/*
 * 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 (
	"encoding/json"
	"fmt"
	"io"
	"log"
	"os"
	"os/exec"
	"sync"
	"testing"
	"time"

	common "gerrit.automotivelinux.org/gerrit/src/xds/xds-common.git"
	"gerrit.automotivelinux.org/gerrit/src/xds/xds-server.git/lib/xdsconfig"
	"gerrit.automotivelinux.org/gerrit/src/xds/xds-server.git/lib/xsapiv1"
	socketio_client "github.com/sebd71/go-socket.io-client"
)

// IOSockClient
type IOSockClient struct {
	URL       string
	Conn      *socketio_client.Client
	Options   *socketio_client.Options
	EmitMutex *sync.Mutex
	Connected bool
	//ServerDiscoChan chan Disconnection
	EscapeKeys []byte
}

//global client
var HTTPCli *common.HTTPClient
var logDir string
var sCli *IOSockClient
var prefixURL string

// Debug function used to print debug logs
func Debug(t *testing.T, args ...interface{}) {
	if os.Getenv("VERBOSE") != "" {
		t.Log(args...)
	}
}

// Debugf function used to print debug logs
func Debugf(t *testing.T, format string, args ...interface{}) {
	if os.Getenv("VERBOSE") != "" {
		t.Logf(format, args...)
	}
}

// Copy copies from src to dst until either EOF
func Copy(src, dst string) error {
	in, err := os.Open(src)
	if err != nil {
		return err
	}
	defer in.Close()

	out, err := os.Create(dst)
	if err != nil {
		return err
	}
	defer out.Close()

	_, err = io.Copy(out, in)
	if err != nil {
		return err
	}
	return out.Close()
}

// init function will run once before execution of test functions begins.
func init() {
	// Check dependency
	err := checkTestDep()
	if err != nil {
		log.Fatal(err)
	}
}

// isCommandAvailable verify if a command/utility is available
func isCommandAvailable(name string) bool {
	cmd := exec.Command("/bin/sh", "-c", "command -v "+name)
	if err := cmd.Run(); err != nil {
		return false
	}
	return true
}

// checkTestDep checks if all dependency tools are available to be able to run tests
func checkTestDep() error {
	for _, cmd := range dependency_tools {
		if !isCommandAvailable(cmd) {
			return fmt.Errorf(cmd + " is not installed and is mandatory to run tests")
		}
	}
	return nil
}

// initEnv
func initEnv(launchProcess bool) {
	if launchProcess {
		/*kill xds-server if needed*/
		cmd := exec.Command("pkill", "-9", "xds-server")
		if err := cmd.Start(); err != nil {
			log.Fatal(err)
		}
		cmd.Wait()
	}
	/*set environment variable*/
	rootTestLog := "/tmp/xds-server-test"
	if err := os.Setenv(envRootCfgDir, rootTestLog); err != nil {
		log.Fatal(err)
	}
	sdkDir := rootTestLog + "/sdks/"
	if err := os.Setenv(envXdtSdk, sdkDir); err != nil {
		log.Fatal(err)
	}
	if err := os.Setenv(envXdsServerWorkspaceDir, rootTestLog); err != nil {
		log.Fatal(err)
	}
	if err := os.Setenv(envXdsServerRootCfgDir, rootTestLog); err != nil {
		log.Fatal(err)
	}
	if err := os.Setenv("XDS_LOG_SILLY", "1"); err != nil {
		log.Fatal(err)
	}
	/*remove and recreate working directories*/
	os.RemoveAll(rootTestLog)
	os.MkdirAll(rootTestLog, 0755)
	logDir = rootTestLog + "/logs/"
	os.MkdirAll(logDir, 0755)
}

/*prepare xds-server process*/
func launchXdsServer(proc **os.Process) *os.File {
	logFile := logDir + logFileXdsServer
	file, err := os.OpenFile(logFile, os.O_CREATE|os.O_WRONLY, 0644)
	if err != nil {
		log.Fatal(err)
	}
	var argsProcess = []string{"../bin/xds-server",
		"-l", "debug",
		"-c", testConfigFile,
	}

	tmpProc, err := os.StartProcess(argsProcess[0], argsProcess, &os.ProcAttr{
		Files: []*os.File{os.Stdin, file, file},
	})
	if err != nil {
		log.Fatal(err)
	}
	*proc = tmpProc
	return file
}

