package cmd

import (
	"excel_export/biz/config"
	"excel_export/biz/db"
	"excel_export/biz/export"
	"fmt"
	"os"
	"strconv"
	"sync"
	"time"
)

type Csv struct {
	conf    *config.Config
	dirTemp string
}

func NewCsv(conf *config.Config) *Csv {
	return &Csv{
		conf: conf,
	}
}

func (e *Csv) Export(sysName, jobName string, begin, end time.Time, batch int) error {
	job, dbStr, err := config.GetJob(e.conf, sysName, jobName)
	if err != nil {
		return err
	}

	d, err := db.NewDb(dbStr)
	if err != nil {
		return err
	}

	return e.JobHandler(job, d, map[string]interface{}{
		"begin": begin,
		"end":   end,
		"last":  0,
	}, batch)
}

func (e *Csv) JobHandler(job config.Job, d export.DataFetcher, params map[string]interface{}, batch int) error {

	for i, task := range job.Tasks {
		fmt.Printf("执行导出任务：%d\n", i+1)
		params["task"] = i
		if err := e.TaskExport(d, task, params, batch, job.GetFileName(params)); err != nil {
			return err
		}
	}
	return nil
}

func (e *Csv) TaskExport(d export.DataFetcher, t config.Task, params map[string]interface{}, batch int, fileName string) error {
	var i int
	var wg sync.WaitGroup
	for i = 0; i < 1000; i++ {

		f, err := e.getCsvFile(i)
		if err != nil {
			return err
		}

		sql := t.GetSql(params)

		e := export.NewCsvExporter(d, f)
		e.(*export.CsvExporter).WaitGroup(&wg)
		wg.Add(1)
		e.Export(sql+" limit "+strconv.Itoa(batch), t.PK)

		count, last := e.Last()
		fmt.Printf("已导出 %d 条数据\n", batch*i+count)

		if count == 0 {
			return nil
		}

		if count < batch {
			break
		}

		params["last"] = last
		time.Sleep(time.Microsecond * 30)
	}
	wg.Wait()
	//fmt.Println("tempDir", e.dirTemp)
	//todo 合并csv文件，并删除 临时目录
	err := e.mergeCsvToExcel(e.dirTemp, i, fileName)
	fmt.Println(err)

	//重置临时路径
	e.dirTemp = ""

	return nil
}

func (e *Csv) getCsvFile(index int) (*export.Csv, error) {

	if e.dirTemp == "" {
		path, err := os.MkdirTemp(os.TempDir(), "")
		if err != nil {
			return nil, err
		}
		e.dirTemp = path
	}

	filename := e.dirTemp + "/data_{index}.csv"

	f := export.NewCsv(filename, map[string]string{
		"index": strconv.Itoa(index),
	})

	return f, nil
}

func (e *Csv) mergeCsvToExcel(path string, max int, out string) error {
	m := NewMerge(
		Reader{Path: path, Index: max},
		Writer{File: out, Limit: 1000000},
	)
	if err := m.Merge(); err != nil {
		return err
	}

	return m.Clear()
}