package net

import (
	"b612.me/stario"
	"b612.me/starlog"
	"context"
	"encoding/hex"
	"fmt"
	"net"
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"time"
)

type TcpClient struct {
	DialTimeout     int
	LocalAddr       string
	RemoteAddr      string
	UsingKeepAlive  bool
	KeepAlivePeriod int
	KeepAliveIdel   int
	KeepAliveCount  int
	UseLinger       int
	Interactive     bool
	UserTimeout     int
	ShowRecv        bool
	ShowAsHex       bool
	SaveToFolder    string
	Rmt             *TcpConn
	LogPath         string
	stopCtx         context.Context
	stopFn          context.CancelFunc
}

func (s *TcpClient) Close() error {
	return s.Rmt.Close()
}

func (s *TcpClient) handleInteractive() {
	var currentCmd string
	notifyMap := make(map[string]chan struct{})
	if !s.Interactive {
		return
	}
	starlog.Infoln("Interactive mode enabled")
	for {
		select {
		case <-s.stopCtx.Done():
			starlog.Infoln("Interactive mode stopped due to context done")
			return
		default:
		}
		cmd := stario.MessageBox("", "").MustString()
		if cmd == "" {
			continue
		}
		cmdf := strings.Fields(cmd)
		switch cmdf[0] {
		case "hex":
			currentCmd = "hex"
			starlog.Infoln("Switch to hex mode,send hex to remote client")
		case "text":
			currentCmd = "text"
			starlog.Infoln("Switch to text mode,send text to remote client")
		case "close":
			if s.Rmt.TCPConn == nil {
				starlog.Errorln("No client selected")
				continue
			}
			s.Rmt.TCPConn.Close()
			starlog.Infof("Client %s closed\n", s.Rmt.RemoteAddr().String())
			s.Rmt = nil
			currentCmd = ""
		case "startauto":
			if s.Rmt == nil {
				starlog.Errorln("No client selected")
				continue
			}
			notifyMap[s.Rmt.RemoteAddr().String()] = make(chan struct{})
			go func(conn *TcpConn) {
				for {
					select {
					case <-notifyMap[conn.RemoteAddr().String()]:
						starlog.Infoln("Auto send stopped")
						return
					default:
					}
					_, err := conn.Write([]byte(strings.Repeat("B612", 256)))
					if err != nil {
						starlog.Errorln("Write error:", err)
						return
					}
				}
			}(s.Rmt)
			starlog.Infoln("Auto send started")
		case "closeauto":
			if s.Rmt == nil {
				starlog.Errorln("No client selected")
				continue
			}
			close(notifyMap[s.Rmt.RemoteAddr().String()])
		case "send":
			if s.Rmt == nil {
				starlog.Errorln("No client selected")
				continue
			}
			if currentCmd == "hex" {
				data, err := hex.DecodeString(strings.TrimSpace(strings.TrimPrefix(cmd, "send")))
				if err != nil {
					starlog.Errorln("Hex decode error:", err)
					continue
				}
				_, err = s.Rmt.Write(data)
				if err != nil {
					starlog.Errorln("Write error:", err)
				} else {
					if s.Rmt.f != nil {
						s.Rmt.f.Write([]byte(time.Now().String() + " send\n"))
						s.Rmt.f.Write(data)
						s.Rmt.f.Write([]byte("\n"))
					}
				}
			} else {
				_, err := s.Rmt.Write([]byte(strings.TrimSpace(strings.TrimPrefix(cmd, "send"))))
				if err != nil {
					starlog.Errorln("Write error:", err)
				} else {
					if s.Rmt.f != nil {
						s.Rmt.f.Write([]byte(time.Now().String() + " send\n"))
						s.Rmt.f.Write([]byte(cmdf[1]))
						s.Rmt.f.Write([]byte("\n"))
					}
				}
			}
			starlog.Infof("Send to %s success\n", s.Rmt.RemoteAddr().String())
		}
	}
}

