#include "app.h"

#include <algorithm>
#include <vector>

#include <curses.h>

#include "util.h"

namespace telegram_tui {

namespace {

const std::vector<std::string> kShinoaBanner = {
        "  ____  _     _                   ",      " / ___|| |__ (_)_ __   ___   __ _ ",
        " \\___ \\| '_ \\| | '_ \\ / _ \\ / _` |", "  ___) | | | | | | | | (_) | (_| |",
        " |____/|_| |_|_|_| |_|\\___/ \\__,_|",
};

} // namespace

void App::handle_help_menu_key(int ch) {
	switch (ch) {
	case 27:
	case 'h':
	case '?':
	case KEY_F(1):
		help_menu_open_ = false;
		status_line_ = "Closed help.";
		return;
	case '1':
		help_menu_page_ = 0;
		status_line_ = "Help.";
		return;
	case '2':
		help_menu_page_ = 1;
		status_line_ = "Settings.";
		return;
	case '3':
		help_menu_page_ = 2;
		status_line_ = "About.";
		return;
	case KEY_LEFT:
		help_menu_page_ = (help_menu_page_ + 2) % 3;
		return;
	case KEY_RIGHT:
		help_menu_page_ = (help_menu_page_ + 1) % 3;
		return;
	case 't':
		if (help_menu_page_ != 1) {
			return;
		}
		auto_reload_chat_history_ = !auto_reload_chat_history_;
		persist_config();
		status_line_ = auto_reload_chat_history_ ? "Auto-reload history enabled."
		                                         : "Auto-reload history disabled.";
		return;
	default:
		return;
	}
}

void App::draw_help_menu(int height, int width) {
	const int menu_width = std::min(width - 4, 92);
	const int menu_height = std::min(height - 4, 24);
	const int top = std::max(1, (height - menu_height) / 2);
	const int left = std::max(1, (width - menu_width) / 2);

	WINDOW *window = newwin(menu_height, menu_width, top, left);
	if (window == nullptr) {
		return;
	}

	box(window, 0, 0);
	const char *title =
	        help_menu_page_ == 0 ? " Help " : (help_menu_page_ == 1 ? " Settings " : " About ");
	mvwprintw(window, 0, 2, "%s", title);
	const std::string page_tabs =
	        help_menu_page_ == 0 ? "[1] Help  2 Settings  3 About"
	                             : (help_menu_page_ == 1 ? "1 Help  [2] Settings  3 About"
	                                                     : "1 Help  2 Settings  [3] About");
	mvwaddnstr(window, 1, 2, page_tabs.c_str(), menu_width - 4);
	mvwhline(window, 2, 1, ACS_HLINE, menu_width - 2);
	const auto help_item = [](const std::string &key, const std::string &description) {
		std::string line = "  " + key;
		const int key_width = std::max(16, utf8_display_width(key));
		const int padding = std::max(2, key_width - utf8_display_width(key) + 2);
		line.append(static_cast<std::size_t>(padding), ' ');
		line += description;
		return line;
	};

	std::vector<std::string> lines;
	if (help_menu_page_ == 0) {
		lines = {
		        "Navigation",
		        help_item("? / h", "Open or close help"),
		        help_item("Tab", "Switch focus"),
		        help_item("Enter", "Open selected chat"),
		        help_item("Up / Down", "Move chats or attachment selection"),
		        help_item("PgUp / PgDn", "Scroll messages"),
		        "",
		        "Compose",
		        help_item("i", "Compose a message"),
		        help_item("g", "Open saved GIF picker"),
		        help_item("a", "Prepare reply to latest"),
		        help_item(">r <msg> [text]", "Prepare a reply"),
		        help_item(">paste [caption]", "Send clipboard image"),
		        "",
		        "Message Actions",
		        help_item(">f <msg...>", "Forward messages"),
		        help_item(">e <msg> <text>", "Edit a message"),
		        help_item(">d <msg...>", "Delete your messages"),
		        help_item("m / o", "Attachments menu / open selected"),
		};
	} else if (help_menu_page_ == 1) {
		lines = {
		        "Settings",
		        std::string("  [") + (auto_reload_chat_history_ ? 'x' : ' ') +
		                "] Auto-reload open chat history [t]",
		        "",
		        "Behavior",
		        "  On:  Enter in the message pane reloads history.",
		        "  Off: Press r to reload the current chat manually.",
		        "",
		        "Menu",
		        help_item("1 / 2 / 3", "Switch help pages"),
		        help_item("Left / Right", "Cycle pages"),
		        help_item("Esc", "Close the help overlay"),
		};
	} else {
		lines = {
		        "",
		        "",
		};
	}

	const int content_top = 3;
	const int content_height = menu_height - 6;
	if (help_menu_page_ == 2) {
		int row = content_top;
		for (const auto &line : kShinoaBanner) {
			if (row >= content_top + content_height) {
				break;
			}
			const int x = std::max(2, (menu_width - static_cast<int>(line.size())) / 2);
			mvwaddnstr(window, row++, x, line.c_str(), menu_width - x - 1);
		}
		const std::vector<std::string> about_lines = {
		        "",
		        "Telegram TUI with message refs, reply prep, attachment navigation,",
		        "and keyboard-first chat workflows.",
		};
		for (const auto &line : about_lines) {
			if (row >= content_top + content_height) {
				break;
			}
			const int x = std::max(2, (menu_width - static_cast<int>(line.size())) / 2);
			mvwaddnstr(window, row++, x, line.c_str(), menu_width - x - 1);
		}
	} else {
		for (std::size_t i = 0; i < lines.size() && static_cast<int>(i) < content_height;
		     ++i) {
			mvwaddnstr(window, static_cast<int>(i) + content_top, 2, lines[i].c_str(),
			           menu_width - 4);
		}
	}

	mvwhline(window, menu_height - 3, 1, ACS_HLINE, menu_width - 2);
	mvwaddnstr(window, menu_height - 2, 2, "Esc close", menu_width - 4);
	wrefresh(window);
	delwin(window);
}

} // namespace telegram_tui