package ruleEngine

import (
	"github.com/gogf/gf/container/gqueue"
	"sparrow/pkg/protocol"
	"sparrow/pkg/server"
	"sync"
	"sync/atomic"
)

type MailBox struct {
	system                 System
	id                     string
	parentRef              Ref
	actor                  Actor
	dispatcher             IDispatcher
	highPriorityMessages   *gqueue.Queue
	normalPriorityMessages *gqueue.Queue
	busyState              int32
	readySate              int32
	throughPut             int // 处理的吞吐量
	closed                 bool
	mu                     sync.Mutex
}

const (
	_ int32 = iota
	FREE
	BUSY
	NOTREADY
	READY
)

func NewMailBox(
	system System,
	selfId string, parentRef Ref, actor Actor,
	dispatcher IDispatcher,
) *MailBox {
	return &MailBox{
		highPriorityMessages:   gqueue.New(),
		normalPriorityMessages: gqueue.New(),
		system:                 system,
		id:                     selfId,
		parentRef:              parentRef,
		actor:                  actor,
		dispatcher:             dispatcher,
		throughPut:             10,
	}
}

// set mailbox ready status
func (m *MailBox) setReadyStat(stat int32) {
	v := atomic.LoadInt32(&stat)
	m.readySate = v
}

func (m *MailBox) getReadyStat() int32 {
	return atomic.LoadInt32(&m.readySate)
}

func (m *MailBox) getBusyStat() int32 {
	return atomic.LoadInt32(&m.busyState)
}

// set mailbox busy status
func (m *MailBox) setBusyStat(stat int32) {
	v := atomic.LoadInt32(&stat)
	m.busyState = v
}

func (m *MailBox) tryInit(attempt int) {
	server.Log.Debugf("Try to init actor, attempt %d", attempt)
	err := m.actor.Init(m)
	if err != nil {
		server.Log.Errorf("failed to init actor, err :%s, attempt %d", err.Error(), attempt)
		attempt += 1
		if attempt > 10 {
			_ = m.system.StopActorById(m.id)
		}
		_ = m.dispatcher.Submit(func() {
			m.tryInit(attempt)
		})
	}
	m.setReadyStat(READY)
	m.setBusyStat(FREE)
	m.tryProcessQueue(false)
}

func (m *MailBox) tryProcessQueue(newMsg bool) {
	if m.getReadyStat() != READY {
		server.Log.Debugf("MessageBox is not ready")
		return
	}

	if newMsg || m.normalPriorityMessages.Size() > 0 || m.highPriorityMessages.Size() > 0 {
		if m.getBusyStat() == FREE {
			m.setBusyStat(BUSY)
			err := m.dispatcher.Submit(func() {
				m.processMailbox()
			})
			if err != nil {
				server.Log.Error(err)
			}
		}
	} else {
		server.Log.Debugf("MessageBox is empty")
	}
}

func (m *MailBox) processMailbox() {
	var noMoreElement bool
	for i := 0; i < m.throughPut; i++ {
		var msg protocol.ActorMsg
		var getQueue *gqueue.Queue
		if m.highPriorityMessages.Size() > 0 {
			getQueue = m.highPriorityMessages
		} else if m.normalPriorityMessages.Size() > 0 {
			getQueue = m.normalPriorityMessages
		}
		if getQueue == nil {
			noMoreElement = true
			break
		}
		msg, ok := getQueue.Pop().(protocol.ActorMsg)
		if !ok {
			noMoreElement = true
			break
		}
		if msg != nil {
			server.Log.Debugf("Going to process message:%s, %v", m.id, msg)
			if err := m.actor.Process(msg); err != nil {
				strategy := m.actor.OnProcessFailure(err)
				if strategy._stop {
					_ = m.system.StopActorById(m.id)
				}
			}
		} else {
			noMoreElement = true
			break
		}
	}
	if noMoreElement {
		m.setBusyStat(FREE)
		_ = m.dispatcher.Submit(func() {
			m.tryProcessQueue(false)
		})
	} else {
		_ = m.dispatcher.Submit(func() {
			m.processMailbox()
		})
	}
}

// Init 邮箱初始化
func (m *MailBox) Init() error {
	return m.dispatcher.Submit(func() {
		m.tryInit(1)
	})
}

func (m *MailBox) GetActorId() string {
	return m.id
}

func (m *MailBox) Tell(msg protocol.ActorMsg) {
	m.enqueue(msg, false)
}

// push a message to queue
func (m *MailBox) enqueue(msg protocol.ActorMsg, isHighPriority bool) {
	if isHighPriority {
		m.highPriorityMessages.Push(msg)
	} else {
		m.normalPriorityMessages.Push(msg)
	}
	m.tryProcessQueue(true)
}

func (m *MailBox) TellWithHighPriority(msg protocol.ActorMsg) {
	m.enqueue(msg, true)
}

func (m *MailBox) GetSelf() string {
	return m.id
}

func (m *MailBox) GetParentRef() Ref {
	return m.parentRef
}

func (m *MailBox) TellActor(actorId string, msg protocol.ActorMsg) {
	m.system.Tell(actorId, msg)
}

func (m *MailBox) Stop(actorId string) error {
	return m.system.StopActorById(actorId)
}

func (m *MailBox) GetOrCreateChildActor(actorId string, dispatcherName string, creator Creator) (Ref, error) {
	actorRef := m.system.GetActor(actorId)
	if actorRef == nil {
		return m.system.CreateChildActor(dispatcherName, creator, m.id)
	}
	return actorRef, nil
}

func (m *MailBox) BroadcastChildren(msg protocol.ActorMsg) error {
	return m.system.BroadcastToChildren(m.id, msg)
}

func (m *MailBox) destroy() error {
	m.mu.Lock()
	defer m.mu.Unlock()
	if m.closed {
		return nil
	}
	m.highPriorityMessages.Close()
	m.normalPriorityMessages.Close()
	m.setReadyStat(NOTREADY)
	if err := m.actor.Destroy(); err != nil {
		server.Log.Warnf("Failed to destroy actor :%s, err :%s", m.id, err.Error())
	}
	m.closed = true
	return nil
}