/*
 * Copyright (C) 2017-2018 "IoT.bzh"
 * Author Clément Bénier <clement.benier@iot.bzh>
 *
 * 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 xdsservertest

import (
	"bytes"
	"fmt"
	"log"
	"os"
	"os/exec"
	"path"
	"regexp"
	"strconv"
	"strings"
	"testing"
	"time"

	common "gerrit.automotivelinux.org/gerrit/src/xds/xds-common.git"
	"gerrit.automotivelinux.org/gerrit/src/xds/xds-server.git/lib/xsapiv1"
	"github.com/stretchr/testify/require"
)

func launchSSHd(sshDir string, proc **os.Process, sshdCmd string) (*os.File, string) {
	port := "22222"
	argsProcessSSHd := []string{
		sshdCmd,
		"-f",
		sshDir + "/sshd_config",
		"-D",
		"-h",
		sshDir + "/ssh_host_rsa_key",
		"-o",
		"AuthorizedKeysFile=" + sshDir + "/authorized_keys",
		"-p",
		port,
	}
	logFile := logDir + logFileSSHd
	file, err := os.OpenFile(logFile, os.O_CREATE|os.O_WRONLY, 0644)
	if err != nil {
		log.Fatal(err)
	}
	defer file.Close()
	tmpProc, err := os.StartProcess(argsProcessSSHd[0], argsProcessSSHd, &os.ProcAttr{
		Files: []*os.File{os.Stdin, file, file},
	})
	if err != nil {
		log.Fatal(err)
	}
	*proc = tmpProc
	return file, port
}

func InitSSH(t *testing.T, procSSHd **os.Process) (string, string) {
	Debug(t, "Initialise ssh with local user")
	sshDir := path.Join(os.Getenv(envRootCfgDir), "ssh")
	cmd := exec.Command("cp", "-r", sshFixturesDir, sshDir)
	var out bytes.Buffer
	cmd.Stdout = &out
	require.Nil(t, cmd.Run())

	cmd = exec.Command("ls", sshDir)
	cmd.Stdout = &out
	require.Nil(t, cmd.Run())

	files := strings.Split(fmt.Sprint(cmd.Stdout), "\n")

	for _, f := range files {
		if f != "" {
			file := sshDir + "/" + f
			cmd = exec.Command("chmod", "600", file)
			cmd.Stdout = &out
			require.Nil(t, cmd.Run())
		}
	}

	var outSSHd bytes.Buffer
	var sshdCmd string
	cmd = exec.Command("which", "sshd")
	cmd.Stdout = &outSSHd
	if cmd.Run() != nil {
		if common.Exists("/usr/sbin/sshd") {
			sshdCmd = "/usr/sbin/sshd"
		} else if common.Exists("/usr/bin/sshd") {
			sshdCmd = "/usr/sbin/sshd"
		} else {
			require.FailNow(t, "Cannot find sshd command, please install it or set in your PATH")
		}
	} else {
		sshdCmd = strings.TrimSpace(fmt.Sprint(cmd.Stdout))
	}

	var port string
	_, port = launchSSHd(sshDir, procSSHd, sshdCmd)
	go func(p *os.Process) {
		Debug(t, "sshd is launching")
		if status, err := p.Wait(); err != nil {
			log.Fatalf("status=%v\n err=%v\n", status, err)
		}
	}(*procSSHd)
	return sshDir, port
}

