package mingo

type BusCallBack[T any] func(ctx T, event string, data any) error
type BusEventResult struct {
	Bsn string
	Res error
}
type BusOnResultFunc[T any] func(ctx T, event string, data any, allSuccess bool, details []BusEventResult)
type eventItem[T any] struct {
	bsn string
	cb  BusCallBack[T]
}

// 事件总线
// T:上下文泛型
type Bus[T any] struct {
	cbs      map[string][]eventItem[T]
	onResult BusOnResultFunc[T]
}

// event:监听的事件名称
// bsn:业务名称 用于做结果稽查,bsn 确定后，不应更改，以便后续重用
// cb:回调函数
func (t *Bus[T]) On(event string, bsn string, cb BusCallBack[T]) {
	item, exist := t.cbs[event]
	if exist {
		t.cbs[event] = append(item, eventItem[T]{bsn, cb})
	} else {
		t.cbs[event] = []eventItem[T]{{bsn, cb}}
	}
}

// event:监听的事件名称
// data:事件数据
// bsns:仅重试的事件
// 重试情况下，结果回调仍会被触发
func (t *Bus[T]) Retry(ctx T, event string, data any, bsns []string) {
	proc, exist := t.cbs[event]
	if exist {
		res := []BusEventResult{}
		allSuccess := true
		for i := range len(proc) {
			if Includes(bsns, func(item *string) bool { return *item == proc[i].bsn }) {
				err := proc[i].cb(ctx, event, data)
				res = append(res, BusEventResult{
					Bsn: proc[i].bsn,
					Res: err,
				})
				if err != nil {
					allSuccess = false
				}
			}
		}
		if t.onResult != nil {
			t.onResult(ctx, event, data, allSuccess, res)
		}
	}
}

// 触发事件
// event:事件名称
// data:事件参数，推荐使用指针
func (t *Bus[T]) Emit(ctx T, event string, data any) {
	proc, exist := t.cbs[event]
	if exist {
		res := make([]BusEventResult, len(proc))
		allSuccess := true
		for i := range len(proc) {
			err := proc[i].cb(ctx, event, data)
			res[i] = BusEventResult{
				Bsn: proc[i].bsn,
				Res: err,
			}
			if err != nil {
				allSuccess = false
			}
		}
		if t.onResult != nil {
			t.onResult(ctx, event, data, allSuccess, res)
		}
	}
}
func NewBus[T any](onResult BusOnResultFunc[T]) *Bus[T] {
	return &Bus[T]{cbs: make(map[string][]eventItem[T]), onResult: onResult}
}