package main

import (
	"bufio"
	"io"
	"log"
	"net"
	"sync"
	"time"
)

type CartPacketQueue struct {
	mu               sync.RWMutex
	expectedPackages map[uint32]*CartListener
}

const CurrentPacketVersion = 2

type CartListener map[CartId]Listener

func NewCartPacketQueue(connection net.Conn) *CartPacketQueue {

	queue := &CartPacketQueue{
		expectedPackages: make(map[uint32]*CartListener),
	}
	go queue.HandleConnection(connection)
	return queue
}

func (p *CartPacketQueue) RemoveListeners() {
	p.mu.Lock()
	defer p.mu.Unlock()
	for _, l := range p.expectedPackages {
		for _, l := range *l {
			close(l.Chan)
		}
	}
	p.expectedPackages = make(map[uint32]*CartListener)
}

func (p *CartPacketQueue) HandleConnection(connection net.Conn) error {
	defer p.RemoveListeners()
	defer connection.Close()
	var packet CartPacket
	connection.SetReadDeadline(time.Now().Add(time.Millisecond * 200))
	reader := bufio.NewReader(connection)
	for {
		err := ReadCartPacket(reader, &packet)
		if err != nil {
			if err == io.EOF {
				return nil
			}
			log.Printf("Error receiving packet: %v\n", err)
			return err
		}
		if packet.Version != CurrentPacketVersion {
			log.Printf("Incorrect version: %v\n", packet.Version)
			return nil
		}
		if packet.DataLength == 0 {
			go p.HandleData(packet.MessageType, packet.Id, CallResult{
				StatusCode: packet.StatusCode,
				Data:       []byte{},
			})
			continue
		}
		data, err := GetPacketData(reader, packet.DataLength)
		if err != nil {
			log.Printf("Error receiving packet data: %v\n", err)
			return err
		}
		go p.HandleData(packet.MessageType, packet.Id, CallResult{
			StatusCode: packet.StatusCode,
			Data:       data,
		})
	}
}

func (p *CartPacketQueue) HandleData(t uint32, id CartId, data CallResult) {
	p.mu.Lock()
	defer p.mu.Unlock()
	pl, ok := p.expectedPackages[t]
	if ok {
		l, ok := (*pl)[id]
		if ok {
			l.Chan <- data
			l.Count--
			if l.Count == 0 {
				close(l.Chan)
				delete(*pl, id)
			}
		}
	}
}

func (p *CartPacketQueue) Expect(messageType uint32, id CartId) <-chan CallResult {
	p.mu.Lock()
	defer p.mu.Unlock()
	l, ok := p.expectedPackages[messageType]
	if ok {
		if idl, idOk := (*l)[id]; idOk {
			idl.Count++
			return idl.Chan
		}
		ch := make(chan CallResult)
		(*l)[id] = Listener{
			Chan:  ch,
			Count: 1,
		}
		return ch
	}

	ch := make(chan CallResult)
	p.expectedPackages[messageType] = &CartListener{
		id: Listener{
			Chan:  ch,
			Count: 1,
		},
	}

	return ch

}

// package main

// import (
// 	"fmt"
// 	"io"
// 	"log"
// 	"net"
// 	"sync"
// 	"time"
// )

// type CartPacketWithData struct {
// 	MessageType uint32
// 	Id          CartId
// 	Added       time.Time
// 	Consumed    bool
// 	Data        []byte
// }

// type CartPacketQueue struct {
// 	mu      sync.RWMutex
// 	Packets []CartPacketWithData
// 	//connection net.Conn
// }

// const cartCap = 150

// func NewCartPacketQueue(connection net.Conn) *CartPacketQueue {

// 	queue := &CartPacketQueue{
// 		Packets: make([]CartPacketWithData, 0, cartCap),
// 		//connection: connection,
// 	}
// 	go func() {
// 		defer connection.Close()
// 		var packet CartPacket
// 		for {
// 			err := ReadCartPacket(connection, &packet)
// 			if err != nil {
// 				if err == io.EOF {
// 					return
// 				}
// 				log.Printf("Error receiving packet: %v\n", err)
// 				//return
// 			}

// 			data, err := GetPacketData(connection, packet.DataLength)
// 			if err != nil {
// 				log.Printf("Error receiving packet data: %v\n", err)
// 				return
// 			}
// 			go queue.HandleData(packet.MessageType, packet.Id, data)
// 		}
// 	}()
// 	return queue
// }

// func (p *CartPacketQueue) HandleData(t uint32, id CartId, data []byte) {
// 	ts := time.Now()
// 	l := make([]CartPacketWithData, 0, cartCap)
// 	p.mu.RLock()
// 	breakAt := ts.Add(-time.Millisecond * 250)
// 	for _, packet := range p.Packets {
// 		if !packet.Consumed && packet.Added.After(breakAt) {
// 			l = append(l, packet)
// 			if len(l) >= cartCap {
// 				break
// 			}
// 		}
// 	}
// 	p.mu.RUnlock()
// 	p.mu.Lock()
// 	p.Packets = append([]CartPacketWithData{
// 		{
// 			MessageType: t,
// 			Id:          id,
// 			Added:       ts,
// 			Data:        data,
// 		},
// 	}, l...)
// 	p.mu.Unlock()
// }

// func (p *CartPacketQueue) Expect(messageType uint32, id CartId, timeToWait time.Duration) (*CartPacketWithData, error) {
// 	start := time.Now().Add(-time.Millisecond)

// 	for {
// 		if time.Since(start) > timeToWait {
// 			return nil, fmt.Errorf("timeout waiting for message type %d", messageType)
// 		}
// 		p.mu.RLock()
// 		for _, packet := range p.Packets {
// 			if !packet.Consumed && packet.MessageType == messageType && packet.Id == id && packet.Added.After(start) {
// 				packet.Consumed = true
// 				p.mu.RUnlock()
// 				return &packet, nil
// 			}
// 		}
// 		p.mu.RUnlock()
// 		time.Sleep(time.Millisecond * 2)
// 	}
// }