package config

import (
	"errors"
	"fmt"
	"os"
	"path/filepath"

	"github.com/pelletier/go-toml/v2"
)

const CurrentConfigVersion = "2.2.0"

var ErrOutdatedConfig = errors.New("config version mismatch")

type Config struct {
	Path    string
	File    ConfigData
	Session ConfigData
}

type ConfigData struct {
	Downloads    DownloadsConfig              `toml:"downloads"`
	Qobuz        QobuzConfig                  `toml:"qobuz"`
	Tidal        TidalConfig                  `toml:"tidal"`
	Deezer       DeezerConfig                 `toml:"deezer"`
	Yandex       YandexConfig                 `toml:"yandex"`
	Soundcloud   SoundcloudConfig             `toml:"soundcloud"`
	Youtube      YoutubeConfig                `toml:"youtube"`
	Database     DatabaseConfig               `toml:"database"`
	Conversion   ConversionConfig             `toml:"conversion"`
	QobuzFilters QobuzDiscographyFilterConfig `toml:"qobuz_filters"`
	Artwork      ArtworkConfig                `toml:"artwork"`
	Metadata     MetadataConfig               `toml:"metadata"`
	Filepaths    FilepathsConfig              `toml:"filepaths"`
	LastFM       LastFMConfig                 `toml:"lastfm"`
	CLI          CLIConfig                    `toml:"cli"`
	Misc         MiscConfig                   `toml:"misc"`
}

type DownloadsConfig struct {
	Folder               string `toml:"folder"`
	SourceSubdirectories bool   `toml:"source_subdirectories"`
	DiscSubdirectories   bool   `toml:"disc_subdirectories"`
	Concurrency          bool   `toml:"concurrency"`
	MaxConnections       int    `toml:"max_connections"`
	RequestsPerMinute    int    `toml:"requests_per_minute"`
	VerifySSL            bool   `toml:"verify_ssl"`
}

type QobuzConfig struct {
	Quality          int      `toml:"quality"`
	DownloadBooklets bool     `toml:"download_booklets"`
	UseAuthToken     bool     `toml:"use_auth_token"`
	EmailOrUserID    string   `toml:"email_or_userid"`
	PasswordOrToken  string   `toml:"password_or_token"`
	AppID            string   `toml:"app_id"`
	Secrets          []string `toml:"secrets"`
}

type TidalConfig struct {
	Quality        int    `toml:"quality"`
	DownloadVideos bool   `toml:"download_videos"`
	PreferAtmos    bool   `toml:"prefer_atmos"`
	UserID         string `toml:"user_id"`
	CountryCode    string `toml:"country_code"`
	AccessToken    string `toml:"access_token"`
	RefreshToken   string `toml:"refresh_token"`
	TokenExpiry    int64  `toml:"token_expiry"`
}

type DeezerConfig struct {
	Quality                    int    `toml:"quality"`
	LowerQualityIfNotAvailable bool   `toml:"lower_quality_if_not_available"`
	ARL                        string `toml:"arl"`
	Email                      string `toml:"email"`
	Password                   string `toml:"password"`
	RefreshToken               string `toml:"refresh_token"`
}

type YandexConfig struct {
	Quality     int    `toml:"quality"`
	AccessToken string `toml:"access_token"`
	UserID      string `toml:"user_id"`
}

type SoundcloudConfig struct {
	Quality    int    `toml:"quality"`
	ClientID   string `toml:"client_id"`
	AppVersion string `toml:"app_version"`
}

type YoutubeConfig struct {
	Quality              int    `toml:"quality"`
	DownloadVideos       bool   `toml:"download_videos"`
	VideoDownloadsFolder string `toml:"video_downloads_folder"`
}

type DatabaseConfig struct {
	DownloadsEnabled       bool   `toml:"downloads_enabled"`
	DownloadsPath          string `toml:"downloads_path"`
	FailedDownloadsEnabled bool   `toml:"failed_downloads_enabled"`
	FailedDownloadsPath    string `toml:"failed_downloads_path"`
}

