<?php
session_start();
header('Content-Type: application/json');

if (!isset($_SESSION['user_id'])) {
    http_response_code(401);
    echo json_encode(['error' => 'User not authenticated']);
    exit;
}

require_once 'db/config.php';

$request_body = file_get_contents('php://input');
$data = json_decode($request_body, true);

if ($_SERVER['REQUEST_METHOD'] !== 'POST' || json_last_error() !== JSON_ERROR_NONE) {
    http_response_code(400);
    echo json_encode(['error' => 'Invalid request']);
    exit;
}

$project_id = filter_var($data['project_id'] ?? null, FILTER_VALIDATE_INT);
$description = trim($data['description'] ?? '');
$duration = filter_var($data['duration'] ?? null, FILTER_VALIDATE_INT);
$shot_type = trim($data['shot_type'] ?? '');

if (!$project_id || empty($description) || !$duration || empty($shot_type)) {
    http_response_code(400);
    echo json_encode(['error' => 'Invalid input. Required fields: project_id, description, duration, shot_type']);
    exit;
}

try {
    $pdo = db();
    
    // Verify project ownership and status
    $stmt = $pdo->prepare("SELECT status FROM projects WHERE id = ? AND user_id = ?");
    $stmt->execute([$project_id, $_SESSION['user_id']]);
    $project = $stmt->fetch(PDO::FETCH_ASSOC);

    if (!$project) {
        http_response_code(404);
        echo json_encode(['error' => 'Project not found or you do not have permission to access it.']);
        exit;
    }

    if ($project['status'] !== 'draft') {
        http_response_code(403);
        echo json_encode(['error' => 'Project is not in draft status, scenes cannot be added.']);
        exit;
    }
    
    // Insert new scene
    $stmt = $pdo->prepare("INSERT INTO scenes (project_id, user_id, description, duration, shot_type) VALUES (?, ?, ?, ?, ?)");
    $stmt->execute([$project_id, $_SESSION['user_id'], $description, $duration, $shot_type]);
    
    $new_scene_id = $pdo->lastInsertId();
    
    // Fetch the newly created scene
    $stmt = $pdo->prepare("SELECT * FROM scenes WHERE id = ?");
    $stmt->execute([$new_scene_id]);
    $scene = $stmt->fetch(PDO::FETCH_ASSOC);
    
    http_response_code(201);
    echo json_encode($scene);

} catch (PDOException $e) {
    http_response_code(500);
    // error_log("Database error: " . $e->getMessage()); // It's good practice to log the actual error
    echo json_encode(['error' => 'Database error.']);
}