package e2e

import (
	"bytes"
	"flag"
	"fmt"
	"io/ioutil"
	"os"
	"os/exec"
	"strings"
	"testing"

	"github.com/hashicorp/nomad/testutil"
	"github.com/stretchr/testify/assert"
)

var integration = flag.Bool("integration", false, "run integration tests")

const sleepJobOne = `job "sleep" {
	type = "batch"
	datacenters = ["dc1"]
	constraint {
		attribute = "${meta.secondary}"
		value     = 1
	}
	group "group1" {
		restart {
			mode = "fail"
		}
		count = 1
		ephemeral_disk {
			migrate = true
			sticky = true
		}
		task "sleep" {
			template {
				data = "hello world"
				destination = "/local/hello-world"
			}
			driver = "exec"
			config {
				command = "/bin/sleep"
				args = [ "infinity" ]
			}
		}
	}
}`

const sleepJobTwo = `job "sleep" {
	type = "batch"
	datacenters = ["dc1"]
	constraint {
		attribute = "${meta.secondary}"
		value     = 0
	}
	group "group1" {
		restart {
			mode     = "fail"
		}
		count = 1
		ephemeral_disk {
			migrate = true
			sticky = true
		}
		task "sleep" {
			driver = "exec"

			config {
				command = "test"
				args = [ "-f", "/local/hello-world" ]
			}
		}
	}
}`

// isSuccess waits until a given keyword is not present in the output of a
// command. For example, isSuccess will poll for a given timeperiod as long as
// the output of the command of "nomad node-status" includes the keyword
// "initializing." The absence of this keyword means this command has returned
// successfully.
func isSuccess(execCmd *exec.Cmd, retries int, keyword string) (string, error) {
	var successOut string
	var err error

	testutil.WaitForResultRetries(2000, func() (bool, error) {
		var out bytes.Buffer
		cmd := *execCmd
		cmd.Stdout = &out
		err := cmd.Run()

		if err != nil {
			return false, err
		}

		success := (out.String() != "" && !strings.Contains(out.String(), keyword))
		if !success {
			out.Reset()
			return false, err
		}

		successOut = out.String()
		return true, nil
	}, func(cmd_err error) {
		err = cmd_err
	})

	return successOut, err
}

// allNodesAreReady attempts to query the status of a cluster a specific number
// of times
func allNodesAreReady(retries int, flags string) (string, error) {
	var cmd *exec.Cmd
	if flags != "" {
		cmd = exec.Command("nomad", "node-status", flags)
	} else {
		cmd = exec.Command("nomad", "node-status")
	}

	return isSuccess(cmd, retries, "initializing")
}

// jobIsReady attempts sto query the status of a specific job a fixed number of
// times
func jobIsReady(retries int, flags, jobName string) (string, error) {
	var cmd *exec.Cmd
	if flags != "" {
		cmd = exec.Command("nomad", "job", "status", flags, jobName)
	} else {
		cmd = exec.Command("nomad", "job", "status", jobName)
	}
	return isSuccess(cmd, retries, "pending")
}

// startCluster will create a running cluster, given a list of agent config
// files. In order to have a complete cluster, at least one server and one
// client config file should be included.
func startCluster(clusterConfig []string) (func(), error) {
	cmds := make([]*exec.Cmd, 0)

	for _, agentConfig := range clusterConfig {
		cmd := exec.Command("nomad", "agent", "-config", agentConfig)
		err := cmd.Start()

		if err != nil {
			return func() {}, err
		}

		cmds = append(cmds, cmd)
	}

	f := func() {
		for _, cmd := range cmds {
			cmd.Process.Kill()
		}
	}

	return f, nil
}

func bootstrapACL() (string, error) {
	var bootstrapOut bytes.Buffer

	bootstrapCmd := exec.Command("nomad", "acl", "bootstrap")
	bootstrapCmd.Stdout = &bootstrapOut

	if err := bootstrapCmd.Run(); err != nil {
		return "", err
	}

	parts := strings.Split(bootstrapOut.String(), "\n")
	if len(parts) < 2 {
		return "", fmt.Errorf("unexpected bootstrap output")
	}

