success' => false, 'error' => 'Playlist ID required']);
            exit;
        }
        
        $result = $playlists->reorderItems($playlist_id, $item_positions);
        echo json_encode(['success' => (bool)$result]);
        
    } elseif ($action === 'follow') {
        $playlist_id = $_GET['id'] ?? $input['playlist_id'];
        
        if (!$playlist_id) {
            http_response_code(400);
            echo json_encode(['success' => false, 'error' => 'Playlist ID required']);
            exit;
        }
        
        $result = $playlists->follow($playlist_id, $current_user_id);
        echo json_encode(['success' => (bool)$result]);
        
    } elseif ($action === 'unfollow') {
        $playlist_id = $_GET['id'] ?? $input['playlist_id'];
        
        if (!$playlist_id) {
            http_response_code(400);
            echo json_encode(['success' => false, 'error' => 'Playlist ID required']);
            exit;
        }
        
        $result = $playlists->unfollow($playlist_id, $current_user_id);
        echo json_encode(['success' => (bool)$result]);
        
    } elseif ($action === 'add_collaborator') {
        $playlist_id = $_GET['id'] ?? $input['playlist_id'];
        $collaborator_id = $input['collaborator_id'] ?? null;
        $permissions = $input['permissions'] ?? [];
        
        if (!$playlist_id || !$collaborator_id) {
            http_response_code(400);
            echo json_encode(['success' => false, 'error' => 'Playlist ID and collaborator ID required']);
            exit;
        }
        
        $result = $playlists->addCollaborator($playlist_id, $current_user_id, $collaborator_id, $permissions);
        echo json_encode(['success' => (bool)$result]);
        
    } elseif ($action === 'remove_collaborator') {
        $playlist_id = $_GET['id'] ?? $input['playlist_id'];
        $collaborator_id = $input['collaborator_id'] ?? null;
        
        if (!$playlist_id || !$collaborator_id) {
            http_response_code(400);
            echo json_encode(['success' => false, 'error' => 'Playlist ID and collaborator ID required']);
            exit;
        }
        
        $result = $playlists->removeCollaborator($playlist_id, $current_user_id, $collaborator_id);
        echo json_encode(['success' => (bool)$result]);
        
    } else {
        http_response_code(400);
        echo json_encode(['success' => false, 'error' => 'Invalid action']);
    }
}

// PUT - Update playlist
elseif ($method === 'PUT') {
    if (!$current_user_id) {
        http_response_code(401);
        echo json_encode(['success' => false, 'error' => 'Authentication required']);
        exit;
    }
    
    $playlist_id = $_GET['id'] ?? null;
    
    if (!$playlist_id) {
        http_response_code(400);
        echo json_encode(['success' => false, 'error' => 'Playlist ID required']);
        exit;
    }
    
    $input = json_decode(file_get_contents('php://input'), true);
    
    $result = $playlists->update($playlist_id, $current_user_id, $input);
    
    if ($result) {
        echo json_encode(['success' => true]);
    } else {
        http_response_code(403);
        echo json_encode(['success' => false, 'error' => 'Permission denied or invalid data']);
    }
}

// DELETE - Delete playlist
elseif ($method === 'DELETE') {
    if (!$current_user_id) {
        http_response_code(401);
        echo json_encode(['success' => false, 'error' => 'Authentication required']);
        exit;
    }
    
    $playlist_id = $_GET['id'] ?? null;
    
    if (!$playlist_id) {
        http_response_code(400);
        echo json_encode(['success' => false, 'error' => 'Playlist ID required']);
        exit;
    }
    
    $result = $playlists->delete($playlist_id, $current_user_id);
    
    if ($result) {
        echo json_encode(['success' => true]);
    } else {
        http_response_code(403);
        echo json_encode(['success' => false, 'error' => 'Permission denied']);
    }
}

else {
    http_response_code(405);
    echo json_encode(['success' => false, 'error' => 'Method not allowed']);
}