feat(uploads): preview storage paths, detect templates, attach covers and withdraw batches

services/api/internal/library/handler.go

@@ -184,7 +184,7 @@ func (h *Handler) SuggestWriteTemplate(ctx context.Context, req gen.SuggestWrite
 	if err != nil {
 		return nil, err
 	}
-	return gen.SuggestWriteTemplate200JSONResponse{Template: tpl}, nil
+	return gen.SuggestWriteTemplate200JSONResponse{Template: tpl.Template, Matched: &tpl.Matched, Total: &tpl.Total, Examples: &tpl.Examples}, nil
 }
 
 // CheckWriteTemplate реализует gen.StrictServerInterface.

services/api/internal/library/meta/template_suggest.go

@@ -0,0 +1,129 @@
+package meta
+
+import (
+	"path"
+	"sort"
+	"strconv"
+	"strings"
+
+	"golang.org/x/text/unicode/norm"
+)
+
+// TemplateSuggestion compares candidate layouts against the same sample of stored paths.
+type TemplateSuggestion struct {
+	Template string
+	Matched  int
+	Total    int
+	Examples []string
+}
+
+// SuggestFromSamples also works without configured path regexes, using catalog metadata.
+func SuggestFromSamples(exprs []string, samples []TemplateSample) (TemplateSuggestion, error) {
+	candidates := map[string]bool{}
+	paths := make([]string, 0, len(samples))
+	for _, s := range samples {
+		paths = append(paths, s.RelPath)
+		if tpl := inferTemplate(s); tpl != "" {
+			candidates[tpl] = true
+		}
+	}
+	for _, expr := range exprs {
+		if tpl, err := SuggestTemplate([]string{expr}, paths); err == nil {
+			candidates[tpl] = true
+		}
+	}
+	keys := make([]string, 0, len(candidates))
+	for tpl := range candidates {
+		keys = append(keys, tpl)
+	}
+	sort.Strings(keys)
+	best := TemplateSuggestion{Total: len(samples), Examples: []string{}}
+	for _, tpl := range keys {
+		t, err := ParseTemplate(tpl)
+		if err != nil {
+			continue
+		}
+		count := 0
+		var examples []string
+		for _, s := range samples {
+			if rendered, err := t.Render(s.Input); err == nil && rendered == norm.NFC.String(s.RelPath) {
+				count++
+				if len(examples) < 3 {
+					examples = append(examples, s.RelPath)
+				}
+			}
+		}
+		if count > best.Matched {
+			best.Template, best.Matched, best.Examples = tpl, count, examples
+		}
+	}
+	if best.Matched == 0 {
+		return best, ErrNoTemplate
+	}
+	return best, nil
+}
+
+func inferTemplate(s TemplateSample) string {
+	type token struct{ value, placeholder string }
+	segments := strings.Split(norm.NFC.String(s.RelPath), "/")
+	for i, segment := range segments {
+		last := i == len(segments)-1
+		fields := []string{"albumartist", "artist", "album", "year", "genre", "disc"}
+		if last {
+			ext := path.Ext(segment)
+			if ext == "" {
+				return ""
+			}
+			segment = strings.TrimSuffix(segment, ext)
+			fields = []string{"title", "albumartist", "artist", "album", "year", "track", "disc"}
+		}
+		var tokens []token
+		for _, field := range fields {
+			v := cleanValue(fieldValue(s.Input, tnode{field: field}))
+			if v == "" {
+				continue
+			}
+			tokens = append(tokens, token{v, "{" + field + "}"})
+			if field == "track" || field == "disc" {
+				n, _ := strconv.Atoi(v)
+				for width := 2; width <= 3; width++ {
+					padded := strings.Repeat("0", max(0, width-len(v))) + strconv.Itoa(n)
+					if padded != v {
+						tokens = append(tokens, token{padded, "{" + field + ":0" + strconv.Itoa(width) + "}"})
+					}
+				}
+			}
+		}
+		// Longest value wins; stable ties prefer album artist in folders and title in filenames.
+		sort.SliceStable(tokens, func(a, b int) bool { return len(tokens[a].value) > len(tokens[b].value) })
+		var out strings.Builder
+		for at := 0; at < len(segment); {
+			matched := false
+			for _, tok := range tokens {
+				if !strings.HasPrefix(segment[at:], tok.value) {
+					continue
+				}
+				end := at + len(tok.value)
+				if tok.value[0] >= '0' && tok.value[0] <= '9' && ((at > 0 && segment[at-1] >= '0' && segment[at-1] <= '9') || (end < len(segment) && segment[end] >= '0' && segment[end] <= '9')) {
+					continue
+				}
+				out.WriteString(tok.placeholder)
+				at = end
+				matched = true
+				break
+			}
+			if !matched {
+				if strings.ContainsRune("{}[]", rune(segment[at])) {
+					return ""
+				}
+				out.WriteByte(segment[at])
+				at++
+			}
+		}
+		segments[i] = out.String()
+		if last {
+			segments[i] += ".{ext}"
+		}
+	}
+	return strings.Join(segments, "/")
+}

