// Copyright 2022 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.

package blackhole

import (
	"github.com/pingcap/errors"
	"github.com/pingcap/failpoint"
	"github.com/pingcap/log"
	"github.com/pingcap/tiflow/cdc/model"
	"github.com/pingcap/tiflow/cdc/sink/dmlsink"
	"github.com/pingcap/tiflow/pkg/sink"
	"go.uber.org/zap"
)

// Assert EventSink[E event.TableEvent] implementation
var _ dmlsink.EventSink[*model.RowChangedEvent] = (*DMLSink)(nil)

// DMLSink is a black hole sink.
type DMLSink struct{}

// NewDMLSink create a black hole DML sink.
func NewDMLSink() *DMLSink {
	return &DMLSink{}
}

// WriteEvents log the events.
func (s *DMLSink) WriteEvents(rows ...*dmlsink.CallbackableEvent[*model.RowChangedEvent]) (err error) {
	failpoint.Inject("WriteEventsFail", func() { err = errors.New("InjectedErrorForWriteEventsFail") })
	if err == nil {
		for _, row := range rows {
			// NOTE: don't change the log, some tests depend on it.
			log.Debug("BlackHoleSink: WriteEvents", zap.Any("row", row.Event))
			row.Callback()
		}
	}
	return
}

// SchemeOption returns the scheme and the option.
func (s *DMLSink) SchemeOption() (string, bool) {
	return sink.BlackHoleScheme, true
}

// Close do nothing.
func (s *DMLSink) Close() {}

// Dead returns a checker.
func (s *DMLSink) Dead() <-chan struct{} {
	return make(chan struct{})
}