Markdown improvements

app/src/main/java/eu/faircode/email/Markdown.java

@@ -31,15 +31,21 @@ import org.commonmark.ext.task.list.items.TaskListItemsExtension;
 import org.commonmark.node.Node;
 import org.commonmark.parser.Parser;
 import org.commonmark.renderer.html.HtmlRenderer;
+import org.jsoup.nodes.Document;
+import org.jsoup.nodes.Element;
+import org.jsoup.select.Elements;
 
 import java.util.Arrays;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 public class Markdown {
     static String toHtml(String markdown) {
         // https://github.com/commonmark/commonmark-java#usage
         // https://github.com/commonmark/commonmark-java/issues/294
         markdown = markdown.replace('\u00a0', ' ');
+
         List<Extension> extensions = Arrays.asList(
                 InsExtension.create(),
                 TaskListItemsExtension.create(),
@@ -55,23 +61,73 @@ public class Markdown {
         String html = r.render(d);
         if (BuildConfig.DEBUG) {
             Log.i("Markdown md=" + markdown.replace('\n', '|'));
-            Log.i("Markdown html=" + markdown.replace('\n', '|'));
+            Log.i("Markdown html=" + html.replace('\n', '|'));
         }
         return html;
     }
 
     static String fromHtml(String html) {
         // https://github.com/vsch/flexmark-java/wiki/Extensions#html-to-markdown
+        Map<String, String> specialCharsMap = new HashMap<>();
+        //specialCharsMap.put("“", "\"");
+        //specialCharsMap.put("”", "\"");
+        specialCharsMap.put("&ldquo;", "\"");
+        specialCharsMap.put("&rdquo;", "\"");
+        //specialCharsMap.put("‘", "'");
+        //specialCharsMap.put("’", "'");
+        specialCharsMap.put("&lsquo;", "'");
+        specialCharsMap.put("&rsquo;", "'");
+        specialCharsMap.put("&apos;", "'");
+        //specialCharsMap.put("«", "<<");
+        specialCharsMap.put("&laquo;", "<<");
+        //specialCharsMap.put("»", ">>");
+        specialCharsMap.put("&raquo;", ">>");
+        //specialCharsMap.put("…", "...");
+        specialCharsMap.put("&hellip;", "...");
+        //specialCharsMap.put("–", "--");
+        specialCharsMap.put("&endash;", "--");
+        //specialCharsMap.put("—", "---");
+        specialCharsMap.put("&emdash;", "---");
+
         DataHolder options = new MutableDataSet()
                 .set(FlexmarkHtmlConverter.SETEXT_HEADINGS, false)
+                .set(FlexmarkHtmlConverter.OUTPUT_ATTRIBUTES_ID, false)
+                .set(FlexmarkHtmlConverter.TYPOGRAPHIC_REPLACEMENT_MAP, specialCharsMap)
                 .toImmutable();
+
+        // Remove nested/empty tables
+        Document doc = JsoupEx.parse(html);
+        for (Element table : doc.select("table")) {
+            boolean empty = false;
+            Elements children = table.children().select("table");
+            if (children.size() == 0)
+                for (Element tr : table.children()) {
+                    if (tr.children().size() == 1) {
+                        empty = true;
+                        break;
+                    }
+                    if (empty)
+                        break;
+                }
+            if (children.size() > 0 || empty) {
+                table.tagName("div");
+                for (Element child : table.children())
+                    if ("tr".equals(child.tagName()))
+                        child.tagName("div");
+                    else if ("td".equals(child.tagName()))
+                        child.tagName("span");
+            }
+        }
+
         String markdown = FlexmarkHtmlConverter.builder(options)
                 .build()
-                .convert(html);
+                .convert(doc.html());
+
         if (BuildConfig.DEBUG) {
-            Log.i("Markdown html=" + markdown.replace('\n', '|'));
+            Log.i("Markdown html=" + html.replace('\n', '|'));
             Log.i("Markdown md=" + markdown.replace('\n', '|'));
         }
+
         return markdown
                 .replaceAll("(?m)^( *)(\\d+)\\.( +)", "$1$2\\\\.$3")
                 .replaceAll("<br />", "")