type ConversionConfig struct {
	Enabled      bool   `toml:"enabled"`
	Codec        string `toml:"codec"`
	SamplingRate int    `toml:"sampling_rate"`
	BitDepth     int    `toml:"bit_depth"`
	LossyBitrate int    `toml:"lossy_bitrate"`
}

type QobuzDiscographyFilterConfig struct {
	Extras          bool `toml:"extras"`
	Repeats         bool `toml:"repeats"`
	NonAlbums       bool `toml:"non_albums"`
	Features        bool `toml:"features"`
	NonStudioAlbums bool `toml:"non_studio_albums"`
	NonRemaster     bool `toml:"non_remaster"`
}

type ArtworkConfig struct {
	Embed         bool   `toml:"embed"`
	EmbedSize     string `toml:"embed_size"`
	EmbedMaxWidth int    `toml:"embed_max_width"`
	SaveArtwork   bool   `toml:"save_artwork"`
	SavedMaxWidth int    `toml:"saved_max_width"`
}

type MetadataConfig struct {
	SetPlaylistToAlbum     bool     `toml:"set_playlist_to_album"`
	RenumberPlaylistTracks bool     `toml:"renumber_playlist_tracks"`
	Exclude                []string `toml:"exclude"`
}

type FilepathsConfig struct {
	AddSinglesToFolder bool   `toml:"add_singles_to_folder"`
	FolderFormat       string `toml:"folder_format"`
	TrackFormat        string `toml:"track_format"`
	RestrictCharacters bool   `toml:"restrict_characters"`
	TruncateTo         int    `toml:"truncate_to"`
}

type LastFMConfig struct {
	Source         string `toml:"source"`
	FallbackSource string `toml:"fallback_source"`
}

type CLIConfig struct {
	TextOutput       bool `toml:"text_output"`
	ProgressBars     bool `toml:"progress_bars"`
	MaxSearchResults int  `toml:"max_search_results"`
}

type MiscConfig struct {
	Version         string `toml:"version"`
	CheckForUpdates bool   `toml:"check_for_updates"`
}

func Load(path string) (*Config, error) {
	resolvedPath, err := resolvePath(path)
	if err != nil {
		return nil, err
	}

	if _, err = os.Stat(resolvedPath); errors.Is(err, os.ErrNotExist) {
		cfg := DefaultConfigData()
		if err = saveConfigData(resolvedPath, cfg); err != nil {
			return nil, err
		}
		return &Config{Path: resolvedPath, File: cfg, Session: cloneConfigData(cfg)}, nil
	}
	if err != nil {
		return nil, err
	}

	raw, err := os.ReadFile(resolvedPath)
	if err != nil {
		return nil, err
	}

	data := DefaultConfigData()
	if err = toml.Unmarshal(raw, &data); err != nil {
		return nil, err
	}
	applyRuntimeDefaults(&data)

	if data.Misc.Version != CurrentConfigVersion {
		return nil, fmt.Errorf("%w: need to update from %q to %q", ErrOutdatedConfig, data.Misc.Version, CurrentConfigVersion)
	}

	return &Config{Path: resolvedPath, File: data, Session: cloneConfigData(data)}, nil
}

func UpgradeOutdated(path string) (string, error) {
	resolvedPath, err := resolvePath(path)
	if err != nil {
		return "", err
	}
	raw, err := os.ReadFile(resolvedPath)
	if err != nil {
		return "", err
	}
	data := DefaultConfigData()
	if err = toml.Unmarshal(raw, &data); err != nil {
		return "", err
	}
	applyRuntimeDefaults(&data)
	data.Misc.Version = CurrentConfigVersion
	if err = saveConfigData(resolvedPath, data); err != nil {
		return "", err
	}
	return resolvedPath, nil
}

func (c *Config) SaveFile() error {
	return saveConfigData(c.Path, c.File)
}

func DefaultConfigData() ConfigData {
	home, _ := os.UserHomeDir()
	appDir := defaultAppDir()
	downloadsFolder := filepath.Join(home, "StreamripDownloads")

