// Copyright 2026 The Xorm Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package tests

import (
	"testing"

	"github.com/stretchr/testify/require"
	"xorm.io/xorm/schemas"
)

// sameDefinitionIndexes declares two indexes with an identical definition.
// Sync must keep one database index per declared index instead of letting
// both declarations claim the same database index.
type sameDefinitionIndexes struct {
	Id        int64
	RepoId    int64
	CreatedAt int64
}

func (*sameDefinitionIndexes) TableIndices() []*schemas.Index {
	first := schemas.NewIndex("first", schemas.IndexType)
	first.AddColumn("repo_id", "created_at")
	second := schemas.NewIndex("second", schemas.IndexType)
	second.AddColumn("repo_id", "created_at")
	return []*schemas.Index{first, second}
}

func assertSameDefinitionIndexes(t *testing.T, bean *sameDefinitionIndexes) {
	t.Helper()
	tables, err := testEngine.DBMetas()
	require.NoError(t, err)
	require.Len(t, tables, 1)
	require.Len(t, tables[0].Indexes, 2)
	for _, expected := range bean.TableIndices() {
		actual := tables[0].Indexes[expected.Name]
		require.NotNil(t, actual, "missing index %s", expected.Name)
		require.Equal(t, expected.Cols, actual.Cols)
	}
}

func TestSyncSameDefinitionIndexes(t *testing.T) {
	require.NoError(t, PrepareEngine())
	bean := new(sameDefinitionIndexes)
	require.NoError(t, testEngine.Sync(bean))
	assertSameDefinitionIndexes(t, bean)

	for i := 0; i < 10; i++ {
		require.NoError(t, testEngine.Sync(bean))
		assertSameDefinitionIndexes(t, bean)
	}

	for _, index := range bean.TableIndices() {
		_, err := testEngine.Exec(testEngine.Dialect().DropIndexSQL(testEngine.TableName(bean), index))
		require.NoError(t, err)
		require.NoError(t, testEngine.Sync(bean))
		assertSameDefinitionIndexes(t, bean)
	}
}

type renamedIndexBefore struct {
	Id     int64
	RepoId int64 `xorm:"index(old_name)"`
}

func (*renamedIndexBefore) TableName() string {
	return "renamed_index"
}

type renamedIndexAfter struct {
	Id     int64
	RepoId int64 `xorm:"index(new_name)"`
}

func (*renamedIndexAfter) TableName() string {
	return "renamed_index"
}

// TestSyncRenamedIndexKeepsExisting guards the fallback: an index whose
// declared name changed but whose definition did not is kept as it is.
func TestSyncRenamedIndexKeepsExisting(t *testing.T) {
	require.NoError(t, PrepareEngine())
	require.NoError(t, testEngine.Sync(new(renamedIndexBefore)))
	require.NoError(t, testEngine.Sync(new(renamedIndexAfter)))

	tables, err := testEngine.DBMetas()
	require.NoError(t, err)
	require.Len(t, tables, 1)
	require.Len(t, tables[0].Indexes, 1)
	require.NotNil(t, tables[0].Indexes["old_name"])
}