package db

import (
	"database/sql"
	"testing"
)

func openTestDB(t *testing.T) *MetaDB {
	t.Helper()
	m, err := OpenMeta(":memory:")
	if err != nil {
		t.Fatalf("open test db: %v", err)
	}
	t.Cleanup(func() { m.Close() })
	return m
}

func TestAddAndGetRedirect(t *testing.T) {
	m := openTestDB(t)

	if err := m.AddRedirect("old-slug", "new-slug"); err != nil {
		t.Fatalf("AddRedirect: %v", err)
	}

	got, err := m.GetRedirect("old-slug")
	if err != nil {
		t.Fatalf("GetRedirect: %v", err)
	}
	if got != "new-slug" {
		t.Errorf("got %q, want %q", got, "new-slug")
	}
}

func TestGetRedirect_NotFound(t *testing.T) {
	m := openTestDB(t)

	_, err := m.GetRedirect("missing")
	if err != sql.ErrNoRows {
		t.Errorf("expected sql.ErrNoRows, got %v", err)
	}
}

func TestCollapseRedirects(t *testing.T) {
	m := openTestDB(t)

	// a -> b, then b -> c: collapse should make a -> c
	if err := m.AddRedirect("a", "b"); err != nil {
		t.Fatalf("AddRedirect: %v", err)
	}
	if err := m.CollapseRedirects("b", "c"); err != nil {
		t.Fatalf("CollapseRedirects: %v", err)
	}

	got, err := m.GetRedirect("a")
	if err != nil {
		t.Fatalf("GetRedirect: %v", err)
	}
	if got != "c" {
		t.Errorf("got %q, want %q", got, "c")
	}
}

func TestAddRedirect_Upsert(t *testing.T) {
	m := openTestDB(t)

	if err := m.AddRedirect("old", "first"); err != nil {
		t.Fatalf("AddRedirect first: %v", err)
	}
	if err := m.AddRedirect("old", "second"); err != nil {
		t.Fatalf("AddRedirect second: %v", err)
	}

	got, err := m.GetRedirect("old")
	if err != nil {
		t.Fatalf("GetRedirect: %v", err)
	}
	if got != "second" {
		t.Errorf("got %q, want %q", got, "second")
	}
}