package tcp

import (
	"context"
	"fmt"
	"io"
	"log/slog"
	"net"
)

type TcpClient struct {
	conn    *net.TCPConn
	handler func(n int, data []byte)
	ctx     context.CancelFunc
}

func StartTcpClient(rAddr string, handler func(n int, data []byte), readErr func(err error)) (*TcpClient, error) {
	raddr, addErr := net.ResolveTCPAddr("tcp", rAddr)
	if addErr != nil {
		return nil, addErr
	}
	conn, err := net.DialTCP("tcp", nil, raddr)
	ctx, ctxFun := context.WithCancel(context.Background())

	if err != nil {
		return nil, err
	}
	go func() {
		for {
			select {
			case <-ctx.Done():
				return
			default:
			}
			data := make([]byte, 1024)
			l, err := conn.Read(data)
			if err != nil {
				if opErr, ok := err.(*net.OpError); ok {
					slog.Error(fmt.Sprintf("TCP客户端[rAddr:%s]读取数据异常连接可能断开：", rAddr), opErr)
					readErr(err)
				}
				if err == io.EOF {
					slog.Warn(fmt.Sprintf("TCP客户端[rAddr:%s]断开连接：", rAddr))
					readErr(err)
				}
			}
			handler(l, data)
		}
	}()
	return &TcpClient{conn: conn, ctx: ctxFun}, nil
}
func (c *TcpClient) Close() {
	if c.conn != nil {
		slog.Info(fmt.Sprintf("TCP客户端[rAddr:%s]关闭连接", c.conn.RemoteAddr().String()))
		c.ctx()
		c.conn.Close()
		c.conn = nil
	}
}
func (c *TcpClient) Send(data []byte) error {
	if c.conn == nil {
		slog.Error("tcp client send error,conn is nil")
		return fmt.Errorf("TCP未连接车载PC仿真")
	}
	_, err := c.conn.Write(data)
	if err != nil {
		slog.Error("tcp client send error", "error", err)
		return err
	}
	return nil
}