From dcd79702dbad26cba3918473142e4bbf4051f670 Mon Sep 17 00:00:00 2001
From: Peter Stuifzand <peter@stuifzand.eu>
Date: Wed, 29 Aug 2018 20:29:54 +0200
Subject: [PATCH] Fetch microsub endpoint from user (and use it)

---
 package.json                  |   1 +
 src/components/LoginModal.vue |  49 ++++++++++------
 src/helpers/rel-scraper.js    | 103 ++++++++++++++++++++++++++++++++++
 src/store.js                  |   8 +--
 4 files changed, 139 insertions(+), 22 deletions(-)
 create mode 100644 src/helpers/rel-scraper.js

diff --git a/package.json b/package.json
index a327b9b..740516b 100644
--- a/package.json
+++ b/package.json
@@ -8,6 +8,7 @@
     "lint": "vue-cli-service lint"
   },
   "dependencies": {
+    "isomorphic-fetch": "^2.2.1",
     "micropub-helper": "^1.4.0",
     "node-sass": "^4.9.3",
     "vue": "^2.5.17",
diff --git a/src/components/LoginModal.vue b/src/components/LoginModal.vue
index 44415e5..c977132 100644
--- a/src/components/LoginModal.vue
+++ b/src/components/LoginModal.vue
@@ -26,6 +26,7 @@
 <script>
   import Micropub from 'micropub-helper';
   import helper from '@/helpers';
+  import relScraper from '@/helpers/rel-scraper'
 
   const CLIENT_ID = 'https://p83.nl/'
 
@@ -61,14 +62,14 @@
           state: state,
           scope: 'create post channels timeline'
         })
+
         micropub.getAuthUrl().then(url => {
           let options = {
-            micropubEndpoint: micropub.options.micropubEndpoint,
-            tokenEndpoint: micropub.options.tokenEndpoint,
             loginState: state
           }
-          this.$store.dispatch('saveEndpoints', options)
-          window.location = url
+          this.$store.dispatch('saveEndpoints', options).then(() => {
+            window.location = url
+          })
           // eslint-disable-next-line
         }).catch(err => console.log(err))
       }
@@ -92,22 +93,36 @@
         me: this.$route.query['me'],
         state: this.$store.state.loginState,
         scope: 'create post channels timeline',
-        tokenEndpoint: this.$store.state.tokenEndpoint
       })
 
