修复了一点bug，然后增加了图层拆分更多的功能

backend/internal/httpapi/layer_compositions.go

@@ -0,0 +1,124 @@
+package httpapi
+
+import (
+	"errors"
+	"net/http"
+	"strings"
+
+	"git.nianxx.cn/wangxuming/NianAIGC/backend/internal/jobs"
+	"git.nianxx.cn/wangxuming/NianAIGC/backend/internal/layercompositions"
+)
+
+type LayerCompositionsConfig struct {
+	MaxJSONBytes int64
+}
+
+type layerCompositionsHandler struct {
+	platform     *PlatformAuthorizer
+	jobs         *jobs.Service
+	compositions *layercompositions.Service
+	maxJSONBytes int64
+}
+
+func NewLayerCompositionsHandler(platform *PlatformAuthorizer, jobService *jobs.Service, compositions *layercompositions.Service, config LayerCompositionsConfig) (http.Handler, error) {
+	if platform == nil || jobService == nil || compositions == nil {
+		return nil, errors.New("layer composition HTTP dependencies are not configured")
+	}
+	if config.MaxJSONBytes <= 0 {
+		config.MaxJSONBytes = 1 << 20
+	}
+	return &layerCompositionsHandler{platform: platform, jobs: jobService, compositions: compositions, maxJSONBytes: config.MaxJSONBytes}, nil
+}
+
+func (handler *layerCompositionsHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	jobID, matched := matchLayerCompositionRoute(r.URL.Path)
+	if !matched {
+		http.NotFound(w, r)
+		return
+	}
+	if r.Method == http.MethodOptions {
+		w.Header().Set("Allow", "GET, PUT")
+		w.WriteHeader(http.StatusNoContent)
+		return
+	}
+	if r.Method != http.MethodGet && r.Method != http.MethodPut {
+		w.Header().Set("Allow", "GET, PUT")
+		w.WriteHeader(http.StatusMethodNotAllowed)
+		return
+	}
+	session, err := handler.platform.Authorize(r, PlatformApp)
+	if err != nil {
+		writeLayerCompositionError(w, err)
+		return
+	}
+	job, err := handler.jobs.Get(r.Context(), jobs.Scope{OwnerID: session.User.ID}, jobID)
+	if err != nil || job.Capability != "image.generate" {
+		writeJSON(w, http.StatusNotFound, map[string]string{"error": "图层任务不存在"})
+		return
+	}
+	if r.Method == http.MethodGet {
+		composition, found, err := handler.compositions.Get(r.Context(), session.User.ID, jobID)
+		if err != nil {
+			writeLayerCompositionError(w, err)
+			return
+		}
+		if !found {
+			writeJSON(w, http.StatusOK, map[string]any{"composition": nil})
+			return
+		}
+		writeJSON(w, http.StatusOK, map[string]any{"composition": composition})
+		return
+	}
+	input := struct {
+		Version     int64                     `json:"version"`
+		BaseAssetID string                    `json:"baseAssetId"`
+		BaseVisible bool                      `json:"baseVisible"`
+		Layers      []layercompositions.Layer `json:"layers"`
+	}{}
+	if !decodeJobJSON(w, r, handler.maxJSONBytes, &input, false) {
+		return
+	}
+	if !containsString(job.OutputAssetIDs, input.BaseAssetID) {
+		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "底图必须来自当前图层拆分任务"})
+		return
+	}
+	saved, err := handler.compositions.Save(r.Context(), session.User.ID, jobID, input.Version, layercompositions.Composition{
+		BaseAssetID: input.BaseAssetID,
+		BaseVisible: input.BaseVisible,
+		Layers:      input.Layers,
+	})
+	if err != nil {
+		writeLayerCompositionError(w, err)
+		return
+	}
+	writeJSON(w, http.StatusOK, map[string]any{"composition": saved})
+}
+
+func matchLayerCompositionRoute(path string) (string, bool) {
+	const prefix = "/api/layer-compositions/"
+	if !strings.HasPrefix(path, prefix) {
+		return "", false
+	}
+	jobID := strings.TrimPrefix(path, prefix)
+	return jobID, jobID != "" && !strings.Contains(jobID, "/")
+}
+
+func writeLayerCompositionError(w http.ResponseWriter, err error) {
+	switch {
+	case errors.Is(err, layercompositions.ErrConflict):
+		writeJSON(w, http.StatusConflict, map[string]string{"error": "图层工程已在其他页面更新，请重试"})
+	case errors.Is(err, layercompositions.ErrInvalid), errors.Is(err, layercompositions.ErrAssetNotFound):
+		writeJSON(w, http.StatusBadRequest, map[string]string{"error": err.Error()})
+	default:
+		writeJobError(w, err, false)
+	}
+}
+
+func containsString(values []string, wanted string) bool {
+	for _, value := range values {
+		if value == wanted {
+			return true
+		}
+	}
+	return false
+}

