package client

import (
	"archive/zip"
	"bufio"
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"math"
	"net/http"
	"os"
	"os/exec"
	"path"
	"path/filepath"
	"sort"
	"strings"
	"syscall"
	"time"

	"repositories.action2quare.com/ayo/gocommon/logger"
	"repositories.action2quare.com/ayo/gocommon/metric"
	"repositories.action2quare.com/ayo/houston/shared"
	"repositories.action2quare.com/ayo/houston/shared/protos"
)

func lastExecutionArgs(verpath string) []string {
	argf, err := os.Open(path.Join(verpath, "@args"))
	if os.IsNotExist(err) {
		argf, err = os.Open(path.Clean(path.Join(verpath, "..", "@args")))
		if os.IsNotExist(err) {
			return nil
		}
	}
	defer argf.Close()

	var out []string
	dec := json.NewDecoder(argf)
	dec.Decode(&out)
	return out
}

var errUploadZipLogFailed = errors.New("not ok")

func (hc *houstonClient) uploadZipLogFile(zipFile string, name string, version string) error {
	zf, err := os.Open(zipFile)
	if err != nil {
		return err
	}

	if zf == nil {
		return errUploadZipLogFailed
	}

	defer zf.Close()

	req, err := http.NewRequest("POST", hc.config.HttpAddress+"/upload", zf)
	if err != nil {
		logger.Println(err)
	}
	req.Header.Set("Houston-Service-Name", name)
	req.Header.Set("Houston-Service-Version", version)
	req.Header.Set("Houston-Service-Filename", path.Base(filepath.ToSlash(zipFile)))
	req.Header.Set("Content-Type", "application/zip")
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return errUploadZipLogFailed
	}

	return nil
}

func zipLogFiles(storageRoot string, req *shared.UploadRequest) (string, []string, error) {
	root := path.Join(storageRoot, req.Name, req.Version)
	matches, err := filepath.Glob(path.Join(root, req.Filter))
	if err != nil {
		return "", nil, err
	}

	if len(matches) == 0 {
		return "", nil, nil
	}

	for i, file := range matches {
		file = filepath.ToSlash(file)
		matches[i] = file
	}

	root = path.Join(root, path.Dir(req.Filter))
	zipFileName := path.Join(os.TempDir(), path.Base(filepath.ToSlash(matches[0]))) + ".zip"
	os.Remove(zipFileName)
	f, err := os.OpenFile(zipFileName, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0600)

	if err != nil {
		return "", nil, err
	}
	defer f.Close()

	w := zip.NewWriter(f)
	defer w.Close()

	oldestFile := ""
	for i, file := range matches {
		if file == root {
			continue
		}

		if fi, err := os.Lstat(file); err == nil {
			if (fi.Mode() & os.ModeSymlink) == os.ModeSymlink {
				matches[i] = ""
				continue
			}
		}

		if len(oldestFile) == 0 {
			oldestFile = path.Base(filepath.ToSlash(file))
		}

		relative := file[len(root)+1:]
		fw, err := w.Create(relative)
		if err != nil {
			return "", nil, err
		}

		src, err := os.Open(file)
		if err != nil {
			return "", nil, err
		}
		defer src.Close()

		if _, err = io.Copy(fw, src); err != nil {
			return "", nil, err
		}
	}

	return f.Name(), matches, nil
}

func prepareProcessLaunch(storageRoot string, req *shared.StartProcessRequest) *procmeta {
	if len(req.Args) == 0 {
		return nil
	}
	verpath := path.Join(storageRoot, req.Name, req.Version)
	fi, err := os.Stat(verpath)

	if err == nil && fi.IsDir() {
		exefile := "./" + path.Clean(strings.TrimPrefix(req.Args[0], "/"))
		os.Chmod(path.Join(verpath, exefile), 0777)

		exef, _ := os.Executable()
		expanded := make([]string, len(req.Args))
		for i, arg := range req.Args {
			expanded[i] = os.ExpandEnv(arg)
		}
		exename := path.Join(path.Dir(exef), verpath, exefile)

		logger.Println("exefile :", exefile)
		logger.Println("verpath :", verpath)
		logger.Println("exef :", exef)
		logger.Println("path.Dir :", path.Dir(exef))
		logger.Println("exename :", exename)

		cmd := exec.Command(os.ExpandEnv(exename), expanded[1:]...)

