feat: implement retrieve by hash function

internal/api/handler.go

@@ -0,0 +1,38 @@
+package api
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"github.com/babariviere/short/internal/db"
+	"github.com/babariviere/short/internal/oas"
+	"github.com/jackc/pgx/v5"
+)
+
+var _ oas.Handler = (*handler)(nil)
+
+type handler struct {
+	oas.UnimplementedHandler
+	queries *db.Queries
+}
+
+func NewHandler(queries *db.Queries) *handler {
+	return &handler{
+		queries: queries,
+	}
+}
+
+func (h *handler) RedirectLongURL(ctx context.Context, params oas.RedirectLongURLParams) (oas.RedirectLongURLRes, error) {
+	res, err := h.queries.GetURLByHash(ctx, params.Hash)
+	if err != nil {
+		if errors.Is(err, pgx.ErrNoRows) {
+			return &oas.RedirectLongURLNotFound{}, nil
+		}
+		return nil, fmt.Errorf("unable to fetch URL by hash: %w", err)
+	}
+
+	return &oas.RedirectLongURLTemporaryRedirect{
+		Location: oas.NewOptString(res.LongUrl),
+	}, nil
+}