From 1f2d5f662dfb2bce27db385b7a86b5eb258ab8d0 Mon Sep 17 00:00:00 2001
From: Philipp Wolfer <ph.wolfer@gmail.com>
Date: Tue, 14 Nov 2023 00:39:17 +0100
Subject: [PATCH] JSPF loves export

---
 backends/backends.go       |   2 +
 backends/jspf/jspf.go      | 101 +++++++++++++++++++++++++++++++++++++
 backends/jspf/jspf_test.go |  18 +++++++
 backends/jspf/models.go    |  10 ++++
 4 files changed, 131 insertions(+)

diff --git a/backends/backends.go b/backends/backends.go
index 9086404..9584a59 100644
--- a/backends/backends.go
+++ b/backends/backends.go
@@ -30,6 +30,7 @@ import (
 	"github.com/spf13/viper"
 	"go.uploadedlobster.com/scotty/backends/dump"
 	"go.uploadedlobster.com/scotty/backends/funkwhale"
+	"go.uploadedlobster.com/scotty/backends/jspf"
 	"go.uploadedlobster.com/scotty/backends/listenbrainz"
 	"go.uploadedlobster.com/scotty/backends/maloja"
 	"go.uploadedlobster.com/scotty/backends/scrobblerlog"
@@ -79,6 +80,7 @@ func GetBackends() []BackendInfo {
 var knownBackends = map[string]func() models.Backend{
 	"dump":             func() models.Backend { return &dump.DumpBackend{} },
 	"funkwhale-api":    func() models.Backend { return &funkwhale.FunkwhaleApiBackend{} },
+	"jspf":             func() models.Backend { return &jspf.JspfBackend{} },
 	"listenbrainz-api": func() models.Backend { return &listenbrainz.ListenBrainzApiBackend{} },
 	"maloja-api":       func() models.Backend { return &maloja.MalojaApiBackend{} },
 	"scrobbler-log":    func() models.Backend { return &scrobblerlog.ScrobblerLogBackend{} },
diff --git a/backends/jspf/jspf.go b/backends/jspf/jspf.go
index f23ac28..9af9087 100644
--- a/backends/jspf/jspf.go
+++ b/backends/jspf/jspf.go
@@ -21,3 +21,104 @@ THE SOFTWARE.
 */
 
 package jspf
+
+import (
+	"encoding/json"
+	"os"
+	"time"
+
+	"github.com/spf13/viper"
+	"go.uploadedlobster.com/scotty/models"
+)
+
+type JspfBackend struct {
+	filePath   string
+	title      string
+	creator    string
+	identifier string
+}
+
+func (b JspfBackend) FromConfig(config *viper.Viper) models.Backend {
+	b.filePath = config.GetString("file-path")
+	b.title = config.GetString("title")
+	b.creator = config.GetString("username")
+	b.identifier = config.GetString("identifier")
+	return b
+}
+
+func (b JspfBackend) ImportLoves(loves []models.Love, oldestTimestamp time.Time) (models.ImportResult, error) {
+	result := models.ImportResult{
+		TotalCount:    len(loves),
+		ImportCount:   0,
+		LastTimestamp: oldestTimestamp,
+	}
+
+	tracks := make([]Track, 0, result.TotalCount)
+	for _, love := range loves {
+		if love.Created.Unix() > result.LastTimestamp.Unix() {
+			result.LastTimestamp = love.Created
+		}
+
+		extension := MusicBrainzTrackExtension{
+			AddedAt:            love.Created,
+			AddedBy:            love.UserName,
+			AdditionalMetadata: love.AdditionalInfo,
+			ArtistIdentifiers:  make([]string, len(love.ArtistMbids)),
+		}
+
+		for i, mbid := range love.ArtistMbids {
+			extension.ArtistIdentifiers[i] = "https://musicbrainz.org/artist/" + string(mbid)
+		}
+
+		if love.ReleaseMbid != "" {
+			extension.ReleaseIdentifier = "https://musicbrainz.org/release/" + string(love.ReleaseMbid)
+		}
+
+		track := Track{
+			Title:    love.TrackName,
+			Album:    love.ReleaseName,
+			Creator:  love.ArtistName(),
+			TrackNum: love.TrackNumber,
+			Extension: map[string]any{
+				"https://musicbrainz.org/doc/jspf#track": extension,
+			},
+		}
+
+		if love.RecordingMbid != "" {
+			track.Identifier = append(track.Identifier, "https://musicbrainz.org/recording/"+string(love.RecordingMbid))
+		}
+
+		tracks = append(tracks, track)
+
+		result.ImportCount += 1
+	}
+
+	err := b.writeJspf(tracks)
+	return result, err
+}
+
+func (b JspfBackend) writeJspf(tracks []Track) error {
+	playlist := Jspf{
+		Playlist: Playlist{
+			Title:      b.title,
+			Creator:    b.creator,
+			Identifier: b.identifier,
+			Date:       time.Now(),
+			Tracks:     tracks,
+		},
+	}
+
+	file, err := os.Create(b.filePath)
+	if err != nil {
+		return err
+	}
+
+	defer file.Close()
+	jspfJson, err := json.MarshalIndent(playlist, "", "\t")
+	if err != nil {
+		return err
+	}
+
+	_, err = file.Write(jspfJson)
+	return err
+}
diff --git a/backends/jspf/jspf_test.go b/backends/jspf/jspf_test.go
index 5522c24..2f1f31f 100644
--- a/backends/jspf/jspf_test.go
+++ b/backends/jspf/jspf_test.go
@@ -21,3 +21,21 @@ THE SOFTWARE.
 */
 
 package jspf_test
+
+import (
+	"testing"
+
+	"github.com/spf13/viper"
+	"github.com/stretchr/testify/assert"
+	"go.uploadedlobster.com/scotty/backends/scrobblerlog"
+)
+
+func TestFromConfig(t *testing.T) {
+	config := viper.New()
+	config.Set("file-path", "/foo/bar.jspf")
+	config.Set("title", "My Playlist")
+	config.Set("username", "outsidecontext")
+	config.Set("identifier", "http://example.com/playlist1")
+	backend := scrobblerlog.ScrobblerLogBackend{}.FromConfig(config)
+	assert.IsType(t, scrobblerlog.ScrobblerLogBackend{}, backend)
+}
diff --git a/backends/jspf/models.go b/backends/jspf/models.go
index bb2b8b0..622a827 100644
--- a/backends/jspf/models.go
+++ b/backends/jspf/models.go
@@ -65,3 +65,13 @@ type Attribution map[string]string
 type Link map[string]string
 
 type Meta map[string]string
+
+// Extension for "https://musicbrainz.org/doc/jspf#track"
+// as used by ListenBrainz.
+type MusicBrainzTrackExtension struct {
+	AddedAt            time.Time      `json:"added_at,omitempty"`
+	AddedBy            string         `json:"added_by,omitempty"`
+	ReleaseIdentifier  string         `json:"release_identifier,omitempty"`
+	ArtistIdentifiers  []string       `json:"artist_identifiers,omitempty"`
+	AdditionalMetadata map[string]any `json:"additional_metadata,omitempty"`
+}