feat(admin): 分类管理（分类树增删改移 + 后台页面）

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

api/internal/adminstore/category.go

@@ -0,0 +1,297 @@
+package adminstore
+
+import (
+	"context"
+	"crypto/rand"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"regexp"
+	"strings"
+
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgconn"
+)
+
+// randomHex returns n random lowercase hex characters for fallback ltree slugs.
+func randomHex(n int) string {
+	b := make([]byte, (n+1)/2)
+	if _, err := rand.Read(b); err != nil {
+		return "x"
+	}
+	return hex.EncodeToString(b)[:n]
+}
+
+// Category-management errors, mapped to client statuses by the handler.
+var (
+	// ErrDuplicatePath is returned when a category path already exists.
+	ErrDuplicatePath = errors.New("duplicate category path")
+	// ErrCategoryHasChildren blocks deleting a node that still has children.
+	ErrCategoryHasChildren = errors.New("category has children")
+	// ErrCategoryInUse blocks deleting a node still referenced by products.
+	ErrCategoryInUse = errors.New("category in use")
+	// ErrInvalidParent is returned for a missing parent or an illegal move
+	// (onto itself or one of its own descendants).
+	ErrInvalidParent = errors.New("invalid parent category")
+)
+
+// CategoryInput is the payload accepted when creating or editing a category.
+// Slug is the ltree label (ASCII); when empty it is derived from NameEN, then
+// from a random suffix, since ltree labels cannot contain CJK or spaces.
+type CategoryInput struct {
+	NameZH       string  `json:"name_zh"`
+	NameEN       *string `json:"name_en"`
+	Slug         *string `json:"slug"`
+	ParentID     *string `json:"parent_id"`
+	GPCBrickCode *string `json:"gpc_brick_code"`
+}
+
+var slugInvalid = regexp.MustCompile(`[^a-z0-9_]+`)
+
+// slugify converts a string into a valid ltree label ([a-z0-9_]).
+func slugify(s string) string {
+	s = strings.ToLower(strings.TrimSpace(s))
+	s = slugInvalid.ReplaceAllString(s, "_")
+	s = strings.Trim(s, "_")
+	for strings.Contains(s, "__") {
+		s = strings.ReplaceAll(s, "__", "_")
+	}
+	return s
+}
+
+// resolveSlug picks an ltree label from the explicit slug, then NameEN, then a
+// random fallback so a Chinese-only category still gets a valid path label.
+func resolveSlug(in CategoryInput) string {
+	if in.Slug != nil {
+		if s := slugify(*in.Slug); s != "" {
+			return s
+		}
+	}
+	if in.NameEN != nil {
+		if s := slugify(*in.NameEN); s != "" {
+			return s
+		}
+	}
+	return "cat_" + randomHex(6)
+}
+
+func trimPtr(p *string) *string {
+	if p == nil {
+		return nil
+	}
+	t := strings.TrimSpace(*p)
+	if t == "" {
+		return nil
+	}
+	return &t
+}
+
+// CreateCategory inserts a new category node. With no parent it becomes a root
+// (level 0); otherwise its path is parentPath.slug and level is parentLevel+1.
+func (s *Store) CreateCategory(ctx context.Context, actor string, in CategoryInput) (*Category, error) {
+	name := strings.TrimSpace(in.NameZH)
+	if name == "" {
+		return nil, errors.New("name_zh required")
+	}
+
+	parentPath := ""
+	parentLevel := -1
+	var parentID *string
+	if pid := trimPtr(in.ParentID); pid != nil {
+		var path string
+		var level int
+		err := s.pool.QueryRow(ctx, "SELECT path::text, level FROM category WHERE id = $1", *pid).Scan(&path, &level)
+		if errors.Is(err, pgx.ErrNoRows) {
+			return nil, ErrInvalidParent
+		}
+		if err != nil {
+			return nil, err
+		}
+		parentPath, parentLevel, parentID = path, level, pid
+	}
+
+	slug := resolveSlug(in)
+	path := slug
+	if parentPath != "" {
+		path = parentPath + "." + slug
+	}
+	level := parentLevel + 1
+
+	var c Category
+	err := s.pool.QueryRow(ctx, `
+INSERT INTO category (name_zh, name_en, parent_id, path, gpc_brick_code, level)
+VALUES ($1, $2, $3, $4::ltree, $5, $6)
+RETURNING id, name_zh, name_en, path::text, level, parent_id::text, gpc_brick_code, 0`,
+		name, trimPtr(in.NameEN), parentID, path, trimPtr(in.GPCBrickCode), level).
+		Scan(&c.ID, &c.NameZH, &c.NameEN, &c.Path, &c.Level, &c.ParentID, &c.GPCBrickCode, &c.ProductCount)
+	if isUniqueViolation(err) {
+		return nil, ErrDuplicatePath
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	_ = s.writeAudit(ctx, actor, "create", "category", &c.ID, []string{"name_zh", "path"}, nil, c)
+	return &c, nil
+}
+
+// UpdateCategory renames a node and/or moves it under a new parent. Moving
+// rewrites the path of the node and every descendant via ltree, keeping level
+// in sync. Moving a node onto itself or a descendant is rejected.
+func (s *Store) UpdateCategory(ctx context.Context, id, actor string, in CategoryInput) (*Category, error) {
