#include "sdl_context.h"
#include "keyboard_map.h"

#include <atomic>
#include <cassert>
#include "../platform.h"

#include <cmath>
#include <iostream>
#include <fstream>
#include <stdexcept>
#include <sstream>
#include <algorithm>
void SDLContext::SDL_Deleter::operator ()(SDL_Window* window) {
    SDL_DestroyWindow(window);
}

void SDLContext::SDL_Deleter::operator ()(SDL_Renderer* renderer) {
    SDL_DestroyRenderer(renderer);
}

void SDLContext::SDL_Deleter::operator ()(SDL_Surface* surface) {
    SDL_FreeSurface(surface);
}

void SDLContext::SDL_Deleter::operator ()(SDL_Texture* texture) {
    SDL_DestroyTexture(texture);
}

void SDLContext::SDL_Audio_Deleter::operator()(SDL_AudioDeviceID x) {
    SDL_CloseAudioDevice(x);
}

struct SDL_INIT_Context {

    SDL_INIT_Context() {
        if (SDL_Init(SDL_INIT_VIDEO|SDL_INIT_TIMER|SDL_INIT_AUDIO|SDL_INIT_JOYSTICK) < 0) {
            SDL_Log("Unable to initialize SDL: %s", SDL_GetError());
            exit(1);
        }
        if (SDL_NumJoysticks() > 0) {
            if (SDL_IsGameController(0)) {
                controller = SDL_JoystickOpen(0);
                SDL_JoystickEventState(SDL_ENABLE);
            }
        }

        inited = true;
    }
    ~SDL_INIT_Context() {
        if (controller) SDL_JoystickClose(controller);
        SDL_Quit();
    }


    bool inited = false;
    SDL_Joystick *controller = nullptr;
};

static SDL_INIT_Context init_context = {};

SDLContext::SDLContext() {
    if (!init_context.inited) throw std::runtime_error("SDL not inited");

}
void handle_sdl_error(const char *msg) {
    char buff[512];

    snprintf(buff, sizeof(buff), "SDL critical error (check video driver): %s %s",msg, SDL_GetError());
    throw std::runtime_error(buff);
}


void SDLContext::generateCRTTexture(SDL_Renderer* renderer, SDL_Texture** texture, int width, int height, CrtFilterType type) {

    if (type == CrtFilterType::autoselect) {
        if (height >= 1200) type = CrtFilterType::scanlines_2;
        else type = CrtFilterType::scanlines;
    }

    int interfer = 1;
    switch (type) {
        case CrtFilterType::scanlines: interfer = 2;break;
        case CrtFilterType::scanlines_2: interfer = 3;break;
        case CrtFilterType::rgb_matrix_2: interfer = 3;break;
        case CrtFilterType::rgb_matrix_3: interfer = 4;break;
        default: break;
    }

    if (type == CrtFilterType::scanlines || type == CrtFilterType::scanlines_2) {
        width = 32;
    } else {
        unsigned int mult_of_base = std::max<unsigned int>((height+320)/640,interfer);
        width = width * interfer / mult_of_base;
    }
    {
        unsigned int mult_of_base = std::max<unsigned int>((height+240)/480,interfer);
        height = height * interfer / mult_of_base;
    }
    // Vytvoř novou texturu ve správné velikosti
    *texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_RGBA8888, SDL_TEXTUREACCESS_STREAMING, width, height);
    if (!*texture) {
        type = CrtFilterType::none;
        return;  //crt filter failed to create, do not use filter
    }
    SDL_SetTextureBlendMode(*texture, SDL_BLENDMODE_MUL);


    // Zamkni texturu pro přímý přístup k pixelům
    void* pixels;
    int pitch;
    if (SDL_LockTexture(*texture, nullptr, &pixels, &pitch)<0) {
        SDL_DestroyTexture(*texture);
        *texture = nullptr;
        type = CrtFilterType::none;
        return;
    }

    Uint32* pixelArray = (Uint32*)pixels;

    if (type == CrtFilterType::scanlines) {

        Uint32 darkPixel = 0xA0A0A0FF;
        Uint32 transparentPixel = 0xFFFFFFC0;

        for (int y = 0; y < height; y++) {
            Uint32 color = ((y & 1)== 0) ? darkPixel : transparentPixel;
            for (int x = 0; x < width; x++) {
                pixelArray[y * (pitch / 4) + x] = color;
            }
        }
    }
    else if (type == CrtFilterType::scanlines_2) {


        Uint32 darkPixel = 0x808080FF;
        Uint32 transparentPixel = 0xFFFFFFE0;

        for (int y = 0; y < height; y++) {
            Uint32 color = (y % 3== 2) ? darkPixel : transparentPixel;
            for (int x = 0; x < width; x++) {
                pixelArray[y * (pitch / 4) + x] = color;
            }
        }
    } else {

        static Uint32 red_pixel = 0xFF8080A0;
        static Uint32 green_pixel = 0x80FF80A0;
        static Uint32 blue_pixel = 0x8080FFA0;
        static Uint32 dark_pixel = 0x000000C0;
        for (int y = 2; y < height; y++) {
            if (type == CrtFilterType::rgb_matrix_2) {
                for (int x = 2; x < width; x+=3) {
                    Uint32 *pos = pixelArray+y*(pitch/4)+x-2;
                    if ((y % 3) == 2) {
                        pos[0] = pos[1] = pos[2] = dark_pixel;
                    } else {
                        pos[0] = red_pixel;
                        pos[1] = green_pixel;
                        pos[2] = blue_pixel;
                    }
                }
            } else {
                for (int x = 2; x < width; x+=3) {
                    Uint32 *pos = pixelArray+y*(pitch/4)+x-2;
                    if ((y & 3) == 3) {
                        pos[0] = pos[1] = pos[2] = dark_pixel;
                    } else {
                        pos[0] = red_pixel;
                        pos[1] = green_pixel;
                        pos[2] = blue_pixel;
                    }
                }
            }
        }

