/**
 * @file Window.cpp
 * @author apio (cloudapio.eu)
 * @brief UI windows.
 *
 * @copyright Copyright (c) 2023, the Luna authors.
 *
 */

#include <errno.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <ui/App.h>
#include <ui/Window.h>
#include <ui/ipc/Server.h>
#include <unistd.h>

static Result<u32*> create_shm_region(const char* path, int* outfd, ui::Rect rect)
{
    int fd = shm_open(path, O_RDWR, 0600);
    shm_unlink(path);
    if (fd < 0) return err(errno);

    usize size = rect.width * rect.height * 4; // 4 bytes per pixel

    void* p = mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
    if (p == MAP_FAILED)
    {
        shm_unlink(path);
        close(fd);
        return 0;
    }

    if (outfd) *outfd = fd;
    else
        close(fd);
    return (u32*)p;
}

namespace ui
{
    Result<Window*> Window::create(Rect rect)
    {
        auto window = TRY(make_owned<Window>());

        ui::CreateWindowRequest request;
        request.rect = rect;
        auto response = TRY(os::IPC::send_sync<ui::CreateWindowResponse>(App::the().client(), request));

        u32* pixels = TRY(create_shm_region(response.shm_path, nullptr, rect));

        window->m_canvas = ui::Canvas { rect.width, rect.height, rect.width, (u8*)pixels };
        window->m_id = response.window;

        Window* p = window.ptr();

        App::the().register_window(move(window), {});

        return p;
    }

    Window::~Window()
    {
        if (m_canvas.ptr) munmap(m_canvas.ptr, ((usize)m_canvas.width) * ((usize)m_canvas.height) * 4);
    }

    void Window::set_title(StringView title)
    {
        ui::SetWindowTitleRequest request;
        request.window = m_id;
        SET_IPC_STRING(request.title, title.chars());
        os::IPC::send_async(App::the().client(), request);
    }

    void Window::update()
    {
        ui::InvalidateRequest request;
        request.window = m_id;
        os::IPC::send_async(App::the().client(), request);
    }

    void Window::close()
    {
        App& app = App::the();

        ui::CloseWindowRequest request;
        request.window = m_id;
        os::IPC::send_async(app.client(), request);

        if (this == app.main_window()) app.set_should_close(true);

        app.unregister_window(this, {});
    }

    Result<void> Window::draw()
    {
        m_canvas.fill(m_background);
        if (m_main_widget) return m_main_widget->draw(m_canvas);
        update();
        return {};
    }

    Result<void> Window::handle_mousemove(ui::Point position)
    {
        if (m_main_widget) TRY(m_main_widget->handle_mousemove(position));
        return {};
    }
}