backend/internal/httpapi/layer_compositions_test.go

@@ -0,0 +1,94 @@
+package httpapi
+
+import (
+	"context"
+	"net/http"
+	"strings"
+	"testing"
+	"time"
+
+	"git.nianxx.cn/wangxuming/NianAIGC/backend/internal/assets"
+	"git.nianxx.cn/wangxuming/NianAIGC/backend/internal/identity"
+	"git.nianxx.cn/wangxuming/NianAIGC/backend/internal/jobs"
+	"git.nianxx.cn/wangxuming/NianAIGC/backend/internal/layercompositions"
+)
+
+type layerCompositionRepositoryStub struct {
+	value layercompositions.Composition
+	found bool
+}
+
+func (repository *layerCompositionRepositoryStub) FindLayerComposition(_ context.Context, ownerID, jobID string) (layercompositions.Composition, bool, error) {
+	if !repository.found || repository.value.OwnerID != ownerID || repository.value.JobID != jobID {
+		return layercompositions.Composition{}, false, nil
+	}
+	return repository.value, true, nil
+}
+
+func (repository *layerCompositionRepositoryStub) SaveLayerComposition(_ context.Context, value layercompositions.Composition, version int64) (layercompositions.Composition, error) {
+	if repository.found && repository.value.Version != version {
+		return layercompositions.Composition{}, layercompositions.ErrConflict
+	}
+	if !repository.found && version != 0 {
+		return layercompositions.Composition{}, layercompositions.ErrConflict
+	}
+	value.Version = version + 1
+	value.CreatedAt = time.Date(2026, 9, 2, 8, 0, 0, 0, time.UTC)
+	value.UpdatedAt = value.CreatedAt
+	repository.value = value
+	repository.found = true
+	return value, nil
+}
+
+type layerCompositionAssetCatalog map[string]assets.Asset
+
+func (catalog layerCompositionAssetCatalog) GetOwner(_ context.Context, ownerID, assetID string) (assets.Asset, bool, error) {
+	asset, found := catalog[assetID]
+	return asset, found && asset.OwnerID == ownerID, nil
+}
+
+func TestLayerCompositionsHTTPPersistsOnlyOwnedJobOutputsAndAssets(t *testing.T) {
+	jobStore := &httpJobStore{values: map[string]jobs.Job{
+		"job-1": {ID: "job-1", OwnerID: "owner", Capability: "image.generate", OutputAssetIDs: []string{"base"}},
+		"job-2": {ID: "job-2", OwnerID: "another-owner", Capability: "image.generate", OutputAssetIDs: []string{"foreign-base"}},
+	}}
+	jobService := jobs.NewService(jobStore, nil)
+	repository := &layerCompositionRepositoryStub{}
+	compositionService := layercompositions.NewService(repository, layerCompositionAssetCatalog{
+		"base":  {ID: "base", OwnerID: "owner", Kind: assets.KindImage},
+		"layer": {ID: "layer", OwnerID: "owner", Kind: assets.KindImage},
+	})
+	authorizer, err := NewPlatformAuthorizer(AuthState{Required: true, Configured: true}, &fixedSessionResolver{session: identity.Session{User: identity.User{ID: "owner", ClientID: "platform", Role: "user"}}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	handler, err := NewLayerCompositionsHandler(authorizer, jobService, compositionService, LayerCompositionsConfig{})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	missing := serveJSON(t, handler, http.MethodGet, "/api/layer-compositions/job-1", nil)
+	if missing.Code != http.StatusOK || strings.TrimSpace(missing.Body.String()) != `{"composition":null}` {
+		t.Fatalf("missing=%d %s", missing.Code, missing.Body.String())
+	}
+
+	saved := serveJSON(t, handler, http.MethodPut, "/api/layer-compositions/job-1", map[string]any{
+		"version": 0, "baseAssetId": "base", "baseVisible": true,
+		"layers": []any{map[string]any{"id": "layer-1", "assetId": "layer", "name": "主体", "visible": true, "box": []any{100, 100, 900, 900}, "rotation": 15, "source": "provider"}},
+	})
+	if saved.Code != http.StatusOK || repository.value.Version != 1 || repository.value.Layers[0].Rotation != 15 {
+		t.Fatalf("saved=%d %s value=%#v", saved.Code, saved.Body.String(), repository.value)
+	}
+
+	foreignJob := serveJSON(t, handler, http.MethodGet, "/api/layer-compositions/job-2", nil)
+	if foreignJob.Code != http.StatusNotFound {
+		t.Fatalf("foreign job=%d %s", foreignJob.Code, foreignJob.Body.String())
+	}
+
+	invalidBase := serveJSON(t, handler, http.MethodPut, "/api/layer-compositions/job-1", map[string]any{
+		"version": 1, "baseAssetId": "layer", "baseVisible": true, "layers": []any{},
+	})
+	if invalidBase.Code != http.StatusBadRequest {
+		t.Fatalf("invalid base=%d %s", invalidBase.Code, invalidBase.Body.String())
+	}
+}

