package responder

import(
	"strings"
	"strconv"
	"errors"
	"bufio"
	"time"
	"net"
	"fmt"
	"os"
)

const error404StatusEnd	= "HTTP/1.1 404 Not Found\r\n\r\n"
const error400StatusEnd	= "HTTP/1.1 400 Bad Request\r\n\r\n"

func handler(conn net.Conn, docUrl string, codeVal string) (ret bool) {
defer func() {
	if r := recover(); r != nil {
			conn.Close()
			ret = false
			return
	}
}()
	defer conn.Close()
	contentLen := strconv.Itoa(len(codeVal))
	timeout := 11 * time.Second
	conn.SetReadDeadline(time.Now().Add(timeout))
	c := bufio.NewReader(conn)
	line, _, _ := c.ReadLine()

	srcFields := strings.Split(string(line), " ")
	if len(srcFields) < 3 {
		conn.Write([]byte(error400StatusEnd))
		return false
	}
	if srcFields[0] != "GET" {
		conn.Write([]byte(error400StatusEnd))
		return false
	}
	if srcFields[2] != "HTTP/1.1" {
		conn.Write([]byte(error400StatusEnd))
		return false
	}
 	if srcFields[1] == docUrl {
		retData := []byte("HTTP/1.1 200 OK\r\n")
		retData = append(retData, []byte("Server: tci-certrobot\r\n")[0:]...)
		retData = append(retData, []byte("Content-Type: text/html\r\n")[0:]...)
		retData = append(retData, []byte("Content-Length: " + contentLen)[0:]...)
		retData = append(retData, []byte("\r\nConnection: close\r\n\r\n")[0:]...)
		conn.Write(retData)
		conn.Write([]byte(codeVal))
		return true
	}
	conn.Write([]byte(error404StatusEnd))
	return false
}

func SpinServer(c chan int, portnum string, documentUrl string, code string) bool{
	l, err := net.Listen("tcp", portnum)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error listening:", err.Error())
		return false
	}
	defer l.Close()
	go func(){
		<- c
		fmt.Fprintf(os.Stderr, "Closing!\n")
		l.Close()
	}()
	for {
		conn, err := l.Accept()
		if err != nil { // TODO: нужна обработка закрытия "сокета".
			if errors.Is(err, net.ErrClosed) {
				return true
			}
			fmt.Fprintf(os.Stderr, "FATAL: Accept error!\n", err.Error())
			return false
		}
		go handler(conn, documentUrl, code)
	}

	return true
}