    }

    // Odemkni texturu
    SDL_UnlockTexture(*texture);
}

static void crash_sdl_exception() {
    try {
        throw;
    } catch (std::exception &e) {
        display_error("Display server - unhandled exception: %s", e.what());
    } catch (...) {
        display_error("Display server - unhandled unknown exception (probably crash)");
    }
    abort();
}


void SDLContext::init_video(const VideoConfig &config, const char *title) {
    static Uint32 update_request_event = SDL_RegisterEvents(1);
    static Uint32 refresh_request_event = SDL_RegisterEvents(1);
    _update_request_event = update_request_event;
    _refresh_request = refresh_request_event;

    assert(!_render_thread.joinable());


    int width = config.window_width;
    int height = config.window_height;
    aspect_x = config.aspect_x;
    aspect_y = config.aspect_y;
    _crt_filter = config.crt_filter ;
    if (_crt_filter == CrtFilterType::none) {
        _crt_filter = CrtFilterType::autoselect;
        _enable_crt = false;
    }


    _fullscreen_mode = config.fullscreen;
    _mouse_size = config.cursor_size;

    std::atomic<bool> done = false;
    std::exception_ptr e;
    _render_thread = std::jthread([&](std::stop_token stp){
        bool err = false;
        try {
            SDL_Window *window = SDL_CreateWindow(title,
                        SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
                        width, height, SDL_WINDOW_RESIZABLE|(_fullscreen_mode?SDL_WINDOW_FULLSCREEN_DESKTOP:0));

            if (!window) {
                handle_sdl_error("SDL Error create window");
            }

            _window.reset(window);
            SDL_Renderer *renderer = SDL_CreateRenderer(_window.get(), -1, config.composer);
            if (!renderer) {
                handle_sdl_error("Failed to create composer");
            }

            SDL_RendererInfo rinfo;
            SDL_GetRendererInfo(renderer, &rinfo);

            if (istrcmp(config.scale_quality, "auto") == 0) {
                if (rinfo.flags & SDL_RENDERER_ACCELERATED) {
                    SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "best");
                }
            } else {
                SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, config.scale_quality);
            }

            _renderer.reset(renderer);
            SDL_Texture *texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_ARGB1555, SDL_TEXTUREACCESS_STREAMING, 640, 480);
            if (!texture) {
                handle_sdl_error("Failed to create render target");
            }

            SDL_SetTextureBlendMode(texture, SDL_BLENDMODE_BLEND);
            _texture.reset(texture);
            texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_ARGB1555, SDL_TEXTUREACCESS_STREAMING, 640, 480);
            if (!texture) {
                handle_sdl_error("Failed to create second render target");
            }
            SDL_SetTextureBlendMode(texture, SDL_BLENDMODE_BLEND);
            _texture2.reset(texture);
            _visible_texture = _texture.get();
            _hidden_texture = _texture2.get();
        } catch (...) {
            e = std::current_exception();
            err = true;
        }
        done = true;
        done.notify_all();

        if (!err) {
            try {
                SDL_ShowCursor(SDL_DISABLE);
                event_loop(stp);
            } catch (...) {
                SDL_ShowCursor(SDL_ENABLE);
                crash_sdl_exception();
            }
        }
        _texture.reset();
        _texture2.reset();
        _renderer.reset();
        _window.reset();
    });

    done.wait(false);
    if (e) {
        _render_thread.join();
        std::rethrow_exception(e);
    }


}

void SDLContext::close_video() {
    _render_thread.request_stop();
    _render_thread.join();
}

int SDLContext::check_axis_dir(int &cooldown, int value) {
    int range = 0x8000-_jcontrol_map.walk_deadzone;
    int step = range >> 4;
    int max_speed = range+(step<<2);
    if (value == 0) {
        cooldown = -1;
    } else if (cooldown>0) {
        cooldown -= step;
        if (cooldown < 0) cooldown = 0;
    } else {
        if (value > 0) {
            if (cooldown < 0) value = step;
            cooldown = max_speed-value;
            return 1;
        }
        else if (value < 0) {
            if (cooldown < 0) value = -step;
            cooldown = max_speed+value;
            return -1;
        }
    }
    return 0;
}

int SDLContext::adjust_deadzone(int v, short deadzone) {
    if (v > deadzone) return v - deadzone;
    if (v < -deadzone) return v + deadzone;
    return 0;
}

static int axis_dynamic(int c) {
    double f = std::floor(std::pow(std::abs(c)*0.001,2)*0.025);

    if (c < 0) return static_cast<int>(-f);
    else return static_cast<int>(f);

}

void SDLContext::joystick_handle() {

    int a1 = SDL_JoystickGetAxis(init_context.controller, _jcontrol_map.swap_axis?2:0);
    int a2 = SDL_JoystickGetAxis(init_context.controller, _jcontrol_map.swap_axis?3:1);
    if (std::abs(a1) - std::abs(a2) > 0x2000) a2 = 0;
    else if (std::abs(a2) - std::abs(a1) >0x2000) a1 = 0;
    else {
        a1 = 0;
        a2 = 0;
    }
    int axis1 =  check_axis_dir(axis1_cooldown,adjust_deadzone(a1, _jcontrol_map.walk_deadzone));
    int axis2 =  check_axis_dir(axis2_cooldown,adjust_deadzone(a2, _jcontrol_map.walk_deadzone));
    int axis3 =  axis_dynamic(adjust_deadzone(SDL_JoystickGetAxis(init_context.controller,_jcontrol_map.swap_axis?0:2), _jcontrol_map.cursor_deadzone));
    int axis4 =  axis_dynamic(adjust_deadzone(SDL_JoystickGetAxis(init_context.controller,_jcontrol_map.swap_axis?1:3), _jcontrol_map.cursor_deadzone));

