<?php
/**
 * API - Forzar descarga inmediata de un archivo multimedia
 * Agrega/reinicia el item en la cola y ejecuta el worker sincrónicamente para ese item.
 */

require_once '../config/config.php';
requireAuthentication();

header('Content-Type: application/json; charset=utf-8');
header('Cache-Control: no-cache, no-store, must-revalidate');

if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    http_response_code(405);
    echo json_encode(['success' => false, 'error' => 'Method not allowed']);
    exit;
}

try {
    $input = json_decode(file_get_contents('php://input'), true) ?: [];
    $messageId = isset($input['message_id']) ? intval($input['message_id']) : 0;

    if (!$messageId) {
        echo json_encode(['success' => false, 'error' => 'message_id requerido']);
        exit;
    }

    $db = Database::getInstance();

    // Obtener info del mensaje
    $msg = $db->fetchOne(
        "SELECT id, media_url, whatsapp_media_id, message_type, local_file, conversation_id
         FROM conversations
         WHERE id = ?",
        [$messageId]
    );

    if (!$msg) {
        echo json_encode(['success' => false, 'error' => 'Mensaje no encontrado']);
        exit;
    }

    // Si ya tiene archivo local, retornar éxito directo
    if (!empty($msg['local_file']) && file_exists($_SERVER['DOCUMENT_ROOT'] . '/' . $msg['local_file'])) {
        echo json_encode(['success' => true, 'status' => 'already_downloaded', 'local_file' => $msg['local_file']]);
        exit;
    }

    // Determinar el media_id a descargar
    $mediaId = !empty($msg['whatsapp_media_id']) ? $msg['whatsapp_media_id'] : $msg['media_url'];
    if (empty($mediaId)) {
        echo json_encode(['success' => false, 'error' => 'Sin media_id disponible']);
        exit;
    }

    // Buscar o crear entrada en media_queue
    $existing = $db->fetchOne(
        "SELECT id, status, attempts FROM media_queue WHERE conversation_id = ? OR media_id = ? LIMIT 1",
        [$msg['id'], $mediaId]
    );

    if ($existing) {
        // Resetear a pending para que sea procesado
        $db->query(
            "UPDATE media_queue SET status = 'pending', attempts = 0, result = NULL, updated_at = NOW() WHERE id = ?",
            [$existing['id']]
        );
        $queueId = $existing['id'];
    } else {
        // Crear nueva entrada en la cola
        $convInfo = $db->fetchOne("SELECT user_id FROM conversations WHERE id = ?", [$msg['id']]);
        $userId = $convInfo['user_id'] ?? 0;

        // Determinar subdirectorio por mes
        $subdir = date('Y/m');

        $db->query(
            "INSERT INTO media_queue (media_id, subdir, status, attempts, conversation_id, media_url, message_type, created_at)
             VALUES (?, ?, 'pending', 0, ?, ?, ?, NOW())",
            [$mediaId, $subdir, $msg['id'], $mediaId, $msg['message_type'] ?? 'image']
        );
        $queueId = $db->lastInsertId();
    }

    // Ejecutar descarga inmediata usando MediaService
    $result = ['success' => false, 'status' => 'queued'];

    try {
        require_once '../classes/MediaService.php';
        $mediaService = new MediaService();

        $subdir = date('Y/m');
        $localPath = $mediaService->fetchAndStoreFromGraph($mediaId, $subdir);

        if ($localPath) {
            // Actualizar el mensaje con el archivo local
            $db->query(
                "UPDATE conversations SET local_file = ?, updated_at = NOW() WHERE id = ?",
                [$localPath, $messageId]
            );
            // Marcar como completado en la cola
            $db->query(
                "UPDATE media_queue SET status = 'completed', result = ?, updated_at = NOW() WHERE id = ?",
                ['OK: ' . $localPath, $queueId]
            );

            $result = ['success' => true, 'status' => 'downloaded', 'local_file' => $localPath];
        } else {
            // Falló la descarga pero quedó en cola para el worker
            $db->query(
                "UPDATE media_queue SET status = 'failed', attempts = attempts + 1, updated_at = NOW() WHERE id = ?",
                [$queueId]
            );
            $result = ['success' => false, 'status' => 'failed', 'message' => 'No se pudo descargar ahora. Quedó en cola para reintento automático.'];
        }
    } catch (Exception $e) {
        error_log('[force_download_media] Error al descargar: ' . $e->getMessage());
        $result = ['success' => false, 'status' => 'failed', 'message' => 'Error: ' . $e->getMessage()];
    }

    echo json_encode($result);

} catch (Exception $e) {
    error_log('[force_download_media] Exception: ' . $e->getMessage());
    http_response_code(500);
    echo json_encode(['success' => false, 'error' => $e->getMessage()]);
}