/*wait for terminal prompt*/
func waitForPrompt(t *testing.T, channel chan xsapiv1.TerminalOutMsg, prompt string) string {
	step := 1 * time.Millisecond
	timeout := 10 * time.Second
	current := 0 * time.Second
	out := ""
	re := regexp.MustCompile("^" + prompt)

	for {
		select {
		case outMsg := <-channel:
			out += string(outMsg.Stdout)
			if string(outMsg.Stderr) != "" {
				out += string(outMsg.Stderr)
			}
			for _, line := range strings.Split(out, "\n") {
				if re.MatchString(line) {
					return line
				}
			}
		case <-time.After(step):
			current = current + step
			if current >= timeout {
				require.FailNow(t, "Never received prompt message from terminal (output:"+out+")")
			}
		}
	}
}

func ConnectTargetEvents(t *testing.T, channel chan xsapiv1.TargetConfig) {
	sCli.Conn.On(xsapiv1.EVTTargetAdd, func(e xsapiv1.EventMsg) {
		target, _ := e.DecodeTargetEvent()
		channel <- target
	})

	args := xsapiv1.EventRegisterArgs{Name: xsapiv1.EVTTargetAdd}
	require.Nil(t, HTTPCli.Post("/events/register", args, nil))

	sCli.Conn.On(xsapiv1.EVTTargetRemove, func(e xsapiv1.EventMsg) {
		target, _ := e.DecodeTargetEvent()
		channel <- target
	})

	args = xsapiv1.EventRegisterArgs{Name: xsapiv1.EVTTargetRemove}
	require.Nil(t, HTTPCli.Post("/events/register", args, nil))
}

func DisconnectTargetEvents(t *testing.T) {
	args := xsapiv1.EventRegisterArgs{Name: xsapiv1.EVTTargetAdd}
	require.Nil(t, HTTPCli.Post("/events/unregister", args, nil))
	args = xsapiv1.EventRegisterArgs{Name: xsapiv1.EVTTargetRemove}
	require.Nil(t, HTTPCli.Post("/events/unregister", args, nil))
}

func ConnectTermEvents(t *testing.T, channel chan xsapiv1.TerminalConfig) {
	sCli.Conn.On(xsapiv1.EVTTargetTerminalAdd, func(e xsapiv1.EventMsg) {
		termEvt, _ := e.DecodeTerminalEvent()
		channel <- termEvt
	})

	args := xsapiv1.EventRegisterArgs{Name: xsapiv1.EVTTargetTerminalAdd}
	require.Nil(t, HTTPCli.Post("/events/register", args, nil))

	sCli.Conn.On(xsapiv1.EVTTargetTerminalStateChange, func(e xsapiv1.EventMsg) {
		termEvt, _ := e.DecodeTerminalEvent()
		channel <- termEvt
	})

	args = xsapiv1.EventRegisterArgs{Name: xsapiv1.EVTTargetTerminalStateChange}
	require.Nil(t, HTTPCli.Post("/events/register", args, nil))

	sCli.Conn.On(xsapiv1.EVTTargetTerminalRemove, func(e xsapiv1.EventMsg) {
		termEvt, _ := e.DecodeTerminalEvent()
		channel <- termEvt
	})

	args = xsapiv1.EventRegisterArgs{Name: xsapiv1.EVTTargetTerminalRemove}
	require.Nil(t, HTTPCli.Post("/events/register", args, nil))
}

func DisconnectTermEvents(t *testing.T) {
	args := xsapiv1.EventRegisterArgs{Name: xsapiv1.EVTTargetTerminalAdd}
	require.Nil(t, HTTPCli.Post("/events/unregister", args, nil))
	args = xsapiv1.EventRegisterArgs{Name: xsapiv1.EVTTargetTerminalStateChange}
	require.Nil(t, HTTPCli.Post("/events/unregister", args, nil))
	args = xsapiv1.EventRegisterArgs{Name: xsapiv1.EVTTargetTerminalRemove}
	require.Nil(t, HTTPCli.Post("/events/unregister", args, nil))
}

