feat(telegram): preserve source media groups (#226)

* feat(telegram): preserve source media groups * fix(telegram): rewind batch readers before inspection
2026-09-05 15:46:37 +08:00 · 2026-08-04 16:46:29 +08:00
parent 52f880f0f2
commit 1d794a7b9c
9 changed files with 694 additions and 70 deletions
@@ -0,0 +1,140 @@
+package telegram
+
+import (
+	"bytes"
+	"io"
+	"testing"
+
+	"github.com/krau/SaveAny-Bot/pkg/storagetypes"
+)
+
+func TestPlanMediaGroups(t *testing.T) {
+	tests := []struct {
+		name      string
+		items     []batchMediaItem
+		wantSizes []int
+	}{
+		{
+			name: "same source album",
+			items: []batchMediaItem{
+				albumItem("a", 1, true),
+				albumItem("a", 1, true),
+			},
+			wantSizes: []int{2},
+		},
+		{
+			name: "different source albums",
+			items: []batchMediaItem{
+				albumItem("a", 1, true),
+				albumItem("b", 1, true),
+			},
+			wantSizes: []int{1, 1},
+		},
+		{
+			name: "ungrouped messages",
+			items: []batchMediaItem{
+				albumItem("", 1, true),
+				albumItem("", 1, true),
+			},
+			wantSizes: []int{1, 1},
+		},
+		{
+			name: "different target chats",
+			items: []batchMediaItem{
+				albumItem("a", 1, true),
+				albumItem("a", 2, true),
+			},
+			wantSizes: []int{1, 1},
+		},
+		{
+			name: "ineligible media does not bridge albums",
+			items: []batchMediaItem{
+				albumItem("a", 1, true),
+				albumItem("a", 1, false),
+				albumItem("a", 1, true),
+			},
+			wantSizes: []int{1, 1, 1},
+		},
+		{
+			name:      "maximum album size",
+			items:     repeatedAlbumItems(11),
+			wantSizes: []int{10, 1},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			groups := planMediaGroups(tt.items)
+			if len(groups) != len(tt.wantSizes) {
+				t.Fatalf("got %d groups, want %d", len(groups), len(tt.wantSizes))
+			}
+			for i, want := range tt.wantSizes {
+				if got := len(groups[i]); got != want {
+					t.Errorf("group %d has %d items, want %d", i, got, want)
+				}
+			}
+		})
+	}
+}
+
+func TestMediaCaption(t *testing.T) {
+	empty := ""
+	original := "original caption"
+	tests := []struct {
+		name     string
+		override *string
+		wantLen  int
+	}{
+		{name: "filename fallback", wantLen: 1},
+		{name: "preserve empty source caption", override: &empty, wantLen: 0},
+		{name: "preserve source caption", override: &original, wantLen: 1},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := len(mediaCaption("file.jpg", tt.override)); got != tt.wantLen {
+				t.Fatalf("got %d caption options, want %d", got, tt.wantLen)
+			}
+		})
+	}
+}
+
+func TestInspectBatchItemRewindsBeforeMimetypeDetection(t *testing.T) {
+	data := []byte("\x89PNG\r\n\x1a\n\x00\x00\x00\rIHDR")
+	reader := bytes.NewReader(data)
+	if _, err := reader.Seek(4, io.SeekStart); err != nil {
+		t.Fatalf("failed to set initial reader offset: %v", err)
+	}
+
+	mediaItem, err := new(Telegram).inspectBatchItem(nil, storagetypes.BatchItem{
+		Reader:      reader,
+		StoragePath: "photo.png",
+		Size:        int64(len(data)),
+	})
+	if err != nil {
+		t.Fatalf("inspectBatchItem returned an error: %v", err)
+	}
+	if !mediaItem.albumEligible {
+		t.Fatal("albumEligible = false, want true for PNG input")
+	}
+	if offset, err := reader.Seek(0, io.SeekCurrent); err != nil {
+		t.Fatalf("failed to get final reader offset: %v", err)
+	} else if offset != 0 {
+		t.Fatalf("reader offset = %d, want 0", offset)
+	}
+}
+
+func albumItem(group string, chatID int64, eligible bool) batchMediaItem {
+	return batchMediaItem{
+		item:          storagetypes.BatchItem{SourceGroupKey: group},
+		chatID:        chatID,
+		albumEligible: eligible,
+	}
+}
+
+func repeatedAlbumItems(count int) []batchMediaItem {
+	items := make([]batchMediaItem, count)
+	for i := range items {
+		items[i] = albumItem("a", 1, true)
+	}
+	return items
+}