#include "Client.h"
#include "IPC.h"
#include "Mouse.h"
#include "Screen.h"
#include "Window.h"
#include <errno.h>
#include <moon/Keyboard.h>
#include <os/ArgumentParser.h>
#include <os/File.h>
#include <os/LocalServer.h>
#include <os/Process.h>
#include <os/Security.h>
#include <pwd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/poll.h>
#include <time.h>
#include <unistd.h>

Result<int> luna_main(int argc, char** argv)
{
    srand((unsigned)time(NULL));

    TRY(os::Security::pledge("stdio rpath wpath cpath unix proc exec tty signal id", NULL));

    StringView socket_path = "/tmp/wind.sock";
    StringView user;

    os::ArgumentParser parser;
    parser.add_description("The display server for Luna's graphical user interface."_sv);
    parser.add_system_program_info("wind"_sv);
    parser.add_value_argument(socket_path, 's', "socket"_sv, "the path for the local IPC socket"_sv);
    parser.add_value_argument(user, 'u', "user"_sv, "the user to run as"_sv);
    parser.parse(argc, argv);

    if (geteuid() != 0)
    {
        os::eprintln("error: wind must be run as root to initialize resources, run with --user=<USERNAME> to drop "
                     "privileges afterwards");
        return 1;
    }

    auto mouse = TRY(os::File::open("/dev/mouse", os::File::ReadOnly));
    mouse->set_buffer(os::File::NotBuffered);
    mouse->set_close_on_exec();

    auto keyboard = TRY(os::File::open("/dev/kbd", os::File::ReadOnly));
    keyboard->set_buffer(os::File::NotBuffered);
    keyboard->set_close_on_exec();

    auto screen = TRY(Screen::open());

    Mouse mouse_pointer { screen.canvas() };

    ioctl(STDIN_FILENO, TTYSETGFX, 1);

    setpgid(0, 0);

    int fd = open("/dev/null", O_RDONLY);
    if (fd >= 0)
    {
        dup2(fd, STDIN_FILENO);
        close(fd);
    }

    clearenv();

    if (!user.is_empty())
    {
        auto* pwd = getpwnam(user.chars());
        if (pwd)
        {
            setgid(pwd->pw_gid);
            setuid(pwd->pw_uid);
        }
    }

    auto server = TRY(os::LocalServer::create(socket_path, false));
    TRY(server->listen(20));

    StringView args[] = { "/usr/bin/init"_sv, "--user"_sv };
    TRY(os::Process::spawn("/usr/bin/init"_sv, Slice<StringView> { args, 2 }, false));

    ui::Color background = ui::BLACK;

    Vector<Client> clients;
    Vector<struct pollfd> fds;
    TRY(fds.try_append({ .fd = mouse->fd(), .events = POLLIN, .revents = 0 }));
    TRY(fds.try_append({ .fd = keyboard->fd(), .events = POLLIN, .revents = 0 }));
    TRY(fds.try_append({ .fd = server->fd(), .events = POLLIN, .revents = 0 }));

    TRY(os::Security::pledge("stdio rpath wpath cpath unix signal proc", NULL));

    while (1)
    {
        screen.canvas().fill(background);
        for (auto* window : g_windows) window->draw(screen.canvas());
        mouse_pointer.draw(screen.canvas());
        screen.sync();

        for (auto& pfd : fds) { pfd.revents = 0; }

        int rc = poll(fds.data(), fds.size(), 1000);
        if (!rc) continue;
        if (rc < 0 && errno != EINTR) { os::println("poll: error: %s", strerror(errno)); }

        if (fds[0].revents & POLLIN)
        {
            moon::MousePacket packet;
            TRY(mouse->read_typed(packet));
            mouse_pointer.update(packet);
        }
        if (fds[1].revents & POLLIN)
        {
            moon::KeyboardPacket packet;
            TRY(keyboard->read_typed(packet));
            os::println("%s key %d", packet.released ? "Released" : "Pressed", packet.key);
        }
        for (usize i = 0; i < clients.size(); i++)
        {
            if (fds[i + 3].revents & POLLIN) wind::handle_ipc(clients[i]);
            if (fds[i + 3].revents & POLLHUP)
            {
                os::println("wind: Client %d disconnected", i);
                fds.remove_at(i + 3);
                auto client = clients.remove_at(i);
                client.conn.disconnect();
                for (auto& window : client.windows)
                {
                    if (window)
                    {
                        g_windows.remove(window);
                        delete window;
                    }
                }
            }
        }
        if (fds[2].revents & POLLIN)
        {
            auto client = TRY(server->accept());
            os::println("wind: New client connected!");
            TRY(fds.try_append({ .fd = client.fd(), .events = POLLIN, .revents = 0 }));
            Client c { move(client), {} };
            TRY(clients.try_append(move(c)));
        }
    }
}