package session

import (
	"bufio"
	"fmt"
	"io"
	"time"

	"badat.dev/maeqtt/v2/mqtt/packets"
)

type Connection struct {
	MaxPacketSize   *uint32
	RecvMax         uint16
	TopicAliasMax   uint16
	WantsRespInf    bool
	WantsProblemInf bool
	Will            packets.Will

	KeepAliveInterval time.Duration
	keepAliveTicker   time.Ticker

	PacketChannel          chan packets.ClientPacket
	ClientDisconnectedChan chan bool

	rw io.ReadWriteCloser
}

func (c *Connection) resetKeepAlive() {
	if c.KeepAliveInterval != 0 {
		// TODO IMPLEMENT THIS
		//s.keepAliveTicker.Reset(s.KeepAliveInterval)
	}
}

func (c *Connection) readPacket() (*packets.ClientPacket, error) {
	return packets.ReadPacket(bufio.NewReader(c.rw))
}

func (c *Connection) sendPacket(p packets.ServerPacket) error {
	c.resetKeepAlive()
	return p.Write(c.rw)
}

func (c *Connection) close() error {
	close(c.PacketChannel)
	return c.rw.Close()
}

func (c *Connection) packetReadLoop() {
	for {
		pack, err := c.readPacket()
		if err == io.EOF {
			c.ClientDisconnectedChan <- true
		} else if err != nil {
			panic(fmt.Errorf("Unimplemented error handling, %e", err).Error())
		} else {
			c.PacketChannel <- *pack
		}
	}
}

func NewConnection(p packets.ConnectPacket, rw io.ReadWriteCloser) Connection {
	conn := Connection{}
	conn.rw = rw

	if p.Properties.ReceiveMaximum.Value != nil {
		conn.RecvMax = *p.Properties.ReceiveMaximum.Value
	} else {
		conn.RecvMax = 65535
	}
	conn.MaxPacketSize = p.Properties.MaximumPacketSize.Value

	if p.Properties.TopicAliasMaximum.Value != nil {
		conn.TopicAliasMax = *p.Properties.TopicAliasMaximum.Value
	} else {
		conn.TopicAliasMax = 0
	}

	if p.Properties.RequestProblemInformation.Value != nil {
		conn.WantsRespInf = *p.Properties.RequestProblemInformation.Value != 0
	} else {
		conn.WantsRespInf = false
	}

	conn.KeepAliveInterval = time.Duration(p.KeepAliveInterval) * time.Second

	conn.PacketChannel = make(chan packets.ClientPacket)

	go conn.packetReadLoop()
	return conn
}