+	name := strings.TrimSpace(in.NameZH)
+	if name == "" {
+		return nil, errors.New("name_zh required")
+	}
+
+	tx, err := s.pool.Begin(ctx)
+	if err != nil {
+		return nil, err
+	}
+	defer tx.Rollback(ctx)
+
+	var oldPath string
+	var oldLevel int
+	var oldParent *string
+	err = tx.QueryRow(ctx, "SELECT path::text, level, parent_id::text FROM category WHERE id = $1", id).
+		Scan(&oldPath, &oldLevel, &oldParent)
+	if errors.Is(err, pgx.ErrNoRows) {
+		return nil, ErrNotFound
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	if _, err := tx.Exec(ctx,
+		"UPDATE category SET name_zh = $1, name_en = $2, gpc_brick_code = $3 WHERE id = $4",
+		name, trimPtr(in.NameEN), trimPtr(in.GPCBrickCode), id); err != nil {
+		return nil, err
+	}
+
+	newParent := trimPtr(in.ParentID)
+	if !strEq(newParent, oldParent) {
+		if err := s.moveCategoryTx(ctx, tx, id, oldPath, newParent); err != nil {
+			return nil, err
+		}
+	}
+
+	if err := tx.Commit(ctx); err != nil {
+		return nil, err
+	}
+
+	out, err := s.getCategory(ctx, id)
+	if err != nil {
+		return nil, err
+	}
+	_ = s.writeAudit(ctx, actor, "update", "category", &id, []string{"name_zh", "name_en", "gpc_brick_code", "parent_id"}, nil, out)
+	return out, nil
+}
+
+// moveCategoryTx re-parents a subtree. The node's slug (last path label) is
+// preserved; only its ancestor prefix and level change.
+func (s *Store) moveCategoryTx(ctx context.Context, tx pgx.Tx, id, oldPath string, newParent *string) error {
+	slug := oldPath
+	if i := strings.LastIndex(oldPath, "."); i >= 0 {
+		slug = oldPath[i+1:]
+	}
+
+	newBase := slug
+	if newParent != nil {
+		var parentPath string
+		err := tx.QueryRow(ctx, "SELECT path::text FROM category WHERE id = $1", *newParent).Scan(&parentPath)
+		if errors.Is(err, pgx.ErrNoRows) {
+			return ErrInvalidParent
+		}
+		if err != nil {
+			return err
+		}
+		// Disallow moving a node under itself or one of its descendants.
+		if parentPath == oldPath || strings.HasPrefix(parentPath, oldPath+".") {
+			return ErrInvalidParent
+		}
+		newBase = parentPath + "." + slug
+	}
+
+	// Rewrite the node and all descendants in one statement; level tracks depth.
+	_, err := tx.Exec(ctx, `
+UPDATE category
+SET path  = ($1::ltree || subpath(path, nlevel($2::ltree) - 1)),
+    level = nlevel($1::ltree) + (nlevel(path) - nlevel($2::ltree)) - 1
+WHERE path = $2::ltree OR path <@ $2::ltree`, newBase, oldPath)
+	if isUniqueViolation(err) {
+		return ErrDuplicatePath
+	}
+	if err != nil {
+		return err
+	}
+
+	_, err = tx.Exec(ctx, "UPDATE category SET parent_id = $1 WHERE id = $2", newParent, id)
+	return err
+}
+
+// DeleteCategory removes a leaf node not referenced by any product. Nodes with
+// children or in-use nodes are rejected with a specific error.
+func (s *Store) DeleteCategory(ctx context.Context, id, actor string) error {
+	before, err := s.getCategory(ctx, id)
+	if err != nil {
+		return err
+	}
+
+	var children int
+	if err := s.pool.QueryRow(ctx, "SELECT count(*) FROM category WHERE parent_id = $1", id).Scan(&children); err != nil {
+		return err
+	}
+	if children > 0 {
+		return ErrCategoryHasChildren
+	}
+
+	var products int
+	if err := s.pool.QueryRow(ctx, "SELECT count(*) FROM product WHERE category_id = $1", id).Scan(&products); err != nil {
+		return err
+	}
+	if products > 0 {
+		return fmt.Errorf("%w: %d products", ErrCategoryInUse, products)
+	}
+
+	ct, err := s.pool.Exec(ctx, "DELETE FROM category WHERE id = $1", id)
+	if err != nil {
+		// A concurrent product assignment can still trip the FK.
+		if isForeignKeyViolation(err) {
+			return ErrCategoryInUse
+		}
+		return err
+	}
+	if ct.RowsAffected() == 0 {
+		return ErrNotFound
+	}
+
+	_ = s.writeAudit(ctx, actor, "delete", "category", &id, []string{"path"}, before, nil)
+	return nil
+}
+
+func (s *Store) getCategory(ctx context.Context, id string) (*Category, error) {
+	var c Category
+	err := s.pool.QueryRow(ctx, `
+SELECT c.id, c.name_zh, c.name_en, c.path::text, c.level, c.parent_id::text,
+       c.gpc_brick_code,
+       (SELECT count(*) FROM product p WHERE p.category_id = c.id)
+FROM category c WHERE c.id = $1`, id).
+		Scan(&c.ID, &c.NameZH, &c.NameEN, &c.Path, &c.Level, &c.ParentID, &c.GPCBrickCode, &c.ProductCount)
+	if errors.Is(err, pgx.ErrNoRows) {
+		return nil, ErrNotFound
+	}
+	if err != nil {
+		return nil, err
+	}
+	return &c, nil
+}
+
+func isUniqueViolation(err error) bool {
+	var pgErr *pgconn.PgError
+	return errors.As(err, &pgErr) && pgErr.Code == "23505"
+}
+
+func isForeignKeyViolation(err error) bool {
+	var pgErr *pgconn.PgError
+	return errors.As(err, &pgErr) && pgErr.Code == "23503"
+}

