package health

import (
	"crypto/tls"
	"encoding/base64"
	"fmt"
	"net"
	"os"
	"syscall"

	cnsm "git.loafle.net/commons/service_matcher-go"
	cuej "git.loafle.net/commons/util-go/encoding/json"
	ocmm "git.loafle.net/overflow/commons-go/model/meta"
	ocmsc "git.loafle.net/overflow/commons-go/model/sensorconfig"
	"git.loafle.net/overflow/crawler-go"
)

type SocketHealthCrawler struct {
	crawler.Crawler
	m cnsm.Matcher
}

func (s *SocketHealthCrawler) SetMatcher(m cnsm.Matcher) {
	s.m = m
}

func (s *SocketHealthCrawler) GetConnection(config *ocmsc.SensorConfig) (net.Conn, error) {
	connection := config.Connection
	metaIPTypeKey := connection.MetaIPTypeKey
	ip := connection.IP
	port := connection.Port
	metaPortTypeKey := connection.MetaPortTypeKey
	metaCryptoTypeKey := connection.MetaCryptoTypeKey

	addr := net.JoinHostPort(ip, port.String())

	network := ""
	switch metaIPTypeKey {
	case ocmm.MetaIPTypeEnumV6.String():
		switch metaPortTypeKey {
		case ocmm.MetaPortTypeEnumUDP.String():
			network = "udp6"
		default:
			network = "tcp6"
		}
	default:
		switch metaPortTypeKey {
		case ocmm.MetaPortTypeEnumUDP.String():
			network = "udp"
		default:
			network = "tcp"
		}
	}

	conn, err := net.Dial(network, addr)
	if err != nil {
		ee := ToSocketErrorEnum(err)
		return nil, fmt.Errorf(ee.String())
	}

	switch metaCryptoTypeKey {
	case ocmm.MetaCryptoTypeEnumTLS.String():
		cfg := &tls.Config{
			InsecureSkipVerify: true,
			ServerName:         ip,
			ClientAuth:         tls.RequestClientCert,
		}
		tlsConn := tls.Client(conn, cfg)
		if err := tlsConn.Handshake(); err != nil {
			return nil, err
		}

		conn = tlsConn
	default:
	}

	return conn, nil
}

func ToSocketErrorEnum(err error) SocketErrorEnum {
	if e, ok := err.(net.Error); ok && e.Timeout() {
		return SocketErrorEnumTIMOUT
	}
	n, ok := err.(*net.OpError).Err.(*os.SyscallError).Err.(syscall.Errno)
	if !ok {
		return SocketErrorEnumUNKNOWN
	}
	switch n {
	case syscall.EHOSTUNREACH:
		return SocketErrorEnumHOSTUNREACH
	case syscall.ECONNREFUSED:
		return SocketErrorEnumCONNREFUSED
	default:
		return SocketErrorEnumUNKNOWN
	}

}

func (s *SocketHealthCrawler) CheckHealth(config *ocmsc.SensorConfig, conn net.Conn) error {

	connection := config.Connection
	port, _ := cuej.NumberToInt(connection.Port)
	info := cnsm.NewMatchInfo(connection.IP, port)

	if s.m.IsPrePacket() {

		buf := make([]byte, 1024)
		n, _ := conn.Read(buf)
		p := cnsm.NewPacket(buf, n)
		if !s.m.Match(info, 0, p) {
			return fmt.Errorf("Not Matched")
		}

		for i := 0; i < s.m.PacketCount(); i++ {
			pack := s.m.Packet(i)
			conn.Write(pack.Buffer)
			buf := make([]byte, 1024)
			n, _ := conn.Read(buf)

			if !s.m.HasResponse(i + 1) { // empty last response
				break
			}

			p := cnsm.NewPacket(buf, n)
			if !s.m.Match(info, i+1, p) {
				return fmt.Errorf("Not Matched")
			}
		}

		return nil

	} else {
		for i := 0; i < s.m.PacketCount(); i++ {
			pack := s.m.Packet(i)
			conn.Write(pack.Buffer)
			buf := make([]byte, 1024)
			n, _ := conn.Read(buf)

			if !s.m.HasResponse(i) { // empty last response
				break
			}

			p := cnsm.NewPacket(buf, n)
			if !s.m.Match(info, i, p) {
				return fmt.Errorf("Not Matched")
			}
		}
	}

	return nil
}

func convertBase64(buf []byte) string {
	return base64.StdEncoding.EncodeToString(buf)
}