/*
Copyright 2016 The Kubernetes Authors All rights reserved.

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 e2e_node

import (
	"bytes"
	"flag"
	"fmt"
	"io/ioutil"
	"net/http"
	"os"
	"os/exec"
	"strings"
	"time"

	"github.com/golang/glog"
)

var serverStartTimeout = flag.Duration("server-start-timeout", time.Second*120, "Time to wait for each server to become healthy.")

type e2eService struct {
	etcdCmd              *exec.Cmd
	etcdCombinedOut      bytes.Buffer
	etcdDataDir          string
	apiServerCmd         *exec.Cmd
	apiServerCombinedOut bytes.Buffer
	kubeletCmd           *exec.Cmd
	kubeletCombinedOut   bytes.Buffer
	kubeletStaticPodDir  string
	nodeName             string
}

func newE2eService(nodeName string) *e2eService {
	return &e2eService{nodeName: nodeName}
}

func (es *e2eService) start() error {
	if _, err := getK8sBin("kubelet"); err != nil {
		return err
	}
	if _, err := getK8sBin("kube-apiserver"); err != nil {
		return err
	}

	cmd, err := es.startEtcd()
	if err != nil {
		return err
	}
	es.etcdCmd = cmd

	cmd, err = es.startApiServer()
	if err != nil {
		return err
	}
	es.apiServerCmd = cmd

	cmd, err = es.startKubeletServer()
	if err != nil {
		return err
	}
	es.kubeletCmd = cmd

	return nil
}

func (es *e2eService) stop() {
	if es.kubeletCmd != nil {
		err := es.kubeletCmd.Process.Kill()
		if err != nil {
			glog.Errorf("Failed to stop kubelet.\n%v", err)
		}
	}
	if es.kubeletStaticPodDir != "" {
		err := os.RemoveAll(es.kubeletStaticPodDir)
		if err != nil {
			glog.Errorf("Failed to delete kubelet static pod directory %s.\n%v", es.kubeletStaticPodDir, err)
		}
	}
	if es.apiServerCmd != nil {
		err := es.apiServerCmd.Process.Kill()
		if err != nil {
			glog.Errorf("Failed to stop kube-apiserver.\n%v", err)
		}
	}
	if es.etcdCmd != nil {
		err := es.etcdCmd.Process.Kill()
		if err != nil {
			glog.Errorf("Failed to stop etcd.\n%v", err)
		}
	}
	if es.etcdDataDir != "" {
		err := os.RemoveAll(es.etcdDataDir)
		if err != nil {
			glog.Errorf("Failed to delete etcd data directory %s.\n%v", es.etcdDataDir, err)
		}
	}
}

func (es *e2eService) startEtcd() (*exec.Cmd, error) {
	dataDir, err := ioutil.TempDir("", "node-e2e")
	if err != nil {
		return nil, err
	}
	es.etcdDataDir = dataDir
	cmd := exec.Command("etcd")
	// Execute etcd in the data directory instead of using --data-dir because the flag sometimes requires additional
	// configuration (e.g. --name in version 0.4.9)
	cmd.Dir = es.etcdDataDir
	hcc := newHealthCheckCommand(
		"http://127.0.0.1:4001/v2/keys/", // Trailing slash is required,
		cmd,
		&es.etcdCombinedOut)
	return cmd, es.startServer(hcc)
}

func (es *e2eService) startApiServer() (*exec.Cmd, error) {
	cmd := exec.Command("sudo", getApiServerBin(),
		"--v", "2", "--logtostderr", "--log_dir", "./",
		"--etcd-servers", "http://127.0.0.1:4001",
		"--insecure-bind-address", "0.0.0.0",
		"--service-cluster-ip-range", "10.0.0.1/24",
		"--kubelet-port", "10250",
		"--allow-privileged", "true",
	)
	hcc := newHealthCheckCommand(
		"http://127.0.0.1:8080/healthz",
		cmd,
		&es.apiServerCombinedOut)
	return cmd, es.startServer(hcc)
}

func (es *e2eService) startKubeletServer() (*exec.Cmd, error) {
	dataDir, err := ioutil.TempDir("", "node-e2e-pod")
	if err != nil {
		return nil, err
	}
	es.kubeletStaticPodDir = dataDir
	cmd := exec.Command("sudo", getKubeletServerBin(),
		"--v", "2", "--logtostderr", "--log_dir", "./",
		"--api-servers", "http://127.0.0.1:8080",
		"--address", "0.0.0.0",
		"--port", "10250",
		"--hostname-override", es.nodeName, // Required because hostname is inconsistent across hosts
		"--volume-stats-agg-period", "10s", // Aggregate volumes frequently so tests don't need to wait as long
		"--allow-privileged", "true",
		"--serialize-image-pulls", "false",
		"--config", es.kubeletStaticPodDir,
		"--file-check-frequency", "10s", // Check file frequently so tests won't wait too long
	)
	hcc := newHealthCheckCommand(
		"http://127.0.0.1:10255/healthz",
		cmd,
		&es.kubeletCombinedOut)
	return cmd, es.startServer(hcc)
}

func (es *e2eService) startServer(cmd *healthCheckCommand) error {
	cmdErrorChan := make(chan error)
	go func() {
		err := cmd.Run()
		if err != nil {
			cmdErrorChan <- fmt.Errorf("%s Failed with error \"%v\".  Command output:\n%v", cmd, err, *cmd.OutputBuffer)
		}
		close(cmdErrorChan)
	}()

	endTime := time.Now().Add(*serverStartTimeout)
	for endTime.After(time.Now()) {
		select {
		case err := <-cmdErrorChan:
			return err
		case <-time.After(time.Second):
			resp, err := http.Get(cmd.HealthCheckUrl)
			if err == nil && resp.StatusCode == http.StatusOK {
				return nil
			}
		}
	}
	return fmt.Errorf("Timeout waiting for service %s", cmd)
}

type healthCheckCommand struct {
	*exec.Cmd
	HealthCheckUrl string
	OutputBuffer   *bytes.Buffer
}

func newHealthCheckCommand(healthCheckUrl string, cmd *exec.Cmd, combinedOutput *bytes.Buffer) *healthCheckCommand {
	cmd.Stdout = combinedOutput
	cmd.Stderr = combinedOutput
	return &healthCheckCommand{
		HealthCheckUrl: healthCheckUrl,
		Cmd:            cmd,
		OutputBuffer:   combinedOutput,
	}
}

func (hcc *healthCheckCommand) String() string {
	return fmt.Sprintf("`%s %s` health-check: %s", hcc.Path, strings.Join(hcc.Args, " "), hcc.HealthCheckUrl)
}
