// SPDX-FileCopyrightText: 2016 Citra Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later

#include <SDL.h>

#include "common/logging/log.h"
#include "common/scm_rev.h"
#include "common/settings.h"
#include "core/core.h"
#include "core/hid/hid_core.h"
#include "core/perf_stats.h"
#include "input_common/drivers/keyboard.h"
#include "input_common/drivers/mouse.h"
#include "input_common/drivers/touch_screen.h"
#include "input_common/main.h"
#include "yuzu_cmd/emu_window/emu_window_sdl2.h"
#include "yuzu_cmd/yuzu_icon.h"

EmuWindow_SDL2::EmuWindow_SDL2(InputCommon::InputSubsystem* input_subsystem_, Core::System& system_)
    : input_subsystem{input_subsystem_}, system{system_} {
    input_subsystem->Initialize();
    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_JOYSTICK | SDL_INIT_GAMECONTROLLER) < 0) {
        LOG_CRITICAL(Frontend, "Failed to initialize SDL2! Exiting...");
        exit(1);
    }
    SDL_SetMainReady();
}

EmuWindow_SDL2::~EmuWindow_SDL2() {
    system.HIDCore().UnloadInputDevices();
    input_subsystem->Shutdown();
    SDL_Quit();
}

InputCommon::MouseButton EmuWindow_SDL2::SDLButtonToMouseButton(u32 button) const {
    switch (button) {
    case SDL_BUTTON_LEFT:
        return InputCommon::MouseButton::Left;
    case SDL_BUTTON_RIGHT:
        return InputCommon::MouseButton::Right;
    case SDL_BUTTON_MIDDLE:
        return InputCommon::MouseButton::Wheel;
    case SDL_BUTTON_X1:
        return InputCommon::MouseButton::Backward;
    case SDL_BUTTON_X2:
        return InputCommon::MouseButton::Forward;
    default:
        return InputCommon::MouseButton::Undefined;
    }
}

std::pair<float, float> EmuWindow_SDL2::MouseToTouchPos(s32 touch_x, s32 touch_y) const {
    int w, h;
    SDL_GetWindowSize(render_window, &w, &h);
    const float fx = static_cast<float>(touch_x) / w;
    const float fy = static_cast<float>(touch_y) / h;

    return {std::clamp<float>(fx, 0.0f, 1.0f), std::clamp<float>(fy, 0.0f, 1.0f)};
}

void EmuWindow_SDL2::OnMouseButton(u32 button, u8 state, s32 x, s32 y) {
    const auto mouse_button = SDLButtonToMouseButton(button);
    if (state == SDL_PRESSED) {
        const auto [touch_x, touch_y] = MouseToTouchPos(x, y);
        input_subsystem->GetMouse()->PressButton(x, y, mouse_button);
        input_subsystem->GetMouse()->PressMouseButton(mouse_button);
        input_subsystem->GetMouse()->PressTouchButton(touch_x, touch_y, mouse_button);
    } else {
        input_subsystem->GetMouse()->ReleaseButton(mouse_button);
    }
}

void EmuWindow_SDL2::OnMouseMotion(s32 x, s32 y) {
    const auto [touch_x, touch_y] = MouseToTouchPos(x, y);
    input_subsystem->GetMouse()->Move(x, y, 0, 0);
    input_subsystem->GetMouse()->MouseMove(touch_x, touch_y);
    input_subsystem->GetMouse()->TouchMove(touch_x, touch_y);
}

void EmuWindow_SDL2::OnFingerDown(float x, float y, std::size_t id) {
    input_subsystem->GetTouchScreen()->TouchPressed(x, y, id);
}

void EmuWindow_SDL2::OnFingerMotion(float x, float y, std::size_t id) {
    input_subsystem->GetTouchScreen()->TouchMoved(x, y, id);
}

void EmuWindow_SDL2::OnFingerUp() {
    input_subsystem->GetTouchScreen()->ReleaseAllTouch();
}

void EmuWindow_SDL2::OnKeyEvent(int key, u8 state) {
    if (state == SDL_PRESSED) {
        input_subsystem->GetKeyboard()->PressKey(static_cast<std::size_t>(key));
    } else if (state == SDL_RELEASED) {
        input_subsystem->GetKeyboard()->ReleaseKey(static_cast<std::size_t>(key));
    }
}

bool EmuWindow_SDL2::IsOpen() const {
    return is_open;
}

bool EmuWindow_SDL2::IsShown() const {
    return is_shown;
}

void EmuWindow_SDL2::OnResize() {
    int width, height;
    SDL_GL_GetDrawableSize(render_window, &width, &height);
    UpdateCurrentFramebufferLayout(width, height);
}

void EmuWindow_SDL2::ShowCursor(bool show_cursor) {
    SDL_ShowCursor(show_cursor ? SDL_ENABLE : SDL_DISABLE);
}

void EmuWindow_SDL2::Fullscreen() {
    SDL_DisplayMode display_mode;
    switch (Settings::values.fullscreen_mode.GetValue()) {
    case Settings::FullscreenMode::Exclusive:
        // Set window size to render size before entering fullscreen -- SDL2 does not resize window
        // to display dimensions automatically in this mode.
        if (SDL_GetDesktopDisplayMode(0, &display_mode) == 0) {
            SDL_SetWindowSize(render_window, display_mode.w, display_mode.h);
        } else {
            LOG_ERROR(Frontend, "SDL_GetDesktopDisplayMode failed: {}", SDL_GetError());
        }

        if (SDL_SetWindowFullscreen(render_window, SDL_WINDOW_FULLSCREEN) == 0) {
            return;
        }

