/**
 * @file App.cpp
 * @author apio (cloudapio.eu)
 * @brief UI application event loop.
 *
 * @copyright Copyright (c) 2023, the Luna authors.
 *
 */

#include <os/ArgumentParser.h>
#include <os/File.h>
#include <os/IPC.h>
#include <ui/App.h>
#include <ui/ipc/Client.h>
#include <ui/ipc/Server.h>

namespace ui
{
    void handle_socket_event(int, int status)
    {
        if (status & POLLHUP) ui::App::the().set_should_close(true);
        if (status & POLLIN) { ui::App::the().process_events(); }
    }

    App* App::s_app { nullptr };

    App::App()
    {
        s_app = this;
    }

    App::~App()
    {
        s_app = nullptr;
    }

    Result<void> App::init(StringView socket_path)
    {
        m_client = TRY(os::IPC::Client::connect(socket_path, false));
        m_client->set_message_handler(
            [this](os::IPC::Client& client, u8 id, void* arg) { this->handle_ipc_event(client, id, arg); }, nullptr);

        TRY(m_loop.register_fd_listener(m_client->fd(), handle_socket_event));

        return {};
    }

    Result<int> App::run()
    {
        TRY(m_main_window->draw());

        return m_loop.run();
    }

    App& App::the()
    {
        check(s_app);
        return *s_app;
    }

    Rect App::screen_rect()
    {
        ui::GetScreenRectRequest request {};
        auto response = m_client->send_sync<ui::GetScreenRectResponse>(request).release_value();
        return response.rect;
    }

    Result<void> App::register_window(OwnedPtr<Window>&& window, Badge<Window>)
    {
        int id = window->id();
        check(TRY(m_windows.try_set(id, move(window))));
        return {};
    }

    void App::unregister_window(Window* window, Badge<Window>)
    {
        int id = window->id();
        check(m_windows.try_remove(id));
    }

    Window* App::find_window(int id)
    {
        auto* window = m_windows.try_get_ref(id);
        check(window);
        return window->ptr();
    }

    Result<void> App::handle_ipc_event(os::IPC::Client&, u8 id, void*)
    {
        switch (id)
        {
        case MOUSE_EVENT_REQUEST_ID: {
            MouseEventRequest request;
            if (!TRY(m_client->read_message(request))) return {};
            auto* window = find_window(request.window);
            auto move_result = window->handle_mouse_move(request.position).value_or(ui::EventResult::DidNotHandle);
            auto button_result =
                window->handle_mouse_buttons(request.position, request.buttons).value_or(ui::EventResult::DidNotHandle);
            if (move_result == ui::EventResult::DidHandle || button_result == ui::EventResult::DidHandle)
                window->draw();
            return {};
        }
        case MOUSE_LEAVE_REQUEST_ID: {
            MouseLeaveRequest request;
            if (!TRY(m_client->read_message(request))) return {};
            auto* window = find_window(request.window);
            if (window->handle_mouse_leave().value_or(ui::EventResult::DidNotHandle) == ui::EventResult::DidHandle)
                window->draw();
            return {};
        }
        case KEY_EVENT_REQUEST_ID: {
            KeyEventRequest request;
            if (!TRY(m_client->read_message(request))) return {};
            auto* window = find_window(request.window);
            if (window->handle_key_event(request).value_or(ui::EventResult::DidNotHandle) == ui::EventResult::DidHandle)
                window->draw();
            return {};
        }
        default: fail("Unexpected IPC request from server!");
        }
    }

    bool App::process_events()
    {
        check(m_main_window);
        m_client->check_for_messages().release_value();
        return !m_should_close;
    }
}