		cmd.Dir = verpath
		stdin, _ := cmd.StdinPipe()

		seq++
		return &procmeta{
			id:      seq,
			cmd:     cmd,
			name:    req.Name,
			args:    req.Args,
			version: req.Version,
			verpath: verpath,
			state:   int32(protos.ProcessState_Stopped),
			stdin:   stdin,
		}
	}
	return nil
}

func makeLogFilePrefix(meta *procmeta, index int) string {
	now := time.Now().UTC()
	ext := path.Ext(meta.args[0])
	nameonly := path.Base(filepath.ToSlash(meta.args[0]))
	if len(ext) > 0 {
		nameonly = nameonly[:len(nameonly)-len(ext)]
	}
	ts := now.Format("2006-01-02T15-04-05")
	if index == 0 {

		return path.Join(meta.verpath, "logs", fmt.Sprintf("%s_%s", nameonly, ts))
	}

	return path.Join(meta.verpath, "logs", fmt.Sprintf("%s_%d_%s", nameonly, index, ts))
}

func (hc *houstonClient) launch(meta *procmeta) error {
	stdout, err := meta.cmd.StdoutPipe()
	if err != nil {
		return err
	}

	err = os.MkdirAll(path.Join(meta.verpath, "logs"), 0775)
	if err != nil {
		return err
	}

	stdReader := func(jobName string, r io.ReadCloser, index int) {
		defer func() {
			reco := recover()
			if reco != nil {
				logger.Println(reco)
			}
		}()

		defer func() {
			overflow := index / 64
			offset := index % 64
			key := fmt.Sprintf("%s-%d", meta.args[0], overflow)
			runningFlags := hc.siblingProcIndex[key]
			mask := uint64(1 << offset)
			runningFlags = runningFlags ^ mask
			hc.siblingProcIndex[key] = runningFlags
		}()

		defer r.Close()

		reader := bufio.NewReader(r)
		thisFileSize := 0
		logFileIndex := 0

		logFileNamePrefix := makeLogFilePrefix(meta, index)
		logFileName := fmt.Sprintf("%s_%d.log", logFileNamePrefix, logFileIndex)
		targetFile, err := os.Create(logFileName)
		if err != nil {
			logger.Println("failed to create log file :", logFileName)
			return
		}

		exef, _ := os.Executable()
		var linkPath string
		if index == 0 {
			linkPath = path.Join(path.Dir(exef), path.Dir(logFileName), meta.name+".log")
		} else {
			linkPath = path.Join(path.Dir(exef), path.Dir(logFileName), fmt.Sprintf("%s_%d.log", meta.name, index))
		}

		os.Remove(linkPath)
		os.Symlink(path.Base(filepath.ToSlash(targetFile.Name())), linkPath)

		defer func() {
			if targetFile != nil {
				targetFile.Close()
			}
		}()

		readingMetric := false
		var metricBuffer []byte
		defer func() {
			logger.Println("stdReader is terminated :", meta.name)
			if meta.isState(protos.ProcessState_Running) {
				hc.operationChan <- &protos.OperationQueryResponse{
					Operation: string(shared.Exception),
					Args: map[string]string{
						"id": fmt.Sprintf("%d", meta.id),
					},
				}
			}
		}()

		metricExporter := metric.NewPrometheusExport(hc.config.MetricNamespace)
		defer metricExporter.Shutdown()

		for {
			buff, err := reader.ReadBytes('\n')
			if err != nil {
				logger.Println("ReadBytes at stdReader return err :", err, meta.name)
				break
			}

