Skip to content

Commit

Permalink
Initial implementation
Browse files Browse the repository at this point in the history
  • Loading branch information
cristaloleg committed Oct 2, 2023
1 parent c78e9e8 commit 97c18c3
Show file tree
Hide file tree
Showing 6 changed files with 307 additions and 1 deletion.
18 changes: 18 additions & 0 deletions .github/dependabot.yml
Original file line number Diff line number Diff line change
@@ -0,0 +1,18 @@
version: 2
updates:
- package-ecosystem: "gomod"
commit-message:
prefix: "deps:"
directory: "/"
schedule:
interval: "weekly"
day: "sunday"
time: "09:00"
- package-ecosystem: "github-actions"
commit-message:
prefix: "ci:"
directory: "/"
schedule:
interval: "weekly"
day: "sunday"
time: "09:00"
17 changes: 17 additions & 0 deletions .github/workflows/build.yml
Original file line number Diff line number Diff line change
@@ -0,0 +1,17 @@
name: build

on:
push:
branches: [main]
pull_request:
branches: [main]
schedule:
- cron: '0 0 * * 0' # run "At 00:00 on Sunday"

# See https://github.com/cristalhq/.github/.github/workflows
jobs:
build:
uses: cristalhq/.github/.github/workflows/[email protected]

vuln:
uses: cristalhq/.github/.github/workflows/[email protected]
43 changes: 42 additions & 1 deletion README.md
Original file line number Diff line number Diff line change
@@ -1,2 +1,43 @@
# magneturi
A Go package for magnet links

# magneturi

[![build-img]][build-url]
[![pkg-img]][pkg-url]
[![version-img]][version-url]

Go package for magnet links.

## Features

* Simple API.
* Dependency-free.

See [docs][pkg-url] for more details.

## Install

Go version 1.17+

```
go get github.com/cristalhq/magneturi
```

## Example

```go
TODO
```

See examples: [example_test.go](example_test.go).

## License

[MIT License](LICENSE).

[build-img]: https://github.com/cristalhq/magneturi/workflows/build/badge.svg
[build-url]: https://github.com/cristalhq/magneturi/actions
[pkg-img]: https://pkg.go.dev/badge/cristalhq/magneturi
[pkg-url]: https://pkg.go.dev/github.com/cristalhq/magneturi
[version-img]: https://img.shields.io/github/v/release/cristalhq/magneturi
[version-url]: https://github.com/cristalhq/magneturi/releases
1 change: 1 addition & 0 deletions example_test.go
Original file line number Diff line number Diff line change
@@ -0,0 +1 @@
package magneturi_test
3 changes: 3 additions & 0 deletions go.mod
Original file line number Diff line number Diff line change
@@ -0,0 +1,3 @@
module github.com/cristalhq/magneturi

go 1.17
226 changes: 226 additions & 0 deletions magneturi.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,226 @@
package magneturi

import (
"errors"
"net/url"
"sort"
"strconv"
"strings"
)

const magnetPrefix = "magnet:?"

// Magnet represents a Magnet URI.
type Magnet struct {
// ExactTopics is a "xt".
ExactTopics []string

// DisplayName is a "dn".
// A filename to display to the user, for convenience.
DisplayName string

// ExactLength is a "xl".
// The file size, in bytes
ExactLength int64

// Trackers is a "tr".
Trackers []string

// WebSeed is a "ws".
// The payload data served over HTTP(S)
// TODO(cristaloleg): clarify is this string or []string.

// AcceptableSources is "as".
// Refers to a direct download from a web server.
AcceptableSources []string

// ExactSource is a "xs".
ExactSource []string

// KeywordTopic is a "kt".
// Specifies a string of search keywords to search for in P2P networks, rather than a particular file.
KeywordTopic []string

// ManifestTopic is a "mt".
// Link to the metafile that contains a list of magneto.
ManifestTopic string

// Select Only
// Lists specific files torrent clients should download.
// TODO(cristaloleg): implement BEP53.

