/*
© Copyright IBM Corporation 2017, 2018

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 (
	"archive/tar"
	"bufio"
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"io/ioutil"
	"log"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"testing"
	"time"

	"github.com/docker/docker/api/types"
	"github.com/docker/docker/api/types/container"
	"github.com/docker/docker/api/types/network"
	"github.com/docker/docker/api/types/volume"
	"github.com/docker/docker/client"
	"github.com/docker/docker/pkg/jsonmessage"
	"github.com/docker/docker/pkg/stdcopy"
)

func imageName() string {
	image, ok := os.LookupEnv("TEST_IMAGE")
	if !ok {
		image = "mq-devserver:latest-x86-64"
	}
	return image
}

func coverage() bool {
	cover := os.Getenv("TEST_COVER")
	if cover == "true" || cover == "1" {
		return true
	}
	return false
}

// coverageDir returns the host directory to use for code coverage data
func coverageDir(t *testing.T) string {
	dir, err := os.Getwd()
	if err != nil {
		t.Fatal(err)
	}
	return filepath.Join(dir, "coverage")
}

// coverageBind returns a string to use to add a bind-mounted directory for code coverage data
func coverageBind(t *testing.T) string {
	return coverageDir(t) + ":/var/coverage"
}

// terminationLog returns the name of the file to use for the termination log message
func terminationLog(t *testing.T) string {
	// Warning: this directory must be accessible to the Docker daemon,
	// in order to enable the bind mount
	return "/tmp/" + t.Name() + "-termination-log"
}

// terminationBind returns a string to use to bind-mount a termination log file.
// This is done using a bind, because you can't copy files from /dev out of the container.
func terminationBind(t *testing.T) string {
	n := terminationLog(t)
	// Remove it if it already exists
	os.Remove(n)
	// Create the empty file
	f, err := os.OpenFile(n, os.O_WRONLY|os.O_CREATE, 0600)
	if err != nil {
		t.Fatal(err)
	}
	f.Close()
	return n + ":/dev/termination-log"
}

// Returns the termination message, or an empty string if not set
func terminationMessage(t *testing.T) string {
	b, err := ioutil.ReadFile(terminationLog(t))
	if err != nil {
		t.Log(err)
	}
	return string(b)
}

func cleanContainer(t *testing.T, cli *client.Client, ID string) {
	i, err := cli.ContainerInspect(context.Background(), ID)
	if err == nil {
		// Log the results and continue
		t.Logf("Inspected container %v: %#v", ID, i)
		s, err := json.MarshalIndent(i, "", "    ")
		if err != nil {
			t.Fatal(err)
		}
		t.Logf("Inspected container %v: %v", ID, string(s))
	}
	t.Logf("Stopping container: %v", ID)
	timeout := 10 * time.Second
	// Stop the container.  This allows the coverage output to be generated.
	err = cli.ContainerStop(context.Background(), ID, &timeout)
	if err != nil {
		// Just log the error and continue
		t.Log(err)
	}
	t.Log("Container stopped")

	// If a code coverage file has been generated, then rename it to match the test name
	os.Rename(filepath.Join(coverageDir(t), "container.cov"), filepath.Join(coverageDir(t), t.Name()+".cov"))
	// Log the container output for any container we're about to delete
	t.Logf("Console log from container %v:\n%v", ID, inspectTextLogs(t, cli, ID))

	m := terminationMessage(t)
	if m != "" {
		t.Logf("Termination message: %v", m)
	}
	os.Remove(terminationLog(t))

	t.Logf("Removing container: %s", ID)
	opts := types.ContainerRemoveOptions{
		RemoveVolumes: true,
		Force:         true,
	}
	err = cli.ContainerRemove(context.Background(), ID, opts)
	if err != nil {
		t.Error(err)
	}
}

// runContainer creates and starts a container.  If no image is specified in
// the container config, then the image name is retrieved from the TEST_IMAGE
// environment variable.
func runContainer(t *testing.T, cli *client.Client, containerConfig *container.Config) string {
	if containerConfig.Image == "" {
		containerConfig.Image = imageName()
	}
	// if coverage
	containerConfig.Env = append(containerConfig.Env, "COVERAGE_FILE="+t.Name()+".cov")
	hostConfig := container.HostConfig{
		Binds: []string{
			coverageBind(t),
			terminationBind(t),
		},
	}
	networkingConfig := network.NetworkingConfig{}
	t.Logf("Running container (%s)", containerConfig.Image)
	ctr, err := cli.ContainerCreate(context.Background(), containerConfig, &hostConfig, &networkingConfig, t.Name())
	if err != nil {
		t.Fatal(err)
	}
	startContainer(t, cli, ctr.ID)
	return ctr.ID
}

func runContainerOneShot(t *testing.T, cli *client.Client, command ...string) (int64, string) {
	containerConfig := container.Config{
		Entrypoint: command,
	}
	id := runContainer(t, cli, &containerConfig)
	defer cleanContainer(t, cli, id)
	return waitForContainer(t, cli, id, 10), inspectLogs(t, cli, id)
}

