package main

import (
	"bufio"
	"bytes"
	"flag"
	"fmt"
	"os"
	"path"
	"runtime"
	"strings"
	"sync"

	"git.algo.com.cn/public/saasapi"
	"google.golang.org/protobuf/encoding/protojson"
)

const (
	convertBatchSize = 100000
	convertedExt     = ".converted"
)

type convertParams struct {
	mapCfg     *MapConfig
	sourcePath string
	destPath   string
}

type convertResult struct {
	resultBuf      bytes.Buffer
	convertedLines int
}

func RunConvert(args ...string) error {
	fs := flag.NewFlagSet("convert", flag.ExitOnError)
	mapCfgFile := paramMap(fs)
	sourcePath := paramSourcePath(fs)
	destPath := paramDestPath(fs)

	if err := fs.Parse(args); err != nil {
		fmt.Fprintln(os.Stderr, "command line parse error", "err", err)
		return err
	}

	if fs.NArg() > 0 || *mapCfgFile == "" || len(*sourcePath) == 0 || len(*destPath) == 0 {
		fs.PrintDefaults()
		return nil
	}

	mapCfg, err := LoadMapFile(*mapCfgFile)
	if err != nil {
		fmt.Fprintln(os.Stderr, "LoadConfigFile error", "err", err)
		return err
	}

	convertParams := convertParams{
		mapCfg:     mapCfg,
		sourcePath: *sourcePath,
		destPath:   *destPath,
	}

	return doConvert(convertParams)
}

func doConvert(convertParams convertParams) error {
	fsInfo, err := os.Stat(convertParams.sourcePath)
	if err != nil {
		return err
	}

	if !fsInfo.IsDir() {
		// 如果是文件，直接写入
		return doFileConvert(convertParams)
	}

	// 读取目录下信息
	dirEntry, err := os.ReadDir(convertParams.sourcePath)
	if err != nil {
		return err
	}

	// 遍历目录
	for _, dir := range dirEntry {
		newParam := convertParams
		newParam.sourcePath = path.Join(convertParams.sourcePath, dir.Name())

		if dir.IsDir() {
			newParam.destPath = path.Join(convertParams.destPath, dir.Name())
		}

		if err = doConvert(newParam); err != nil {
			return err
		}
	}

	return nil
}

func doFileConvert(convertParams convertParams) error {
	// 读取文件并按行遍历，以\t分割为两列，第一列为userid，第二列解析为string数组
	sourceFile, err := os.Open(convertParams.sourcePath)
	if err != nil {
		return err
	}
	defer sourceFile.Close()

	if _, err = os.Stat(convertParams.destPath); os.IsNotExist(err) {
		os.MkdirAll(convertParams.destPath, os.ModePerm)
	}

	destName := path.Join(convertParams.destPath, path.Base(convertParams.sourcePath)+convertedExt)
	destFile, err := os.Create(destName)
	if err != nil {
		return err
	}
	defer destFile.Close()

	scaner := bufio.NewScanner(sourceFile)
	destWriter := bufio.NewWriter(destFile)
	defer destWriter.Flush()

	// 启动处理协程
	workers := []chan []string{}
	results := []chan convertResult{}
	processedLine := 0

	wg := sync.WaitGroup{}
	convertMaxWorkers := runtime.GOMAXPROCS(0)
	for range convertMaxWorkers {
		workerChan := make(chan []string)
		workers = append(workers, workerChan)
		resultChan := make(chan convertResult)
		results = append(results, resultChan)

		go func(workerChan <-chan []string, resultChan chan<- convertResult) {
			for lines := range workerChan {
				convertBatch(lines, convertParams, resultChan)
			}
		}(workerChan, resultChan)
	}

	// 启动写入协程
	go func() {
		i := 0

		// TIP: 不要改成for range
		for {
			select {
			case result, ok := <-results[i%convertMaxWorkers]:
				if !ok {
					return
				}
				destWriter.Write(result.resultBuf.Bytes())
				destWriter.Flush()
				processedLine += result.convertedLines
				fmt.Printf("\rconverted records: %v [%v]", processedLine, destName)
				i++
				wg.Done()
			}

