import { createQuery } from '@tanstack/svelte-query';
import { api } from './client';
import { qk } from './queries';
import type { Playlist, PlaylistDetail } from './types';

export type PlaylistKind = 'user' | 'system' | 'all';

export type ListPlaylistsResponse = {
  owned: Playlist[];
  public: Playlist[];
};

export async function listPlaylists(kind?: PlaylistKind): Promise<ListPlaylistsResponse> {
  const k = kind ?? 'user';
  return api.get<ListPlaylistsResponse>(`/api/playlists?kind=${k}`);
}

export async function getPlaylist(id: string): Promise<PlaylistDetail> {
  return api.get<PlaylistDetail>(`/api/playlists/${encodeURIComponent(id)}`);
}

// #415 stage 2/3: rotation-aware play order for a system playlist.
// Same shape as getPlaylist but tracks are server-ordered (unplayed
// this rotation first, then heard; resets when exhausted).
// Intentionally uncached — it varies per play, unlike getPlaylist.
// {variant} is the raw system_variant (#411 R2: generic by-kind).
export async function systemShuffle(variant: string): Promise<PlaylistDetail> {
  return api.get<PlaylistDetail>(
    `/api/playlists/system/${encodeURIComponent(variant)}/shuffle`,
  );
}

// #411 R2: generic by-kind refresh. Rebuilds the caller's system
// playlists and returns the named kind's fresh row. Replaces the
// former per-kind refreshForYou/refreshDiscover.
export type RefreshSystemResponse = {
  playlist_id: string | null;
  track_count: number;
  track_ids: string[];
};
export async function refreshSystem(variant: string): Promise<RefreshSystemResponse> {
  return api.post<RefreshSystemResponse>(
    `/api/playlists/system/${encodeURIComponent(variant)}/refresh`,
    {},
  );
}

export type CreatePlaylistInput = {
  name: string;
  description?: string;
  is_public?: boolean;
};

export async function createPlaylist(input: CreatePlaylistInput): Promise<Playlist> {
  return api.post<Playlist>('/api/playlists', input);
}

export type UpdatePlaylistInput = {
  name?: string;
  description?: string;
  is_public?: boolean;
};

export async function updatePlaylist(id: string, input: UpdatePlaylistInput): Promise<Playlist> {
  return api.patch<Playlist>(`/api/playlists/${encodeURIComponent(id)}`, input);
}

export async function deletePlaylist(id: string): Promise<void> {
  await api.del(`/api/playlists/${encodeURIComponent(id)}`);
}

export async function appendTracks(playlistID: string, trackIDs: string[]): Promise<PlaylistDetail> {
  return api.post<PlaylistDetail>(
    `/api/playlists/${encodeURIComponent(playlistID)}/tracks`,
    { track_ids: trackIDs }
  );
}

export async function removePlaylistTrack(playlistID: string, position: number): Promise<PlaylistDetail> {
  return api.del<PlaylistDetail>(
    `/api/playlists/${encodeURIComponent(playlistID)}/tracks/${position}`
  );
}

export async function reorderPlaylist(playlistID: string, orderedPositions: number[]): Promise<PlaylistDetail> {
  return api.put<PlaylistDetail>(
    `/api/playlists/${encodeURIComponent(playlistID)}/tracks`,
    { ordered_positions: orderedPositions }
  );
}

export function createPlaylistsQuery(kind?: PlaylistKind) {
  return createQuery({
    queryKey: qk.playlists(kind),
    queryFn: () => listPlaylists(kind),
    staleTime: 30_000
  });
}

export function createPlaylistQuery(id: string) {
  return createQuery({
    queryKey: qk.playlist(id),
    queryFn: () => getPlaylist(id),
    staleTime: 30_000
  });
}