Implemented listenbrainz-archive backend with listen export support

internal/backends/lbarchive/lbarchive.go

@@ -0,0 +1,121 @@
+/*
+Copyright © 2025 Philipp Wolfer <phw@uploadedlobster.com>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+package lbarchive
+
+import (
+	"context"
+	"time"
+
+	lbapi "go.uploadedlobster.com/scotty/internal/backends/listenbrainz"
+	"go.uploadedlobster.com/scotty/internal/config"
+	"go.uploadedlobster.com/scotty/internal/i18n"
+	"go.uploadedlobster.com/scotty/internal/models"
+	"go.uploadedlobster.com/scotty/pkg/listenbrainz"
+)
+
+const batchSize = 2000
+
+type ListenBrainzArchiveBackend struct {
+	filePath string
+}
+
+func (b *ListenBrainzArchiveBackend) Name() string { return "listenbrainz-archive" }
+
+func (b *ListenBrainzArchiveBackend) Options() []models.BackendOption {
+	return []models.BackendOption{{
+		Name:  "file-path",
+		Label: i18n.Tr("Export ZIP file path"),
+		Type:  models.String,
+	}}
+}
+
+func (b *ListenBrainzArchiveBackend) InitConfig(config *config.ServiceConfig) error {
+	b.filePath = config.GetString("file-path")
+	return nil
+}
+
+func (b *ListenBrainzArchiveBackend) ExportListens(
+	ctx context.Context, oldestTimestamp time.Time,
+	results chan models.ListensResult, progress chan models.TransferProgress) {
+	startTime := time.Now()
+	minTime := oldestTimestamp
+	if minTime.Unix() < 1 {
+		minTime = time.Unix(1, 0)
+	}
+
+	totalDuration := startTime.Sub(oldestTimestamp)
+	p := models.TransferProgress{
+		Export: &models.Progress{
+			Total: int64(totalDuration.Seconds()),
+		},
+	}
+
+	archive, err := listenbrainz.OpenArchive(b.filePath)
+	if err != nil {
+		p.Export.Abort()
+		progress <- p
+		results <- models.ListensResult{Error: err}
+		return
+	}
+	defer archive.Close()
+
+	userInfo, err := archive.UserInfo()
+	if err != nil {
+		p.Export.Abort()
+		progress <- p
+		results <- models.ListensResult{Error: err}
+		return
+	}
+
+	listens := make(models.ListensList, 0, batchSize)
+	for rawListen, err := range archive.IterListens(oldestTimestamp) {
+		if err != nil {
+			p.Export.Abort()
+			progress <- p
+			results <- models.ListensResult{Error: err}
+			return
+		}
+
+		listen := lbapi.AsListen(rawListen)
+		if listen.UserName == "" {
+			listen.UserName = userInfo.Name
+		}
+		listens = append(listens, listen)
+
+		// Update the progress
+		p.Export.TotalItems += 1
+		remainingTime := startTime.Sub(listen.ListenedAt)
+		p.Export.Elapsed = int64(totalDuration.Seconds() - remainingTime.Seconds())
+
+		// Allow the importer to start processing the listens by
+		// sending them in batches.
+		if len(listens) >= batchSize {
+			results <- models.ListensResult{Items: listens}
+			progress <- p
+			listens = listens[:0]
+		}
+	}
+
+	results <- models.ListensResult{Items: listens}
+	p.Export.Complete()
+	progress <- p
+}