// MusicRoom - yt-dlp integration module
// Handles fetching audio from URLs via yt-dlp

export interface FetchRequest {
  id: string;
  url: string;
  status: "pending" | "downloading" | "processing" | "complete" | "error";
  progress: number;
  error?: string;
  filename?: string;
  createdAt: number;
  completedAt?: number;
  userId: number;
}

// In-memory store of active fetch requests
const fetchRequests = new Map<string, FetchRequest>();

// Generate unique request ID
function generateId(): string {
  return Math.random().toString(36).substring(2, 10);
}

// Get all requests for a user
export function getUserRequests(userId: number): FetchRequest[] {
  return [...fetchRequests.values()].filter(r => r.userId === userId);
}

// Get request by ID
export function getRequest(id: string): FetchRequest | undefined {
  return fetchRequests.get(id);
}

// Create a new fetch request
export function createFetchRequest(url: string, userId: number): FetchRequest {
  const request: FetchRequest = {
    id: generateId(),
    url,
    status: "pending",
    progress: 0,
    createdAt: Date.now(),
    userId,
  };
  fetchRequests.set(request.id, request);
  return request;
}

// Update request status
export function updateRequest(id: string, updates: Partial<FetchRequest>): void {
  const request = fetchRequests.get(id);
  if (request) {
    Object.assign(request, updates);
  }
}

// Remove completed/failed requests older than given age (ms)
export function cleanupOldRequests(maxAge: number = 3600000): void {
  const now = Date.now();
  for (const [id, request] of fetchRequests) {
    if (request.status === "complete" || request.status === "error") {
      if (now - request.createdAt > maxAge) {
        fetchRequests.delete(id);
      }
    }
  }
}

// TODO: Implement actual yt-dlp download
// This will:
// 1. Spawn yt-dlp process with URL
// 2. Parse progress output
// 3. Update request status
// 4. Move completed file to music directory
// 5. Trigger library rescan
export async function startDownload(request: FetchRequest, musicDir: string): Promise<void> {
  // Stub - to be implemented
  console.log(`[ytdlp] Would download: ${request.url} to ${musicDir}`);
  updateRequest(request.id, { status: "error", error: "Not implemented yet" });
}