    int newx  =  this->ms_event.x + axis3;
    int newy  =  this->ms_event.y + axis4;
    if (newx <0) newx = 0;
    if (newx > 639) newx = 639;
    if (newy <0) newy = 0;
    if (newy > 479) newy = 479;
    if (axis3 || axis4) {
        this->ms_event.x = (uint16_t)newx;
        this->ms_event.y = (uint16_t)newy;
        this->ms_event.event = 1;
        this->ms_event.event_type = 1;
        if (_mouse) {
            SDL_Point pt(this->ms_event.x, this->ms_event.y);
            SDL_Rect winrc = get_window_aspect_rect();
            pt = to_window_point(winrc,pt);
            _mouse_rect.x = pt.x;
            _mouse_rect.y = pt.y;
            SDL_Event event;
            event.type = _refresh_request;
            SDL_PushEvent(&event);
        }
    }

    SDL_Scancode scn = {};
    switch(axis2) {
        case -1:  scn = SDL_SCANCODE_UP;break;
        case 1:   scn = SDL_SCANCODE_DOWN;break;
        default:break;
    }
    switch(axis1) {
        case -1:  if (_jcontrol_mod_key) scn = SDL_SCANCODE_END; else scn = SDL_SCANCODE_LEFT;break;
        case 1:   if (_jcontrol_mod_key) scn = SDL_SCANCODE_PAGEDOWN; else scn = SDL_SCANCODE_RIGHT;break;
        default:break;
    }
    if (scn != SDL_Scancode{}) {
        std::lock_guard _(_mx);
        _keyboard_queue.push(sdl_keycode_map.get_bios_code(scn,false, false));
    }
}

void SDLContext::configure_controller(const JoystickConfig &cfg) {
    _jcontrol_map = cfg;
}
bool SDLContext::is_joystick_used() const {
    return _jcontrol_used;
}

 bool SDLContext::is_joystick_enabled() const {
    return init_context.controller != 0 && _jcontrol_map.enabled;
}

void SDLContext::generate_j_event(int button, char up) {
    if (_jcontrol_map.enabled && button >= 0 && button < static_cast<int>(sizeof(_jcontrol_map.buttons)/sizeof(JoystickButton))) {
        if (!_jcontrol_used) {
            SDL_AddTimer(25,[](Uint32 tm, void *ptr){
                SDLContext *me = reinterpret_cast<SDLContext *>(ptr);
                me->joystick_handle();
                return tm;
            }, this);
            _jcontrol_used = true;
        }
        JoystickButton b = _jcontrol_mod_key?_jcontrol_map.buttons_mod[button]:_jcontrol_map.buttons[button];
        SDL_Scancode cd = {};
        switch (b) {
            default: break;
            case JoystickButton::enter: if (!up) cd = SDL_SCANCODE_RETURN;break;
            case JoystickButton::space: if (!up) cd = SDL_SCANCODE_SPACE; break;
            case JoystickButton::ctrl: _key_control = !up; break;
            case JoystickButton::lclick: ms_event.tl1 = !up;
                                         ms_event.event = 1;
                                         ms_event.event_type|= up?MS_EVENT_MOUSE_LRELEASE:MS_EVENT_MOUSE_LPRESS;
                                         break;
            case JoystickButton::rclick: ms_event.tl2 = !up;
                                         ms_event.event = 1;
                                         ms_event.event_type|= up?MS_EVENT_MOUSE_RRELEASE:MS_EVENT_MOUSE_RPRESS;
                                         break;
            case JoystickButton::ctrl_lclick:_key_control = !up;
                                         ms_event.tl1 = !up;
                                         ms_event.event = 1;
                                         ms_event.event_type|= up?MS_EVENT_MOUSE_LRELEASE:MS_EVENT_MOUSE_LPRESS;
                                         break;
            case JoystickButton::escape: if (!up) cd = SDL_SCANCODE_ESCAPE;break;
            case JoystickButton::up: if (!up) cd = SDL_SCANCODE_UP;break;
            case JoystickButton::down: if (!up) cd = SDL_SCANCODE_DOWN;break;
            case JoystickButton::left: if (!up) cd = SDL_SCANCODE_PAGEDOWN;break;
            case JoystickButton::right: if (!up) cd = SDL_SCANCODE_END;break;
            case JoystickButton::turn_left: if (!up) cd = SDL_SCANCODE_LEFT;break;
            case JoystickButton::turn_right: if (!up) cd = SDL_SCANCODE_RIGHT;break;
            case JoystickButton::merge: if (!up) cd = SDL_SCANCODE_INSERT;break;
            case JoystickButton::map: if (!up) cd = SDL_SCANCODE_TAB;break;
            case JoystickButton::split1: if (!up) cd = SDL_SCANCODE_1;break;
            case JoystickButton::split2: if (!up) cd = SDL_SCANCODE_2;break;
            case JoystickButton::split3: if (!up) cd = SDL_SCANCODE_3;break;
            case JoystickButton::split4: if (!up) cd = SDL_SCANCODE_4;break;
            case JoystickButton::split5: if (!up) cd = SDL_SCANCODE_5;break;
            case JoystickButton::split6: if (!up) cd = SDL_SCANCODE_6;break;
            case JoystickButton::F1: if (!up) cd = SDL_SCANCODE_F1;break;
            case JoystickButton::F2: if (!up) cd = SDL_SCANCODE_F2;break;
            case JoystickButton::F3: if (!up) cd = SDL_SCANCODE_F3;break;
            case JoystickButton::F4: if (!up) cd = SDL_SCANCODE_F4;break;
            case JoystickButton::F5: if (!up) cd = SDL_SCANCODE_F5;break;
            case JoystickButton::F6: if (!up) cd = SDL_SCANCODE_F6;break;
            case JoystickButton::F7: if (!up) cd = SDL_SCANCODE_F7;break;
            case JoystickButton::F8: if (!up) cd = SDL_SCANCODE_F8;break;
            case JoystickButton::F9: if (!up) cd = SDL_SCANCODE_F9;break;
            case JoystickButton::F10: if (!up) cd = SDL_SCANCODE_F10;break;
            case JoystickButton::F11: if (!up) cd = SDL_SCANCODE_F11;break;
            case JoystickButton::F12: if (!up) cd = SDL_SCANCODE_F12;break;
            case JoystickButton::backspace: if (!up) cd = SDL_SCANCODE_BACKSPACE;break;
            case JoystickButton::mod_key: _jcontrol_mod_key = !up;
        }
        if (cd != SDL_Scancode{}) {
            std::lock_guard _(_mx);
            _keyboard_queue.push(sdl_keycode_map.get_bios_code(cd, 0, 0));
        }
    }
}


