package main

import (
	"flag"
	"fmt"
	"net/http"
	"os"
	"path/filepath"

	"git.algo.com.cn/public/saasapi"
	"git.algo.com.cn/public/saasapi/pkg/saashttp"
)

type downloadTaskParams struct {
	taskSha256 string
	destPath   string
	saasHttp   *saashttp.SaasClient
}

func RunTaskDownload(args ...string) error {
	fs := flag.NewFlagSet("download", flag.ExitOnError)
	cfgFile := paramConfig(fs)
	sha256 := paramSha256(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 || len(*sha256) == 0 || len(*destPath) == 0 {
		fs.PrintDefaults()
		return nil
	}

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

	downloadTaskParams := downloadTaskParams{
		taskSha256: *sha256,
		destPath:   *destPath,
		saasHttp: &saashttp.SaasClient{
			Client:  &http.Client{},
			ApiUrls: saashttp.InitAPIUrl(&cfg.ApiUrls),
			Auth:    &cfg.Auth,
		},
	}

	return doTaskDownload(downloadTaskParams)

}
func doTaskDownload(downloadTaskParams downloadTaskParams) error {
	infoTaskParams := infoTaskParams{
		taskSha256: downloadTaskParams.taskSha256,
		saasHttp:   downloadTaskParams.saasHttp,
	}
	taskInfo, err := doTaskInfo(infoTaskParams)
	if err != nil {
		return err
	}

	if len(taskInfo.GetSourcePath()) == 0 {
		err = fmt.Errorf("task download failed. task info source path is empty")
		fmt.Fprintln(os.Stderr, err)
		return err
	}

	totalFiles := len(taskInfo.GetTaskFileInfos())
	fi := 0
	for _, finfo := range taskInfo.GetTaskFileInfos() {
		fi++
		var f *os.File
		offset := int64(0)
		totalBlocks := len(finfo.GetFileBlocks())
		bi := 0
		for _, binfo := range finfo.GetFileBlocks() {
			bi++
			if binfo.GetUploaded() {
				if f == nil {
					fname := finfo.GetFileName()
					if len(downloadTaskParams.destPath) > 0 {
						fname = filepath.Join(downloadTaskParams.destPath, fname)
					}

					os.MkdirAll(filepath.Dir(fname), os.ModePerm)

					f, err = os.Create(fname)
					if err != nil {
						return err
					}
				}

				blockRes, err := downloadTaskParams.saasHttp.TaskDownload(
					binfo.GetBlockSha256(),
					f,
					offset,
					int(binfo.GetBlockLength()),
				)

				if err != nil {
					return err
				}

				if blockRes.GetCode() != saasapi.ErrorCode_SUCC {
					err = fmt.Errorf("download block error, code %d, msg %s", blockRes.GetCode(), blockRes.GetStatus())
					fmt.Fprintln(os.Stderr, err)
					return err
				} else {
					fmt.Printf("download block success. file: %v, sha256 %v. block %v/%v, file %v/%v\n",
						finfo.GetFileName(), binfo.GetBlockSha256(),
						bi, totalBlocks, fi, totalFiles,
					)
				}

			} else {
				fmt.Printf("download block. file: %v, sha256 %v. block %v/%v, file %v/%v\n",
					finfo.GetFileName(), binfo.GetBlockSha256(),
					bi, totalBlocks, fi, totalFiles,
				)
			}
			offset += int64(binfo.GetBlockLength())

		}

		if f != nil {
			f.Close()
		}
	}

	return nil
}