// Copyright 2016 fatedier, fatedier@gmail.com
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package main

import (
	"encoding/base64"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net/http"
	"os"
	"os/signal"
	"strconv"
	"strings"
	"syscall"
	"time"

	docopt "github.com/docopt/docopt-go"
	"github.com/rodaine/table"
	ini "github.com/vaughan0/go-ini"

	"github.com/fatedier/frp/client"
	"github.com/fatedier/frp/models/config"
	"github.com/fatedier/frp/utils/log"
	"github.com/fatedier/frp/utils/version"
)

var (
	configFile string = "./frpc.ini"
)

var usage string = `frpc is the client of frp

Usage: 
    frpc [-c config_file] [-L log_file] [--log-level=<log_level>] [--server-addr=<server_addr>]
    frpc reload [-c config_file]
    frpc status [-c config_file]
    frpc -h | --help
    frpc -v | --version

Options:
    -c config_file              set config file
    -L log_file                 set output log file, including console
    --log-level=<log_level>     set log level: debug, info, warn, error
    --server-addr=<server_addr> addr which frps is listening for, example: 0.0.0.0:7000
    -h --help                   show this screen
    -v --version                show version
`

func main() {
	var err error
	confFile := "./frpc.ini"
	// the configures parsed from file will be replaced by those from command line if exist
	args, err := docopt.Parse(usage, nil, true, version.Full(), false)

	if args["-c"] != nil {
		confFile = args["-c"].(string)
	}

	conf, err := ini.LoadFile(confFile)
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}

	config.ClientCommonCfg, err = config.LoadClientCommonConf(conf)
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
	config.ClientCommonCfg.ConfigFile = confFile

	// check if reload command
	if args["reload"] != nil {
		if args["reload"].(bool) {
			if err = CmdReload(); err != nil {
				fmt.Printf("frpc reload error: %v\n", err)
				os.Exit(1)
			} else {
				fmt.Printf("reload success\n")
				os.Exit(0)
			}
		}
	}

	// check if status command
	if args["status"] != nil {
		if args["status"].(bool) {
			if err = CmdStatus(); err != nil {
				fmt.Printf("frpc get status error: %v\n", err)
				os.Exit(1)
			} else {
				os.Exit(0)
			}
		}
	}

	if args["-L"] != nil {
		if args["-L"].(string) == "console" {
			config.ClientCommonCfg.LogWay = "console"
		} else {
			config.ClientCommonCfg.LogWay = "file"
			config.ClientCommonCfg.LogFile = args["-L"].(string)
		}
	}

	if args["--log-level"] != nil {
		config.ClientCommonCfg.LogLevel = args["--log-level"].(string)
	}

	if args["--server-addr"] != nil {
		addr := strings.Split(args["--server-addr"].(string), ":")
		if len(addr) != 2 {
			fmt.Println("--server-addr format error: example 0.0.0.0:7000")
			os.Exit(1)
		}
		serverPort, err := strconv.ParseInt(addr[1], 10, 64)
		if err != nil {
			fmt.Println("--server-addr format error, example 0.0.0.0:7000")
			os.Exit(1)
		}
		config.ClientCommonCfg.ServerAddr = addr[0]
		config.ClientCommonCfg.ServerPort = int(serverPort)
	}

	if args["-v"] != nil {
		if args["-v"].(bool) {
			fmt.Println(version.Full())
			os.Exit(0)
		}
	}

	pxyCfgs, visitorCfgs, err := config.LoadProxyConfFromFile(config.ClientCommonCfg.User, conf, config.ClientCommonCfg.Start)
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}

	log.InitLog(config.ClientCommonCfg.LogWay, config.ClientCommonCfg.LogFile,
		config.ClientCommonCfg.LogLevel, config.ClientCommonCfg.LogMaxDays)

	svr := client.NewService(pxyCfgs, visitorCfgs)

	// Capture the exit signal if we use kcp.
	if config.ClientCommonCfg.Protocol == "kcp" {
		go HandleSignal(svr)
	}

	err = svr.Run()
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
}

func HandleSignal(svr *client.Service) {
	ch := make(chan os.Signal)
	signal.Notify(ch, syscall.SIGINT, syscall.SIGTERM)
	<-ch
	svr.Close()
	time.Sleep(250 * time.Millisecond)
	os.Exit(0)
}

func CmdReload() error {
	if config.ClientCommonCfg.AdminPort == 0 {
		return fmt.Errorf("admin_port shoud be set if you want to use reload feature")
	}

	req, err := http.NewRequest("GET", "http://"+
		config.ClientCommonCfg.AdminAddr+":"+fmt.Sprintf("%d", config.ClientCommonCfg.AdminPort)+"/api/reload", nil)
	if err != nil {
		return err
	}