api/internal/adminstore/category_test.go

@@ -0,0 +1,130 @@
+package adminstore
+
+import (
+	"context"
+	"errors"
+	"os"
+	"testing"
+	"time"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+// newTestStore connects to the test database, skipping when it is unreachable
+// or migrations have not been applied.
+func newTestStore(t *testing.T) *Store {
+	t.Helper()
+	dsn := os.Getenv("OPENGOODS_DATABASE_URL")
+	if dsn == "" {
+		dsn = "postgres://opengoods:opengoods@localhost:5432/opengoods?sslmode=disable"
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+	pool, err := pgxpool.New(ctx, dsn)
+	if err != nil {
+		t.Skipf("no database: %v", err)
+	}
+	if err := pool.Ping(ctx); err != nil {
+		pool.Close()
+		t.Skipf("database not reachable: %v", err)
+	}
+	var hasTable bool
+	if err := pool.QueryRow(ctx, "SELECT to_regclass('public.category') IS NOT NULL").Scan(&hasTable); err != nil || !hasTable {
+		pool.Close()
+		t.Skip("migrations not applied (category missing)")
+	}
+	t.Cleanup(pool.Close)
+	return New(pool)
+}
+
+func ptr(s string) *string { return &s }
+
+func TestCategoryLifecycle(t *testing.T) {
+	s := newTestStore(t)
+	ctx := context.Background()
+
+	root, err := s.CreateCategory(ctx, "tester", CategoryInput{
+		NameZH: "测试根", Slug: ptr("test_root_" + randomHex(6)),
+	})
+	if err != nil {
+		t.Fatalf("create root: %v", err)
+	}
+	t.Cleanup(func() { _, _ = s.pool.Exec(ctx, "DELETE FROM category WHERE path <@ $1::ltree", root.Path) })
+
+	if root.Level != 0 || root.ParentID != nil {
+		t.Fatalf("root level/parent wrong: level=%d parent=%v", root.Level, root.ParentID)
+	}
+
+	child, err := s.CreateCategory(ctx, "tester", CategoryInput{
+		NameZH: "测试子", NameEN: ptr("Test Child"), ParentID: &root.ID,
+	})
+	if err != nil {
+		t.Fatalf("create child: %v", err)
+	}
+	if child.Level != 1 || child.ParentID == nil || *child.ParentID != root.ID {
+		t.Fatalf("child hierarchy wrong: %+v", child)
+	}
+
+	// Deleting a node with children must fail.
+	if err := s.DeleteCategory(ctx, root.ID, "tester"); !errors.Is(err, ErrCategoryHasChildren) {
+		t.Fatalf("expected ErrCategoryHasChildren, got %v", err)
+	}
+
+	// Rename child.
+	renamed, err := s.UpdateCategory(ctx, child.ID, "tester", CategoryInput{NameZH: "测试子-改名"})
+	if err != nil {
+		t.Fatalf("rename: %v", err)
+	}
+	if renamed.NameZH != "测试子-改名" {
+		t.Fatalf("rename not applied: %q", renamed.NameZH)
+	}
+
+	// Move child to a second root, descendants' path/level should follow.
+	root2, err := s.CreateCategory(ctx, "tester", CategoryInput{
+		NameZH: "测试根2", Slug: ptr("test_root2_" + randomHex(6)),
+	})
+	if err != nil {
+		t.Fatalf("create root2: %v", err)
+	}
+	t.Cleanup(func() { _, _ = s.pool.Exec(ctx, "DELETE FROM category WHERE path <@ $1::ltree", root2.Path) })
+
+	moved, err := s.UpdateCategory(ctx, child.ID, "tester", CategoryInput{NameZH: "测试子-改名", ParentID: &root2.ID})
+	if err != nil {
+		t.Fatalf("move: %v", err)
+	}
+	if moved.ParentID == nil || *moved.ParentID != root2.ID {
+		t.Fatalf("move parent wrong: %+v", moved)
+	}
+	if moved.Level != 1 {
+		t.Fatalf("moved level wrong: %d", moved.Level)
+	}
+
+	// Moving a node under itself must be rejected.
+	if _, err := s.UpdateCategory(ctx, root2.ID, "tester", CategoryInput{NameZH: "测试根2", ParentID: &child.ID}); !errors.Is(err, ErrInvalidParent) {
+		t.Fatalf("expected ErrInvalidParent for self-move, got %v", err)
+	}
+
+	// Duplicate path on create must be rejected.
+	if _, err := s.CreateCategory(ctx, "tester", CategoryInput{NameZH: "dup", Slug: ptr(root.Path)}); !errors.Is(err, ErrDuplicatePath) {
+		t.Fatalf("expected ErrDuplicatePath, got %v", err)
+	}
+
+	// Now the leaf can be deleted.
+	if err := s.DeleteCategory(ctx, child.ID, "tester"); err != nil {
+		t.Fatalf("delete leaf: %v", err)
+	}
+}
+
+func TestSlugify(t *testing.T) {
+	cases := map[string]string{
+		"Cooking Oil":  "cooking_oil",
+		"  Hello--Wld": "hello_wld",
+		"食品":           "",
+		"a__b":         "a_b",
+	}
+	for in, want := range cases {
+		if got := slugify(in); got != want {
+			t.Errorf("slugify(%q) = %q, want %q", in, got, want)
+		}
+	}
+}

