package main

import (
	"os"
	"path/filepath"

	"git.milar.in/milarin/adverr"
	"git.milar.in/milarin/slices"
)

type Playlist struct {
	Name  string `json:"name"`
	Songs []Song `json:"songs"`
}

type Song struct {
	Name string `json:"name"`
	File string `json:"file"`
}

func GetAllPlaylists() ([]Playlist, error) {
	playlistNames, err := GetAllPlaylistNames()
	if err != nil {
		return nil, err
	}

	playlists := make([]Playlist, 0, len(playlistNames))
	for _, playlistName := range playlistNames {
		songs, err := GetSongsByPlaylist(playlistName)
		if err != nil {
			return nil, err
		}

		playlists = append(playlists, Playlist{
			Name:  playlistName,
			Songs: songs,
		})
	}

	return playlists, nil
}

func GetAllPlaylistNames() ([]string, error) {
	entries, err := os.ReadDir(LibraryPath)
	if err != nil {
		return nil, err
	}

	directories := slices.Filter(entries, And(IsDir, Not(IsHidden)))
	return slices.Map(directories, FsEntry2Name), nil
}

func GetSongsByPlaylist(playlist string) ([]Song, error) {
	entries, err := os.ReadDir(filepath.Join(LibraryPath, playlist))
	if err != nil {
		return nil, err
	}

	symlinks := slices.Filter(entries, IsSymlink)
	return slices.Map(symlinks, func(entry os.DirEntry) Song {
		return Song{
			Name: FsEntry2Name(entry),
			File: filepath.Base(adverr.Must(os.Readlink(filepath.Join(LibraryPath, playlist, entry.Name())))),
		}
	}), nil
}