import { Injectable } from '@angular/core';
import { HttpClient, HttpParams } from '@angular/common/http';
import { Observable } from 'rxjs';

export interface DownloadFormat {
  id: string;
  resolution?: string;
  fps?: number;
  ext?: string;
  vcodec?: string;
  acodec?: string;
  sizeEstimate?: number;
  label: string;
}

export type DownloadState = 'queued' | 'running' | 'merging' | 'completed' | 'failed';

export interface DownloadJob {
  id: string;
  userId: string;
  provider: string;
  videoId: string;
  state: DownloadState;
  progress: number;
  createdAt: string;
  updatedAt: string;
  filePath?: string | null;
  fileExt?: string | null;
  fileSize?: number | null;
  error?: string | null;
  url?: string;
}

@Injectable({ providedIn: 'root' })
export class DownloadService {
  constructor(private http: HttpClient) {}

  listFormats(
    provider: string,
    videoId: string,
    opts?: { instance?: string; slug?: string; sourceUrl?: string }
  ): Observable<{ url: string; formats: DownloadFormat[]; title: string; duration: number }> {
    let params = new HttpParams();
    if (opts?.instance) params = params.set('instance', opts.instance);
    if (opts?.slug) params = params.set('slug', opts.slug);
    if (opts?.sourceUrl) params = params.set('sourceUrl', opts.sourceUrl);
    return this.http.get<{ url: string; formats: DownloadFormat[]; title: string; duration: number }>(
      `/proxy/api/download/${encodeURIComponent(provider)}/${encodeURIComponent(videoId)}/formats`,
      { params, withCredentials: true }
    );
  }

  startDownload(
    provider: string,
    videoId: string,
    body?: { formatId?: string; audioOnly?: boolean; sourceUrl?: string },
    opts?: { instance?: string; slug?: string }
  ): Observable<{ jobId: string }> {
    let params = new HttpParams();
    if (opts?.instance) params = params.set('instance', opts.instance);
    if (opts?.slug) params = params.set('slug', opts.slug);
    return this.http.post<{ jobId: string }>(
      `/proxy/api/download/${encodeURIComponent(provider)}/${encodeURIComponent(videoId)}`,
      body || {},
      { params, withCredentials: true }
    );
  }

  getJob(id: string): Observable<DownloadJob> {
    return this.http.get<DownloadJob>(`/proxy/api/download/jobs/${encodeURIComponent(id)}`, { withCredentials: true });
  }

  cancelJob(id: string): Observable<void> {
    return this.http.delete<void>(`/proxy/api/download/jobs/${encodeURIComponent(id)}`, { withCredentials: true });
  }

  fileUrl(id: string): string {
    return `/proxy/api/download/jobs/${encodeURIComponent(id)}/file`;
  }
}