func AddTargets(t *testing.T, nbTargets int, chTarget chan xsapiv1.TargetConfig) []string {
	listID := make([]string, nbTargets)
	for i := 0; i < nbTargets; i++ {
		/*target is local*/
		target := xsapiv1.TargetConfig{
			Name: "fakeTarget" + strconv.Itoa(i),
			Type: xsapiv1.TypeTgtStandard,
			IP:   "127.0.0.1",
		}
		/*add target*/
		require.Nil(t, HTTPCli.Post("/targets", target, &target))
		Debugf(t, "add target %v", target.Name)
		targetEvt := <-chTarget //waiting for event targetAdd
		require.Equal(t, target.ID, targetEvt.ID)
		listID[i] = target.ID
	}
	for i := 0; i < nbTargets; i++ {
		var target xsapiv1.TargetConfig
		require.Nil(t, HTTPCli.Get("/targets/"+listID[i], &target))
		require.Equal(t, target.Status, "Enable")
	}
	return listID
}

func AddTerms(t *testing.T, nbTerms int, listID []string, chTermEvt chan xsapiv1.TerminalConfig, sshDir string, port string) {
	for j := 0; j < len(listID); j++ {
		listTermsID := make([]string, nbTerms)
		for i := 0; i < nbTerms; i++ {
			term := xsapiv1.TerminalConfig{
				Name: "terminal" + strconv.Itoa(i),
				Type: xsapiv1.TypeTermSSH,
				Options: []string{
					"-p",
					port,
					"-i",
					sshDir + "/ssh",
					"-o",
					"StrictHostKeyChecking=no",
				},
			}
			/*add terminal on target*/
			require.Nil(t, HTTPCli.Post("/targets/"+listID[j]+"/terminals", term, &term))
			Debugf(t, "add terminal %v", term.Name)
			termEvt := <-chTermEvt //waiting for event terminalAdd*/
			require.Equal(t, term.ID, termEvt.ID)
			listTermsID[i] = term.ID
		}
		require.Equal(t, len(listTermsID), nbTerms)
		for i := 0; i < nbTerms; i++ {
			var term xsapiv1.TerminalConfig
			require.Nil(t, HTTPCli.Get("/targets/"+listID[j]+"/terminals/"+listTermsID[i], &term))
			require.Equal(t, term.Status, "Close")
		}
	}
}

func PostTerms(t *testing.T, post string, chTermEvt chan xsapiv1.TerminalConfig, chTerm chan xsapiv1.TerminalOutMsg,
	prompt string) {
	var status string
	switch post {
	case "open":
		status = "Open"
	case "close":
		status = "Closing"
	}
	var targets []xsapiv1.TargetConfig
	require.Nil(t, HTTPCli.Get("/targets", &targets))
	for i := 0; i < len(targets); i++ {
		var terms []xsapiv1.TerminalConfig
		require.Nil(t, HTTPCli.Get("/targets/"+targets[i].ID+"/terminals", &terms))
		listTermsID := make([]string, len(terms))
		for j := 0; j < len(terms); j++ {
			var term xsapiv1.TerminalConfig
			/*post action on term*/
			require.Nil(t, HTTPCli.Post("/targets/"+targets[i].ID+"/terminals/"+terms[j].ID+"/"+post, terms[j], &term))
			Debugf(t, "%v terminal %v", post, term.Name)
			termEvt := <-chTermEvt //waiting for event terminalStateChange
			if post == "open" {
				data := []byte("PS1=" + prompt + " bash -norc\n")
				require.Nil(t, sCli.Conn.Emit(xsapiv1.TerminalInEvent, data))
				waitForPrompt(t, chTerm, prompt)
			}
			require.Equal(t, term.ID, termEvt.ID)
			require.Equal(t, term.Status, status)
			require.Equal(t, termEvt.Status, status)
			listTermsID[i] = term.ID
		}
		time.Sleep(10 * time.Millisecond)
		for j := 0; j < len(listTermsID); j++ {
			var term xsapiv1.TerminalConfig
			require.Nil(t, HTTPCli.Get("/targets/"+targets[i].ID+"/terminals/"+listTermsID[i], &term))
			require.True(t, strings.EqualFold(term.Status, post))
			Debugf(t, "check that term status %v is %v", term.Name, post)
		}
	}
}