-      micropub
-        .getToken(code)
-        .then(token => {
-          this.$store.dispatch('tokenResponse', {
-            access_token: token,
-            me: micropub.options.me,
-            scope: micropub.options.scope
+      relScraper(this.$route.query['me']).then(rels => {
+        micropub.options.tokenEndpoint = rels.token_endpoint
+        micropub.options.authEndpoint = rels.auth_endpoint
+        micropub.options.micropubEndpoint = rels.micropub
+
+        let options = {
+          tokenEndpoint: rels.token_endpoint,
+          authEndpoint: rels.auth_endpoint,
+          micropubEndpoint: rels.micropub,
+          microsubEndpoint: rels.microsub
+        }
+
+        this.$store.dispatch('saveEndpoints', options)
+
+        micropub
+          .getToken(code)
+          .then(token => {
+            this.$store.dispatch('tokenResponse', {
+              access_token: token,
+              me: micropub.options.me,
+              scope: micropub.options.scope
+            })
+            this.show = false
+            this.$router.push('/')
           })
-          this.show = false
-          this.$router.push('/')
-        })
-        // eslint-disable-next-line
-        .catch(err => console.log(err));
+          // eslint-disable-next-line
+          .catch(err => console.log(err));
+      })
     }
   }
 </script>
diff --git a/src/helpers/rel-scraper.js b/src/helpers/rel-scraper.js
new file mode 100644
index 0000000..68a5d5f
--- /dev/null
+++ b/src/helpers/rel-scraper.js
@@ -0,0 +1,103 @@
+import fetch from 'isomorphic-fetch'
+
+export default function(url) {
+  let baseUrl = url;
+  let endpoints = {
+    micropub: null,
+    microsub: null,
+    authorization_endpoint: null,
+    token_endpoint: null,
+    media_endpoint: null,
+  };
+
+  return new Promise((resolve, reject) => {
+    fetch(url)
+      .then(res => {
+        if (!res.ok) {
+          return reject('Error getting page');
+        }
+        baseUrl = res.url;
+
+        // Check for endpoints in headers
+        const linkHeaders = res.headers.get('link');
+        if (linkHeaders) {
+          const links = linkHeaders.split(',');
+          links.forEach(link => {
+            Object.keys(endpoints).forEach(key => {
+              const rel = link.match(/rel=("([^"]*)"|([^,"<]+))/);
+              if (
+                rel &&
+                rel[1] &&
+                (' ' + rel[1].toLowerCase() + ' ').indexOf(' ' + key + ' ') >= 0
+              ) {
+                const linkValues = link.match(/[^<>|\s]+/g);
+                if (linkValues && linkValues[0]) {
+                  let endpointUrl = linkValues[0];
+                  endpointUrl = new URL(endpointUrl, url).toString();
+                  endpoints[key] = endpointUrl;
+                }
+              }
+            });
+          });
+        }
+        return res.text();
+      })
+      .then(html => {
+        // Get rel links
+        const rels = htmlScraper(html, baseUrl);
+
+        // Save necessary endpoints.
+        if (rels) {
+          Object.keys(endpoints).forEach(key => {
+            if (rels[key] && rels[key][0]) {
+              endpoints[key] = rels[key][0];
+            }
+          });
+        }
+        return resolve(endpoints);
+      })
+      .catch(err => {
+        // eslint-disable-next-line
+        console.log(err);
+        reject('Error fetching url');
+      });
+  });
+}
+
+function htmlScraper(htmlString, url) {
+  let rels = {};
+  let baseUrl = url;
+
+  const doc = new DOMParser().parseFromString(htmlString, 'text/html');
+  const baseEl = doc.querySelector('base[href]');
+  const relEls = doc.querySelectorAll('[rel][href]');
+
+  if (baseEl) {
+    const value = baseEl.getAttribute('href');
+    const url = new URL(value, url);
+    baseUrl = url.toString();
+  }
+
+  if (relEls.length) {
+    relEls.forEach(relEl => {
+      const names = relEl
+        .getAttribute('rel')
+        .toLowerCase()
+        .split('\\s+');
+      const value = relEl.getAttribute('href');
+      if (names.length && value !== null) {
+        names.forEach(name => {
+          if (!rels[name]) {
+            rels[name] = [];
+          }
+          const url = new URL(value, baseUrl).toString();
+          if (rels[name].indexOf(url) === -1) {
+            rels[name].push(url)
+          }
+        })
+      }
+    })
+  }
+
+  return rels
+}
diff --git a/src/store.js b/src/store.js
index d3cffd2..13d4670 100644
--- a/src/store.js
+++ b/src/store.js
@@ -2,8 +2,6 @@ import Vue from 'vue'
 import Vuex from 'vuex'
 import Micropub from 'micropub-helper';
 
-const baseurl = "https://microsub.stuifzandapp.com/microsub"
-
 Vue.use(Vuex)
 
 export default new Vuex.Store({
@@ -54,7 +52,7 @@ export default new Vuex.Store({
 
   actions: {
     fetchChannels({commit}) {
-      fetch(baseurl + '?action=channels', {
+      fetch(this.state.microsubEndpoint + '?action=channels', {
         headers: {
           'Authorization': 'Bearer ' + this.state.access_token
         }
@@ -68,7 +66,7 @@ export default new Vuex.Store({
       commit('clearTimeline', {channel: channel})
     },
     fetchTimeline({commit}, channel) {
-      let url = baseurl + '?action=timeline&channel=' + channel.uid
+      let url = this.state.microsubEndpoint + '?action=timeline&channel=' + channel.uid
       if (channel.after) {
         url += '&after=' + channel.after;
       }
@@ -99,7 +97,7 @@ export default new Vuex.Store({
       commit('newAccessToken', response)
     },
     markRead(x, {channel, entry}) {
-      let url = baseurl + '?action=timeline&method=mark_read&channel=' + encodeURIComponent(channel) + '&entry=' + encodeURIComponent(entry);
+      let url = this.state.microsubEndpoint + '?action=timeline&method=mark_read&channel=' + encodeURIComponent(channel) + '&entry=' + encodeURIComponent(entry);
       return fetch(url, {
         method: 'POST',
         headers: {