	authStr := "Basic " + base64.StdEncoding.EncodeToString([]byte(config.ClientCommonCfg.AdminUser+":"+
		config.ClientCommonCfg.AdminPwd))

	req.Header.Add("Authorization", authStr)
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return err
	} else {
		if resp.StatusCode != 200 {
			return fmt.Errorf("admin api status code [%d]", resp.StatusCode)
		}
		defer resp.Body.Close()
		body, err := ioutil.ReadAll(resp.Body)
		if err != nil {
			return err
		}
		res := &client.GeneralResponse{}
		err = json.Unmarshal(body, &res)
		if err != nil {
			return fmt.Errorf("unmarshal http response error: %s", strings.TrimSpace(string(body)))
		} else if res.Code != 0 {
			return fmt.Errorf(res.Msg)
		}
	}
	return nil
}

func CmdStatus() error {
	if config.ClientCommonCfg.AdminPort == 0 {
		return fmt.Errorf("admin_port shoud be set if you want to get proxy status")
	}

	req, err := http.NewRequest("GET", "http://"+
		config.ClientCommonCfg.AdminAddr+":"+fmt.Sprintf("%d", config.ClientCommonCfg.AdminPort)+"/api/status", nil)
	if err != nil {
		return err
	}

	authStr := "Basic " + base64.StdEncoding.EncodeToString([]byte(config.ClientCommonCfg.AdminUser+":"+
		config.ClientCommonCfg.AdminPwd))

	req.Header.Add("Authorization", authStr)
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return err
	} else {
		if resp.StatusCode != 200 {
			return fmt.Errorf("admin api status code [%d]", resp.StatusCode)
		}
		defer resp.Body.Close()
		body, err := ioutil.ReadAll(resp.Body)
		if err != nil {
			return err
		}
		res := &client.StatusResp{}
		err = json.Unmarshal(body, &res)
		if err != nil {
			return fmt.Errorf("unmarshal http response error: %s", strings.TrimSpace(string(body)))
		}

		fmt.Println("Proxy Status...")
		if len(res.Tcp) > 0 {
			fmt.Printf("TCP")
			tbl := table.New("Name", "Status", "LocalAddr", "Plugin", "RemoteAddr", "Error")
			for _, ps := range res.Tcp {
				tbl.AddRow(ps.Name, ps.Status, ps.LocalAddr, ps.Plugin, ps.RemoteAddr, ps.Err)
			}
			tbl.Print()
			fmt.Println("")
		}
		if len(res.Udp) > 0 {
			fmt.Printf("UDP")
			tbl := table.New("Name", "Status", "LocalAddr", "Plugin", "RemoteAddr", "Error")
			for _, ps := range res.Udp {
				tbl.AddRow(ps.Name, ps.Status, ps.LocalAddr, ps.Plugin, ps.RemoteAddr, ps.Err)
			}
			tbl.Print()
			fmt.Println("")
		}
		if len(res.Http) > 0 {
			fmt.Printf("HTTP")
			tbl := table.New("Name", "Status", "LocalAddr", "Plugin", "RemoteAddr", "Error")
			for _, ps := range res.Http {
				tbl.AddRow(ps.Name, ps.Status, ps.LocalAddr, ps.Plugin, ps.RemoteAddr, ps.Err)
			}
			tbl.Print()
			fmt.Println("")
		}
		if len(res.Https) > 0 {
			fmt.Printf("HTTPS")
			tbl := table.New("Name", "Status", "LocalAddr", "Plugin", "RemoteAddr", "Error")
			for _, ps := range res.Https {
				tbl.AddRow(ps.Name, ps.Status, ps.LocalAddr, ps.Plugin, ps.RemoteAddr, ps.Err)
			}
			tbl.Print()
			fmt.Println("")
		}
		if len(res.Stcp) > 0 {
			fmt.Printf("STCP")
			tbl := table.New("Name", "Status", "LocalAddr", "Plugin", "RemoteAddr", "Error")
			for _, ps := range res.Stcp {
				tbl.AddRow(ps.Name, ps.Status, ps.LocalAddr, ps.Plugin, ps.RemoteAddr, ps.Err)
			}
			tbl.Print()
			fmt.Println("")
		}
		if len(res.Xtcp) > 0 {
			fmt.Printf("XTCP")
			tbl := table.New("Name", "Status", "LocalAddr", "Plugin", "RemoteAddr", "Error")
			for _, ps := range res.Xtcp {
				tbl.AddRow(ps.Name, ps.Status, ps.LocalAddr, ps.Plugin, ps.RemoteAddr, ps.Err)
			}
			tbl.Print()
			fmt.Println("")
		}
	}
	return nil
}