	data := ConfigData{
		Downloads: DownloadsConfig{
			Folder:               downloadsFolder,
			SourceSubdirectories: false,
			DiscSubdirectories:   true,
			Concurrency:          true,
			MaxConnections:       6,
			RequestsPerMinute:    60,
			VerifySSL:            true,
		},
		Qobuz: QobuzConfig{
			Quality:          3,
			DownloadBooklets: true,
			UseAuthToken:     false,
		},
		Tidal: TidalConfig{
			Quality:        3,
			DownloadVideos: true,
			PreferAtmos:    false,
		},
		Deezer: DeezerConfig{
			Quality:                    2,
			LowerQualityIfNotAvailable: true,
		},
		Yandex: YandexConfig{
			Quality: 2,
		},
		Soundcloud: SoundcloudConfig{
			Quality: 0,
		},
		Youtube: YoutubeConfig{
			Quality:              0,
			DownloadVideos:       false,
			VideoDownloadsFolder: filepath.Join(downloadsFolder, "YouTubeVideos"),
		},
		Database: DatabaseConfig{
			DownloadsEnabled:       true,
			DownloadsPath:          filepath.Join(appDir, "downloads.db"),
			FailedDownloadsEnabled: true,
			FailedDownloadsPath:    filepath.Join(appDir, "failed_downloads.db"),
		},
		Conversion: ConversionConfig{
			Enabled:      false,
			Codec:        "ALAC",
			SamplingRate: 48000,
			BitDepth:     24,
			LossyBitrate: 320,
		},
		QobuzFilters: QobuzDiscographyFilterConfig{},
		Artwork: ArtworkConfig{
			Embed:         true,
			EmbedSize:     "large",
			EmbedMaxWidth: -1,
			SaveArtwork:   true,
			SavedMaxWidth: -1,
		},
		Metadata: MetadataConfig{
			SetPlaylistToAlbum:     true,
			RenumberPlaylistTracks: true,
			Exclude:                []string{},
		},
		Filepaths: FilepathsConfig{
			AddSinglesToFolder: false,
			FolderFormat:       "{albumartist} - {title} ({year}) [{container}] [{bit_depth}B-{sampling_rate}kHz]",
			TrackFormat:        "{tracknumber:02}. {artist} - {title}{explicit}",
			RestrictCharacters: false,
			TruncateTo:         120,
		},
		LastFM: LastFMConfig{
			Source: "qobuz",
		},
		CLI: CLIConfig{
			TextOutput:       true,
			ProgressBars:     true,
			MaxSearchResults: 100,
		},
		Misc: MiscConfig{
			Version:         CurrentConfigVersion,
			CheckForUpdates: true,
		},
	}

	return data
}

func resolvePath(path string) (string, error) {
	if path != "" {
		return path, os.MkdirAll(filepath.Dir(path), 0o755)
	}
	appDir := defaultAppDir()
	if err := os.MkdirAll(appDir, 0o755); err != nil {
		return "", err
	}
	return filepath.Join(appDir, "config.toml"), nil
}

func defaultAppDir() string {
	base, err := os.UserConfigDir()
	if err != nil {
		return "."
	}
	return filepath.Join(base, "streamrip")
}

func saveConfigData(path string, data ConfigData) error {
	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
		return err
	}
	b, err := toml.Marshal(data)
	if err != nil {
		return err
	}
	return os.WriteFile(path, b, 0o644)
}

func applyRuntimeDefaults(data *ConfigData) {
	home, _ := os.UserHomeDir()
	appDir := defaultAppDir()
	if data.Downloads.Folder == "" {
		data.Downloads.Folder = filepath.Join(home, "StreamripDownloads")
	}
	if data.Database.DownloadsPath == "" {
		data.Database.DownloadsPath = filepath.Join(appDir, "downloads.db")
	}
	if data.Database.FailedDownloadsPath == "" {
		data.Database.FailedDownloadsPath = filepath.Join(appDir, "failed_downloads.db")
	}
	if data.Youtube.VideoDownloadsFolder == "" {
		data.Youtube.VideoDownloadsFolder = filepath.Join(data.Downloads.Folder, "YouTubeVideos")
	}
}

func cloneConfigData(in ConfigData) ConfigData {
	out := in
	out.Qobuz.Secrets = append([]string(nil), in.Qobuz.Secrets...)
	out.Metadata.Exclude = append([]string(nil), in.Metadata.Exclude...)
	return out
}