feat: implement command mode

3 files changed, 299 insertions, 16 deletions

diff --git a/src/game/game.cpp b/src/game/game.cpp
index 3127d40..0b3e85e 100644
--- a/src/game/game.cpp
+++ b/src/game/game.cpp
@@ -1,8 +1,12 @@
 #include "game.hpp"
 
 #include "engine/data/bounds.hpp"
+#include "engine/escape.hpp"
+#include "game/keycodes.hpp"
 #include "util/algorithm.hpp"
+#include "util/string.hpp"
 
+#include <fmt/color.h>
 #include <fmt/core.h>
 
 #include <algorithm>
@@ -24,7 +28,8 @@ Game::Game(
 	  _generation_tracker(std::move(generation_tracker)),
 	  _status_manager(std::move(status_manager)),
 	  _user_input_observer(std::move(user_input_observer)),
-	  _cell_helper(std::move(cell_helper))
+	  _cell_helper(std::move(cell_helper)),
+	  _current_mode(Mode::NORMAL)
 {
 }
 
@@ -35,7 +40,7 @@ void Game::on_start() noexcept
 	std::shared_ptr<IStatusLine> statusline =
 		_statusline_factory(Bounds({.width = scene_size.get_width(), .height = 1}));
 
-	_scene->register_component(statusline, Vector2({0, 0}));
+	_scene->register_component(statusline, Vector2({.x = 0, .y = 1}));
 
 	_status_manager->bind(statusline);
 
@@ -81,11 +86,49 @@ void Game::on_start() noexcept
 			scene_size.get_width(),
 			scene_size.get_height()));
 
-	_last_update_time = std::chrono::system_clock::now();
+	_commands["ping"] = CommandInfo(
+		{.option_cnt = 0,
+		 .function = [this](CommandInfo::Options /*options*/)
+		 {
+			 _erase_entire_line();
+
+			 const auto position = _cursor_controller->where();
+
+			 _cursor_controller->move_to(Vector2({.x = 0, .y = position.get_y()}));
+
+			 std::cout << "pong!";
+			 std::cout.flush();
+		 }});
 }
 
 void Game::on_update() noexcept
 {
+	if (_current_mode == Mode::COMMAND)
+	{
+		_on_command_mode_update();
+		return;
+	}
+
+	_on_normal_mode_update();
+}
+
+void Game::on_exit() const noexcept
+{
+	for (auto row : *_scene->get_matrix())
+	{
+		for (auto &col : row)
+		{
+			fmt::print("{}", col);
+		}
+
+		fmt::print("\n");
+	}
+
+	std::cout.flush();
+}
+
+void Game::_on_normal_mode_update() noexcept
+{
 	const auto pressed_key = _user_input_observer->get_currently_pressed_key();
 
 	auto cursor_has_moved = false;
@@ -124,6 +167,26 @@ void Game::on_update() noexcept
 	case 'q':
 		std::exit(EXIT_SUCCESS);
 
+	case ':':
+		_last_pos_before_command_mode = _cursor_controller->where();
+
+		_cursor_controller->move_to(Vector2({.x = 0, .y = 0}));
+
+		_erase_entire_line();
+
+		std::cout << ":";
+		std::cout.flush();
+
+		_cursor_controller->update_position(
+			_cursor_controller->where() + Vector2::right());
+
+		_cursor_controller->set_cursor_style(CursorStyle::BlinkingBar);
+
+		_command_mode_input = "";
+
+		_current_mode = Mode::COMMAND;
+		return;
+
 	case 'i':
 	{
 		const auto position = _cursor_controller->where();
@@ -208,7 +271,6 @@ void Game::on_update() noexcept
 
 	if (_generation_tracker->get_is_paused() && !is_generation_stepping)
 	{
-		_last_update_time = time_now;
 		return;
 	}
 
@@ -218,7 +280,6 @@ void Game::on_update() noexcept
 
 	if (time_since_last_gen.count() <= _min_time_since_last_gen_millis)
 	{
-		_last_update_time = time_now;
 		return;
 	}
 