		}
	}()

	// 读取文件并塞给协程处理
	batch := []string{}
	batchCount := 0
	for scaner.Scan() {
		line := scaner.Text()
		if line == "" {
			continue
		}

		batch = append(batch, line)
		if len(batch) == convertBatchSize {
			// 将batch写入协程
			wg.Add(1)
			workers[batchCount%convertMaxWorkers] <- batch
			batch = nil
			batchCount++
		}
	}

	if len(batch) > 0 {
		wg.Add(1)
		workers[batchCount%convertMaxWorkers] <- batch
	}

	wg.Wait()
	// 关闭所有工作协程的通道
	for _, workerChan := range workers {
		close(workerChan)
	}
	for _, resultChan := range results {
		close(resultChan)
	}
	fmt.Println("")

	return nil
}

func convertBatch(lines []string, convertParams convertParams, resultChan chan<- convertResult) {
	byteBuf := bytes.Buffer{}
	byteBuf.Grow(1024 * 1024 * 10)

	jasonMarshal := protojson.MarshalOptions{Multiline: false, Indent: ""}

	for _, line := range lines {
		// 按\t分割为两列
		parts := strings.Split(line, "\t")
		if len(parts) != 2 {
			continue
		}

		// 读取userid
		userid := parts[0]
		if len(userid) == 0 {
			continue
		}

		value := parts[1]
		value = strings.ReplaceAll(value, "[", "")
		value = strings.ReplaceAll(value, "]", "")
		// 第二列解析为string数组
		targets := strings.Split(value, " ")

		saasWriteItem := &saasapi.WriteItem{
			Userid: userid,
		}

		// 遍历targets，转换成saasapi.WriteCmd
		for _, target := range targets {
			if targetinfo, ok := convertParams.mapCfg.Targets[target]; ok {
				if targetinfo.WriteByte != nil {
					// 转换byte区
					if saasWriteItem.WriteBytes == nil {
						saasWriteItem.WriteBytes = &saasapi.Bytes{}
					}
					saasWriteItem.WriteBytes.Bytes = append(saasWriteItem.WriteBytes.Bytes, *targetinfo.WriteByte)
					if targetinfo.WriteBytePos < 64 {
						saasWriteItem.WriteBytes.Index_1 |= 1 << targetinfo.WriteBytePos
					} else if targetinfo.WriteBytePos < 128 {
						saasWriteItem.WriteBytes.Index_2 |= 1 << (targetinfo.WriteBytePos - 64)
					}
				}

				if targetinfo.WriteUint32 != nil {
					// 转换uint32区
					if saasWriteItem.WriteUint32S == nil {
						saasWriteItem.WriteUint32S = &saasapi.Uint32S{}
					}
					saasWriteItem.WriteUint32S.Uint32S = append(saasWriteItem.WriteUint32S.Uint32S, *targetinfo.WriteUint32)
					saasWriteItem.WriteUint32S.Index_1 |= 1 << targetinfo.WriteUint32Pos
				}

				if targetinfo.WriteFlag != nil && targetinfo.WriteExpire != nil {
					// 转换flag区
					if saasWriteItem.WriteFlagsWithExpire == nil {
						saasWriteItem.WriteFlagsWithExpire = &saasapi.FlagsWithExpire{}
					}
					saasWriteItem.WriteFlagsWithExpire.FlagsWithExpire = append(
						saasWriteItem.WriteFlagsWithExpire.FlagsWithExpire, &saasapi.FlagWithExpire{
							Flag:   *targetinfo.WriteFlag,
							Expire: *targetinfo.WriteExpire,
						})
					saasWriteItem.WriteFlagsWithExpire.Index_1 |= 1 << targetinfo.WriteFlagWithExpirePos
				}
			}
		}

		byteBuf.WriteString(jasonMarshal.Format(saasWriteItem))
		byteBuf.WriteString("\n")
	}

	resultChan <- convertResult{byteBuf, len(lines)}
}