package fusenrender

import (
	"context"

	"github.com/474420502/execute/triggered"
	"github.com/474420502/passer"
	sm "github.com/lni/dragonboat/v4/statemachine"
)

// 结构体异步传递后, 执行的注册函数, 实际上就是update的handler
var FsPasser *passer.Passer[sm.Result] = func() *passer.Passer[sm.Result] {

	fsPasser := passer.NewPasser[sm.Result]()

	fsPasser.RegisterPasser(&CmdEnqueue{}, func(cxt context.Context, obj any) (sm.Result, error) {

		var smqueue = cxt.Value(ctxSMQueue{}).(*SMQueue)
		var dequeueHandler = cxt.Value(ctxDequeueHandler{}).(*triggered.EventExecute[bool])

		cmd := obj.(*CmdEnqueue)
		key := cmd.Item.GetKey()

		smqueue.mu.Lock()
		var queue *PriorityQueue[QueueItem]
		var ok bool
		if queue, ok = smqueue.queues[cmd.Group]; !ok {
			queue = NewPriorityQueue[QueueItem]()
			smqueue.queues[cmd.Group] = queue
		}
		smqueue.mu.Unlock()

		queue.Push(&Slice[QueueItem]{
			Key:   key,
			Value: cmd.Item,
		})

		countPutPop.Use(func(item *CountPutPop) {
			item.PutCount++
		})

		var result sm.Result
		dequeueHandler.Notify(dequeueHandler.NULL) // 通知可以执行update
		return result, nil
	})

	fsPasser.RegisterPasser(&CmdDequeue{}, func(cxt context.Context, obj any) (sm.Result, error) {

		var smqueue = cxt.Value(ctxSMQueue{}).(*SMQueue)
		var e = cxt.Value(ctxEntry{}).(*sm.Entry)

		var queue *PriorityQueue[QueueItem]
		var ok bool
		cmd := obj.(*CmdDequeue)
		smqueue.mu.Lock()
		if queue, ok = smqueue.queues[cmd.Group]; !ok {
			queue = NewPriorityQueue[QueueItem]()
			smqueue.queues[cmd.Group] = queue
		}
		smqueue.mu.Unlock()

		var result sm.Result
		if queue.Empty() {
			return result, nil
		}

		item := queue.Pop()
		if item == nil {
			result.Value = 0
			return result, nil
		}

		if item != nil {
			d, err := item.Encode()
			if err != nil {
				return result, err
			}
			e.Result.Data = d
			result.Data = d

			smqueue.counter.Notify(queue.Size())

			// log.Println("queue remain:", queue.Size())
		}

		return result, nil
	})

	return fsPasser
}()