package pixiv

import (
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"strings"
	"syscall"
)

type artworkFile struct {
	directory string
	filename  string
	url       string
}
type artwork struct {
	tags  []string
	files []artworkFile
}

func getExtension(fullpath string) (ext string) {
	parts := strings.Split(fullpath, ".")
	ext = parts[len(parts)-1]
	return
}

//DownloadIllust .
func (p *Pixiv) downloadIllust(i Illust) (err error) {
	if !i.Complited() {
		err = p.ComplateIllust(&i)
		if err != nil {
			return
		}
	}

	var art artwork

	for pageNumber, page := range i.Pages {
		directory := fmt.Sprintf("%s/%s_%s/", p.WorkDirectory, i.UserID, i.UserAccount)
		filename := fmt.Sprintf("%s_p%d.%s", i.ID, pageNumber, getExtension(page.URLs.Original))
		art.files = append(art.files,
			artworkFile{directory: directory,
				filename: filename,
				url:      page.URLs.Original})
	}

	for _, file := range art.files {
		err := os.MkdirAll(file.directory, 0755)
		if err != nil {
			return err
		}
		if _, err = os.Stat(file.directory + file.filename); os.IsNotExist(err) {
			outfile, err := os.Create(file.directory + file.filename)
			if err != nil {
				return err
			}
			defer outfile.Close()
			//log.Printf("Downloading %s to %s", file.url, outfile.Name())
			err = p.downloadTo(file.url, outfile)
			if err != nil {
				return err
			}
			if p.setxattr {
				err = syscall.Setxattr(outfile.Name(), "user.xdg.tags", []byte(i.TagsString()), 0)
				if err != nil {
					return err
				}
			}
		} else {
			err = nil
			continue
		}
	}
	return
}

func (p *Pixiv) downloadTo(addr string, file *os.File) (err error) {
	req, err := http.NewRequest("GET", addr, nil)
	if err != nil {
		err = fmt.Errorf("NewRequest failed (%s)", addr)
		return
	}
	req.AddCookie(&p.phpsessid)
	req.Header.Set("User-Agent", p.Ua)
	req.Header.Set("Referer", "https://www.pixiv.net")
	var resp *http.Response
	for i := 0; i < p.RetryCount; i++ {
		resp, err = p.client.Do(req)
		if err != nil {
			log.Printf("%s", err.Error())
			log.Printf("Retry %d of %d...", i, p.RetryCount)
			continue
		}
		defer resp.Body.Close()
		if resp.StatusCode != http.StatusOK {
			log.Printf("GET %s failed: bad status code: %d", addr, resp.StatusCode)
			log.Printf("Retry %d of %d...", i, p.RetryCount)
			continue
		}
		err = file.Truncate(0)
		if err != nil {
			return
		}
		_, err = io.Copy(file, resp.Body)
		if err != nil {
			log.Printf("%s", err.Error())
			log.Printf("Retry %d of %d...", i, p.RetryCount)
			continue
		}
		break
	}
	return
}

func (p *Pixiv) downloadWorker() {
	for illust := range p.DownloadChannel {
		err := p.downloadIllust(illust)
		if err != nil {
			p.logChannel <- fmt.Sprintf("%s %s %s\n", illust.ID, "illust", "failed")
			continue
		}
		p.logChannel <- fmt.Sprintf("%s %s %s\n", illust.ID, "illust", "downloaded")
	}
	return
}