db

type Play struct {
	// StartTime is the time at which playback started.
	StartTime time.Time `json:"t"`
	// IPAddress is the IPv4 or IPv6 address of the client playing the song.
	IPAddress string `datastore:"IpAddress" json:"ip"`
}

type PlayArray []Play

type PlayDump struct {
	// Song entity's key ID from Datastore.
	SongID string `json:"songId"`
	// Play information.
	Play Play `json:"play"`
}

type PlayStats struct {
	// Plays is the number of plays.
	Plays int `json:"plays"`
	// TotalSec is the total duration in seconds of played songs.
	TotalSec float64 `json:"totalSec"`
	// FirstPlays is the number of songs that were first played in the interval.
	FirstPlays int `json:"firstPlays"`
	// LastPlays is the number of songs that were last played in the interval.
	LastPlays int `json:"lastPlays"`
}

type Song struct {
	// SHA1 is a hash of the audio portion of the file.
	SHA1 string `datastore:"Sha1" json:"sha1,omitempty"`

	// SongID is the Song entity's key ID from Datastore. Only set in search results.
	SongID string `datastore:"-" json:"songId,omitempty"`

	// Filename is a relative path from the base of the music directory.
	// Clients can pass this to the server's /song endpoint to download the
	// song's music data.
	Filename string `json:"filename,omitempty"`

	// CoverFilename is a relative path from the base of the covers directory.
	// Must be escaped for Cloud Storage when constructing CoverURL.
	// Clients can pass this to the server's /cover endpoint to get a scaled
	// copy of the cover.
	CoverFilename string `datastore:",noindex" json:"coverFilename,omitempty"`

	// Canonical versions used for display.
	Artist string `datastore:",noindex" json:"artist"`
	Title  string `datastore:",noindex" json:"title"`
	Album  string `datastore:",noindex" json:"album"`

	// Lowercase versions used for searching and sorting.
	// Additional normalization is performed: see query.Normalize.
	ArtistLower string `json:"-"`
	TitleLower  string `json:"-"`
	AlbumLower  string `json:"-"`

	// AlbumArtist contains the album's artist if it isn't the same as Artist.
	// This corresponds to the TPE2 ID3 tag, which may hold the performer name
	// in the case of a classical album, or the remixer name in the case of an
	// album consisting of songs remixed by a single artist.
	AlbumArtist string `datastore:",noindex" json:"albumArtist,omitempty"`

	// DiscSubtitle contains the disc's subtitle, if any.
	DiscSubtitle string `json:"discSubtitle,omitempty"`

	// Keywords contains words from ArtistLower, TitleLower, AlbumLower, and
	// AlbumArtist and DiscSubtitle (after normalization). It is used for searching.
	Keywords []string `json:"-"`

	// AlbumID is an opaque ID uniquely identifying the album
	// (generally, a MusicBrainz release ID taken from a "MusicBrainz Album Id" ID3v2 tag).
	AlbumID string `datastore:"AlbumId" json:"albumId,omitempty"`

	// CoverID is an opaque ID from a "nup Cover Id" ID3v2 tag used to specify cover art.
	// If unset, AlbumID and then RecordingID is used when looking for art.
	CoverID string `datastore:"-" json:"-"`

	// RecordingID is an opaque ID uniquely identifying the recording (generally, the MusicBrainz ID
	// corresponding to the MusicBrainz recording entity, taken from a UFID ID3v2 tag).
	// This is used to find cover art if neither AlbumID nor CoverID is set.
	// It is also used to find updated metadata for the song in MusicBrainz.
	RecordingID string `datastore:"-" json:"-"`

	// OrigAlbumID and OrigRecordingID contain the original values of AlbumID and RecordingID
	// if they were overridden by JSON files. These are only used by the client.
	OrigAlbumID     string `datastore:"-" json:"-"`
	OrigRecordingID string `datastore:"-" json:"-"`

	// Track is the song's track number, or 0 if unset.
	Track int `json:"track"`
	// Disc is the song's disc number, or 0 if unset.
	Disc int `json:"disc"`

	// Date is the date on which this song was recorded or released in UTC.
	// It is used when listing songs or albums in chronological order.
	// This is vaguely defined because the ID3v2 fields related to it are a mess:
	// https://github.com/derat/nup/issues/42
	Date time.Time `json:"date,omitempty"`

	// Length is the song's duration in seconds.
	Length float64 `json:"length"`

	// TrackGain is the song's dB gain adjustment independent of its album. More info:
	//  https://en.wikipedia.org/wiki/ReplayGain
	//  https://wiki.hydrogenaud.io/index.php?title=ReplayGain_specification
	//  https://productionadvice.co.uk/tidal-normalization-upgrade/
	TrackGain float64 `datastore:",noindex" json:"trackGain"`
	// AlbumGain is the song's dB gain adjustment relative to its album.
	AlbumGain float64 `datastore:",noindex" json:"albumGain"`
	// PeakAmp is the song's peak amplitude, with 1.0 representing the highest
	// amplitude that can be played without clipping.
	PeakAmp float64 `datastore:",noindex" json:"peakAmp"`

	// Rating is the song's rating in the range [1, 5], or 0 if unrated.
	// The server should call SetRating to additionally update the RatingAtLeast* fields.
	Rating int `json:"rating"`

	// RatingAtLeast* are true if Rating is at least the specified value.
	// These are maintained to sidestep Datastore's restriction against using multiple
	// inequality filters in a query.
	RatingAtLeast1 bool `json:"-"`
	RatingAtLeast2 bool `json:"-"`
	RatingAtLeast3 bool `json:"-"`
	RatingAtLeast4 bool `json:"-"`

	// FirstStartTime is the first time the song was played.
	FirstStartTime time.Time `json:"-"`
	// LastStartTime is the last time the song was played.
	LastStartTime time.Time `json:"-"`

	// NumPlays is the number of times the song has been played.
	NumPlays int `json:"-"`

	// Plays contains the song's playback history.
	// Only used for importing data -- in Datastore, Play is a descendant of Song.
	Plays []Play `datastore:"-" json:"plays,omitempty"`

	// Tags contains tags assigned to the song by the user.
	Tags []string `json:"tags"`

	// LastModifiedTime is the time that the song was modified.
	LastModifiedTime time.Time `json:"-"`
}

type Stats struct {
	// Songs is the total number of songs in the database.
	Songs int `json:"songs"`
	// Albums is the total number of albums in the database.
	// This is computed by counting distinct Song.AlbumID values.
	Albums int `json:"albums"`
	// TotalSec is the total duration in seconds of all songs.
	TotalSec float64 `json:"totalSec"`
	// Ratings maps from a rating in [1, 5] (or 0 for unrated) to number of songs with that rating.
	Ratings map[int]int `json:"ratings"`
	// SongDecades maps from the year at the beginning of a decade (e.g. 1990) to the number of
	// songs in the database with a Date field in the decade. 0 is used for songs with unset dates.
	SongDecades map[int]int `json:"songDecades"`
	// Tags maps from tag to number of songs with that tag.
	Tags map[string]int `json:"tags"`
	// Years maps from year (e.g. 2020) to stats about plays in that year.
	Years map[int]PlayStats `json:"years"`
	// UpdateTime is the time at which these stats were generated.
	UpdateTime time.Time `json:"updateTime"`
}