// Extra is a "x." and other unparsed params.
Extra map[string][]string
}

var errNoPrefix = errors.New("magnet URI prefix not found")

// Parse magnet URI.
func Parse(raw string) (*Magnet, error) {
if !strings.HasPrefix(raw, magnetPrefix) {
return nil, errNoPrefix
}

parts := strings.Split(raw, magnetPrefix)
if len(parts) <= 1 {
return nil, errNoPrefix
}

m := &Magnet{
Extra: make(map[string][]string),
}

exactTopics := make(map[string]struct{})
trackers := make(map[string]struct{})
acceptableSources := make(map[string]struct{})

params := strings.Split(parts[1], "&")

for _, param := range params {
params := strings.Split(param, "=")
if len(params) < 2 || params[1] == "" {
continue
}

switch key, value := params[0], params[1]; key {
case "dn":
decoded, err := url.QueryUnescape(value)
if err != nil {
return nil, err
}
m.DisplayName = decoded

case "xt":
exactTopics[value] = struct{}{}

case "kt":
m.KeywordTopic = append(m.KeywordTopic, strings.Split(value, "+")...)

case "mt":
m.ManifestTopic = value

case "tr":
v, err := url.QueryUnescape(value)
if err != nil {
return nil, err
}
trackers[v] = struct{}{}

case "as":
v, err := url.QueryUnescape(value)
if err != nil {
return nil, err
}
acceptableSources[v] = struct{}{}

case "xl":
size, err := strconv.ParseInt(value, 10, 64)
if err != nil {
return nil, err
}
m.ExactLength = size

case "xs":
v, err := url.QueryUnescape(value)
if err != nil {
return nil, err
}
m.ExactSource = append(m.ExactSource, v)

default:
v, err := url.QueryUnescape(value)
if err != nil {
return nil, err
}
m.Extra[key] = append(m.Extra[key], v)
}
}

m.ExactTopics = make([]string, 0, len(exactTopics))
for topic := range exactTopics {
m.ExactTopics = append(m.ExactTopics, topic)
}

m.Trackers = make([]string, 0, len(trackers))
for tracker := range trackers {
m.Trackers = append(m.Trackers, tracker)
}

m.AcceptableSources = make([]string, 0, len(acceptableSources))
for as := range acceptableSources {
m.AcceptableSources = append(m.AcceptableSources, as)
}
return m, nil
}

// Normalize will sort all fields with multiple values.
func (m *Magnet) Normalize() {
sort.Strings(m.ExactTopics)
sort.Strings(m.Trackers)
sort.Strings(m.AcceptableSources)
sort.Strings(m.ExactSource)
sort.Strings(m.KeywordTopic)
for _, v := range m.Extra {
sort.Strings(v)
}
}

// Encode magnet URI.
func (m *Magnet) Encode() string {
var b strings.Builder
// TODO(cristaloleg): calculate this dynamically or estimate.
b.Grow(512)

b.WriteString(magnetPrefix)
b.WriteString("dn=")
b.WriteString(url.QueryEscape(m.DisplayName))

for _, xt := range m.ExactTopics {
b.WriteString("&xt=")
b.WriteString(xt)
}

if m.ExactLength > 0 {
b.WriteString("&xl=")
b.WriteString(strconv.FormatInt(m.ExactLength, 10))
}

for _, tr := range m.Trackers {
b.WriteString("&tr=")
b.WriteString(url.QueryEscape(tr))
}

// TODO(cristaloleg): add ws.

for _, as := range m.AcceptableSources {
b.WriteString("&as=")
b.WriteString(url.QueryEscape(as))
}

for _, xs := range m.ExactSource {
b.WriteString("&xs=")
b.WriteString(url.QueryEscape(xs))
}

if len(m.KeywordTopic) > 0 {
b.WriteString("&kt=")
b.WriteString(strings.Join(m.KeywordTopic, "+"))
}

if m.ManifestTopic != "" {
b.WriteString("&mt=")
b.WriteString(m.ManifestTopic)
}

// TODO(cristaloleg): add so.

for key, param := range m.Extra {
for _, paramValue := range param {
b.WriteByte('&')
b.WriteString(key)
b.WriteByte('=')
b.WriteString(paramValue)
}
}
return b.String()
}

0 comments on commit 97c18c3

Please sign in to comment.