void SDLContext::event_loop(std::stop_token stp) {

    static Uint32 exit_loop_event = SDL_RegisterEvents(1);
    std::stop_callback stopcb(stp,[&]{
        SDL_Event event;
        event.type = exit_loop_event;
        SDL_PushEvent(&event);
    });


    SDL_Event e;
    while (SDL_WaitEvent(&e)) {
        SDL_Scancode kbdevent = {};
        if (e.type == SDL_QUIT) {
            _quit_requested = true;
            if (_quit_callback) _quit_callback();
        } else if (e.type == exit_loop_event) {
            break;
        } else if (e.type == _update_request_event) {
            update_screen();
        } else if (e.type == _refresh_request) {
            update_screen(true);
        } else if (e.type == SDL_WINDOWEVENT) {
                if (e.window.event == SDL_WINDOWEVENT_SIZE_CHANGED) {
                    _crt_effect.reset();
                }
         } else if (e.type == SDL_KEYDOWN || e.type == SDL_KEYUP) {
            _key_capslock = e.key.keysym.mod & KMOD_CAPS;
            _key_shift =e.key.keysym.mod & KMOD_SHIFT;
            _key_control  =e.key.keysym.mod & KMOD_CTRL;
            if (e.type == SDL_KEYDOWN) {
                if (e.key.keysym.sym == SDLK_RETURN && (e.key.keysym.mod & KMOD_ALT)) {
                    _fullscreen_mode = !_fullscreen_mode;
                    SDL_SetWindowFullscreen(_window.get(), _fullscreen_mode ? SDL_WINDOW_FULLSCREEN_DESKTOP : 0);
                } else {
                    auto code =sdl_keycode_map.get_bios_code(e.key.keysym.scancode,
                            e.key.keysym.mod & KMOD_SHIFT, e.key.keysym.mod & KMOD_CTRL);
                    if (code) {
                        std::lock_guard _(_mx);
                        _keyboard_queue.push(code);
                    }
                }
            }
        } else if (e.type == SDL_MOUSEMOTION) {
            SDL_Event temp;
            while (SDL_PeepEvents(&temp, 1, SDL_GETEVENT, SDL_MOUSEMOTION, SDL_MOUSEMOTION)) {
                e= temp;
            }

            SDL_Point mspt(e.motion.x, e.motion.y);
            SDL_Rect winrc = get_window_aspect_rect();
            SDL_Point srcpt = to_source_point(winrc, mspt);
            ms_event.event = 1;
            ms_event.event_type |= 1;
            ms_event.x = srcpt.x;
            ms_event.y = srcpt.y;
            if (_mouse) {
                _mouse_rect.x = e.motion.x;
                _mouse_rect.y = e.motion.y;
                update_screen(true);

            }
        } else if (e.type == SDL_MOUSEBUTTONDOWN || e.type == SDL_MOUSEBUTTONUP) {
            int button = e.button.button;
            int up =  e.type == SDL_MOUSEBUTTONUP?1:0;
            ms_event.event = 1;
            int shift = 0;
            switch (button) {
                default: break;
                case 1: ms_event.tl1 = !up; shift = 1; break;
                case 2: ms_event.tl3 = !up; shift = 5; break;
                case 3: ms_event.tl2 = !up; shift = 3; break;
            }
            ms_event.event_type |= (1<<(shift+up));
            if (e.type == SDL_MOUSEBUTTONDOWN && e.button.clicks == 2 && e.button.button == 1) {
                ms_event.event_type |= MS_EVENT_MOUSE_LDBLCLK;
            }
        } else if (e.type == SDL_MOUSEWHEEL) {
            if (e.wheel.y > 0) kbdevent =SDL_SCANCODE_UP;
            else if (e.wheel.y < 0) kbdevent =SDL_SCANCODE_DOWN;
        } else if (e.type == SDL_JOYBUTTONDOWN) {
            generate_j_event(e.jbutton.button, 0);
        } else if (e.type == SDL_JOYBUTTONUP) {
            generate_j_event(e.jbutton.button, 1);
        }

        if (kbdevent != SDL_Scancode{}) {
            auto code =sdl_keycode_map.get_bios_code(kbdevent,false, false);
            std::lock_guard _(_mx);
            _keyboard_queue.push(code);
        }