// getHTTPClient
func getHTTPClient(lvl int, url string) (*common.HTTPClient, *os.File) {
	logFile := logDir + logFileClient
	file, err := os.OpenFile(logFile, os.O_CREATE|os.O_WRONLY, 0644)
	if err != nil {
		log.Fatal(err)
	}
	conf := common.HTTPClientConfig{
		URLPrefix:           "/api/v1",
		HeaderClientKeyName: "Xds-Sid",
		CsrfDisable:         true,
		LogOut:              file,
		LogPrefix:           "XDSSERVERTEST: ",
		LogLevel:            lvl,
	}

	// Try to connect during 30 seconds
	var HTTPcli *common.HTTPClient
	retry := 30
	for retry > 0 {
		if HTTPcli, err = common.HTTPNewClient(url, conf); err == nil {
			break
		}
		if retry < 25 {
			log.Printf("Establishing connection to XDS Server (retry %d/10)", retry)
		}
		time.Sleep(time.Second)
		retry--
	}
	if retry == 0 {
		log.Fatalf("Cannot establish connection with xds-server:\n %v", err)
	}

	log.Printf("HTTP session ID : %v", HTTPcli.GetClientID())

	// Basic check
	var ver xsapiv1.Version
	err = HTTPcli.Get("/version", &ver)
	if err != nil {
		log.Fatal(err)
	}
	return HTTPcli, file
}

func NewIoSocketClient(url, clientID string) (*IOSockClient, error) {
	var err error

	sCli := &IOSockClient{
		URL:       url,
		EmitMutex: &sync.Mutex{},
		Options: &socketio_client.Options{
			Transport: "websocket",
			Header:    make(map[string][]string),
		},
	}
	sCli.Options.Header["XDS-SID"] = []string{clientID}

	sCli.Conn, err = socketio_client.NewClient(url, sCli.Options)
	if err != nil {
		return nil, fmt.Errorf("IO.socket connection error: " + err.Error())
	}

	sCli.Conn.On("connection", func() {
		sCli.Connected = true
	})

	sCli.Conn.On("disconnection", func(err error) {
		if err != nil {
			log.Printf("WS disconnection event with err: %v\n", err)
		}
		sCli.Connected = false
	})

	return sCli, nil
}

// TestMain is the main entry point of testsuite
func TestMain(m *testing.M) {

	/* useful for debugging, preventing from launching xds-server
	 * it can be launch separately */
	launchProcess := true
	log.Printf("TestMain: launchProcess is %v, so launching xds-server", launchProcess)
	initEnv(launchProcess)

	var proc *os.Process
	var fileXdsServer *os.File
	if launchProcess {
		fileXdsServer = launchXdsServer(&proc)
		go func(p *os.Process) {
			log.Print("xds-server is launching")
			if status, err := p.Wait(); err != nil {
				log.Fatalf("status=%v\n err=%v\n", status, err)
			}
			os.Exit(0)
		}(proc)
		defer fileXdsServer.Close()
	}

	// Extract URL from _test-config.json file
	fd, _ := os.Open(testConfigFile)
	defer fd.Close()
	fCfg := xdsconfig.FileConfig{}
	if err := json.NewDecoder(fd).Decode(&fCfg); err != nil {
		log.Fatalf("Cannot decode test config file %v : %v", testConfigFile, err)
	}

	if fCfg.HTTPPort == "" {
		log.Fatalf("Cannot retrieve httpPort in test config file %v", testConfigFile)
	}
	prefixURL := "http://localhost:" + fCfg.HTTPPort

	// Start HTTP client to send test commands
	lvl := common.HTTPLogLevelDebug
	var fileHTTPClient *os.File
	HTTPCli, fileHTTPClient = getHTTPClient(lvl, prefixURL)
	defer fileHTTPClient.Close()
	var err error
	sCli, err = NewIoSocketClient(prefixURL, HTTPCli.GetClientID())
	if err != nil {
		log.Fatal(err)
	}
	if HTTPCli == nil {
		log.Fatal("HTTPCli is nil")
	}

	// Run tests
	res := m.Run()
	defer os.Exit(res)

	// Gracefully stop xds-server process
	if err := proc.Signal(os.Interrupt); err != nil {
		log.Fatalf("xds-server proc interrupt error : %v", err)
	}

	// Should not be executed, normal exit must be above go routine after on p.Wait returns
	time.Sleep(10 * time.Second)
	log.Printf("xds-server not gravefully stop, kill it\n")
	proc.Kill()
}