package mygo

import (

"os"

"path/filepath"

"strconv"

"strings"

)

// DownloadEvent is passed to Page.OnWillDownload listeners. Setting Path

// chooses where the file goes; preventing the event cancels the download.

type DownloadEvent struct {

Preventable

// URL of the download.

URL string

// SuggestedName is the file name the page or the server suggests.

SuggestedName string

// Path is where the file is saved: by default SuggestedName in the

// Downloads directory, numbered when a file has that name. A file

// already at a Path listeners set is replaced.

Path string

}

// Download is a finished download, passed to Page.OnDownloadDone.

type Download struct {

URL string

Path string

// Err is why the download failed, or nil.

Err error

}

// OnWillDownload is called when a page starts a download: a link with the

// download attribute, or a response the page cannot show, such as a file

// sent as an attachment. Without listeners, downloads are saved to the

// Downloads directory.

func (p *Page) OnWillDownload(fn func(e *DownloadEvent)) (off func()) {

return p.w.onWillDownload.add(fn, false)

}

// OnDownloadDone is called when a download ended.

func (p *Page) OnDownloadDone(fn func(d *Download)) (off func()) {

return p.w.onDownloadDone.add(fn, false)

}

func (h *windowHandler) DownloadStarted(url, suggested string) string {

name := filepath.Base(filepath.Clean("/" + strings.ReplaceAll(suggested, `\`, "/")))

if name == "/" || name == "." || name == "" {

name = "download"

}

e := &DownloadEvent{URL: url, SuggestedName: name}

if dir, err := App.Path(PathDownloads); err == nil && os.MkdirAll(dir, 0o755) == nil {

e.Path = uniquePath(filepath.Join(dir, name))

}

fire1(&h.w.onWillDownload, e)

if e.prevented || e.Path == "" {

return ""

}

return e.Path

}

func (h *windowHandler) DownloadFinished(url, path string, err error) {

fire1(&h.w.onDownloadDone, &Download{URL: url, Path: path, Err: err})

}

// uniquePath numbers path, like "name (2).ext", when a file has its name.

func uniquePath(path string) string {

if _, err := os.Lstat(path); err != nil {

return path

}

ext := filepath.Ext(path)

base := strings.TrimSuffix(path, ext)

for i := 2; ; i++ {

p := base + " (" + strconv.Itoa(i) + ")" + ext

if _, err := os.Lstat(p); err != nil {

return p

}

}

}