feat(tui): add ncurses backend and session loop

1 files changed, 76 insertions, 0 deletions

diff --git a/ricochet/src/tui/screen.hh b/ricochet/src/tui/screen.hh
new file mode 100644
index 0000000..f0df278
--- /dev/null
+++ b/ricochet/src/tui/screen.hh
@@ -0,0 +1,76 @@
+/*
+ * 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/document.hh"
+#include "ricochet/tui/session.hh"
+
+#include <chrono>
+#include <cstddef>
+#include <cstdio>
+#include <memory>
+#include <optional>
+#include <string>
+#include <vector>
+
+namespace ricochet::tui::detail {
+
+// Layout supplies one printable spacing character and its combining marks per
+// glyph, with a measured width. Raw document text never goes directly to curses.
+struct PaintGlyph
+{
+  CellPoint position {};
+  int width { 1 };
+  std::wstring text {};
+  TextStyle style {};
+};
+
+struct Frame
+{
+  std::vector<PaintGlyph> glyphs {};
+  std::optional<CellPoint> cursor {};
+};
+
+struct InputBatch
+{
+  std::vector<InputEvent> events {};
+  bool consumed { false };
+};
+
+class Screen
+{
+public:
+  Screen( std::FILE& input, std::FILE& output, TerminalOptions options );
+  ~Screen();
+  Screen( const Screen& ) = delete;
+  Screen& operator=( const Screen& ) = delete;
+
+  ScreenSize size() const;
+  TerminalCapabilities capabilities() const;
+  InputBatch read_events( std::size_t limit );
+  // Wait only polls descriptors; wgetch remains the sole terminal reader.
+  std::optional<TerminalClosed> wait( int wake_fd, std::chrono::milliseconds max_wait );
+  void draw( const Frame& frame );
+
+private:
+  class Impl;
+  std::unique_ptr<Impl> impl_;
+};
+
+} // namespace ricochet::tui::detail