    }
}



void SDLContext::present_rect(uint16_t *pixels, unsigned int pitch,
        unsigned int x, unsigned int y, unsigned int xs, unsigned ys) {


    auto beg = pixels + y * pitch + x;
    SDL_Rect r = {static_cast<int>(x),
                  static_cast<int>(y),
                  static_cast<int>(xs),
                  static_cast<int>(ys)};

    std::lock_guard _(_mx);
    signal_push();
    push_update_msg(r, beg, pitch);
}

std::uint16_t SDLContext::pop_keyboard_code()  {
    std::lock_guard _(_mx);
    std::uint16_t out = _keyboard_queue.front();
    _keyboard_queue.pop();
    return out;
}

bool SDLContext::is_keyboard_ready() const {
    std::lock_guard _(_mx);
    return !_keyboard_queue.empty();
}

void SDLContext::show_slide_transition(const SDL_Rect &visible_from,
        const SDL_Rect &visible_where, const SDL_Rect &hidden_from,
        const SDL_Rect &hidden_where) {
    std::lock_guard _(_mx);
    push_item(DisplayRequest::slide_transition);
    push_item(SlideTransitionReq{visible_from, visible_where,hidden_from, hidden_where});
}

void SDLContext::signal_push() {
    if (_display_update_queue.empty()) {
        SDL_Event event;
        event.type = _update_request_event;
        SDL_PushEvent(&event);
    }

}

void SDLContext::refresh_screen() {
    SDL_Rect winrc = get_window_aspect_rect();
    SDL_RenderClear(_renderer.get());
    if (slide_transition) {
        SDL_SetTextureAlphaMod(_hidden_texture, 255);
        SDL_SetTextureAlphaMod(_visible_texture, 255);
        SDL_RenderCopy(_renderer.get(), _hidden_texture, NULL, &winrc);
        SDL_Rect visible_where_win = to_window_rect(winrc, slide_transition->visible_where);
        SDL_Rect hidden_where_win = to_window_rect(winrc, slide_transition->hidden_where);
        SDL_RenderCopy(_renderer.get(), _visible_texture, &slide_transition->visible_from, &visible_where_win);
        SDL_RenderCopy(_renderer.get(), _hidden_texture, &slide_transition->hidden_from, &hidden_where_win);
    }
    else if (blend_transition) {
        SDL_SetTextureAlphaMod(_hidden_texture, 255);
        SDL_RenderCopy(_renderer.get(), _hidden_texture, NULL, &winrc);
        if (blend_transition->phase >= 0) {
            float f = blend_transition->phase;
            SDL_SetTextureAlphaMod(_visible_texture, 255);
            SDL_Rect wrkarea = to_window_rect(winrc, blend_transition->wrkarea);
            SDL_Rect src1 = transition_rect(blend_transition->prev, blend_transition->next, f);
            SDL_RenderCopy(_renderer.get(), _visible_texture, &src1, &wrkarea);
            if (SDL_SetTextureAlphaMod(_hidden_texture, (uint8_t)(255.0f*(f)))!= -1) {
                SDL_Rect trgnxt = to_window_rect(winrc, blend_transition->next);
                SDL_Rect trgwin = transition_rect(trgnxt, wrkarea, f);
                SDL_RenderCopy(_renderer.get(), _hidden_texture, &blend_transition->wrkarea, &trgwin);
            }
        } else {
            float f = blend_transition->phase;
            SDL_Rect wrkarea = to_window_rect(winrc, blend_transition->wrkarea);
            SDL_Rect src1 = transition_rect(blend_transition->prev, blend_transition->next, 1+f);
            SDL_RenderCopy(_renderer.get(), _hidden_texture, &src1, &wrkarea);
            if (SDL_SetTextureAlphaMod(_visible_texture, (uint8_t)(255.0f*(1+f))) != -1) {
                SDL_Rect trgnxt = to_window_rect(winrc, blend_transition->next);
                SDL_Rect trgwin = transition_rect(trgnxt, wrkarea, 1+f);
                SDL_RenderCopy(_renderer.get(), _visible_texture, &blend_transition->wrkarea, &trgwin);
            }
        }
    } else {
        SDL_SetTextureAlphaMod(_visible_texture, 255);
        SDL_RenderCopy(_renderer.get(), _visible_texture, NULL, &winrc);
    }
    for (const auto &sprite: _sprites) if (sprite.shown) {
        SDL_Rect rc = to_window_rect(winrc,sprite._rect);
        SDL_RenderCopy(_renderer.get(), sprite._txtr.get(), NULL, &rc);
    }
    if (_mouse) {
        SDL_Rect recalc_rect = to_window_rect(winrc, _mouse_rect);
        recalc_rect.w = static_cast<int>(recalc_rect.w * _mouse_size);
        recalc_rect.h = static_cast<int>(recalc_rect.h * _mouse_size);
        SDL_Point f= to_window_point({0,0,winrc.w, winrc.h}, _mouse_finger);
        recalc_rect.x = _mouse_rect.x - static_cast<int>(f.x * _mouse_size);
        recalc_rect.y = _mouse_rect.y - static_cast<int>(f.y * _mouse_size);
        SDL_RenderCopy(_renderer.get(), _mouse.get(), NULL, &recalc_rect);
    }
    if (winrc.h >= 720 && _crt_filter != CrtFilterType::none && _enable_crt)  {
        if (!_crt_effect) {
            SDL_Texture *txt;
              generateCRTTexture(_renderer.get(), &txt, winrc.w, winrc.h, _crt_filter);
            _crt_effect.reset(txt);
        }
        SDL_RenderCopy(_renderer.get(), _crt_effect.get(), NULL, &winrc);
    }
    SDL_RenderPresent(_renderer.get());

