package uploadfiles

import (
	"io"
	"os"
	"path/filepath"

	"lmika.dev/lmika/weiro/models"
)

type Provider struct {
	baseDir string
}

func New(baseDir string) *Provider {
	return &Provider{
		baseDir: baseDir,
	}
}

func (p *Provider) AdoptFile(site models.Site, up models.Upload, filename string) error {
	fullPath := p.uploadFileName(site, up)
	baseDir := filepath.Dir(fullPath)

	if err := os.MkdirAll(baseDir, 0755); err != nil {
		return err
	}

	if err := os.Rename(filename, fullPath); err == nil {
		return nil
	}

	// Can't rename, possibly because of a cross-link device issue. So copy instead
	if err := moveFile(filename, fullPath); err != nil {
		return err
	}

	return nil
}

func moveFile(src, dst string) error {
	if err := copyFile(src, dst); err != nil {
		_ = os.Remove(dst)
		return err
	}
	_ = os.Remove(src)
	return nil
}

func copyFile(src, dst string) error {
	in, err := os.Open(src)
	if err != nil {
		return err
	}
	defer in.Close()

	out, err := os.Create(dst)
	if err != nil {
		return err
	}
	defer out.Close()

	if _, err = io.Copy(out, in); err != nil {
		return err
	}
	return err
}

func (p *Provider) OpenUpload(site models.Site, up models.Upload) (io.ReadCloser, error) {
	fullPath := p.uploadFileName(site, up)
	return os.Open(fullPath)
}

func (p *Provider) DeleteUpload(site models.Site, up models.Upload) error {
	fullPath := p.uploadFileName(site, up)
	if err := os.Remove(fullPath); err != nil {
		if os.IsNotExist(err) {
			return nil
		}
		return err
	}
	return nil
}

func (p *Provider) UploadDir(site models.Site) string {
	return filepath.Join(p.baseDir, site.GUID)
}

func (p *Provider) uploadFileName(site models.Site, up models.Upload) string {
	return filepath.Join(p.baseDir, site.GUID, up.Slug)
}