#include "client.hh"

#include "face_registry.hh"
#include "context.hh"
#include "buffer_manager.hh"
#include "user_interface.hh"
#include "file.hh"
#include "remote.hh"
#include "client_manager.hh"
#include "event_manager.hh"
#include "window.hh"

#include <signal.h>
#include <unistd.h>

namespace Kakoune
{

Client::Client(std::unique_ptr<UserInterface>&& ui,
               std::unique_ptr<Window>&& window,
               SelectionList selections,
               EnvVarMap env_vars,
               String name)
    : m_ui{std::move(ui)}, m_window{std::move(window)},
      m_input_handler{std::move(selections), Context::Flags::None,
                      std::move(name)},
      m_env_vars(env_vars)
{
    context().set_client(*this);
    context().set_window(*m_window);

    m_window->options().register_watcher(*this);
    m_ui->set_ui_options(m_window->options()["ui_options"].get<UserInterface::Options>());
}

Client::~Client()
{
    m_window->options().unregister_watcher(*this);
}

Optional<Key> Client::get_next_key(EventMode mode)
{
    if (not m_pending_keys.empty())
    {
        Key key = m_pending_keys.front();
        m_pending_keys.erase(m_pending_keys.begin());
        return key;
    }
    if (mode != EventMode::Pending and m_ui->is_key_available())
        return m_ui->get_key();
    return {};
}

void Client::handle_available_input(EventMode mode)
{
    if (mode == EventMode::Urgent)
    {
        Key key = m_ui->get_key();
        if (key == ctrl('c'))
            killpg(getpgrp(), SIGINT);
        else
            m_pending_keys.push_back(key);
    }
    else
    {
        try
        {
            while (Optional<Key> key = get_next_key(mode))
            {
                if (*key == ctrl('c'))
                    killpg(getpgrp(), SIGINT);
                else
                {
                    m_input_handler.handle_key(*key);
                    m_input_handler.clear_mode_trash();
                    context().window().forget_timestamp();
                }
            }
        }
        catch (Kakoune::runtime_error& error)
        {
            context().print_status({ error.what().str(), get_face("Error") });
            context().hooks().run_hook("RuntimeError", error.what(), context());
        }
        catch (Kakoune::client_removed&)
        {
            ClientManager::instance().remove_client(*this);
        }
    }
}

void Client::print_status(DisplayLine status_line)
{
    m_pending_status_line = std::move(status_line);
}

DisplayLine Client::generate_mode_line() const
{
    auto pos = context().selections().main().cursor();
    auto col = context().buffer()[pos.line].char_count_to(pos.column);

    DisplayLine status;
    Face info_face = get_face("Information");
    Face status_face = get_face("StatusLine");

    status.push_back({ context().buffer().display_name(), status_face });
    status.push_back({ format(" {}:{} ", pos.line+1, col+1), status_face });
    if (context().buffer().is_modified())
        status.push_back({ "[+]", info_face });
    if (m_input_handler.is_recording())
        status.push_back({ format("[recording ({})]", m_input_handler.recording_reg()), info_face });
    if (context().buffer().flags() & Buffer::Flags::New)
        status.push_back({ "[new file]", info_face });
    if (context().user_hooks_support().is_disabled())
        status.push_back({ "[no-hooks]", info_face });
    if (context().buffer().flags() & Buffer::Flags::Fifo)
        status.push_back({ "[fifo]", info_face });
    status.push_back({ " ", status_face });
    for (auto& atom : m_input_handler.mode_line())
        status.push_back(std::move(atom));
    status.push_back({ format(" - {}@[{}]", context().name(), Server::instance().session()), status_face });

    return status;
}

void Client::change_buffer(Buffer& buffer)
{
    if (m_buffer_reload_dialog_opened)
        close_buffer_reload_dialog();

    auto& client_manager = ClientManager::instance();
    m_window->options().unregister_watcher(*this);
    client_manager.add_free_window(std::move(m_window),
                                   std::move(context().selections()));
    WindowAndSelections ws = client_manager.get_free_window(buffer);

    m_window = std::move(ws.window);
    m_window->options().register_watcher(*this);
    m_ui->set_ui_options(m_window->options()["ui_options"].get<UserInterface::Options>());

