// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
// SPDX-License-Identifier: GPL-3.0-or-later

// SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later

#include "common/assert.h"
#include "common/logging.h"
#include "common/settings.h"
#include "common/settings_enums.h"
#include "core/frontend/applets/controller.h"
#include "hid_core/frontend/emulated_controller.h"
#include "hid_core/hid_core.h"
#include "hid_core/hid_types.h"
#include <array>

namespace Core::Frontend {

ControllerApplet::~ControllerApplet() = default;

DefaultControllerApplet::DefaultControllerApplet(HID::HIDCore& hid_core_) : hid_core{hid_core_} {}

DefaultControllerApplet::~DefaultControllerApplet() = default;

void DefaultControllerApplet::Close() const {}

void DefaultControllerApplet::ReconfigureControllers(ReconfigureCallback callback,
                                                     const ControllerParameters& parameters) const {
    LOG_INFO(Service_HID, "called, deducing the best configuration based on the given parameters!");

    const std::size_t min_supported_players =
        parameters.enable_single_mode ? 1 : parameters.min_players;
    using Core::HID::NpadStyleIndex;
    const std::size_t max_supported_players = parameters.enable_single_mode ? 1 : parameters.max_players;
    std::size_t num_selected_players = 0;
    std::array<bool, HID::HIDCore::available_controllers> keep_connected{};

    // reserve existing AND valid players before filling slots. include Handheld, but not other
    for (std::size_t index = 0; index < hid_core.available_controllers - 1; ++index) {
        const auto* controller = hid_core.GetEmulatedControllerByIndex(index);
        if (!parameters.keep_controllers_connected || !controller->IsConnected() || num_selected_players >= max_supported_players) continue;

        const auto style = controller->GetNpadStyleIndex();
        keep_connected[index] =
            (style == NpadStyleIndex::Fullkey && parameters.allow_pro_controller) ||
            (style == NpadStyleIndex::JoyconDual && parameters.allow_dual_joycons) ||
            (style == NpadStyleIndex::JoyconLeft && parameters.allow_left_joycon) ||
            (style == NpadStyleIndex::JoyconRight && parameters.allow_right_joycon) ||
            (style == NpadStyleIndex::Handheld && parameters.enable_single_mode && parameters.allow_handheld && !Settings::IsDockedMode()) ||
            (style == NpadStyleIndex::GameCube && parameters.allow_gamecube_controller);
        num_selected_players += keep_connected[index];
    }
    auto* handheld = hid_core.GetEmulatedController(Core::HID::NpadIdType::Handheld);
    if (!keep_connected[hid_core.available_controllers - 2]) handheld->Disconnect();

    // Deduce the best configuration based on the input parameters.
    for (std::size_t index = 0; index < hid_core.available_controllers - 2; ++index) {
        auto* controller = hid_core.GetEmulatedControllerByIndex(index);

        if (keep_connected[index]) continue;
        controller->Disconnect();

        // only add players still needed to reach the minimum
        if (num_selected_players >= min_supported_players) continue;
        ++num_selected_players;

        // Connect controllers based on the following priority list from highest to lowest priority:
        // Pro Controller -> Dual Joycons -> Left Joycon/Right Joycon -> Handheld
        if (parameters.allow_pro_controller) {
            controller->SetNpadStyleIndex(Core::HID::NpadStyleIndex::Fullkey);
            controller->Connect(true);
        } else if (parameters.allow_dual_joycons) {
            controller->SetNpadStyleIndex(Core::HID::NpadStyleIndex::JoyconDual);
            controller->Connect(true);
        } else if (parameters.allow_left_joycon && parameters.allow_right_joycon) {
            // Assign left joycons to even player indices and right joycons to odd player indices.
            // We do this since Captain Toad Treasure Tracker expects a left joycon for Player 1 and
            // a right Joycon for Player 2 in 2 Player Assist mode.
            if (index % 2 == 0) {
                controller->SetNpadStyleIndex(Core::HID::NpadStyleIndex::JoyconLeft);
                controller->Connect(true);
            } else {
                controller->SetNpadStyleIndex(Core::HID::NpadStyleIndex::JoyconRight);
                controller->Connect(true);
            }
        } else if (index == 0 && parameters.enable_single_mode && parameters.allow_handheld &&
                   !Settings::IsDockedMode()) {
            // We should *never* reach here under any normal circumstances.
            controller->SetNpadStyleIndex(Core::HID::NpadStyleIndex::Handheld);
            controller->Connect(true);
        } else {
            ASSERT_MSG(false, "Unable to add a new controller based on the given parameters!");
        }
    }

    callback(true);
}

} // namespace Core::Frontend