        LOG_ERROR(Frontend, "Fullscreening failed: {}", SDL_GetError());
        LOG_INFO(Frontend, "Attempting to use borderless fullscreen...");
        [[fallthrough]];
    case Settings::FullscreenMode::Borderless:
        if (SDL_SetWindowFullscreen(render_window, SDL_WINDOW_FULLSCREEN_DESKTOP) == 0) {
            return;
        }

        LOG_ERROR(Frontend, "Borderless fullscreening failed: {}", SDL_GetError());
        [[fallthrough]];
    default:
        // Fallback algorithm: Maximise window.
        // Works on all systems (unless something is seriously wrong), so no fallback for this one.
        LOG_INFO(Frontend, "Falling back on a maximised window...");
        SDL_MaximizeWindow(render_window);
        break;
    }
}

void EmuWindow_SDL2::WaitEvent() {
    // Called on main thread
    SDL_Event event;

    if (!SDL_WaitEvent(&event)) {
        const char* error = SDL_GetError();
        if (!error || strcmp(error, "") == 0) {
            // https://github.com/libsdl-org/SDL/issues/5780
            // Sometimes SDL will return without actually having hit an error condition;
            // just ignore it in this case.
            return;
        }

        LOG_CRITICAL(Frontend, "SDL_WaitEvent failed: {}", error);
        exit(1);
    }

    switch (event.type) {
    case SDL_WINDOWEVENT:
        switch (event.window.event) {
        case SDL_WINDOWEVENT_SIZE_CHANGED:
        case SDL_WINDOWEVENT_RESIZED:
        case SDL_WINDOWEVENT_MAXIMIZED:
        case SDL_WINDOWEVENT_RESTORED:
            OnResize();
            break;
        case SDL_WINDOWEVENT_MINIMIZED:
        case SDL_WINDOWEVENT_EXPOSED:
            is_shown = event.window.event == SDL_WINDOWEVENT_EXPOSED;
            OnResize();
            break;
        case SDL_WINDOWEVENT_CLOSE:
            is_open = false;
            break;
        }
        break;
    case SDL_KEYDOWN:
    case SDL_KEYUP:
        OnKeyEvent(static_cast<int>(event.key.keysym.scancode), event.key.state);
        break;
    case SDL_MOUSEMOTION:
        // ignore if it came from touch
        if (event.button.which != SDL_TOUCH_MOUSEID)
            OnMouseMotion(event.motion.x, event.motion.y);
        break;
    case SDL_MOUSEBUTTONDOWN:
    case SDL_MOUSEBUTTONUP:
        // ignore if it came from touch
        if (event.button.which != SDL_TOUCH_MOUSEID) {
            OnMouseButton(event.button.button, event.button.state, event.button.x, event.button.y);
        }
        break;
    case SDL_FINGERDOWN:
        OnFingerDown(event.tfinger.x, event.tfinger.y,
                     static_cast<std::size_t>(event.tfinger.touchId));
        break;
    case SDL_FINGERMOTION:
        OnFingerMotion(event.tfinger.x, event.tfinger.y,
                       static_cast<std::size_t>(event.tfinger.touchId));
        break;
    case SDL_FINGERUP:
        OnFingerUp();
        break;
    case SDL_QUIT:
        is_open = false;
        break;
    default:
        break;
    }

    const u32 current_time = SDL_GetTicks();
    if (current_time > last_time + 2000) {
        const auto results = system.GetAndResetPerfStats();
        const auto title =
            fmt::format("yuzu {} | {}-{} | FPS: {:.0f} ({:.0f}%)", Common::g_build_fullname,
                        Common::g_scm_branch, Common::g_scm_desc, results.average_game_fps,
                        results.emulation_speed * 100.0);
        SDL_SetWindowTitle(render_window, title.c_str());
        last_time = current_time;
    }
}

// Credits to Samantas5855 and others for this function.
void EmuWindow_SDL2::SetWindowIcon() {
    SDL_RWops* const yuzu_icon_stream = SDL_RWFromConstMem((void*)yuzu_icon, yuzu_icon_size);
    if (yuzu_icon_stream == nullptr) {
        LOG_WARNING(Frontend, "Failed to create yuzu icon stream.");
        return;
    }
    SDL_Surface* const window_icon = SDL_LoadBMP_RW(yuzu_icon_stream, 1);
    if (window_icon == nullptr) {
        LOG_WARNING(Frontend, "Failed to read BMP from stream.");
        return;
    }
    // The icon is attached to the window pointer
    SDL_SetWindowIcon(render_window, window_icon);
    SDL_FreeSurface(window_icon);
}

void EmuWindow_SDL2::OnMinimalClientAreaChangeRequest(std::pair<u32, u32> minimal_size) {
    SDL_SetWindowMinimumSize(render_window, minimal_size.first, minimal_size.second);
}