From c6183dce061302571bb49601b247c9438706589e Mon Sep 17 00:00:00 2001
From: Jamie Mansfield <jmansfield@cadixdev.org>
Date: Wed, 7 Apr 2021 12:22:00 +0100
Subject: [PATCH] Support OAuth servers using standard responses

---
 api/form.go | 66 +++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 57 insertions(+), 9 deletions(-)

diff --git a/api/form.go b/api/form.go
index 2b370a4..9856b9f 100644
--- a/api/form.go
+++ b/api/form.go
@@ -1,12 +1,14 @@
 package api
 
 import (
+	"encoding/json"
 	"fmt"
 	"io"
 	"io/ioutil"
+	"mime"
 	"net/http"
 	"net/url"
-	"strings"
+	"strconv"
 )
 
 type httpClient interface {
@@ -18,12 +20,16 @@ type FormResponse struct {
 	StatusCode int
 
 	requestURI string
-	values     url.Values
+	values     map[string]string
 }
 
 // Get the response value named k.
 func (f FormResponse) Get(k string) string {
-	return f.values.Get(k)
+	v, ok := f.values[k]
+	if !ok {
+		return ""
+	}
+	return v
 }
 
 // Err returns an Error object extracted from the response.
@@ -69,19 +75,40 @@ func PostForm(c httpClient, u string, params url.Values) (*FormResponse, error)
 	r := &FormResponse{
 		StatusCode: resp.StatusCode,
 		requestURI: u,
+		values:     make(map[string]string),
 	}
 
-	if contentType(resp.Header.Get("Content-Type")) == formType {
+	// since mine.ParseMediaType always returns the media type regardless of error, and
+	// that we don't use the params - we can just ignore any errors.
+	mediaType, _, _ := mime.ParseMediaType(resp.Header.Get("Content-Type"))
+
+	if mediaType == formType {
+		var bb []byte
+		bb, err = ioutil.ReadAll(resp.Body)
+		if err != nil {
+			return r, err
+		}
+
+		values, err := url.ParseQuery(string(bb))
+		if err != nil {
+			return r, err
+		}
+
+		readFormValues(r, values)
+	} else if mediaType == jsonType {
 		var bb []byte
 		bb, err = ioutil.ReadAll(resp.Body)
 		if err != nil {
 			return r, err
 		}
 
-		r.values, err = url.ParseQuery(string(bb))
+		var values map[string]interface{}
+		err = json.Unmarshal(bb, &values)
 		if err != nil {
 			return r, err
 		}
+
+		readJsonValues(r, values)
 	} else {
 		_, err = io.Copy(ioutil.Discard, resp.Body)
 		if err != nil {
@@ -93,10 +120,31 @@ func PostForm(c httpClient, u string, params url.Values) (*FormResponse, error)
 }
 
 const formType = "application/x-www-form-urlencoded"
+const jsonType = "application/json"
+
+// readFormValues feeds information from a url.Values into a FormResponse's values
+// map.
+func readFormValues(r *FormResponse, values url.Values) {
+	for key, value := range values {
+		if len(value) < 1 {
+			continue
+		}
 
-func contentType(t string) string {
-	if i := strings.IndexRune(t, ';'); i >= 0 {
-		return t[0:i]
+		r.values[key] = value[0]
+	}
+}
+
+// readJsonValues feeds information from an un-marshaled JSON response into a
+// FormResponse's values map.
+func readJsonValues(r *FormResponse, values map[string]interface{}) {
+	for key, value := range values {
+		// Go's JSON library uses float64 and int64 for numbers.
+		if v, ok := value.(string); ok {
+			r.values[key] = v
+		} else if v, ok := value.(int64); ok {
+			r.values[key] = strconv.FormatInt(v, 10)
+		} else if v, ok := value.(float64); ok {
+			r.values[key] = strconv.FormatFloat(v, 'f', -1, 64)
+		}
 	}
-	return t
 }