package catalogpublication

import (
	"context"
	"errors"
	"regexp"
	"testing"

	"github.com/DATA-DOG/go-sqlmock"
	"github.com/go-sql-driver/mysql"
)

func TestEnsureTiDBCheckConstraintsEnabled(t *testing.T) {
	tests := []struct {
		name      string
		expect    func(sqlmock.Sqlmock)
		wantError string
	}{
		{
			name: "already enabled",
			expect: func(mock sqlmock.Sqlmock) {
				mock.ExpectQuery(regexp.QuoteMeta(tidbCheckConstraintSettingQuery)).
					WillReturnRows(sqlmock.NewRows([]string{"@@GLOBAL.tidb_enable_check_constraint"}).AddRow("ON"))
			},
		},
		{
			name: "enable and verify",
			expect: func(mock sqlmock.Sqlmock) {
				mock.ExpectQuery(regexp.QuoteMeta(tidbCheckConstraintSettingQuery)).
					WillReturnRows(sqlmock.NewRows([]string{"@@GLOBAL.tidb_enable_check_constraint"}).AddRow("OFF"))
				mock.ExpectExec(regexp.QuoteMeta(tidbEnableCheckConstraint)).
					WillReturnResult(sqlmock.NewResult(0, 0))
				mock.ExpectQuery(regexp.QuoteMeta(tidbCheckConstraintSettingQuery)).
					WillReturnRows(sqlmock.NewRows([]string{"@@GLOBAL.tidb_enable_check_constraint"}).AddRow("ON"))
			},
		},
		{
			name: "mysql does not expose TiDB setting",
			expect: func(mock sqlmock.Sqlmock) {
				mock.ExpectQuery(regexp.QuoteMeta(tidbCheckConstraintSettingQuery)).
					WillReturnError(&mysql.MySQLError{Number: 1193, Message: "Unknown system variable"})
			},
		},
		{
			name: "enable failure is explicit",
			expect: func(mock sqlmock.Sqlmock) {
				mock.ExpectQuery(regexp.QuoteMeta(tidbCheckConstraintSettingQuery)).
					WillReturnRows(sqlmock.NewRows([]string{"@@GLOBAL.tidb_enable_check_constraint"}).AddRow("OFF"))
				mock.ExpectExec(regexp.QuoteMeta(tidbEnableCheckConstraint)).
					WillReturnError(errors.New("permission denied"))
			},
			wantError: "enable TiDB CHECK constraints for Catalog schema: permission denied",
		},
		{
			name: "verification fails closed",
			expect: func(mock sqlmock.Sqlmock) {
				mock.ExpectQuery(regexp.QuoteMeta(tidbCheckConstraintSettingQuery)).
					WillReturnRows(sqlmock.NewRows([]string{"@@GLOBAL.tidb_enable_check_constraint"}).AddRow("OFF"))
				mock.ExpectExec(regexp.QuoteMeta(tidbEnableCheckConstraint)).
					WillReturnResult(sqlmock.NewResult(0, 0))
				mock.ExpectQuery(regexp.QuoteMeta(tidbCheckConstraintSettingQuery)).
					WillReturnRows(sqlmock.NewRows([]string{"@@GLOBAL.tidb_enable_check_constraint"}).AddRow("OFF"))
			},
			wantError: "enable TiDB CHECK constraints for Catalog schema: setting remains disabled",
		},
	}
	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			db, mock, err := sqlmock.New()
			if err != nil {
				t.Fatal(err)
			}
			defer db.Close()
			test.expect(mock)

			err = ensureTiDBCheckConstraintsEnabled(context.Background(), db)
			if test.wantError == "" && err != nil {
				t.Fatal(err)
			}
			if test.wantError != "" && (err == nil || err.Error() != test.wantError) {
				t.Fatalf("error = %v, want %q", err, test.wantError)
			}
			if err := mock.ExpectationsWereMet(); err != nil {
				t.Fatal(err)
			}
		})
	}
}