/*
NAME
  rtmp.go

DESCRIPTION
  See Readme.md

AUTHORS
  Saxon Nelson-Milton <saxon@ausocean.org>
  Dan Kortschak <dan@ausocean.org>

LICENSE
  rtmp.go is Copyright (C) 2017 the Australian Ocean Lab (AusOcean)

  It is free software: you can redistribute it and/or modify them
  under the terms of the GNU General Public License as published by the
  Free Software Foundation, either version 3 of the License, or (at your
  option) any later version.

  It is distributed in the hope that it will be useful, but WITHOUT
  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  for more details.

  You should have received a copy of the GNU General Public License
  along with revid in gpl.txt. If not, see http://www.gnu.org/licenses.

  Derived from librtmp under the GNU Lesser General Public License 2.1
  Copyright (C) 2005-2008 Team XBMC http://www.xbmc.org
  Copyright (C) 2008-2009 Andrej Stepanchuk
  Copyright (C) 2009-2010 Howard Chu
*/

package rtmp

import (
	"fmt"
	"log"
	"net"

	"golang.org/x/sys/unix"
)

// int RTMP_Connect(RTMP *r, RTMPPacket* cp);
// rtmp.c +1032
func C_RTMP_Connect(r *C_RTMP, cp *C_RTMPPacket) (ok bool) {
	if r.Link.hostname == "" {
		return false
	}

	var hostname string
	if r.Link.socksport != 0 {
		hostname = fmt.Sprintf("%s:%d", r.Link.sockshost, r.Link.socksport)
	} else {
		hostname = fmt.Sprintf("%s:%d", r.Link.hostname, r.Link.port)
	}
	addr, err := net.ResolveTCPAddr("tcp4", hostname)
	if err != nil {
		return false
	}
	r.m_sb.conn, err = net.DialTCP("tcp4", nil, addr)
	if err != nil {
		return false
	}
	if r.Link.socksport != 0 {
		if !C_SocksNegotiate(r, addr) {
			return false
		}
	}

	f, err := r.m_sb.conn.File()
	if err != nil {
		log.Printf("failed to get fd to set timeout: %v", err)
		return false
	}
	tv := setTimeval(int(r.Link.timeout))
	err = unix.SetsockoptTimeval(int(f.Fd()), unix.SOL_SOCKET, unix.SO_RCVTIMEO, &tv)
	if err != nil {
		log.Printf("failed to set timeout: %v", err)
	}

	r.m_bSendCounter = true

	return C_RTMP_Connect1(r, cp)
}

// int SocksNegotiate(RTMP* r);
// rtmp.c +1062
func C_SocksNegotiate(r *C_RTMP, addr *net.TCPAddr) (ok bool) {
	ip := addr.IP.To4()
	packet := []byte{
		0x4, // SOCKS version
		0x1, // Establish a TCP/IP stream connection
		byte(r.Link.port >> 8), byte(r.Link.port),
		ip[0], ip[1], ip[2], ip[3],
		0x0, // Empty user ID string
	}

	C_WriteN(r, packet)

	if C_ReadN(r, packet[:8]) != 8 {
		return false
	}

	if packet[0] == 0x0 && packet[1] == 0x5a {
		return true
	}
	// TODO: use new logger here
	log.Println("C_SocksNegotitate: SOCKS returned error code!")
	return false
}

// int RTMPSockBuf_Fill(RTMPSockBuf* sb);
// rtmp.c +4253
func C_RTMPSockBuf_Fill(sb *C_RTMPSockBuf) int {
	if sb.sb_size == 0 {
		sb.sb_start = 0
	}

	n, err := sb.conn.Read(sb.sb_buf[sb.sb_start+sb.sb_size:])
	if err != nil {
		return 0
	}
	sb.sb_size += n
	return n
}

// int RTMPSockBuf_Send(RTMPSockBuf* sb, const char* buf, int len);
// rtmp.c +4297
// TODO replace send with golang net connection send
func C_RTMPSockBuf_Send(sb *C_RTMPSockBuf, buf []byte) int32 {
	n, err := sb.conn.Write(buf)
	if err != nil {
		return -1
	}
	return int32(n)
}

// int
// RTMPSockBuf_Close(RTMPSockBuf *sb)
// rtmp.c +4369
func C_RTMPSockBuf_Close(sb *C_RTMPSockBuf) int32 {
	if sb.conn != nil {
		err := sb.conn.Close()
		sb.conn = nil
		if err == nil {
			return 1
		}
	}
	return 0
}