	secretIDLine := strings.Split(parts[1], " ")
	if secretIDLine[0] != "Secret" {
		return "", fmt.Errorf("unable to find secret id in bootstrap output")
	}
	return secretIDLine[len(secretIDLine)-1], nil
}

func startACLServer(serverConfig string) (func(), string, error) {
	cmd := exec.Command("nomad", "agent", "-config", serverConfig)
	if err := cmd.Start(); err != nil {
		return func() {}, "", err
	}

	f := func() {
		cmd.Process.Kill()
	}

	var secretID string
	var err error
	testutil.WaitForResultRetries(2000, func() (bool, error) {

		secretIDOutput, err := bootstrapACL()
		if err != nil {
			return false, err
		}

		secretID = secretIDOutput
		return true, nil
	}, func(cmd_err error) {
		err = cmd_err
	})

	if err != nil {
		return func() {}, "", err
	}

	return f, secretID, nil
}

func TestJobMigrations(t *testing.T) {
	flag.Parse()
	if !*integration {
		t.Skip("skipping test in non-integration mode.")
	}

	t.Parallel()
	assert := assert.New(t)

	clusterConfig := []string{"server.hcl", "client1.hcl", "client2.hcl"}
	stopCluster, err := startCluster(clusterConfig)
	assert.Nil(err)
	defer stopCluster()

	_, err = allNodesAreReady(10, "")
	assert.Nil(err)

	fh, err := ioutil.TempFile("", "nomad-sleep-1")
	assert.Nil(err)

	defer os.Remove(fh.Name())
	_, err = fh.WriteString(sleepJobOne)

	assert.Nil(err)

	jobCmd := exec.Command("nomad", "run", fh.Name())
	err = jobCmd.Run()
	assert.Nil(err)

	firstJobOutput, err := jobIsReady(20, "", "sleep")
	assert.Nil(err)
	assert.NotContains(firstJobOutput, "failed")
	assert.NotContains(firstJobOutput, "pending")

	fh2, err := ioutil.TempFile("", "nomad-sleep-2")
	assert.Nil(err)

	defer os.Remove(fh2.Name())
	_, err = fh2.WriteString(sleepJobTwo)
	assert.Nil(err)

	secondJobCmd := exec.Command("nomad", "run", fh2.Name())
	err = secondJobCmd.Run()
	assert.Nil(err)

	jobOutput, err := jobIsReady(20, "", "sleep")
	assert.Nil(err)
	assert.NotContains(jobOutput, "failed")
	assert.Contains(jobOutput, "complete")
}

func TestMigrations_WithACLs(t *testing.T) {
	flag.Parse()
	if !*integration {
		t.Skip("skipping test in non-integration mode.")
	}

	t.Parallel()
	assert := assert.New(t)

	stopServer, secretID, err := startACLServer("server_acl.hcl")
	assert.Nil(err)
	defer stopServer()

	clusterConfig := []string{"client1.hcl", "client2.hcl"}
	stopCluster, err := startCluster(clusterConfig)
	assert.Nil(err)
	defer stopCluster()

	_, err = allNodesAreReady(10, "-token="+secretID)
	assert.Nil(err)

	fh, err := ioutil.TempFile("", "nomad-sleep-1")
	assert.Nil(err)

	defer os.Remove(fh.Name())
	_, err = fh.WriteString(sleepJobOne)

	assert.Nil(err)

	jobCmd := exec.Command("nomad", "run", "-token="+secretID, fh.Name())
	err = jobCmd.Run()
	assert.Nil(err)

	_, err = jobIsReady(20, "-token="+secretID, "sleep")
	assert.Nil(err)

	fh2, err := ioutil.TempFile("", "nomad-sleep-2")
	assert.Nil(err)

	defer os.Remove(fh2.Name())
	_, err = fh2.WriteString(sleepJobTwo)

	assert.Nil(err)

	secondJobCmd := exec.Command("nomad", "run", "-token="+secretID, fh2.Name())
	err = secondJobCmd.Run()
	assert.Nil(err)

	jobOutput, err := jobIsReady(20, "-token="+secretID, "sleep")
	assert.Nil(err)

	assert.NotContains(jobOutput, "failed")
	assert.NotContains(jobOutput, "pending")
	assert.Contains(jobOutput, "complete")
}