//
// Copyright (c) 2017 anygone contributors (see AUTHORS file)
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice, this
//   list of conditions and the following disclaimer.
//
// * Redistributions in binary form must reproduce the above copyright notice,
//   this list of conditions and the following disclaimer in the documentation
//   and/or other materials provided with the distribution.
//
// * Neither the name of anygone nor the names of its
//   contributors may be used to endorse or promote products derived from
//   this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//

package main

import (
	"fmt"
	"io/ioutil"
	"log"
	"os"

	"go.anytun.org/anygone/tuntap"
)

var (
	al  = log.New(os.Stdout, "[anygone]\t", log.LstdFlags)
	adl = log.New(ioutil.Discard, "[anygone dbg]\t", log.LstdFlags)
)

func init() {
	//	if _, exists := os.LookupEnv("ANYGONE_DEBUG"); exists {
	adl.SetOutput(os.Stderr)
	//	}
}

func main() {
	cfg, err := NewConfig()
	if err != nil {
		fmt.Printf("Error while parsing commandline: %v\n\n", err)
		cfg.PrintUsage()
		os.Exit(2)
	}
	if cfg.Help {
		cfg.PrintUsage()
		os.Exit(0)
	}
	if cfg.Version {
		cfg.PrintVersion()
		os.Exit(0)
	}
	cfg.Dump()

	al.Println("just started...")

	dev, err := tuntap.NewDevice(cfg.DeviceType, cfg.DeviceName)
	if err != nil {
		al.Printf("Error while opening device: %v", err)
		os.Exit(1)
	}
	al.Printf("Device '%s': opened", dev.Name())

	if cfg.IFConfig.Valid {
		if err = dev.AddAddress(cfg.IFConfig.Net); err != nil {
			al.Printf("Error while configuring device: %v", err)
			os.Exit(1)
		}
		al.Printf("Device '%s': added address %s", dev.Name(), cfg.IFConfig.Net.String())
	}

	if err = dev.SetMTU(1400); err != nil { // TODO: hardcoded value
		al.Printf("Error while configuring device: %v", err)
		os.Exit(1)
	}
	if err = dev.Up(); err != nil {
		al.Printf("Error while configuring device: %v", err)
		os.Exit(1)
	}

	if cfg.PostUp != "" {
		al.Printf("Device '%s': running post-up script: %s", dev.Name(), cfg.PostUp)
		if err = dev.RunPostUp(cfg.PostUp); err != nil {
			al.Printf("Error while running post-up script: %v", err)
			os.Exit(1)
		}
		al.Printf("Device '%s': post-up script returned 0", dev.Name())
	}

	for {
		pkt, err := dev.ReadPacket()
		if err != nil {
			al.Printf("Error while reading packet from device: %v", err)
			os.Exit(1)
		}
		payload := ""
		for i, b := range pkt.Packet {
			if i == 0 {
				payload = fmt.Sprintf("{0x%02X", b)
			} else {
				payload = payload + fmt.Sprintf(", 0x%02X", b)
			}
		}
		payload = payload + "}"
		adl.Printf("got packet: Type {0x%04X}, Payload %s", pkt.Protocol, payload)
	}
}