			if readingMetric {
				metricBuffer = append(metricBuffer, buff...)
			} else if buff[0] == metric.METRIC_HEAD_INLINE {
				readingMetric = true
				metricBuffer = append(metricBuffer, buff[1:]...)
			}

			if readingMetric {
				if metricBuffer[len(metricBuffer)-2] == metric.METRIC_TAIL_INLINE {
					readingMetric = false

					metricBuffer = metricBuffer[:len(metricBuffer)-2]
					if metricBuffer[0] == '{' {
						var desc metric.MetricDescription
						if err := json.Unmarshal(metricBuffer, &desc); err != nil {
							logger.Println("unmarshal metric failed :", err, string(metricBuffer))
							continue
						}

						if desc.ConstLabels == nil {
							desc.ConstLabels = make(map[string]string)
						}

						for k, v := range hc.config.ConstLabels {
							desc.ConstLabels[k] = v
						}

						desc.ConstLabels["job"] = jobName

						metricExporter.RegisterMetric(&desc)
					} else {
						key, val := metric.ReadMetricValue(metricBuffer)
						metricExporter.UpdateMetric(key, val)
					}

					metricBuffer = metricBuffer[:0]
				}

				continue
			}

			for written := 0; written < len(buff); {
				n, err := targetFile.Write(buff)
				if err != nil {
					logger.Println("write log file failed :", logFileName, err)
					break
				} else {
					written += n
					thisFileSize += n
				}
			}

			if thisFileSize > 5*1024*1024 {
				logFileIndex++
				logFileName = fmt.Sprintf("%s_%d.log", logFileNamePrefix, logFileIndex)
				nextTargetFile, err := os.Create(logFileName)
				if err != nil {
					logger.Println("failed to create log file :", logFileName)
				} else {
					targetFile.Close()
					targetFile = nextTargetFile
					os.Remove(linkPath)
					os.Symlink(path.Base(filepath.ToSlash(targetFile.Name())), linkPath)
					thisFileSize = 0
				}
			}
		}
	}

	index := 0
	for overflow := 0; ; overflow++ {
		key := fmt.Sprintf("%s-%d", meta.args[0], overflow)
		runningFlags := hc.siblingProcIndex[key]
		if runningFlags == math.MaxUint64 {
			index += 64
		} else {
			for si := 0; si < 64; si++ {
				mask := uint64(1 << si)
				if runningFlags&mask == 0 {
					index += si
					runningFlags |= mask
					break
				}
			}
			hc.siblingProcIndex[key] = runningFlags
			break
		}
	}

	go stdReader(meta.name, stdout, index)

	logger.Println("startChildProcess :", meta.cmd.Args)
	meta.cmd.Env = append(meta.cmd.Env, fmt.Sprintf("HOUSTON_SIBLIING_INDEX=%d", index))
	err = meta.cmd.Start()
	if err == nil {
		logger.Println("process index, pid =", index, meta.cmd.Process.Pid)
		set_affinity(meta.cmd.Process.Pid, index)
		meta.setState(protos.ProcessState_Running)
	}

	return err
}

var errPrepareprocessLaunchFailed = errors.New("prepareProcessLaunch failed")

func (hc *houstonClient) startChildProcess(req *shared.StartProcessRequest, op protos.OperationClient) error {
	meta := prepareProcessLaunch(hc.config.StorageRoot, req)
	if meta == nil {
		return errPrepareprocessLaunchFailed
	}
	if err := hc.launch(meta); err != nil {
		return err
	}

	// launch가 성공하면 args 저장. this and parent folder
	vers := hc.deploys[req.Name]
	for _, ver := range vers {
		if ver.Version == req.Version {
			ver.Args = meta.args
		}
	}

	if argfile, err := os.Create(path.Join(hc.config.StorageRoot, req.Name, "@args")); err == nil {
		enc := json.NewEncoder(argfile)
		enc.Encode(req.Args)
		argfile.Close()
	}
	if argfile, err := os.Create(path.Join(hc.config.StorageRoot, req.Name, req.Version, "@args")); err == nil {
		enc := json.NewEncoder(argfile)
		enc.Encode(req.Args)
		argfile.Close()
	}

