Initial commit

backend/internal/items/repository.go

@@ -0,0 +1,81 @@
+package items
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+
+	"github.com/uptrace/bun"
+)
+
+// BunRepository is the Postgres implementation of Repository. It is the
+// only file in the package that speaks Bun/SQL.
+type BunRepository struct {
+	db *bun.DB
+}
+
+// NewBunRepository wraps a *bun.DB opened by internal/database.
+func NewBunRepository(db *bun.DB) *BunRepository {
+	return &BunRepository{db: db}
+}
+
+// List returns items newest-first, honoring the (already normalized) filter.
+// An empty result set encodes as [] on the wire, not null.
+func (r *BunRepository) List(ctx context.Context, f Filter) ([]Item, error) {
+	var out []Item
+	q := r.db.NewSelect().Model(&out)
+	if f.Status != "" {
+		q = q.Where("i.status = ?", f.Status)
+	}
+	if err := q.
+		Order("i.created_at DESC", "i.id DESC").
+		Limit(f.Limit).
+		Offset(f.Offset).
+		Scan(ctx); err != nil {
+		return nil, err
+	}
+	if out == nil {
+		out = []Item{}
+	}
+	return out, nil
+}
+
+// Get fetches a single item by id, mapping missing rows to ErrNotFound.
+func (r *BunRepository) Get(ctx context.Context, id int64) (Item, error) {
+	var item Item
+	err := r.db.NewSelect().Model(&item).Where("i.id = ?", id).Scan(ctx)
+	if errors.Is(err, sql.ErrNoRows) {
+		return Item{}, ErrNotFound
+	}
+	return item, err
+}
+
+// Create inserts item and reads back the generated columns.
+func (r *BunRepository) Create(ctx context.Context, item *Item) error {
+	return r.db.NewInsert().Model(item).Returning("*").Scan(ctx, item)
+}
+
+// Update persists item (matched by primary key); ErrNotFound when the row
+// is gone.
+func (r *BunRepository) Update(ctx context.Context, item *Item) error {
+	res, err := r.db.NewUpdate().Model(item).WherePK().Exec(ctx)
+	if err != nil {
+		return err
+	}
+	if n, _ := res.RowsAffected(); n == 0 {
+		return ErrNotFound
+	}
+	return nil
+}
+
+// Delete removes an item by id; ErrNotFound when the row is gone.
+func (r *BunRepository) Delete(ctx context.Context, id int64) error {
+	res, err := r.db.NewDelete().Model((*Item)(nil)).Where("i.id = ?", id).Exec(ctx)
+	if err != nil {
+		return err
+	}
+	if n, _ := res.RowsAffected(); n == 0 {
+		return ErrNotFound
+	}
+	return nil
+}