func RemoveTermsTargets(t *testing.T, chTarget chan xsapiv1.TargetConfig, chTermEvt chan xsapiv1.TerminalConfig) {
	var targets []xsapiv1.TargetConfig
	require.Nil(t, HTTPCli.Get("/targets", &targets))
	for i := 0; i < len(targets); i++ {
		var terms []xsapiv1.TerminalConfig
		require.Nil(t, HTTPCli.Get("/targets/"+targets[i].ID+"/terminals", &terms))
		for j := 0; j < len(terms); j++ {
			var term xsapiv1.TerminalConfig
			require.Nil(t, HTTPCli.Delete("/targets/"+targets[i].ID+"/terminals/"+terms[j].ID, &term))
			termEvt := <-chTermEvt
			require.Equal(t, term.ID, termEvt.ID)
			require.NotNil(t, HTTPCli.Delete("/targets/"+targets[i].ID+"/terminals/"+terms[j].ID, &term))
			Debugf(t, "remove terminal %v", term.Name)
		}
		var tgtRes xsapiv1.TargetConfig
		require.Nil(t, HTTPCli.Delete("/targets/"+targets[i].ID, &tgtRes))
		targetEvt := <-chTarget //waiting for remove terminal event
		require.Equal(t, tgtRes.ID, targetEvt.ID)
		require.Equal(t, targets[i].ID, tgtRes.ID)
	}
}
func TestTarget(t *testing.T) {
	prompt := "--PROMPT--"
	var procSSHd *os.Process
	sshDir, port := InitSSH(t, &procSSHd)
	defer procSSHd.Kill()

	nbTargets := 2
	nbTermsByTarget := 2
	/*channel for target events*/
	chTarget := make(chan xsapiv1.TargetConfig)
	defer close(chTarget)
	ConnectTargetEvents(t, chTarget)

	/*channel for terminal events*/
	chTermEvt := make(chan xsapiv1.TerminalConfig)
	defer close(chTermEvt)
	ConnectTermEvents(t, chTermEvt)

	/*check that targetArray is empty at startup*/
	var targetArray []xsapiv1.TargetConfig
	require.Nil(t, HTTPCli.Get("/targets", &targetArray))
	require.Equal(t, len(targetArray), 0)

	listID := AddTargets(t, nbTargets, chTarget)
	AddTerms(t, nbTermsByTarget, listID, chTermEvt, sshDir, port)

	/*channel for TerminalOutMsg*/
	chTerm := make(chan xsapiv1.TerminalOutMsg)
	defer close(chTerm)

	/*connect on terminalOutMsg event*/
	sCli.Conn.On(xsapiv1.TerminalOutEvent, func(ev xsapiv1.TerminalOutMsg) {
		chTerm <- ev
	})

	/*open terminals*/
	PostTerms(t, "open", chTermEvt, chTerm, prompt)

	/*create toto file through terminals*/
	rootCfgDir := os.Getenv(envRootCfgDir)
	totoFile := path.Join(rootCfgDir, "toto")

	/*test with 2 terminals*/
	for i := 0; i < 2; i++ {
		totoFileCurrent := totoFile + strconv.Itoa(i)
		/*send cmd though term*/
		data := []byte("echo helloWorld" + strconv.Itoa(i) + " >> " + totoFileCurrent + "\n")
		Debugf(t, "send following command through terminal: %v", string(data))
		require.Nil(t, sCli.Conn.Emit(xsapiv1.TerminalInEvent, data))
		waitForPrompt(t, chTerm, prompt) //waiting for terminal prompt

		/*check that toto file is created*/
		_, err := os.Stat(totoFileCurrent)
		require.Nil(t, err)

		/*send cmd though term*/
		data = []byte("cat " + totoFileCurrent + "\n")
		Debugf(t, "send following command through terminal: %v", string(data))
		require.Nil(t, sCli.Conn.Emit(xsapiv1.TerminalInEvent, data))

