// Package subsonic implements the original Subsonic REST API (through
// version 1.16.1) on top of VibeSonic's existing database, scanner,
// streaming, and cover art packages. It does not duplicate business
// logic: every handler here is a thin adapter from Subsonic's wire
// format onto internal/database, internal/library, internal/streaming,
// and internal/coverart.
//
// One set of Go structs (this file and its model_*.go siblings) is
// shared between XML and JSON output via struct tags, so response
// shape can never drift between formats — see response.go for how they
// are serialized.
package subsonic

import "encoding/xml"

// ServerVersion is the highest Subsonic REST API version VibeSonic
// implements. Requests from a client claiming a newer protocol version
// are rejected (error code 20); older clients are accepted, since the
// protocol is additive.
const ServerVersion = "1.16.1"

// Response is the envelope every /rest/* call returns: exactly one of
// the payload fields below is set, matching the single child element
// real Subsonic servers emit inside <subsonic-response>.
type Response struct {
	XMLName xml.Name `xml:"subsonic-response" json:"-"`
	Xmlns   string   `xml:"xmlns,attr" json:"-"`
	Status  string   `xml:"status,attr" json:"status"`
	Version string   `xml:"version,attr" json:"version"`

	// OpenSubsonic core response additions (always populated): the
	// server's real product name and build version, and a flag
	// confirming OpenSubsonic support so clients can detect it from any
	// response, not just getOpenSubsonicExtensions.
	Type          string `xml:"type,attr" json:"type"`
	ServerVersion string `xml:"serverVersion,attr" json:"serverVersion"`
	OpenSubsonic  bool   `xml:"openSubsonic,attr" json:"openSubsonic"`

	Error *Error `xml:"error,omitempty" json:"error,omitempty"`

	License               *License               `xml:"license,omitempty" json:"license,omitempty"`
	MusicFolders          *MusicFolders          `xml:"musicFolders,omitempty" json:"musicFolders,omitempty"`
	Indexes               *Indexes               `xml:"indexes,omitempty" json:"indexes,omitempty"`
	Directory             *Directory             `xml:"directory,omitempty" json:"directory,omitempty"`
	Genres                *Genres                `xml:"genres,omitempty" json:"genres,omitempty"`
	Artists               *ArtistsID3            `xml:"artists,omitempty" json:"artists,omitempty"`
	Artist                *ArtistWithAlbumsID3   `xml:"artist,omitempty" json:"artist,omitempty"`
	Album                 *AlbumWithSongsID3     `xml:"album,omitempty" json:"album,omitempty"`
	Song                  *Child                 `xml:"song,omitempty" json:"song,omitempty"`
	Videos                *Videos                `xml:"videos,omitempty" json:"videos,omitempty"`
	VideoInfo             *VideoInfo             `xml:"videoInfo,omitempty" json:"videoInfo,omitempty"`
	ArtistInfo            *ArtistInfo            `xml:"artistInfo,omitempty" json:"artistInfo,omitempty"`
	ArtistInfo2           *ArtistInfo2           `xml:"artistInfo2,omitempty" json:"artistInfo2,omitempty"`
	AlbumInfo             *AlbumInfo             `xml:"albumInfo,omitempty" json:"albumInfo,omitempty"`
	SimilarSongs          *SimilarSongs          `xml:"similarSongs,omitempty" json:"similarSongs,omitempty"`
	SimilarSongs2         *SimilarSongs2         `xml:"similarSongs2,omitempty" json:"similarSongs2,omitempty"`
	TopSongs              *TopSongs              `xml:"topSongs,omitempty" json:"topSongs,omitempty"`
	AlbumList             *AlbumList             `xml:"albumList,omitempty" json:"albumList,omitempty"`
	AlbumList2            *AlbumList2            `xml:"albumList2,omitempty" json:"albumList2,omitempty"`
	RandomSongs           *Songs                 `xml:"randomSongs,omitempty" json:"randomSongs,omitempty"`
	SongsByGenre          *Songs                 `xml:"songsByGenre,omitempty" json:"songsByGenre,omitempty"`
	NowPlaying            *NowPlaying            `xml:"nowPlaying,omitempty" json:"nowPlaying,omitempty"`
	Starred               *Starred               `xml:"starred,omitempty" json:"starred,omitempty"`
	Starred2              *Starred2              `xml:"starred2,omitempty" json:"starred2,omitempty"`
	SearchResult          *SearchResult          `xml:"searchResult,omitempty" json:"searchResult,omitempty"`
	SearchResult2         *SearchResult2         `xml:"searchResult2,omitempty" json:"searchResult2,omitempty"`
	SearchResult3         *SearchResult3         `xml:"searchResult3,omitempty" json:"searchResult3,omitempty"`
	Playlists             *Playlists             `xml:"playlists,omitempty" json:"playlists,omitempty"`
	Playlist              *PlaylistWithSongs     `xml:"playlist,omitempty" json:"playlist,omitempty"`
	JukeboxStatus         *JukeboxStatus         `xml:"jukeboxStatus,omitempty" json:"jukeboxStatus,omitempty"`
	JukeboxPlaylist       *JukeboxPlaylist       `xml:"jukeboxPlaylist,omitempty" json:"jukeboxPlaylist,omitempty"`
	InternetRadioStations *InternetRadioStations `xml:"internetRadioStations,omitempty" json:"internetRadioStations,omitempty"`
	ChatMessages          *ChatMessages          `xml:"chatMessages,omitempty" json:"chatMessages,omitempty"`
	User                  *User                  `xml:"user,omitempty" json:"user,omitempty"`
	Users                 *Users                 `xml:"users,omitempty" json:"users,omitempty"`
	Bookmarks             *Bookmarks             `xml:"bookmarks,omitempty" json:"bookmarks,omitempty"`
	PlayQueue             *PlayQueue             `xml:"playQueue,omitempty" json:"playQueue,omitempty"`
	Shares                *Shares                `xml:"shares,omitempty" json:"shares,omitempty"`
	Podcasts              *Podcasts              `xml:"podcasts,omitempty" json:"podcasts,omitempty"`
	NewestPodcasts        *NewestPodcasts        `xml:"newestPodcasts,omitempty" json:"newestPodcasts,omitempty"`
	ScanStatus            *ScanStatus            `xml:"scanStatus,omitempty" json:"scanStatus,omitempty"`
	Lyrics                *Lyrics                `xml:"lyrics,omitempty" json:"lyrics,omitempty"`