}

void SDLContext::update_screen(bool force_refresh) {
    {
        std::lock_guard _(_mx);
        if (_display_update_queue.empty()) {
            if (force_refresh) refresh_screen();
            return;
        }
        QueueIter iter = _display_update_queue.data();
        QueueIter end = iter + _display_update_queue.size();
        while (iter != end) {
            DisplayRequest req;
            pop_item(iter, req);
            switch (req) {
                case DisplayRequest::update: {
                    SDL_Rect r;
                    pop_item(iter, r);
                    std::string_view data = pop_data(iter, r.w*r.h*2);
                    if (SDL_UpdateTexture(_texture.get(), &r, data.data(), r.w*2)<0) handle_sdl_error("Update of render target failed");
                }
                break;
                case DisplayRequest::show_mouse_cursor: {
                    SDL_Rect r;
                    pop_item(iter, r);
                    std::string_view data = pop_data(iter, r.w*r.h*2);
                    _mouse.reset(SDL_CreateTexture(_renderer.get(), SDL_PIXELFORMAT_ARGB1555,SDL_TEXTUREACCESS_STATIC, r.w, r.h));
                    if (!_mouse) handle_sdl_error("Failed to create surface for mouse cursor");
                    SDL_SetTextureBlendMode(_mouse.get(), SDL_BLENDMODE_BLEND);
                    _mouse_rect.w = r.w;
                    _mouse_rect.h = r.h;
                    if (SDL_UpdateTexture(_mouse.get(), NULL, data.data(), r.w*2)<0) handle_sdl_error("Update of mouse cursor failed");
                }
                break;
                case DisplayRequest::hide_mouse_cursor: {
                    _mouse.reset();
                }
                break;
                case DisplayRequest::swap_render_buffers: {
                    std::swap(_texture,_texture2);
                }
                break;
                case DisplayRequest::swap_visible_buffers: {
                    std::swap(_visible_texture,_hidden_texture);
                    blend_transition.reset();
                    slide_transition.reset();
                }
                break;
                case DisplayRequest::blend_transition:
                    blend_transition.emplace();
                     pop_item(iter, *blend_transition);
                break;
                case DisplayRequest::slide_transition:
                    slide_transition.emplace();
                     pop_item(iter, *slide_transition);
                break;
                case DisplayRequest::sprite_load: {
                    int id;
                    SDL_Rect r;
                    pop_item(iter, id);
                    pop_item(iter, r);
                    std::string_view data = pop_data(iter, r.w*r.h*2);
                    auto iter = std::find_if(_sprites.begin(), _sprites.end(),[&](const Sprite &x){
                        return x.id == id;
                    });
                    if (iter == _sprites.end()) {
                        iter = _sprites.insert(iter,{id});
                    }
                    iter->_txtr.reset(SDL_CreateTexture(_renderer.get(), SDL_PIXELFORMAT_ARGB1555, SDL_TEXTUREACCESS_STATIC,r.w, r.h));
                    if (!iter->_txtr) handle_sdl_error("Failed to create compositor sprite");
                    SDL_SetTextureBlendMode(iter->_txtr.get(), SDL_BLENDMODE_BLEND);
                    if (SDL_UpdateTexture(iter->_txtr.get(), NULL, data.data(), r.w*2)<0) handle_sdl_error("Update of sprite failed");
                    iter->_rect = r;
                    update_zindex();
                } break;
                case DisplayRequest::sprite_unload: {
                    int id;
                    pop_item(iter, id);
                    auto iter = std::remove_if(_sprites.begin(), _sprites.end(),[&](const Sprite &x){
                        return x.id == id;
                    });
                    _sprites.erase(iter,_sprites.end());
                } break;
                case DisplayRequest::sprite_hide: {
                    int id;
                    pop_item(iter, id);
                    auto iter = std::find_if(_sprites.begin(), _sprites.end(),[&](const Sprite &x){
                        return x.id == id;
                    });
                    if (iter != _sprites.end()) iter->shown = false;
                } break;
                case DisplayRequest::sprite_place: {
                    int id;
                    SDL_Point pt;
                    pop_item(iter, id);
                    pop_item(iter, pt);
                    auto iter = std::find_if(_sprites.begin(), _sprites.end(),[&](const Sprite &x){
                        return x.id == id;
                    });
                    if (iter != _sprites.end()) {
                        iter->shown = true;
                        iter->_rect.x = pt.x;
                        iter->_rect.y = pt.y;
                    }
                } break;
                case DisplayRequest::sprite_scale: {
                    int id;
                    SDL_Rect rc;
                    pop_item(iter, id);
                    pop_item(iter, rc);
                    auto iter = std::find_if(_sprites.begin(), _sprites.end(),[&](const Sprite &x){
                        return x.id == id;
                    });
                    if (iter != _sprites.end()) {
                        iter->shown = true;
                        iter->_rect = rc;
                    }
                } break;
                case DisplayRequest::sprite_zindex: {
                    int id;
                    int zindex;
                    pop_item(iter, id);
                    pop_item(iter, zindex);
                    auto iter = std::find_if(_sprites.begin(), _sprites.end(),[&](const Sprite &x){
                        return x.id == id;
                    });
                    if (iter != _sprites.end()) {
                        iter->zindex = zindex;
                        update_zindex();
                    }
                } break;

            }
        }
        _display_update_queue.clear();

    }
    refresh_screen();
}


void SDLContext::update_zindex() {
    std::stable_sort(_sprites.begin(), _sprites.end(), [&](const Sprite &a, const Sprite &b){
        return a.zindex < b.zindex;
    });

