From 01f1b8481feaa6a8f72e838b6cdb402658caa50b Mon Sep 17 00:00:00 2001
From: Vishesh Handa <me@vhanda.in>
Date: Tue, 11 Aug 2020 13:58:52 +0200
Subject: [PATCH] Add scaffolding for an inline tag processor

This is just a simple test to extract the inline tags, it hasn't been
hooked up to anything.

Related to #44
---
 lib/core/processors/inline_tags.dart  | 28 +++++++++++++++++++++++++++
 test/processors/inline_tags_test.dart | 28 +++++++++++++++++++++++++++
 2 files changed, 56 insertions(+)
 create mode 100644 lib/core/processors/inline_tags.dart
 create mode 100644 test/processors/inline_tags_test.dart

diff --git a/lib/core/processors/inline_tags.dart b/lib/core/processors/inline_tags.dart
new file mode 100644
index 00000000..b7fcfa5a
--- /dev/null
+++ b/lib/core/processors/inline_tags.dart
@@ -0,0 +1,28 @@
+import 'package:gitjournal/core/note.dart';
+
+class InlineTagsProcessor {
+  // FIXME: Make me configurable
+  final List<String> tagPrefixes = ['#'];
+
+  void process(Note note) {}
+
+  Set<String> extractTags(String text) {
+    var tags = <String>{};
+
+    for (var prefix in tagPrefixes) {
+      var regexp = RegExp(r'(^|\s)' + prefix + r'([^ ]+)(\s|$)');
+      var matches = regexp.allMatches(text);
+      for (var match in matches) {
+        var tag = match.group(2);
+
+        if (tag.endsWith('.') || tag.endsWith('!') || tag.endsWith('?')) {
+          tag = tag.substring(0, tag.length - 1);
+        }
+
+        tags.add(tag);
+      }
+    }
+
+    return tags;
+  }
+}
diff --git a/test/processors/inline_tags_test.dart b/test/processors/inline_tags_test.dart
new file mode 100644
index 00000000..9aa9d9bb
--- /dev/null
+++ b/test/processors/inline_tags_test.dart
@@ -0,0 +1,28 @@
+import 'package:test/test.dart';
+
+import 'package:gitjournal/core/processors/inline_tags.dart';
+
+void main() {
+  test('Should parse simple tags', () {
+    var body = "#hello Hi\nthere how#are you #doing now? #dog";
+
+    var p = InlineTagsProcessor();
+    var tags = p.extractTags(body);
+
+    expect(tags, {'hello', 'doing', 'dog'});
+  });
+
+  test('Ignore . at the end of a tag', () {
+    var body = "Hi there #tag.";
+
+    var p = InlineTagsProcessor();
+    var tags = p.extractTags(body);
+
+    expect(tags, {'tag'});
+  });
+
+  // #a#b should be counted as two tags
+  // + should work as a prefix
+  // @ should work as a prefix
+  // test for tags with non-ascii words
+}