	hc.childProcs = append(hc.childProcs, meta)
	op.Refresh(context.Background(), hc.makeOperationQueryRequest())

	return nil
}

func (hc *houstonClient) stopChildProcess(req *shared.StopProcessRequest, op protos.OperationClient) error {
	killer := func(proc *procmeta) {
		proc.setState(protos.ProcessState_Stopping)
		if err := proc.cmd.Process.Signal(syscall.SIGTERM); err != nil {
			proc.cmd.Process.Signal(os.Kill)
		}

		go func() {
			proc.cmd.Wait()
			hc.operationChan <- &protos.OperationQueryResponse{
				Operation: string(shared.Exception),
				Args: map[string]string{
					"id": fmt.Sprintf("%d", proc.id),
				},
			}
		}()
	}

	for _, proc := range hc.childProcs {
		if !proc.isState(protos.ProcessState_Running) {
			continue
		}

		if req.Pid != 0 {
			if req.Pid == int32(proc.cmd.Process.Pid) {
				// 해당 pid만 제거
				killer(proc)
			}
		} else if proc.name == req.Name {
			if len(req.Version) == 0 {
				// program 다 정지
				killer(proc)
			} else if req.Version == proc.version {
				// program의 특정 버전만 정지
				killer(proc)
			}
		}
	}

	op.Refresh(context.Background(), hc.makeOperationQueryRequest())

	return nil
}

func (hc *houstonClient) restartChildProcess(req *shared.RestartProcessRequest, op protos.OperationClient) error {
	for _, proc := range hc.childProcs {
		if proc.cmd.Process.Pid == int(req.Pid) {
			if len(req.Config) > 0 {
				// config.json를 먼저 다운로드 시도
				root := proc.verpath
				if _, err := download(root, hc.makeDownloadUrl(req.Config), "", nil); err != nil {
					return err
				}
			}

			proc.setState(protos.ProcessState_Restart)
			op.Refresh(context.Background(), hc.makeOperationQueryRequest())
			hc.exitChan <- proc.cmd

			break
		}
	}

	return nil
}

func (hc *houstonClient) uploadFiles(req *shared.UploadRequest) error {
	logger.Println("uploadFiles req :", *req)
	for _, child := range hc.childProcs {
		if child.version == req.Version && child.name == req.Name {
			logger.Println("uploadFiles found :", child.version, child.name)

			go func() {
				zipFile, srcFiles, err := zipLogFiles(hc.config.StorageRoot, req)
				if err == nil && len(zipFile) > 0 && len(srcFiles) > 0 {
					if err = hc.uploadZipLogFile(zipFile, child.name, child.version); err == nil {
						// 마지막거 빼고 삭제
						sort.StringSlice(srcFiles).Sort()
						for i := 0; i < len(srcFiles)-1; i++ {
							if len(srcFiles[i]) > 0 {
								os.Remove(srcFiles[i])
							}
						}
					} else {
						logger.Println("uploadZipLogFile failed :", err)
					}
				} else if err != nil {
					logger.Println("zipLogFiles failed :", err)
				}
			}()

			return nil
		}
	}

	// 실행 중이 아닌 폴더에서도 대상을 찾는다
	// 전체 파일을 대상으로
	zipFile, srcFiles, err := zipLogFiles(hc.config.StorageRoot, req)
	if err == nil && len(zipFile) > 0 && len(srcFiles) > 0 {
		if err = hc.uploadZipLogFile(zipFile, req.Name, req.Version); err == nil {
			// 마지막거 빼고 삭제
			sort.StringSlice(srcFiles).Sort()
			for i := 0; i < len(srcFiles)-1; i++ {
				if len(srcFiles[i]) > 0 {
					os.Remove(srcFiles[i])
				}
			}
		} else {
			logger.Println("uploadZipLogFile failed :", err)
		}
	} else if err != nil {
		logger.Println("zipLogFiles failed :", err)
	}

	return nil
}