}
template<typename T>
requires(std::is_trivially_copy_constructible_v<T>)
void  SDLContext::push_item(const T &item) {
    auto b = reinterpret_cast<const char *>(&item);
    auto e = b + sizeof(T);
    auto sz = _display_update_queue.size();
    if (sz == 0) signal_push();
    _display_update_queue.resize(sz + sizeof(T));
    std::copy(b, e, _display_update_queue.begin()+sz);
}

void SDLContext::push_item(const std::string_view &item) {
    auto sz = _display_update_queue.size();
    if (sz == 0) signal_push();
    _display_update_queue.resize(sz + item.size());
    std::copy(item.begin(), item.end(),  _display_update_queue.begin()+sz);
}

void SDLContext::push_update_msg(const SDL_Rect &rc, const uint16_t *data, int pitch) {
    push_item(DisplayRequest::update);
    push_item(rc);
    auto sz = _display_update_queue.size();
    _display_update_queue.resize(sz+rc.w*rc.h*2);
    short *trg = reinterpret_cast<short *>(_display_update_queue.data()+sz);
    for (int yp = 0; yp < rc.h; ++yp) {
        for (int xp = 0; xp < rc.w; ++xp) {
            *trg = data[xp] ^ 0x8000;
            ++trg;
        }
        data += pitch;
    }
}

template<typename T>
requires(std::is_trivially_copy_constructible_v<T>)
void SDLContext::pop_item(QueueIter &iter, T &item) {
    std::copy(iter, iter+sizeof(T), reinterpret_cast<char *>(&item));
    iter += sizeof(T);
}
std::string_view SDLContext::pop_data(QueueIter &iter, std::size_t size) {
    const char *c = iter;
    iter += size;
    return std::string_view(c, size);
}

void SDLContext::swap_render_buffers() {
    std::lock_guard _(_mx);
    push_item(DisplayRequest::swap_render_buffers);
}

void SDLContext::swap_display_buffers() {
    std::lock_guard _(_mx);
    push_item(DisplayRequest::swap_visible_buffers);
}

void SDLContext::show_blend_transition(const SDL_Rect &wrkarea, const SDL_Rect &prev,
        const SDL_Rect &next, float phase) {
    std::lock_guard _(_mx);
    push_item(DisplayRequest::blend_transition);
    push_item(BlendTransitionReq{wrkarea, prev, next, phase});
}

SDL_Rect SDLContext::get_window_aspect_rect() const {
    SDL_Rect w;
    int ww;
    int wh;
    SDL_GetWindowSize(_window.get(), &ww, &wh);
    if (aspect_x && aspect_y) {
        int apw  = wh * aspect_x / aspect_y;
        int aph =  ww * aspect_y / aspect_x;
        int fw;
        int fh;
        if (apw > ww) {
            fw = ww;
            fh = aph;
        } else {
            fw = apw;
            fh = wh;
        }
        w.h = fh;
        w.w = fw;
        w.x = (ww - fw)/2;
        w.y = (wh - fh)/2;
    } else {
        w.x = 0;
        w.y = 0;
        w.w = ww;
        w.h = wh;
    }
    return w;
}

SDL_Point SDLContext::to_window_point(const SDL_Rect &winrc, const SDL_Point &pt) {
    return {
        pt.x * winrc.w / 640 + winrc.x,
        pt.y * winrc.h / 480 + winrc.y,
    };
}

SDL_Point SDLContext::to_source_point(const SDL_Rect &winrc, const SDL_Point &win_pt)  {
    return {
        (win_pt.x - winrc.x) * 640 / winrc.w,
        (win_pt.y - winrc.y) * 480 / winrc.h,
    };
}

int SDLContext::transition_int(int beg, int end, float phase) {
    int w = end - beg;
    return beg + static_cast<int>(std::round(w * phase));
}

SDL_Rect SDLContext::transition_rect(const SDL_Rect &beg, const SDL_Rect &end, float phase) {
    SDL_Rect out;
    out.x = transition_int(beg.x, end.x, phase);
    out.y = transition_int(beg.y, end.y, phase);
    out.w = transition_int(beg.w, end.w, phase);
    out.h = transition_int(beg.h, end.h, phase);
    return out;
}


SDL_Rect SDLContext::to_window_rect(const SDL_Rect &winrc, const SDL_Rect &source_rect) {
    SDL_Point pt1(source_rect.x, source_rect.y);
    SDL_Point pt2(source_rect.x+source_rect.w, source_rect.y+source_rect.h);
    SDL_Point wpt1(to_window_point(winrc, pt1));
    SDL_Point wpt2(to_window_point(winrc, pt2));
    return {wpt1.x, wpt1.y, wpt2.x - wpt1.x, wpt2.y - wpt1.y};
}
void SDLContext::set_quit_callback(std::function<void()> fn) {
    _quit_callback = std::move(fn);
}

SDLContext::AudioInfo SDLContext::init_audio(const AudioConfig &config, SDL_AudioCallback cb, void *cb_ctx) {
    _audio.reset();
    SDL_AudioSpec aspec = {};
    aspec.callback = cb;
    aspec.userdata = cb_ctx;
    aspec.channels = 2;
    aspec.format = AUDIO_F32;
    aspec.freq = 44100;
    aspec.samples = 1024;
    SDL_AudioSpec obtaied = {};
    auto id = SDL_OpenAudioDevice(config.audioDevice, 0, &aspec, &obtaied, SDL_AUDIO_ALLOW_FREQUENCY_CHANGE|SDL_AUDIO_ALLOW_SAMPLES_CHANGE);
    if (id < 1) {
        std::ostringstream err;
        err << "SDL Error create audio:" << SDL_GetError() << "\n";
        int n = SDL_GetNumAudioDevices(0);
        if (n == 0) err << "No audio devices are available" << "\n";
        else {
            err << "Available audio devices:";
            char sep = ' ';
            for (int i = 0; i < n; ++i) {
                err << sep << SDL_GetAudioDeviceName(i, 0);
                sep = ',';
            }
        }
        throw std::runtime_error(err.str());
    }
    _audio.reset(id);