@@ -261,23 +322,171 @@ void Game::on_update() noexcept
 		_set_space(matrix, birth_cell_pos, 'x');
 		_living_cell_positions.push_back(birth_cell_pos);
 	}
+}
+
+void Game::_on_command_mode_update() noexcept
+{
+	const auto pressed_key = _user_input_observer->get_currently_pressed_key();
+
+	switch (pressed_key)
+	{
+	case keycodes::ESCAPE:
+		_erase_entire_line();
+		_return_to_normal_mode();
+		break;
+
+	case keycodes::ENTER:
+		if (!_command_mode_input.empty())
+		{
+			_run_command(_command_mode_input);
+		}
+
+		if (_current_mode != Mode::NORMAL)
+		{
+			_return_to_normal_mode();
+		}
+
+		break;
+
+	case keycodes::BACKSPACE:
+	{
+		const auto position = _cursor_controller->where();
+
+		const auto input_pos_x = static_cast<uint32_t>(position.get_x()) - 1U;
+
+		if (input_pos_x == 0U)
+		{
+			break;
+		}
+
+		_command_mode_input.erase(input_pos_x - 1U, 1U);
+
+		_cursor_controller->move(Vector2::left(), 1U);
+
+		std::cout.put(' ');
+		std::cout.flush();
+
+		_cursor_controller->update_position(
+			_cursor_controller->where() + Vector2::right());
+
+		_cursor_controller->move(Vector2::left(), 1U);
+
+		_erase_line_from_cursor();
+
+		std::cout << _command_mode_input.substr(input_pos_x - 1U);
+		std::cout.flush();
+
+		_cursor_controller->move_to(position);
+		_cursor_controller->move(Vector2::left(), 1U);
 
-	_last_update_time = time_now;
+		break;
+	}
+
+	case keycodes::LEFT_ARROW:
+		if (_cursor_controller->where().get_x() >= 2)
+		{
+			_cursor_controller->move(Vector2::left(), 1U);
+		}
+		break;
+
+	case keycodes::RIGHT_ARROW:
+		if (static_cast<uint32_t>(_cursor_controller->where().get_x()) - 1U <
+			_command_mode_input.size())
+		{
+			_cursor_controller->move(Vector2::right(), 1U);
+		}
+		break;
+
+	case keycodes::UP_ARROW:
+	case keycodes::DOWN_ARROW:
+	case 0:
+		break;
+
+	default:
+		const auto position = _cursor_controller->where();
+
+		const auto input_pos_x = static_cast<uint32_t>(position.get_x()) - 1U;
+
+		if (input_pos_x < _command_mode_input.length())
+		{
+			_command_mode_input.insert(input_pos_x, 1, pressed_key);
+
+			_erase_line_from_cursor();
+
+			std::cout << pressed_key << _command_mode_input.substr(input_pos_x + 1U);
+			std::cout.flush();
+
+			_cursor_controller->move_to(position + Vector2::right());
+			break;
+		}
+
+		_command_mode_input += pressed_key;
+
+		std::cout << pressed_key;
+		std::cout.flush();
+
+		_cursor_controller->update_position(
+			_cursor_controller->where() + Vector2::right());
+
+		break;
+	}
 }
 
-void Game::on_exit() const noexcept
+void Game::_return_to_normal_mode() noexcept
 {
-	for (auto row : *_scene->get_matrix())
+	_cursor_controller->move_to(_last_pos_before_command_mode.value_or(
+		Vector2({.x = CURSOR_FALLBACK_POS_X, .y = CURSOR_FALLBACK_POS_Y})));
+
+	_cursor_controller->set_cursor_style(CursorStyle::BlinkingBlock);
+
+	_current_mode = Mode::NORMAL;
+}
+
+void Game::_run_command(const std::string &command) noexcept
+{
+	const auto split_command = split_string<std::vector<std::string>>(command, ' ');
+
+	if (split_command.size() == 1)
 	{
-		for (auto &col : row)
+		if (!_commands.contains(command))
 		{
-			fmt::print("{}", col);
+			_show_command_error(fmt::format("Error: Not a command: {}", command));
+			return;
 		}
 
-		fmt::print("\n");
+		if (_commands.at(command).option_cnt != 0U)
+		{
+			_show_command_error(
+				fmt::format("Error: Insufficient arguments for command: {}", command));
+			return;
+		}
 	}
 
-	std::cout.flush();
+	const auto &command_name = split_command[0];
+
+	if (!_commands.contains(command_name))
+	{
+		_show_command_error(fmt::format("Error: Not a command: {}", command));
+		return;
+	}
+
+	const auto &command_info = _commands.at(command_name);
+
+	const auto args =
+		decltype(split_command)(split_command.begin() + 1, split_command.end());
+
+	command_info.function(args);
+}
+
+void Game::_show_command_error(const std::string_view &error_message) noexcept
+{
+	_erase_entire_line();
+
+	const auto position = _cursor_controller->where();
+
+	_cursor_controller->move_to(Vector2({.x = 0, .y = position.get_y()}));
+
+	fmt::print(fmt::fg(fmt::color::red), "{}", error_message);
 }
 
 auto Game::_move_cursor(const Vector2 &direction) noexcept -> bool
@@ -293,7 +502,7 @@ auto Game::_move_cursor(const Vector2 &direction) noexcept -> bool
 		return false;
 	}
 