backend/internal/httpapi/method_compat_test.go

@@ -12,8 +12,8 @@ import (
 
 func TestRouteMethodCompatibilityDerivesEverySurfacePath(t *testing.T) {
 	patterns := routeMethodPatterns(GoRouteSurface())
-	if len(patterns) != 47 {
-		t.Fatalf("route patterns=%d want 47", len(patterns))
+	if len(patterns) != 48 {
+		t.Fatalf("route patterns=%d want 48", len(patterns))
 	}
 	for _, pattern := range patterns {
 		if _, ok := pattern.methods[http.MethodOptions]; !ok {

backend/internal/httpapi/route_surface.go

@@ -17,7 +17,7 @@ var goRouteSurface = []RouteSurface{
 	{"GET", "/api/assets"}, {"POST", "/api/assets"}, {"POST", "/api/assets/upload"}, {"DELETE", "/api/assets/{id}"}, {"GET", "/api/assets/{id}/download"},
 	{"GET", "/api/auth/callback"}, {"GET", "/api/auth/captcha"}, {"GET", "/api/auth/login"}, {"GET", "/api/auth/logout"}, {"POST", "/api/auth/logout"}, {"GET", "/api/auth/me"}, {"POST", "/api/auth/password"}, {"POST", "/api/auth/password/change"},
 	{"GET", "/api/billing"}, {"POST", "/api/billing/quote"}, {"GET", "/api/generations/image"}, {"POST", "/api/generations/image"}, {"DELETE", "/api/generations/image/{id}"}, {"GET", "/api/generations/image/{id}"}, {"POST", "/api/generations/image/{id}/retry"}, {"GET", "/api/generations/video"}, {"POST", "/api/generations/video"}, {"DELETE", "/api/generations/video/{id}"}, {"GET", "/api/generations/video/{id}"},
-	{"GET", "/api/health"}, {"GET", "/api/image-templates"}, {"POST", "/api/image-templates"}, {"DELETE", "/api/image-templates/{id}"}, {"PATCH", "/api/image-templates/{id}"}, {"POST", "/api/internal/worker/tick"}, {"DELETE", "/api/logs"}, {"GET", "/api/logs"}, {"POST", "/api/prompt/assemble"}, {"GET", "/api/ready"}, {"GET", "/api/settings"}, {"POST", "/api/settings"}, {"GET", "/api/usage"},
+	{"GET", "/api/health"}, {"GET", "/api/image-templates"}, {"POST", "/api/image-templates"}, {"DELETE", "/api/image-templates/{id}"}, {"PATCH", "/api/image-templates/{id}"}, {"POST", "/api/internal/worker/tick"}, {"GET", "/api/layer-compositions/{id}"}, {"PUT", "/api/layer-compositions/{id}"}, {"DELETE", "/api/logs"}, {"GET", "/api/logs"}, {"POST", "/api/prompt/assemble"}, {"GET", "/api/ready"}, {"GET", "/api/settings"}, {"POST", "/api/settings"}, {"GET", "/api/usage"},
 	{"GET", "/api/v1/assets"}, {"POST", "/api/v1/assets"}, {"GET", "/api/v1/assets/{id}"}, {"GET", "/api/v1/assets/{id}/download"}, {"GET", "/api/v1/capabilities"}, {"GET", "/api/v1/jobs"}, {"POST", "/api/v1/jobs"}, {"GET", "/api/v1/jobs/{id}"}, {"POST", "/api/v1/jobs/{id}/cancel"}, {"GET", "/api/v1/openapi.json"}, {"GET", "/generated-results/{path...}"}, {"GET", "/uploads/{path...}"},
 }