// Package uploader 上传数据
package uploader

import (
	"bufio"
	"context"
	"dypid-client/internal/api"
	"dypid-client/internal/config"
	"fmt"
	"os"
	"path/filepath"
	"runtime"
	"strconv"
	"strings"
	"sync"
	"sync/atomic"
	"time"

	wailsruntime "github.com/wailsapp/wails/v2/pkg/runtime"
	"golang.org/x/sync/errgroup"
)

var progress sync.Map

type Task struct {
	FilePath  string
	FileLines int
}

type Progress struct {
	FileName   string `json:"name"`
	Total      int    `json:"total"`
	Uploaded   int    `json:"uploaded"`
	Percentage int    `json:"percentage"`
}

func StartLooking(ctx context.Context, logChan *chan string, lookingPath string) {
	AddLog(logChan, "===============================================")
	AddLog(logChan, `服务器: `+config.APPConfig.Url)
	AddLog(logChan, `Token: `+config.APPConfig.Token)
	AddLog(logChan, `检测目录: `+config.APPConfig.CheckDir)
	AddLog(logChan, `同时处理文件数: `+strconv.Itoa(config.APPConfig.HandleFileCount))
	AddLog(logChan, `单文件上传线程: `+strconv.Itoa(config.APPConfig.ThreadCount))
	AddLog(logChan, "===============================================")

	AddLog(logChan, "正在创建连接池（连接池可避免首次大量上传时出现网络错误）")
	api.InitConn()
	AddLog(logChan, "创建连接池完成，开始运行程序")

	progress.Clear()
	//推送上传进度
	go func() {
		for {
			select {
			case <-ctx.Done():
				return
			default:
				time.Sleep(250 * time.Millisecond)

				var pg []Progress
				progress.Range(func(key, value any) bool {
					p := value.(Progress)
					pg = append(pg, p)
					return true
				})
				wailsruntime.EventsEmit(ctx, "progress", pg)
			}
		}
	}()

	for {
		uploadData(ctx, logChan, lookingPath)
		select {
		case <-time.After(time.Minute):
		case <-ctx.Done():
			return
		}
	}
}

func uploadData(ctx context.Context, logChan *chan string, lookingPath string) {
	var path = "./"
	if lookingPath != "" {
		path = lookingPath
	}

	//获取文件列表
	files, err := getTxtFiles(path)
	if err != nil {
		AddLog(logChan, "获取文件列表失败："+err.Error())
		return
	}
	if files == nil {
		return
	}

	start := time.Now()
	//检测到文件
	//统计文件行数
	fileLines := make(map[string]int)
	AddLog(logChan, fmt.Sprintf("正在统计 %v 个文件行数", len(files)))
	isAllEmpty := true
	for _, filePath := range files {
		select {
		case <-ctx.Done():
			return
		default:
			file, err := os.Open(filePath)
			if err != nil {
				AddLog(logChan, "打开文件失败："+err.Error())
			}
			// 使用 bufio.Scanner 逐行读取
			scanner := bufio.NewScanner(file)
			lineCount := 0
			for scanner.Scan() {
				lineCount++
			}
			err = file.Close()

			if lineCount == 0 {
				continue
			}
			fileLines[filepath.Base(filePath)] = lineCount
			isAllEmpty = false
			AddLog(logChan, fmt.Sprintf("%s 文件行数：%v", filepath.Base(filePath), lineCount))
		}
	}
	if isAllEmpty {
		AddLog(logChan, "所有文件都为空，不进行上传")
		return
	}

	progress.Clear()
	//添加文件上传任务参数（文件路径，文件行数）
	var tasks []Task
	for fileName, lines := range fileLines {
		tasks = append(tasks, Task{FilePath: path + "/" + fileName, FileLines: lines})
		progress.Store(fileName, Progress{FileName: fileName, Total: lines, Uploaded: 0, Percentage: 0})
	}

