package putp

import (
	"fmt"
	"os"
	"path/filepath"
	"time"

	"github.com/inhies/go-bytesize"
	cliapi "gitlink.org.cn/cloudream/jcs-pub/client/sdk/api/v1"
	"gitlink.org.cn/cloudream/jcs-pub/common/pkgs/iterator"
	jcstypes "gitlink.org.cn/cloudream/jcs-pub/common/types"
)

type FileIterator struct {
	absRootPath   string
	jpathRoot     jcstypes.JPath
	init          bool
	curEntries    []dirEntry
	lastStartTime time.Time
	totalSize     int64
	fileCount     int
}

func (i *FileIterator) MoveNext() (*cliapi.UploadingObject, error) {
	if !i.init {
		es, err := os.ReadDir(i.absRootPath)
		if err != nil {
			return nil, err
		}

		for _, e := range es {
			i.curEntries = append(i.curEntries, dirEntry{
				dir:   jcstypes.JPath{},
				entry: e,
			})
		}

		i.init = true
	}

	for {
		if len(i.curEntries) == 0 {
			return nil, iterator.ErrNoMoreItem
		}

		entry := i.curEntries[0]
		i.curEntries = i.curEntries[1:]

		if entry.entry.IsDir() {
			es, err := os.ReadDir(filepath.Join(i.absRootPath, entry.dir.OSString(), entry.entry.Name()))
			if err != nil {
				return nil, err
			}

			// 多个entry对象共享同一个JPath对象，但因为不会修改JPath，所以没问题
			dir := entry.dir.Clone()
			dir.Push(entry.entry.Name())
			for _, e := range es {
				i.curEntries = append(i.curEntries, dirEntry{
					dir:   dir,
					entry: e,
				})
			}
			continue
		}

		file, err := os.Open(filepath.Join(i.absRootPath, entry.dir.OSString(), entry.entry.Name()))
		if err != nil {
			return nil, err
		}
		info, err := file.Stat()
		if err != nil {
			return nil, err
		}

		i.totalSize += info.Size()
		i.fileCount++

		jpath := i.jpathRoot.ConcatNew(entry.dir)
		path := jpath.PushNew(entry.entry.Name()).String()

		now := time.Now()
		if !i.lastStartTime.IsZero() {
			dt := now.Sub(i.lastStartTime)
			fmt.Printf("\t%v\n", dt)
		}
		i.lastStartTime = now

		fmt.Printf("%v\t%v", path, bytesize.ByteSize(info.Size()))

		return &cliapi.UploadingObject{
			Path: path,
			File: file,
		}, nil
	}
}

func (i *FileIterator) Close() {

}

type dirEntry struct {
	dir   jcstypes.JPath
	entry os.DirEntry
}