From 6790158ed960ad25a55135870aac08bb1da4571a Mon Sep 17 00:00:00 2001
From: Thomas <tschneider.ac@gmail.com>
Date: Sun, 6 Aug 2023 18:13:08 +0200
Subject: [PATCH] Support Markdown

---
 app/build.gradle                              |  2 +
 .../entities/app/MarkdownConverter.java       | 41 +++++++++++++++++++
 .../mastodon/helper/SpannableHelper.java      | 40 +++++++++++++++++-
 3 files changed, 82 insertions(+), 1 deletion(-)
 create mode 100644 app/src/main/java/app/fedilab/android/mastodon/client/entities/app/MarkdownConverter.java

diff --git a/app/build.gradle b/app/build.gradle
index cab8fabe1..beb7c2618 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -185,6 +185,8 @@ dependencies {
     implementation 'com.github.vkay94:DoubleTapPlayerView:1.0.0'
 
 
+    implementation 'io.noties.markwon:core:4.6.2'
+
     //************ CAST **************///
 
     //---> Google libs (google_full)
diff --git a/app/src/main/java/app/fedilab/android/mastodon/client/entities/app/MarkdownConverter.java b/app/src/main/java/app/fedilab/android/mastodon/client/entities/app/MarkdownConverter.java
new file mode 100644
index 000000000..54dd38d58
--- /dev/null
+++ b/app/src/main/java/app/fedilab/android/mastodon/client/entities/app/MarkdownConverter.java
@@ -0,0 +1,41 @@
+package app.fedilab.android.mastodon.client.entities.app;
+/* Copyright 2023 Thomas Schneider
+ *
+ * This file is a part of Fedilab
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * Fedilab is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
+ * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with Fedilab; if not,
+ * see <http://www.gnu.org/licenses>. */
+
+import android.text.style.URLSpan;
+
+import java.util.List;
+
+public class MarkdownConverter {
+
+    public List<MarkdownItem> markdownItems;
+
+    public MarkdownItem getByPosition(int position) {
+        if (markdownItems != null && markdownItems.size() > 0 && position < markdownItems.size()) {
+            for (MarkdownItem markdownItem : markdownItems) {
+                if (markdownItem.position == position) {
+                    return markdownItem;
+                }
+            }
+        }
+        return null;
+    }
+
+    public static class MarkdownItem {
+        public String code;
+        public int position;
+        public URLSpan urlSpan;
+    }
+}
diff --git a/app/src/main/java/app/fedilab/android/mastodon/helper/SpannableHelper.java b/app/src/main/java/app/fedilab/android/mastodon/helper/SpannableHelper.java
index 00549a0dc..50c4d847c 100644
--- a/app/src/main/java/app/fedilab/android/mastodon/helper/SpannableHelper.java
+++ b/app/src/main/java/app/fedilab/android/mastodon/helper/SpannableHelper.java
@@ -84,9 +84,11 @@ import app.fedilab.android.mastodon.client.entities.api.Emoji;
 import app.fedilab.android.mastodon.client.entities.api.Filter;
 import app.fedilab.android.mastodon.client.entities.api.Mention;
 import app.fedilab.android.mastodon.client.entities.api.Status;
+import app.fedilab.android.mastodon.client.entities.app.MarkdownConverter;
 import app.fedilab.android.mastodon.ui.drawer.StatusAdapter;
 import app.fedilab.android.mastodon.viewmodel.mastodon.FiltersVM;
 import es.dmoral.toasty.Toasty;
+import io.noties.markwon.Markwon;
 
 public class SpannableHelper {
 
@@ -149,7 +151,43 @@ public class SpannableHelper {
         }
 
         //Get all links
-        SpannableStringBuilder content = new SpannableStringBuilder(initialContent);
+        MarkdownConverter markdownConverter = new MarkdownConverter();
+        markdownConverter.markdownItems = new ArrayList<>();
+        int next;
+        int position = 0;
+        for (int i = 0; i < initialContent.length(); i = next) {
+            // find the next span transition
+            next = initialContent.nextSpanTransition(i, initialContent.length(), URLSpan.class);
+            MarkdownConverter.MarkdownItem markdownItem = new MarkdownConverter.MarkdownItem();
+            markdownItem.code = initialContent.subSequence(i, next).toString();
+
+            markdownItem.position = position;
+            // get all spans in this range
+            URLSpan[] spans = initialContent.getSpans(i, next, URLSpan.class);
+            if (spans != null && spans.length > 0) {
+                markdownItem.urlSpan = spans[0];
+            }
+
+            if (markdownItem.code.trim().length() > 0) {
+                markdownConverter.markdownItems.add(markdownItem);
+                position++;
+            }
+        }
+        final Markwon markwon = Markwon.create(context);
+
+        final Spanned markdown = markwon.toMarkdown(initialContent.toString());
+        SpannableStringBuilder content = new SpannableStringBuilder(markdown);
+        position = 0;
+        for (MarkdownConverter.MarkdownItem markdownItem : markdownConverter.markdownItems) {
+            Pattern p = Pattern.compile("(" + Pattern.quote(markdownItem.code) + ")", Pattern.CASE_INSENSITIVE);
+            Matcher m = p.matcher(content);
+            while (m.find()) {
+                content.setSpan(markdownItem.urlSpan, m.start(), m.end(), Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
+            }
+            position++;
+        }
+
+
         URLSpan[] urls = content.getSpans(0, (content.length() - 1), URLSpan.class);
         //Loop through links
         for (URLSpan span : urls) {