feat(tui): add Unicode text service and document layout

1 files changed, 75 insertions, 0 deletions

diff --git a/src/tui/text.hh b/src/tui/text.hh
new file mode 100644
index 0000000..c2d4af9
--- /dev/null
+++ b/src/tui/text.hh
@@ -0,0 +1,75 @@
+/*
+ * Ricochet - A minimalist CLI web browser for fast, distraction-free navigation.
+ * Copyright (C) 2026  Richard Qin
+ *
+ * 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.
+ *
+ * This program 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 this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "ricochet/tui/position.hh"
+
+#include <cstddef>
+#include <cstdint>
+#include <string>
+#include <string_view>
+#include <vector>
+
+namespace ricochet::tui::detail {
+
+enum class TextUnitKind : std::uint8_t
+{
+  Glyph,
+  LineBreak,
+  Tab
+};
+enum class WordKind : std::uint8_t
+{
+  Space,
+  Word,
+  Ideograph,
+  Punctuation
+};
+
+struct Grapheme
+{
+  ByteRange bytes {};
+  std::wstring display {};
+  int columns { 1 };
+  TextUnitKind kind { TextUnitKind::Glyph };
+  WordKind word { WordKind::Punctuation };
+  bool break_after { false };
+};
+
+struct TextAnalysis
+{
+  std::vector<Grapheme> graphemes {};
+  // Vim-style reading units: letters/numbers/underscore, punctuation runs,
+  // individual ideographs. Whitespace is excluded; offsets remain UTF-8 bytes.
+  std::vector<ByteRange> words {};
+};
+
+// Called on the UI thread in the same UTF-8 locale as Screen. ICU owns Unicode
+// segmentation/properties; POSIX wcwidth owns terminal widths. No curses types.
+class TextService
+{
+public:
+  explicit TextService( std::size_t glyph_capacity );
+  TextAnalysis analyze( std::string_view utf8, bool line_breaks, bool tabs ) const;
+
+private:
+  std::size_t glyph_capacity_;
+};
+
+} // namespace ricochet::tui::detail