		<-chTerm                         //cmd sent
		termOut := <-chTerm              //result of cat cmd
		waitForPrompt(t, chTerm, prompt) //wait for terminal prompt
		/*check that terminal msg is what was written before*/
		require.Equal(t, string(termOut.Stdout), "helloWorld"+strconv.Itoa(i)+"\r\n")
		Debugf(t, "check terminal output msg: %v", string(termOut.Stdout))
	}

	PostTerms(t, "close", chTermEvt, nil, prompt)

	/*remove targets and terms*/
	RemoveTermsTargets(t, chTarget, chTermEvt)
	DisconnectTargetEvents(t)
	DisconnectTermEvents(t)
}

func TestTargetErrors(t *testing.T) {
	/*cannot create empty target*/
	target := xsapiv1.TargetConfig{}
	var targetRes xsapiv1.TargetConfig
	require.NotNil(t, HTTPCli.Post("/targets", target, &targetRes))
	Debugf(t, "error while creating empty target")
	/*check cannot create target with no IP*/
	target.Type = xsapiv1.TypeTgtStandard
	require.NotNil(t, HTTPCli.Post("/targets", target, &targetRes))
	Debugf(t, "error while creating target without IP")
	target.IP = "127.0.0.1"
	require.Nil(t, HTTPCli.Post("/targets", target, &targetRes))
	Debugf(t, "create target %v", targetRes.Name)

	/*cannot create empty terminal*/
	term := xsapiv1.TerminalConfig{}
	var termRes xsapiv1.TerminalConfig
	require.NotNil(t, HTTPCli.Post("/targets/"+targetRes.ID+"/terminals", term, &termRes))
	Debugf(t, "error while creating empty terminal")
	term.Type = xsapiv1.TypeTermSSH
	require.NotNil(t, HTTPCli.Post("/targets/"+"1010"+"/terminals", term, &termRes))
	Debugf(t, "error while creating terminal on an non existing target")
	require.Nil(t, HTTPCli.Post("/targets/"+targetRes.ID+"/terminals", term, &termRes))
	require.Nil(t, HTTPCli.Post("/targets/"+targetRes.ID+"/terminals", term, &termRes))
	require.Nil(t, HTTPCli.Post("/targets/"+targetRes.ID+"/terminals", term, &termRes))
	require.Nil(t, HTTPCli.Post("/targets/"+targetRes.ID+"/terminals", term, &termRes))
	Debugf(t, "create several terminals")

	/*remove targets and terms*/
	var targetArray []xsapiv1.TargetConfig
	require.Nil(t, HTTPCli.Get("/targets", &targetArray))
	for i := 0; i < len(targetArray); i++ {
		var termArray []xsapiv1.TerminalConfig
		require.Nil(t, HTTPCli.Get("/targets/"+targetArray[i].ID+"/terminals", &termArray))
		for j := 0; j < len(termArray); j++ {
			require.Nil(t, HTTPCli.Delete("/targets/"+targetArray[i].ID+"/terminals/"+termArray[j].ID, &termRes))
			Debugf(t, "delete terminal %v", termRes.Name)
			require.NotNil(t, HTTPCli.Delete("/targets/"+targetArray[i].ID+"/terminals/"+termArray[j].ID, &termRes))
			Debugf(t, "error while deleting an already deleted terminal %v", termRes.Name)
		}
		var tgtRes xsapiv1.TargetConfig
		require.Nil(t, HTTPCli.Delete("/targets/"+targetArray[i].ID, &tgtRes))
		Debugf(t, "delete target %v", tgtRes.Name)
		require.Equal(t, targetArray[i].ID, tgtRes.ID)
		require.NotNil(t, HTTPCli.Delete("/targets/"+targetArray[i].ID, &tgtRes))
		Debugf(t, "error while deleting an already deleted target %v", tgtRes.Name)
	}
}