func startContainer(t *testing.T, cli *client.Client, ID string) {
	t.Logf("Starting container: %v", ID)
	startOptions := types.ContainerStartOptions{}
	err := cli.ContainerStart(context.Background(), ID, startOptions)
	if err != nil {
		t.Fatal(err)
	}
}

func stopContainer(t *testing.T, cli *client.Client, ID string) {
	t.Logf("Stopping container: %v", ID)
	timeout := 10 * time.Second
	err := cli.ContainerStop(context.Background(), ID, &timeout) //Duration(20)*time.Second)
	if err != nil {
		t.Fatal(err)
	}
}

func getCoverageExitCode(t *testing.T, orig int64) int64 {
	f := filepath.Join(coverageDir(t), "exitCode")
	_, err := os.Stat(f)
	if err != nil {
		t.Log(err)
		return orig
	}
	// Remove the file, ready for the next test
	defer os.Remove(f)
	buf, err := ioutil.ReadFile(f)
	if err != nil {
		t.Log(err)
		return orig
	}
	rc, err := strconv.Atoi(string(buf))
	if err != nil {
		t.Log(err)
		return orig
	}
	t.Logf("Retrieved exit code %v from file", rc)
	return int64(rc)
}

// waitForContainer waits until a container has exited
func waitForContainer(t *testing.T, cli *client.Client, ID string, timeout int64) int64 {
	rc, err := cli.ContainerWait(context.Background(), ID)

	if coverage() {
		// COVERAGE: When running coverage, the exit code is written to a file,
		// to allow the coverage to be generated (which doesn't happen for non-zero
		// exit codes)
		rc = getCoverageExitCode(t, rc)
	}

	if err != nil {
		t.Fatal(err)
	}
	return rc
}

// execContainerWithExitCode runs a command in a running container, and returns the exit code
// Note: due to a bug in Docker/Moby code, you always get an exit code of 0 if you attach to the
// container to get output.  This is why these are two separate commands.
func execContainerWithExitCode(t *testing.T, cli *client.Client, ID string, user string, cmd []string) int {
	config := types.ExecConfig{
		User:        user,
		Privileged:  false,
		Tty:         false,
		AttachStdin: false,
		// Note that you still need to attach stdout/stderr, even though they're not wanted
		AttachStdout: true,
		AttachStderr: true,
		Detach:       false,
		Cmd:          cmd,
	}
	resp, err := cli.ContainerExecCreate(context.Background(), ID, config)
	if err != nil {
		t.Fatal(err)
	}
	cli.ContainerExecStart(context.Background(), resp.ID, types.ExecStartCheck{
		Detach: false,
		Tty:    false,
	})
	if err != nil {
		t.Fatal(err)
	}
	inspect, err := cli.ContainerExecInspect(context.Background(), resp.ID)
	if err != nil {
		t.Fatal(err)
	}
	return inspect.ExitCode
}

// execContainerWithOutput runs a command in a running container, and returns the output from stdout/stderr
// Note: due to a bug in Docker/Moby code, you always get an exit code of 0 if you attach to the
// container to get output.  This is why these are two separate commands.
func execContainerWithOutput(t *testing.T, cli *client.Client, ID string, user string, cmd []string) string {
	config := types.ExecConfig{
		User:         user,
		Privileged:   false,
		Tty:          false,
		AttachStdin:  false,
		AttachStdout: true,
		AttachStderr: true,
		Detach:       false,
		Cmd:          cmd,
	}
	resp, err := cli.ContainerExecCreate(context.Background(), ID, config)
	if err != nil {
		t.Fatal(err)
	}
	hijack, err := cli.ContainerExecAttach(context.Background(), resp.ID, config)
	if err != nil {
		t.Fatal(err)
	}
	cli.ContainerExecStart(context.Background(), resp.ID, types.ExecStartCheck{
		Detach: false,
		Tty:    false,
	})
	if err != nil {
		t.Fatal(err)
	}
	buf := new(bytes.Buffer)
	// Each output line has a header, which needs to be removed
	_, err = stdcopy.StdCopy(buf, buf, hijack.Reader)
	if err != nil {
		log.Fatal(err)
	}
	return strings.TrimSpace(buf.String())
}

func waitForReady(t *testing.T, cli *client.Client, ID string) {
	for {
		rc := execContainerWithExitCode(t, cli, ID, "mqm", []string{"chkmqready"})
		if rc == 0 {
			t.Log("MQ is ready")
			return
		}
	}
}

func getIPAddress(t *testing.T, cli *client.Client, ID string) string {
	ctr, err := cli.ContainerInspect(context.Background(), ID)
	if err != nil {
		t.Fatal(err)
	}
	return ctr.NetworkSettings.IPAddress
}