	// 使用 errgroup 控制同时处理的文件数，并开始上传文件任务
	g, egctx := errgroup.WithContext(ctx)
	g.SetLimit(config.APPConfig.HandleFileCount) // 设置同时处理文件数
	// 执行所有任务
	for _, task := range tasks {
		select {
		case <-egctx.Done():
			return
		default:
			g.Go(func() error {
				select {
				case <-egctx.Done():
					return egctx.Err()
				default:
					AddLog(logChan, "正在上传文件："+filepath.Base(task.FilePath))

					processFile(egctx, logChan, task.FilePath, task.FileLines)

					select {
					case <-egctx.Done():
						return egctx.Err()
					default:
						//上传完成，清空文件
						err := os.Truncate(task.FilePath, 0)
						if err != nil {
							AddLog(logChan, "清空文件失败："+err.Error())
						}
						return nil
					}
				}
			})
		}
	}

	select {
	case <-ctx.Done():
		return
	default:
		// 等待所有任务完成
		if err := g.Wait(); err != nil {
			AddLog(logChan, fmt.Sprintf("任务执行出错: %v", err))
		} else {
			AddLog(logChan, "所有任务执行完成！")
		}

		AddLog(logChan, fmt.Sprintf("上传完成，耗时：%s", time.Since(start).String()))
	}
}

// 获取目录中的所有txt文件
func getTxtFiles(dir string) (txtFiles []string, err error) {
	err = filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}

		// 只处理普通文件，跳过目录
		if !info.Mode().IsRegular() {
			return nil
		}

		// 检查文件扩展名是否为.txt
		if strings.ToLower(filepath.Ext(path)) == ".txt" {
			txtFiles = append(txtFiles, path)
		}

		return nil
	})

	return txtFiles, err
}

func processFile(ctx context.Context, logChan *chan string, filePath string, fileLines int) {
	// 打开文件
	file, err := os.Open(filePath)
	if err != nil {
		AddLog(logChan, fmt.Sprintf("[processFile] 无法打开文件 %s: %v", filePath, err))
		return
	}
	defer file.Close()

	// 创建行通道
	lines := make(chan string, 200)
	var countLine int32 = 0
	// 创建指定个worker同时处理文件上传
	for i := 0; i < config.APPConfig.ThreadCount; i++ {
		select {
		case <-ctx.Done():
			return
		default:
			go func() {
				processLines(ctx, logChan, &lines, i, filePath, &countLine)
			}()
		}
	}

	// 读取文件并发送到通道
	scanner := bufio.NewScanner(file)
	go func() {
		defer func() {
			if r := recover(); r != nil {
				_, f, l, _ := runtime.Caller(0)
				fmt.Println("panic:", f+":"+strconv.Itoa(l), r)
			}
		}()
		for scanner.Scan() {
			select {
			case <-ctx.Done():
				return
			default:
				lines <- scanner.Text()
			}
		}
	}()

	// 等待所有行处理完成并推送进度
	for int(countLine) != fileLines {
		select {
		case <-ctx.Done():
			close(lines) //关闭processLines中的上传线程
			return
		default:
			progress.Store(filepath.Base(filePath),
				Progress{
					FileName:   filepath.Base(filePath),
					Total:      fileLines,
					Uploaded:   int(countLine),
					Percentage: int(float64(countLine) / float64(fileLines) * 100),
				},
			)
		}
	}
	//上传完成，进度设为100
	progress.Store(filepath.Base(filePath),
		Progress{
			FileName:   filepath.Base(filePath),
			Total:      fileLines,
			Uploaded:   int(countLine),
			Percentage: 100,
		},
	)
	close(lines) //关闭processLines中的上传线程

	if err := scanner.Err(); err != nil {
		AddLog(logChan, fmt.Sprintf("读取文件 %s 错误: %v", filePath, err))
		return
	}

	AddLog(logChan, fmt.Sprintf("文件【%s】处理完成，共处理 %d 行数据", filepath.Base(filePath), countLine))
}

// processLines 处理接受到的每一行数据并上传（chan 管道接受数据）
func processLines(ctx context.Context, logChan *chan string, lines *chan string, workerID int, filePath string, countLine *int32) {
	for line := range *lines {
		select {
		case <-ctx.Done():
			return
		default:
			// 跳过空行
			if strings.TrimSpace(line) == "" {
				continue
			}
			// 上传数据
			if err := api.UploadDataToServer(ctx, line); err != nil {
				AddLog(logChan, fmt.Sprintf("Worker %d (文件 %s): 上传失败: %v", workerID, filepath.Base(filePath), err))
			}
			atomic.AddInt32(countLine, 1)
		}
	}
}

// AddLog 添加日志
func AddLog(logChan *chan string, message string) {
	*logChan <- message
}