    return {obtaied.freq};
}
void SDLContext::pause_audio(bool pause) {
    SDL_AudioDeviceID id = _audio.get();
    SDL_PauseAudioDevice(id, pause?1:0);
}

void SDLContext::close_audio() {
    _audio.reset();
}

void SDLContext::set_window_icon(const void *icon_data, size_t icon_size) {
    SDL_Surface *surface = SDL_LoadBMP_RW(SDL_RWFromConstMem(icon_data, icon_size), 1);
    if (surface) {
        SDL_SetWindowIcon(_window.get(), surface);
    }
}

extern "C" {
void put_picture_ex(unsigned short x,unsigned short y,const void *p, unsigned short *target_addr, size_t pitch);
}

void  SDLContext::push_hi_image(const unsigned short *image) {
    SDL_Rect rc;
    rc.w= image[0];
    rc.h =image[1];
    push_item(rc);
    auto sz = _display_update_queue.size();
    auto imgsz = rc.w*rc.h;
    _display_update_queue.resize(sz+imgsz*2);
    unsigned short *trg = reinterpret_cast<unsigned short *>(_display_update_queue.data()+sz);
    std::fill(trg, trg+imgsz, 0x8000);
    put_picture_ex(0, 0, image, trg, rc.w);
    std::transform(trg, trg+imgsz, trg, [](unsigned short &x)->unsigned short {return x ^ 0x8000;});
}

void SDLContext::show_mouse_cursor(const unsigned short *ms_hi_format, SDL_Point finger) {
    std::lock_guard _(_mx);
    push_item(DisplayRequest::show_mouse_cursor);
    push_hi_image(ms_hi_format);
    _mouse_finger = finger;
}

void SDLContext::hide_mouse_cursor() {
    std::lock_guard _(_mx);
    push_item(DisplayRequest::hide_mouse_cursor);

}

void SDLContext::load_sprite(int sprite_id, const unsigned short *hi_image) {
    std::lock_guard _(_mx);
    push_item(DisplayRequest::sprite_load);
    push_item(sprite_id);
    push_hi_image(hi_image);

}

void SDLContext::place_sprite(int sprite_id, int x, int y) {
    std::lock_guard _(_mx);
    push_item(DisplayRequest::sprite_place);
    push_item(sprite_id);
    SDL_Point pt{x,y};
    push_item(pt);

}

void SDLContext::scale_sprite(int sprite_id, int x, int y, int w, int h) {
    std::lock_guard _(_mx);
    push_item(DisplayRequest::sprite_scale);
    push_item(sprite_id);
    SDL_Rect pt{x,y,w,h};
    push_item(pt);
}

void SDLContext::hide_sprite(int sprite_id) {
    std::lock_guard _(_mx);
    push_item(DisplayRequest::sprite_hide);
    push_item(sprite_id);
}

void SDLContext::sprite_set_zindex(int sprite_id, int zindex) {
    std::lock_guard _(_mx);
    push_item(DisplayRequest::sprite_hide);
    push_item(sprite_id);
    push_item(zindex);
}

void SDLContext::unload_sprite(int sprite) {
    std::lock_guard _(_mx);
    push_item(DisplayRequest::sprite_unload);
    push_item(sprite);
}

void SDLContext::enable_crt_filter(bool enable)
{
    std::lock_guard _(_mx);
    _enable_crt = enable;
    signal_push();
}

bool SDLContext::is_crt_enabled() const
{
    std::lock_guard _(_mx);
    return _enable_crt;
}

SDLContext::JoystickButton SDLContext::button_from_string(std::string_view s) {
    if (s=="enter") return JoystickButton::enter;
    if (s=="space") return JoystickButton::space;
    if (s=="ctrl") return JoystickButton::ctrl;
    if (s=="lclick") return JoystickButton::lclick;
    if (s=="rclick") return JoystickButton::rclick;
    if (s=="ctrl+lclick") return JoystickButton::ctrl_lclick;
    if (s=="escape") return JoystickButton::escape;
    if (s=="up") return JoystickButton::up;
    if (s=="down") return JoystickButton::down;
    if (s=="left") return JoystickButton::left;
    if (s=="right") return JoystickButton::right;
    if (s=="turn_left") return JoystickButton::turn_left;
    if (s=="turn_right") return JoystickButton::turn_right;
    if (s=="merge_group") return JoystickButton::merge;
    if (s=="split1") return JoystickButton::split1;
    if (s=="split2") return JoystickButton::split2;
    if (s=="split3") return JoystickButton::split3;
    if (s=="split4") return JoystickButton::split4;
    if (s=="split5") return JoystickButton::split5;
    if (s=="split6") return JoystickButton::split6;
    if (s=="map") return JoystickButton::map;
    if (s=="F1") return JoystickButton::F1;
    if (s=="F2") return JoystickButton::F2;
    if (s=="F3") return JoystickButton::F3;
    if (s=="F4") return JoystickButton::F4;
    if (s=="F5") return JoystickButton::F5;
    if (s=="F6") return JoystickButton::F6;
    if (s=="F7") return JoystickButton::F7;
    if (s=="F8") return JoystickButton::F8;
    if (s=="F9") return JoystickButton::F9;
    if (s=="F10") return JoystickButton::F10;
    if (s=="F11") return JoystickButton::F11;
    if (s=="F12") return JoystickButton::F12;
    if (s=="backspace") return JoystickButton::backspace;
    if (s=="mod_key") return JoystickButton::mod_key;
    return JoystickButton::disabled;

}