package sink

import (
	"context"
	"errors"

	"github.com/topfans/backend/services/statisticService/model"
)

// ErrChannelFull channel 满时返回
var ErrChannelFull = errors.New("event channel full")

// ChannelEventSink 把事件推到 channel，由 event_flusher 异步消费
type ChannelEventSink struct {
	ch chan<- *model.Event
}

// NewChannelEventSink 构造 channel sink
func NewChannelEventSink(ch chan<- *model.Event) *ChannelEventSink {
	return &ChannelEventSink{ch: ch}
}

// Submit 非阻塞提交，channel 满时立即返回 ErrChannelFull
func (s *ChannelEventSink) Submit(ctx context.Context, e *model.Event) error {
	if e == nil {
		return errors.New("event is nil")
	}
	select {
	case s.ch <- e:
		return nil
	default:
		return ErrChannelFull
	}
}

// SubmitBatch 批量提交，任一失败立即停止
func (s *ChannelEventSink) SubmitBatch(ctx context.Context, es []*model.Event) error {
	for _, e := range es {
		if err := s.Submit(ctx, e); err != nil {
			return err
		}
	}
	return nil
}

// Close 关闭（channel sink 无状态，no-op）
func (s *ChannelEventSink) Close() error { return nil }