feat(core): persist tasks and recover them after restart

core/tasks/tfile/codec.go

@@ -0,0 +1,85 @@
+package tfile
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"path/filepath"
+
+	"github.com/krau/SaveAny-Bot/config"
+	"github.com/krau/SaveAny-Bot/core"
+	"github.com/krau/SaveAny-Bot/pkg/enums/tasktype"
+	tfilepkg "github.com/krau/SaveAny-Bot/pkg/tfile"
+	"github.com/krau/SaveAny-Bot/storage"
+)
+
+type taskPayload struct {
+	ID        string               `json:"id"`
+	Storage   string               `json:"storage"`
+	Path      string               `json:"path"`
+	File      tfilepkg.FilePayload `json:"file"`
+	ChatID    int64                `json:"chat_id"`
+	MessageID int                  `json:"message_id"`
+}
+
+type taskCodec struct{}
+
+func init() {
+	core.RegisterTaskCodec(tasktype.TaskTypeTgfiles, taskCodec{})
+}
+
+func (taskCodec) Marshal(task core.Executable) ([]byte, error) {
+	t, ok := task.(*Task)
+	if !ok {
+		return nil, fmt.Errorf("unexpected task type %T", task)
+	}
+	filePayload, ok := tfilepkg.FilePayloadOf(t.File)
+	if !ok {
+		return nil, fmt.Errorf("file %T is not serializable", t.File)
+	}
+	p := taskPayload{
+		ID:      t.ID,
+		Storage: t.Storage.Name(),
+		Path:    t.Path,
+		File:    filePayload,
+	}
+	if progress, ok := t.Progress.(*Progress); ok {
+		p.ChatID = progress.ChatID
+		p.MessageID = progress.MessageID
+	}
+	return json.Marshal(p)
+}
+
+func (taskCodec) Unmarshal(data []byte) (core.Executable, error) {
+	var p taskPayload
+	if err := json.Unmarshal(data, &p); err != nil {
+		return nil, fmt.Errorf("invalid task payload: %w", err)
+	}
+	dler := core.DownloaderClient()
+	if dler == nil {
+		return nil, fmt.Errorf("no downloader client available")
+	}
+	file := tfilepkg.FileFromPayload(p.File, dler)
+	stor, err := storage.GetStorageByName(context.Background(), p.Storage)
+	if err != nil {
+		return nil, fmt.Errorf("storage %q: %w", p.Storage, err)
+	}
+	var progress ProgressTracker
+	if p.ChatID != 0 {
+		progress = NewProgressTrack(p.MessageID, p.ChatID)
+	}
+	localPath, err := filepath.Abs(filepath.Join(config.C().Temp.BasePath, fmt.Sprintf("%s_%s", p.ID, file.Name())))
+	if err != nil {
+		return nil, fmt.Errorf("failed to build cache path: %w", err)
+	}
+	return &Task{
+		ID:        p.ID,
+		Ctx:       context.Background(),
+		File:      file,
+		Storage:   stor,
+		Path:      p.Path,
+		Progress:  progress,
+		stream:    false, // recovered tasks always download to cache first
+		localPath: localPath,
+	}, nil
+}

core/tasks/tfile/execute.go

@@ -9,7 +9,6 @@ import (
 
 	"github.com/charmbracelet/log"
 	"github.com/duke-git/lancet/v2/retry"
-	"github.com/krau/SaveAny-Bot/common/tdler"
 	"github.com/krau/SaveAny-Bot/common/utils/fsutil"
 	"github.com/krau/SaveAny-Bot/common/utils/ioutil"
 	"github.com/krau/SaveAny-Bot/config"
@@ -19,8 +18,13 @@ import (
 	"github.com/krau/SaveAny-Bot/storage"
 )
 
-func (t *Task) Execute(ctx context.Context) error {
+func (t *Task) Execute(ctx context.Context) (err error) {
 	logger := log.FromContext(ctx).WithPrefix(fmt.Sprintf("file[%s]", t.File.Name()))
+	defer func() {
+		if t.Progress != nil {
+			t.Progress.OnDone(ctx, t, err)
+		}
+	}()
 	if t.Progress != nil {
 		t.Progress.OnStart(ctx, t)
 	}
@@ -29,35 +33,16 @@ func (t *Task) Execute(ctx context.Context) error {
 	}
 
 	logger.Info("Starting file download")
-	localFile, err := fsutil.CreateFile(t.localPath)
-	if err != nil {
-		return fmt.Errorf("failed to create local file: %w", err)
-	}
-	defer func() {
-		if err := localFile.CloseAndRemove(); err != nil {
-			logger.Errorf("Failed to close local file: %v", err)
-		}
-	}()
-	wrAt := newWriterAt(ctx, localFile, t.Progress, t)
-
-	defer func() {
-		if t.Progress != nil {
-			t.Progress.OnDone(ctx, t, err)
-		}
-	}()
-	_, err = tdler.NewDownloader(t.File).Parallel(ctx, wrAt)
-	if err != nil {
+	if err := t.download(ctx); err != nil {
 		return fmt.Errorf("failed to download file: %w", err)
 	}
-	logger.Infof("File downloaded successfully")
 	if path.Ext(t.File.Name()) == "" {
 		ext := fsutil.DetectFileExt(t.localPath)
 		if ext != "" {
 			t.Path = t.Path + ext
 		}
 	}
-	var fileStat os.FileInfo
-	fileStat, err = os.Stat(t.localPath)
+	fileStat, err := os.Stat(t.localPath)
 	if err != nil {
 		return fmt.Errorf("failed to get file stat: %w", err)
 	}
@@ -97,6 +82,10 @@ func (t *Task) Execute(ctx context.Context) error {
 	if err != nil {
 		return fmt.Errorf("failed to save file after retries: %w", err)
 	}
+	// Cache file is kept on failure so a later restart can resume upload.
+	if err := os.Remove(t.localPath); err != nil {
+		logger.Errorf("Failed to remove cache file: %v", err)
+	}
 	return nil
 }