	// OpenSubsonic extensions.
	OpenSubsonicExtensions []OpenSubsonicExtension `xml:"openSubsonicExtensions,omitempty" json:"openSubsonicExtensions,omitempty"`
	TokenInfo              *TokenInfo              `xml:"tokenInfo,omitempty" json:"tokenInfo,omitempty"`
	PodcastEpisode         *PodcastEpisode         `xml:"podcastEpisode,omitempty" json:"podcastEpisode,omitempty"`
	LyricsList             *LyricsList             `xml:"lyricsList,omitempty" json:"lyricsList,omitempty"`
	PlayQueueByIndex       *PlayQueueByIndex       `xml:"playQueueByIndex,omitempty" json:"playQueueByIndex,omitempty"`
	// SonicMatch is a top-level array (not wrapped in an object) on both
	// getSonicSimilarTracks and findSonicPath, per the OpenSubsonic
	// schema — the two endpoints are otherwise unrelated, so there is no
	// shared wrapper type to name it after.
	SonicMatch        []SonicMatch       `xml:"sonicMatch,omitempty" json:"sonicMatch,omitempty"`
	TranscodeDecision *TranscodeDecision `xml:"transcodeDecision,omitempty" json:"transcodeDecision,omitempty"`
}

// OpenSubsonicExtension describes one extension this server supports,
// as returned by getOpenSubsonicExtensions.
type OpenSubsonicExtension struct {
	Name     string `xml:"name,attr" json:"name"`
	Versions []int  `xml:"versions" json:"versions"`
}

type TokenInfo struct {
	Username string `xml:"username,attr" json:"username"`
}

// ServerName is the real product name advertised in every response's
// "type" attribute, per the OpenSubsonic base response additions.
const ServerName = "vibesonic"

// AppVersion is VibeSonic's own build version, advertised in every
// response's "serverVersion" attribute. Overridable at link time
// (matching cmd/vibesonic's version variable); defaults to "dev".
var AppVersion = "dev"

func newResponse() *Response {
	return &Response{
		Xmlns:         "http://subsonic.org/restapi",
		Status:        "ok",
		Version:       ServerVersion,
		Type:          ServerName,
		ServerVersion: AppVersion,
		OpenSubsonic:  true,
	}
}

// Error is the payload of a failed response.
type Error struct {
	Code    int    `xml:"code,attr" json:"code"`
	Message string `xml:"message,attr" json:"message"`
	HelpURL string `xml:"helpUrl,attr,omitempty" json:"helpUrl,omitempty"`
}

// --- System ---

type License struct {
	Valid          bool   `xml:"valid,attr" json:"valid"`
	Email          string `xml:"email,attr,omitempty" json:"email,omitempty"`
	LicenseExpires string `xml:"licenseExpires,attr,omitempty" json:"licenseExpires,omitempty"`
}

// --- Music folders / genres ---

type MusicFolders struct {
	MusicFolder []MusicFolder `xml:"musicFolder" json:"musicFolder"`
}

type MusicFolder struct {
	ID   string `xml:"id,attr" json:"id"`
	Name string `xml:"name,attr" json:"name"`
}

type Genres struct {
	Genre []Genre `xml:"genre" json:"genre"`
}

type Genre struct {
	Name       string `xml:",chardata" json:"value"`
	SongCount  int    `xml:"songCount,attr" json:"songCount"`
	AlbumCount int    `xml:"albumCount,attr" json:"albumCount"`
}