package ssh

import (
	"encoding/binary"
	"io"
	"net"
	"syscall"
	"unsafe"

	"github.com/kr/pty"
	"golang.org/x/crypto/ssh"
	ice "shylinux.com/x/icebergs"
	"shylinux.com/x/icebergs/base/cli"
	"shylinux.com/x/icebergs/base/mdb"
	"shylinux.com/x/icebergs/base/tcp"
	kit "shylinux.com/x/toolkits"
)

type Winsize struct{ Height, Width, x, y uint16 }

func _ssh_size(fd uintptr, b []byte) {
	w := binary.BigEndian.Uint32(b)
	h := binary.BigEndian.Uint32(b[4:])

	ws := &Winsize{Width: uint16(w), Height: uint16(h)}
	syscall.Syscall(syscall.SYS_IOCTL, fd, uintptr(syscall.TIOCSWINSZ), uintptr(unsafe.Pointer(ws)))
}
func _ssh_sizes(fd uintptr, w, h int) {
	ws := &Winsize{Width: uint16(w), Height: uint16(h)}
	syscall.Syscall(syscall.SYS_IOCTL, fd, uintptr(syscall.TIOCSWINSZ), uintptr(unsafe.Pointer(ws)))
}
func _ssh_handle(m *ice.Message, meta ice.Maps, c net.Conn, channel ssh.Channel, requests <-chan *ssh.Request) {
	m.Logs(CHANNEL, tcp.HOSTPORT, c.RemoteAddr(), "->", c.LocalAddr())
	defer m.Logs("dischan", tcp.HOSTPORT, c.RemoteAddr(), "->", c.LocalAddr())

	shell := kit.Select("bash", kit.Env("SHELL"))
	list := []string{cli.PATH + "=" + kit.Env(cli.PATH)}

	pty, tty, err := pty.Open()
	if m.Warn(err) {
		return
	}
	defer tty.Close()

	h := m.Rich(CHANNEL, "", kit.Data(mdb.STATUS, tcp.OPEN, TTY, tty.Name(), INPUT, pty, OUTPUT, tty, meta))
	meta[CHANNEL] = h

	for request := range requests {
		m.Logs(REQUEST, tcp.HOSTPORT, c.RemoteAddr(), mdb.TYPE, request.Type)

		switch request.Type {
		case "pty-req":
			termLen := request.Payload[3]
			termEnv := string(request.Payload[4 : termLen+4])
			_ssh_size(pty.Fd(), request.Payload[termLen+4:])
			list = append(list, "TERM="+termEnv)

		case "window-change":
			_ssh_size(pty.Fd(), request.Payload)

		case "env":
			var env struct{ Name, Value string }
			if err := ssh.Unmarshal(request.Payload, &env); err != nil {
				continue
			}
			list = append(list, env.Name+"="+env.Value)

		case "exec":
			_ssh_exec(m, shell, []string{"-c", string(request.Payload[4 : request.Payload[3]+4])}, list, channel, channel, func() {
				channel.Close()
			})
		case "shell":
			_ssh_watch(m, meta, h, channel, pty)
			m.Go(func() { io.Copy(channel, pty) })

			_ssh_exec(m, shell, nil, list, tty, tty, func() {
				defer m.Cmd(mdb.MODIFY, CHANNEL, "", mdb.HASH, mdb.HASH, h, mdb.STATUS, tcp.CLOSE)
				_ssh_close(m, c, channel)
			})
		}
		request.Reply(true, nil)
	}
}