services/api/internal/library/meta/template_suggest_test.go

@@ -0,0 +1,22 @@
+package meta
+
+import "testing"
+
+func TestSuggestFromSamplesUsesDominantLayoutWithoutRegexes(t *testing.T) {
+	samples := []TemplateSample{
+		{RelPath: "Кино/Группа крови (1988)/01. Группа крови.flac", Input: in(Fields{Artist: "Кино", Album: "Группа крови", Title: "Группа крови", Year: "1988", Track: "1"}, 1, "flac")},
+		{RelPath: "Кино/Группа крови (1988)/02. Закрой за мной дверь.flac", Input: in(Fields{Artist: "Кино", Album: "Группа крови", Title: "Закрой за мной дверь", Year: "1988", Track: "2"}, 1, "flac")},
+		{RelPath: "Queen/Jazz (1978)/03. Jealousy.mp3", Input: in(Fields{Artist: "Queen", Album: "Jazz", Title: "Jealousy", Year: "1978", Track: "3"}, 1, "mp3")},
+		{RelPath: "Other - Song.flac", Input: in(Fields{Artist: "Other", Album: "Single", Title: "Song"}, 1, "flac")},
+	}
+	got, err := SuggestFromSamples(nil, samples)
+	if err != nil || got.Template != "{albumartist}/{album} ({year})/{track:02}. {title}.{ext}" || got.Matched != 3 || got.Total != 4 || len(got.Examples) != 3 {
+		t.Fatalf("suggestion = %+v, err = %v", got, err)
+	}
+}
+
+func TestSuggestFromSamplesDoesNotGuessWithoutMetadata(t *testing.T) {
+	if _, err := SuggestFromSamples(nil, []TemplateSample{{RelPath: "unknown/file.flac"}}); err == nil {
+		t.Fatal("cannot infer a safe layout without matching metadata")
+	}
+}

services/api/internal/library/templates.go

@@ -183,16 +183,16 @@ func (s *TemplateService) previewOne(ctx context.Context, root, rel string, patt
 const templateSampleSize = 50
 
 // SuggestWriteTemplate подбирает шаблон записи по существующим путям и выражениям источника.
-func (s *TemplateService) SuggestWriteTemplate(ctx context.Context, id uuid.UUID) (string, error) {
+func (s *TemplateService) SuggestWriteTemplate(ctx context.Context, id uuid.UUID) (meta.TemplateSuggestion, error) {
 	if err := requirePerm(ctx, auth.PermManageLibrary); err != nil {
-		return "", err
+		return meta.TemplateSuggestion{}, err
 	}
 	if _, err := s.store.GetSource(ctx, id); err != nil {
-		return "", notFound(err)
+		return meta.TemplateSuggestion{}, notFound(err)
 	}
 	rows, err := s.store.Patterns(ctx, id)
 	if err != nil {
-		return "", err
+		return meta.TemplateSuggestion{}, err
 	}
 	var exprs []string
 	for _, r := range rows {
@@ -200,13 +200,13 @@ func (s *TemplateService) SuggestWriteTemplate(ctx context.Context, id uuid.UUID
 			exprs = append(exprs, r.Regex)
 		}
 	}
-	paths, err := s.store.SampleFiles(ctx, id, 200)
+	samples, err := s.store.TemplateSamples(ctx, id, 200)
 	if err != nil {
-		return "", err
+		return meta.TemplateSuggestion{}, err
 	}
-	tpl, err := meta.SuggestTemplate(exprs, paths)
+	tpl, err := meta.SuggestFromSamples(exprs, samples)
 	if err != nil {
-		return "", apperr.New(http.StatusUnprocessableEntity, CodeTemplateNone, "no path pattern can be turned into a template")
+		return meta.TemplateSuggestion{}, apperr.New(http.StatusUnprocessableEntity, CodeTemplateNone, "no layout could be inferred from catalog paths and metadata")
 	}
 	return tpl, nil
 }