-	if (dest_position.get_y() < 1)
+	if (dest_position.get_y() <= 1)
 	{
 		return false;
 	}
@@ -319,3 +528,16 @@ void Game::_set_space(
 
 	_cursor_controller->move_to(prev_position);
 }
+
+void Game::_erase_entire_line() noexcept
+{
+	fmt::print(ERASE_ENTIRE_LINE, fmt::arg("esc", ESC));
+	std::cout.flush();
+}
+
+void Game::_erase_line_from_cursor() noexcept
+{
+	fmt::print(ERASE_LINE_FROM_CURSOR, fmt::arg("esc", ESC));
+	std::cout.flush();
+}
+
diff --git a/src/game/game.hpp b/src/game/game.hpp
index 8363c4d..a35c0ce 100644
--- a/src/game/game.hpp
+++ b/src/game/game.hpp
@@ -14,14 +14,41 @@
 
 #include <chrono>
 #include <cstddef>
+#include <functional>
 #include <list>
 #include <memory>
+#include <optional>
+#include <string>
+#include <string_view>
+#include <vector>
 
 constexpr auto DEFAULT_MIN_TIME_SINCE_LAST_GEN_MILLIS = 200;
 
 constexpr auto MIN_TIME_SINCE_LAST_GEN_INCREMENT = 50;
 constexpr auto MIN_TIME_SINCE_LAST_GEN_DECREMENT = 50;
 
+constexpr auto CURSOR_FALLBACK_POS_X = 10;
+constexpr auto CURSOR_FALLBACK_POS_Y = 10;
+
+constexpr std::string_view ERASE_ENTIRE_LINE = "{esc}[2K";
+constexpr std::string_view ERASE_LINE_FROM_CURSOR = "{esc}[0K";
+
+enum Mode
+{
+	NORMAL,
+	COMMAND
+};
+
+class CommandInfo
+{
+public:
+	using Options = const std::vector<std::string> &;
+	using CommandFunction = std::function<void(Options)>;
+
+	std::size_t option_cnt;
+	CommandFunction function;
+};
+
 class Game : public IGame
 {
 public:
@@ -50,19 +77,38 @@ private:
 	std::shared_ptr<IUserInputObserver> _user_input_observer;
 	std::shared_ptr<ICellHelper> _cell_helper;
 
-	using TimePoint = std::chrono::system_clock::time_point;
+	Mode _current_mode;
 
-	TimePoint _last_update_time;
-	TimePoint _last_gen_update_time;
+	std::optional<Vector2> _last_pos_before_command_mode;
+
+	std::string _command_mode_input;
+
+	std::unordered_map<std::string, CommandInfo> _commands;
+
+	std::chrono::system_clock::time_point _last_gen_update_time;
 
 	int32_t _min_time_since_last_gen_millis = DEFAULT_MIN_TIME_SINCE_LAST_GEN_MILLIS;
 
 	std::list<Vector2> _living_cell_positions;
 
+	void _on_normal_mode_update() noexcept;
+
+	void _on_command_mode_update() noexcept;
+
+	void _return_to_normal_mode() noexcept;
+
+	void _run_command(const std::string &command) noexcept;
+
+	void _show_command_error(const std::string_view &error_message) noexcept;
+
 	auto _move_cursor(const Vector2 &direction) noexcept -> bool;
 
 	void _set_space(
 		const std::shared_ptr<IMatrix<IScene::MatrixElement>> &matrix,
 		const Vector2 &position,
 		char character) noexcept;
+
+	static void _erase_entire_line() noexcept;
+
+	static void _erase_line_from_cursor() noexcept;
 };
diff --git a/src/game/keycodes.hpp b/src/game/keycodes.hpp
new file mode 100644
index 0000000..84ca5a7
--- /dev/null
+++ b/src/game/keycodes.hpp
@@ -0,0 +1,15 @@
+#pragma once
+
+namespace keycodes
+{
+
+constexpr auto ENTER = 10;
+constexpr auto ESCAPE = 27;
+constexpr auto BACKSPACE = 127;
+
+constexpr auto UP_ARROW = 65;
+constexpr auto DOWN_ARROW = 66;
+constexpr auto RIGHT_ARROW = 67;
+constexpr auto LEFT_ARROW = 68;
+
+} // namespace keycodes