func createNetwork(t *testing.T, cli *client.Client) string {
	name := "test"
	t.Logf("Creating network: %v", name)
	opts := types.NetworkCreate{}
	net, err := cli.NetworkCreate(context.Background(), name, opts)
	if err != nil {
		t.Fatal(err)
	}
	t.Logf("Created network %v with ID %v", name, net.ID)
	return net.ID
}

func removeNetwork(t *testing.T, cli *client.Client, ID string) {
	t.Logf("Removing network ID: %v", ID)
	err := cli.NetworkRemove(context.Background(), ID)
	if err != nil {
		t.Fatal(err)
	}
}

func createVolume(t *testing.T, cli *client.Client) types.Volume {
	v, err := cli.VolumeCreate(context.Background(), volume.VolumesCreateBody{
		Driver:     "local",
		DriverOpts: map[string]string{},
		Labels:     map[string]string{},
		Name:       t.Name(),
	})
	if err != nil {
		t.Fatal(err)
	}
	t.Logf("Created volume %v", t.Name())
	return v
}

func removeVolume(t *testing.T, cli *client.Client, name string) {
	t.Logf("Removing volume %v", name)
	err := cli.VolumeRemove(context.Background(), name, true)
	if err != nil {
		t.Fatal(err)
	}
}

func inspectTextLogs(t *testing.T, cli *client.Client, ID string) string {
	jsonLogs := inspectLogs(t, cli, ID)
	scanner := bufio.NewScanner(strings.NewReader(jsonLogs))
	b := make([]byte, 64*1024)
	scanner.Buffer(b, 1024*1024)
	buf := bytes.NewBuffer(b)
	for scanner.Scan() {
		t := scanner.Text()
		if strings.HasPrefix(t, "{") {
			var e map[string]interface{}
			json.Unmarshal([]byte(scanner.Text()), &e)
			fmt.Fprintf(buf, "{\"message\": \"%v\"}\n", e["message"])
		} else {
			fmt.Fprintln(buf, t)
		}
	}
	err := scanner.Err()
	if err != nil {
		t.Fatal(err)
	}
	return buf.String()
}

func inspectLogs(t *testing.T, cli *client.Client, ID string) string {
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()
	reader, err := cli.ContainerLogs(ctx, ID, types.ContainerLogsOptions{
		ShowStdout: true,
		ShowStderr: true,
	})
	if err != nil {
		log.Fatal(err)
	}
	buf := new(bytes.Buffer)
	// Each output line has a header, which needs to be removed
	_, err = stdcopy.StdCopy(buf, buf, reader)
	if err != nil {
		log.Fatal(err)
	}
	return buf.String()
}

// generateTAR creates a TAR-formatted []byte, with the specified files included.
func generateTAR(t *testing.T, files []struct{ Name, Body string }) []byte {
	buf := new(bytes.Buffer)
	tw := tar.NewWriter(buf)
	for _, file := range files {
		hdr := &tar.Header{
			Name: file.Name,
			Mode: 0600,
			Size: int64(len(file.Body)),
		}
		err := tw.WriteHeader(hdr)
		if err != nil {
			t.Fatal(err)
		}
		_, err = tw.Write([]byte(file.Body))
		if err != nil {
			t.Fatal(err)
		}
	}
	err := tw.Close()
	if err != nil {
		t.Fatal(err)
	}
	return buf.Bytes()
}

// createImage creates a new Docker image with the specified files included.
func createImage(t *testing.T, cli *client.Client, files []struct{ Name, Body string }) string {
	r := bytes.NewReader(generateTAR(t, files))
	tag := strings.ToLower(t.Name())
	buildOptions := types.ImageBuildOptions{
		Context: r,
		Tags:    []string{tag},
	}
	resp, err := cli.ImageBuild(context.Background(), r, buildOptions)
	if err != nil {
		t.Fatal(err)
	}
	// resp (ImageBuildResponse) contains a series of JSON messages
	dec := json.NewDecoder(resp.Body)
	for {
		m := jsonmessage.JSONMessage{}
		err := dec.Decode(&m)
		if m.Error != nil {
			t.Fatal(m.ErrorMessage)
		}
		t.Log(strings.TrimSpace(m.Stream))
		if err == io.EOF {
			break
		}
		if err != nil {
			t.Fatal(err)
		}
	}
	return tag
}

// deleteImage deletes a Docker image
func deleteImage(t *testing.T, cli *client.Client, id string) {
	cli.ImageRemove(context.Background(), id, types.ImageRemoveOptions{
		Force: true,
	})
}

func copyFromContainer(t *testing.T, cli *client.Client, id string, file string) []byte {
	reader, _, err := cli.CopyFromContainer(context.Background(), id, file)
	if err != nil {
		t.Fatal(err)
	}
	defer reader.Close()
	b, err := ioutil.ReadAll(reader)
	if err != nil {
		t.Fatal(err)
	}
	return b
}