veza/apps/web/src/services/discoverService.ts

/**
 * Discover Service - v0.10.1 F351-F355
 * Browse by genre/tag, follow genre/tag
 */

import { apiClient } from '@/services/api/client';
import type { Track } from '@/features/player/types';

export interface Genre {
  slug: string;
  name: string;
}

export interface DiscoverTracksResponse {
  items: Track[];
  next_cursor?: string;
}

/** Backend track shape (snake_case) */
interface BackendTrack {
  id: string;
  creator_id: string;
  title: string;
  artist: string;
  album?: string;
  duration: number;
  cover_art_path?: string;
  play_count?: number;
  like_count?: number;
  created_at: string;
  stream_manifest_url?: string;
  genre?: string;
  user?: { username?: string; avatar?: string };
}

function getTrackPlaybackURL(bt: BackendTrack): string {
  if (bt.stream_manifest_url) {
    return String(bt.stream_manifest_url);
  }
  return `/api/v1/tracks/${bt.id}/stream`;
}

function mapBackendTrackToTrack(bt: BackendTrack): Track {
  return {
    id: String(bt.id ?? ''),
    title: String(bt.title ?? ''),
    artist: bt.artist != null ? String(bt.artist) : undefined,
    album: bt.album != null ? String(bt.album) : undefined,
    duration: Number(bt.duration) || 0,
    url: getTrackPlaybackURL(bt),
    cover: bt.cover_art_path != null ? String(bt.cover_art_path) : undefined,
    genre: bt.genre != null ? String(bt.genre) : undefined,
    like_count: Number(bt.like_count) || 0,
  };
}

export const discoverService = {
  getGenres: async (): Promise<Genre[]> => {
    const response = await apiClient.get<{ genres: Genre[] }>('/discover/genres');
    const data = response.data as { genres?: Genre[] };
    return data?.genres ?? [];
  },

  getTracksByGenre: async (
    genre: string,
    params?: { cursor?: string; limit?: number }
  ): Promise<DiscoverTracksResponse> => {
    const response = await apiClient.get<{
      items?: BackendTrack[];
      next_cursor?: string;
    }>(`/discover/genre/${encodeURIComponent(genre)}`, {
      params: { limit: params?.limit ?? 20, cursor: params?.cursor },
    });
    const d = response.data as { items?: BackendTrack[]; next_cursor?: string };
    const raw = d?.items ?? [];
    return {
      items: raw.map(mapBackendTrackToTrack),
      next_cursor: d?.next_cursor,
    };
  },

  getTracksByTag: async (
    tag: string,
    params?: { cursor?: string; limit?: number }
  ): Promise<DiscoverTracksResponse> => {
    const response = await apiClient.get<{
      items?: BackendTrack[];
      next_cursor?: string;
    }>(`/discover/tag/${encodeURIComponent(tag)}`, {
      params: { limit: params?.limit ?? 20, cursor: params?.cursor },
    });
    const d = response.data as { items?: BackendTrack[]; next_cursor?: string };
    const raw = d?.items ?? [];
    return {
      items: raw.map(mapBackendTrackToTrack),
      next_cursor: d?.next_cursor,
    };
  },

  followGenre: async (genre: string): Promise<void> => {
    await apiClient.post(`/discover/genre/${encodeURIComponent(genre)}/follow`);
  },

  unfollowGenre: async (genre: string): Promise<void> => {
    await apiClient.delete(
      `/discover/genre/${encodeURIComponent(genre)}/follow`
    );
  },

  followTag: async (tag: string): Promise<void> => {
    await apiClient.post(`/discover/tag/${encodeURIComponent(tag)}/follow`);
  },

  unfollowTag: async (tag: string): Promise<void> => {
    await apiClient.delete(
      `/discover/tag/${encodeURIComponent(tag)}/follow`
    );
  },

  /** v0.10.4 F141: Editorial playlists for Discover section */
  getEditorialPlaylists: async (params?: {
    cursor?: string;
    limit?: number;
  }): Promise<{ items: Array<{ id: string; title: string; description?: string; cover_url?: string; track_count: number; user?: { id: string; username: string } }>; next_cursor?: string }> => {
    const response = await apiClient.get<{
      items?: Array<{ id: string; title: string; description?: string; cover_url?: string; track_count: number; user?: { id: string; username: string } }>;
      next_cursor?: string;
    }>('/discover/playlists/editorial', {
      params: { limit: params?.limit ?? 20, cursor: params?.cursor },
    });
    const d = response.data as { items?: unknown[]; next_cursor?: string };
    return {
      items: (d?.items ?? []) as Array<{ id: string; title: string; description?: string; cover_url?: string; track_count: number; user?: { id: string; username: string } }>,
      next_cursor: d?.next_cursor,
    };
  },
};