    context().selections_write_only() = std::move(ws.selections);
    context().set_window(*m_window);
    m_window->set_dimensions(ui().dimensions());

    m_window->hooks().run_hook("WinDisplay", buffer.name(), context());
}

void Client::redraw_ifn()
{
    DisplayLine mode_line = generate_mode_line();
    const bool buffer_changed = context().window().timestamp() != context().buffer().timestamp();
    const bool mode_line_changed = mode_line.atoms() != m_mode_line.atoms();
    const bool status_line_changed = m_status_line.atoms() != m_pending_status_line.atoms();
    if (buffer_changed or status_line_changed or mode_line_changed)
    {
        if (buffer_changed)
        {
            CharCoord dimensions = context().ui().dimensions();
            if (dimensions == CharCoord{0,0})
                return;
            context().window().set_dimensions(dimensions);
            context().window().update_display_buffer(context());
        }
        m_mode_line = std::move(mode_line);
        m_status_line = m_pending_status_line;
        context().ui().draw(context().window().display_buffer(),
                            m_status_line, m_mode_line);
    }
    context().ui().refresh();
}

void Client::reload_buffer()
{
    auto& buffer = context().buffer();
    kak_assert(buffer.flags() & Buffer::Flags::File);
    CharCoord view_pos = context().window().position();
    ByteCoord cursor_pos = context().selections().main().cursor();
    Buffer* buf = create_buffer_from_file(buffer.name());
    kak_assert(buf == &buffer);
    context().selections_write_only() = SelectionList{buffer, buffer.clamp(cursor_pos)};
    context().window().set_position(view_pos);
    context().print_status({ "'" + buffer.display_name() + "' reloaded",
                             get_face("Information") });
}

void Client::on_buffer_reload_key(Key key)
{
    auto& buffer = context().buffer();

    if (key == 'y' or key == ctrl('m'))
        reload_buffer();
    else if (key == 'n' or key == Key::Escape)
    {
        // reread timestamp in case the file was modified again
        buffer.set_fs_timestamp(get_fs_timestamp(buffer.name()));
        print_status({ "'" + buffer.display_name() + "' kept",
                       get_face("Information") });
    }
    else
    {
        print_status({ "'" + key_to_str(key) + "' is not a valid choice",
                       get_face("Error") });
        m_input_handler.on_next_key(KeymapMode::None, [this](Key key, Context&){ on_buffer_reload_key(key); });
        return;
    }

    for (auto& client : ClientManager::instance())
    {
        if (&client->context().buffer() == &buffer and
            client->m_buffer_reload_dialog_opened)
            client->close_buffer_reload_dialog();
    }
}

void Client::close_buffer_reload_dialog()
{
    kak_assert(m_buffer_reload_dialog_opened);
    m_buffer_reload_dialog_opened = false;
    m_ui->info_hide();
    m_input_handler.reset_normal_mode();
}

void Client::check_if_buffer_needs_reloading()
{
    if (m_buffer_reload_dialog_opened)
        return;

    Buffer& buffer = context().buffer();
    auto reload = context().options()["autoreload"].get<YesNoAsk>();
    if (not (buffer.flags() & Buffer::Flags::File) or reload == No)
        return;

    const String& filename = buffer.name();
    time_t ts = get_fs_timestamp(filename);
    if (ts == InvalidTime or ts == buffer.fs_timestamp())
        return;
    if (reload == Ask)
    {
        m_ui->info_show(
            "reload '" + buffer.display_name() + "' ?",
            "'" + buffer.display_name() + "' was modified externally\n"
            "press <ret> or y to reload, <esc> or n to keep",
            CharCoord{}, get_face("Information"), InfoStyle::Prompt);

        m_buffer_reload_dialog_opened = true;
        m_input_handler.on_next_key(KeymapMode::None, [this](Key key, Context&){ on_buffer_reload_key(key); });
    }
    else
        reload_buffer();
}

StringView Client::get_env_var(const String& name) const
{
    auto it = m_env_vars.find(name);
    if (it == m_env_vars.end())
        return {};
    return it->second;
}

StringView Client::get_env_var(StringView name) const
{
    return get_env_var(name.str());
}

void Client::on_option_changed(const Option& option)
{
    if (option.name() == "ui_options")
        m_ui->set_ui_options(option.get<UserInterface::Options>());
}

}