func (s *TcpClient) Run() error {
	var err error
	s.stopCtx, s.stopFn = context.WithCancel(context.Background())
	if s.LogPath != "" {
		err := starlog.SetLogFile(s.LogPath, starlog.Std, true)
		if err != nil {
			starlog.Errorln("SetLogFile error:", err)
			return fmt.Errorf("SetLogFile error: %w", err)
		}
	}
	var localAddr *net.TCPAddr
	if s.LocalAddr != "" {
		localAddr, err = net.ResolveTCPAddr("tcp", s.LocalAddr)
		if err != nil {
			starlog.Errorln("ResolveTCPAddr error:", err)
			return fmt.Errorf("ResolveTCPAddr error: %w", err)
		}
	}
	dialer := net.Dialer{
		LocalAddr: localAddr,
		Timeout:   time.Duration(s.DialTimeout) * time.Second,
		Control:   ControlSetReUseAddr,
	}
	tcpConn, err := dialer.Dial("tcp", s.RemoteAddr)
	if err != nil {
		starlog.Errorln("Dial TCP error:", err)
		return fmt.Errorf("Dial TCP error: %w", err)
	}
	conn := tcpConn.(*net.TCPConn)
	starlog.Infof("Connected to %s LocalAddr: %s\n", conn.RemoteAddr().String(), conn.LocalAddr().String())
	if s.Interactive {
		go s.handleInteractive()
	}
	s.Rmt = s.getTcpConn(conn)

	s.handleConn(s.Rmt)
	return nil
}

func (s *TcpClient) getTcpConn(conn *net.TCPConn) *TcpConn {
	var err error
	var f *os.File
	if s.SaveToFolder != "" {
		f, err = os.Create(filepath.Join(s.SaveToFolder, strings.ReplaceAll(conn.RemoteAddr().String(), ":", "_")))
		if err != nil {
			starlog.Errorf("Create file error for %s: %v\n", conn.RemoteAddr().String(), err)
		}
	}
	return &TcpConn{
		TCPConn: conn,
		f:       f,
	}
}

func (s *TcpClient) handleConn(conn *TcpConn) {
	var err error
	log := starlog.Std.NewFlag()
	err = SetTcpInfo(conn.TCPConn, s.UsingKeepAlive, s.KeepAliveIdel, s.KeepAlivePeriod, s.KeepAliveCount, s.UserTimeout)
	if err != nil {
		log.Errorf("SetTcpInfo error for %s: %v\n", conn.RemoteAddr().String(), err)
		conn.Close()
		return
	}
	if s.UseLinger >= 0 {
		conn.SetLinger(s.UseLinger)
	}
	log.Infof("SetKeepAlive success for %s\n", conn.RemoteAddr().String())
	log.Infof("KeepAlivePeriod: %d, KeepAliveIdel: %d, KeepAliveCount: %d, UserTimeout: %d\n", s.KeepAlivePeriod, s.KeepAliveIdel, s.KeepAliveCount, s.UserTimeout)
	if runtime.GOOS != "linux" {
		log.Warningln("keepAliveCount and userTimeout only work on linux")
	}

	for {
		select {
		case <-s.stopCtx.Done():
			log.Infof("Connection from %s closed due to context done\n", conn.RemoteAddr().String())
			conn.Close()
			return
		default:
		}
		buf := make([]byte, 8192)
		n, err := conn.Read(buf)
		if err != nil {
			log.Errorf("Read error for %s: %v\n", conn.RemoteAddr().String(), err)
			conn.Close()
			return
		}
		if n > 0 {
			if s.ShowRecv {
				if s.ShowAsHex {
					log.Printf("Recv from %s: %x\n", conn.RemoteAddr().String(), buf[:n])
				} else {
					log.Printf("Recv from %s: %s\n", conn.RemoteAddr().String(), string(buf[:n]))
				}
			}
			if conn.f != nil {
				conn.f.Write([]byte(time.Now().String() + " recv\n"))
				conn.f.Write(buf[:n])
				conn.f.Write([]byte("\n"))
			}
		}
	}
}

func (s *TcpClient) Stop() {
	s.stopFn()
	if s.Rmt != nil {
		s.Rmt.Close()
	}
}