api/internal/adminstore/write.go

@@ -354,19 +354,27 @@ func (s *Store) ListBrands(ctx context.Context) ([]Brand, error) {
 	return out, rows.Err()
 }
 
-// Category is a category option for the edit form.
+// Category is a category option for the edit form and the management view.
 type Category struct {
-	ID     string  `json:"id"`
-	NameZH string  `json:"name_zh"`
-	NameEN *string `json:"name_en"`
-	Path   string  `json:"path"`
-	Level  int     `json:"level"`
+	ID           string  `json:"id"`
+	NameZH       string  `json:"name_zh"`
+	NameEN       *string `json:"name_en"`
+	Path         string  `json:"path"`
+	Level        int     `json:"level"`
+	ParentID     *string `json:"parent_id"`
+	GPCBrickCode *string `json:"gpc_brick_code"`
+	ProductCount int     `json:"product_count"`
 }
 
-// ListCategories returns the full category tree.
+// ListCategories returns the full category tree (path order) with the number of
+// products directly assigned to each node.
 func (s *Store) ListCategories(ctx context.Context) ([]Category, error) {
-	rows, err := s.pool.Query(ctx,
-		"SELECT id, name_zh, name_en, path::text, level FROM category ORDER BY path")
+	rows, err := s.pool.Query(ctx, `
+SELECT c.id, c.name_zh, c.name_en, c.path::text, c.level, c.parent_id::text,
+       c.gpc_brick_code,
+       (SELECT count(*) FROM product p WHERE p.category_id = c.id) AS product_count
+FROM category c
+ORDER BY c.path`)
 	if err != nil {
 		return nil, err
 	}
@@ -374,7 +382,8 @@ func (s *Store) ListCategories(ctx context.Context) ([]Category, error) {
 	out := []Category{}
 	for rows.Next() {
 		var c Category
-		if err := rows.Scan(&c.ID, &c.NameZH, &c.NameEN, &c.Path, &c.Level); err != nil {
+		if err := rows.Scan(&c.ID, &c.NameZH, &c.NameEN, &c.Path, &c.Level,
+			&c.ParentID, &c.GPCBrickCode, &c.ProductCount); err != nil {
 			return nil, err
 		}
 		out = append(out, c)