shrmpy/butler-oauth.go

## butler-oauth.go
package main

import (
        "fmt"
        "net"
        "net/http"
        "net/url"
        "regexp"
)

func main() {
        var err = AuthenticateViaOauth()
        if err != nil {
                fmt.Printf("DEBUG bad outcome, %v\n", err.Error())
        }
        fmt.Println("INFO done")
}

const (
        authHTML = `
        <!DOCTYPE html>
        <html>
        <head>
        </head>
        <body>
          <pre id="art"></pre>
          <p id="message">
            Authenticating...
          </p>
          <script>
          'use strict'
          var key = location.hash.replace(/^#/, '')
          location.hash = 'ok'
          var xhr = new XMLHttpRequest()
          var $message = document.querySelector("#message")
          var $art = document.querySelector("#art")
          xhr.onload = function () {
            $art.innerHTML = xhr.responseText
            $message.innerHTML = "You're successfully authenticated! You can close this page."
          }
          xhr.onerror = function () {
            $message.innerHTML = "Copy the following code back in your terminal: " + key
          }
          xhr.open("POST", "/oauth/callback/" + key)
          xhr.send()
          </script>
        </body>
      </html>`
)

var callbackRe = regexp.MustCompile(`^\/oauth\/callback\/(.*)$`)

func AuthenticateViaOauth() error {
        var err error
        var done = make(chan string)
        defer close(done)

        var handler = func(w http.ResponseWriter, r *http.Request) {
                matches := callbackRe.FindStringSubmatch(r.RequestURI)
                if matches != nil {
                        w.Header().Set("Content-Type", "text/plain")
                        fmt.Fprintf(w, "todo request /wharf/status")
                        done <- matches[1]
                        return
                }

                w.Header().Set("Content-Type", "text/html")
                fmt.Fprintf(w, "%s", authHTML)
        }

        http.HandleFunc("/", handler)

        // if we're running `butler login` remotely, we're asking the user to copy-paste
        var addr = "127.0.0.1:226"
        var listener net.Listener
        if listener, err = net.Listen("tcp", "127.0.0.1:0"); err != nil {
                panic(err)
        }
        addr = listener.Addr().String()

        go func() {
                // spin up local web srv to expect the redirect
                if err := http.Serve(listener, nil); err != nil {
                        panic(err)
                }
        }()

        var params = url.Values{}
        params.Add("client_id", "butler")
        params.Add("scope", "wharf")
        params.Add("response_type", "token")
        params.Add("redirect_uri", fmt.Sprintf("http://%s/oauth/callback", addr))
        var query = params.Encode()

        var uri = fmt.Sprintf("https://itch.io/user/oauth?%s", query)

        fmt.Printf("DEBUG to oauth use web browser to visit, %s \n", uri)
        select {
        case key := <-done:
                // todo request /wharf/status to exercise the API (token)
                fmt.Printf("DEBUG token rcvd, %s \n", key)
                return nil
        }
        return err
}
	package main

	import (
	"fmt"
	"net"
	"net/http"
	"net/url"
	"regexp"
	)

	func main() {
	var err = AuthenticateViaOauth()
	if err != nil {
	fmt.Printf("DEBUG bad outcome, %v\n", err.Error())
	}
	fmt.Println("INFO done")
	}

	const (
	authHTML = `
	<!DOCTYPE html>
	<html>
	<head>
	</head>
	<body>
	<pre id="art"></pre>
	<p id="message">
	Authenticating...
	</p>
	<script>
	'use strict'
	var key = location.hash.replace(/^#/, '')
	location.hash = 'ok'
	var xhr = new XMLHttpRequest()
	var $message = document.querySelector("#message")
	var $art = document.querySelector("#art")
	xhr.onload = function () {
	$art.innerHTML = xhr.responseText
	$message.innerHTML = "You're successfully authenticated! You can close this page."
	}
	xhr.onerror = function () {
	$message.innerHTML = "Copy the following code back in your terminal: " + key
	}
	xhr.open("POST", "/oauth/callback/" + key)
	xhr.send()
	</script>
	</body>
	</html>`
	)

	var callbackRe = regexp.MustCompile(`^\/oauth\/callback\/(.*)$`)

	func AuthenticateViaOauth() error {
	var err error
	var done = make(chan string)
	defer close(done)

	var handler = func(w http.ResponseWriter, r *http.Request) {
	matches := callbackRe.FindStringSubmatch(r.RequestURI)
	if matches != nil {
	w.Header().Set("Content-Type", "text/plain")
	fmt.Fprintf(w, "todo request /wharf/status")
	done <- matches[1]
	return
	}

	w.Header().Set("Content-Type", "text/html")
	fmt.Fprintf(w, "%s", authHTML)
	}

	http.HandleFunc("/", handler)

	// if we're running `butler login` remotely, we're asking the user to copy-paste
	var addr = "127.0.0.1:226"
	var listener net.Listener
	if listener, err = net.Listen("tcp", "127.0.0.1:0"); err != nil {
	panic(err)
	}
	addr = listener.Addr().String()

	go func() {
	// spin up local web srv to expect the redirect
	if err := http.Serve(listener, nil); err != nil {
	panic(err)
	}
	}()

	var params = url.Values{}
	params.Add("client_id", "butler")
	params.Add("scope", "wharf")
	params.Add("response_type", "token")
	params.Add("redirect_uri", fmt.Sprintf("http://%s/oauth/callback", addr))
	var query = params.Encode()

	var uri = fmt.Sprintf("https://itch.io/user/oauth?%s", query)

	fmt.Printf("DEBUG to oauth use web browser to visit, %s \n", uri)
	select {
	case key := <-done:
	// todo request /wharf/status to exercise the API (token)
	fmt.Printf("DEBUG token rcvd, %s \n", key)
	return nil
	}
	return err
	}