/*
  Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely.
*/

/* Simple program to test the SDL game controller routines */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "SDL.h"

#ifdef __EMSCRIPTEN__
#include <emscripten/emscripten.h>
#endif

#ifndef SDL_JOYSTICK_DISABLED

#define SCREEN_WIDTH    512
#define SCREEN_HEIGHT   320

/* This is indexed by SDL_GameControllerButton. */
static const struct { int x; int y; } button_positions[] = {
    {387, 167},  /* SDL_CONTROLLER_BUTTON_A */
    {431, 132},  /* SDL_CONTROLLER_BUTTON_B */
    {342, 132},  /* SDL_CONTROLLER_BUTTON_X */
    {389, 101},  /* SDL_CONTROLLER_BUTTON_Y */
    {174, 132},  /* SDL_CONTROLLER_BUTTON_BACK */
    {232, 128},  /* SDL_CONTROLLER_BUTTON_GUIDE */
    {289, 132},  /* SDL_CONTROLLER_BUTTON_START */
    {75,  154},  /* SDL_CONTROLLER_BUTTON_LEFTSTICK */
    {305, 230},  /* SDL_CONTROLLER_BUTTON_RIGHTSTICK */
    {77,  40},   /* SDL_CONTROLLER_BUTTON_LEFTSHOULDER */
    {396, 36},   /* SDL_CONTROLLER_BUTTON_RIGHTSHOULDER */
    {154, 188},  /* SDL_CONTROLLER_BUTTON_DPAD_UP */
    {154, 249},  /* SDL_CONTROLLER_BUTTON_DPAD_DOWN */
    {116, 217},  /* SDL_CONTROLLER_BUTTON_DPAD_LEFT */
    {186, 217},  /* SDL_CONTROLLER_BUTTON_DPAD_RIGHT */
    {232, 174},  /* SDL_CONTROLLER_BUTTON_MISC1 */
    {132, 135},  /* SDL_CONTROLLER_BUTTON_PADDLE1 */
    {330, 135},  /* SDL_CONTROLLER_BUTTON_PADDLE2 */
    {132, 175},  /* SDL_CONTROLLER_BUTTON_PADDLE3 */
    {330, 175},  /* SDL_CONTROLLER_BUTTON_PADDLE4 */
};

/* This is indexed by SDL_GameControllerAxis. */
static const struct { int x; int y; double angle; } axis_positions[] = {
    {74,  153, 270.0},  /* LEFTX */
    {74,  153,   0.0},  /* LEFTY */
    {306, 231, 270.0},  /* RIGHTX */
    {306, 231,   0.0},  /* RIGHTY */
    {91,  -20,   0.0},  /* TRIGGERLEFT */
    {375, -20,   0.0},  /* TRIGGERRIGHT */
};

SDL_Window *window = NULL;
SDL_Renderer *screen = NULL;
SDL_bool retval = SDL_FALSE;
SDL_bool done = SDL_FALSE;
SDL_bool set_LED = SDL_FALSE;
SDL_Texture *background_front, *background_back, *button, *axis;
SDL_GameController *gamecontroller;
SDL_GameController **gamecontrollers;
int num_controllers = 0;

static void UpdateWindowTitle()
{
    if (!window) {
        return;
    }

    if (gamecontroller) {
        const char *name = SDL_GameControllerName(gamecontroller);
        const char *serial = SDL_GameControllerGetSerial(gamecontroller);
        const char *basetitle = "Game Controller Test: ";
        const size_t titlelen = SDL_strlen(basetitle) + SDL_strlen(name) + (serial ? 3 + SDL_strlen(serial) : 0) + 1;
        char *title = (char *)SDL_malloc(titlelen);

        retval = SDL_FALSE;
        done = SDL_FALSE;

        if (title) {
            SDL_snprintf(title, titlelen, "%s%s", basetitle, name);
            if (serial) {
                SDL_strlcat(title, " (", titlelen);
                SDL_strlcat(title, serial, titlelen);
                SDL_strlcat(title, ")", titlelen);
            }
            SDL_SetWindowTitle(window, title);
            SDL_free(title);
        }
    } else {
        SDL_SetWindowTitle(window, "Waiting for controller...");
    }
}

static int FindController(SDL_JoystickID controller_id)
{
    int i;

    for (i = 0; i < num_controllers; ++i) {
        if (controller_id == SDL_JoystickInstanceID(SDL_GameControllerGetJoystick(gamecontrollers[i]))) {
            return i;
        }
    }
    return -1;
}

static void AddController(int device_index, SDL_bool verbose)
{
    SDL_JoystickID controller_id = SDL_JoystickGetDeviceInstanceID(device_index);
    SDL_GameController *controller;
    SDL_GameController **controllers;

    controller_id = SDL_JoystickGetDeviceInstanceID(device_index);
    if (controller_id < 0) {
        SDL_Log("Couldn't get controller ID: %s\n", SDL_GetError());
        return;
    }

    if (FindController(controller_id) >= 0) {
        /* We already have this controller */
        return;
    }

    controller = SDL_GameControllerOpen(device_index);
    if (!controller) {
        SDL_Log("Couldn't open controller: %s\n", SDL_GetError());
        return;
    }

    controllers = (SDL_GameController **)SDL_realloc(gamecontrollers, (num_controllers + 1) * sizeof(*controllers));
    if (!controllers) {
        SDL_GameControllerClose(controller);
        return;
    }

    controllers[num_controllers++] = controller;
    gamecontrollers = controllers;
    gamecontroller = controller;

    if (verbose) {
        const char *name = SDL_GameControllerName(gamecontroller);
        SDL_Log("Opened game controller %s\n", name);
    }

    if (SDL_GameControllerHasSensor(gamecontroller, SDL_SENSOR_ACCEL)) {
        if (verbose) {
            SDL_Log("Enabling accelerometer\n");
        }
        SDL_GameControllerSetSensorEnabled(gamecontroller, SDL_SENSOR_ACCEL, SDL_TRUE);
    }

    if (SDL_GameControllerHasSensor(gamecontroller, SDL_SENSOR_GYRO)) {
        if (verbose) {
            SDL_Log("Enabling gyro\n");
        }
        SDL_GameControllerSetSensorEnabled(gamecontroller, SDL_SENSOR_GYRO, SDL_TRUE);
    }

    UpdateWindowTitle();
}

static void SetController(SDL_JoystickID controller)
{
    int i = FindController(controller);

    if (i < 0) {
        return;
    }

    if (gamecontroller != gamecontrollers[i]) {
        gamecontroller = gamecontrollers[i];
        UpdateWindowTitle();
    }
}

static void DelController(SDL_JoystickID controller)
{
    int i = FindController(controller);

    if (i < 0) {
        return;
    }

    SDL_GameControllerClose(gamecontrollers[i]);

    --num_controllers;
    if (i < num_controllers) {
        SDL_memcpy(&gamecontrollers[i], &gamecontrollers[i+1], (num_controllers - i) * sizeof(*gamecontrollers));
    }

    if (num_controllers > 0) {
        gamecontroller = gamecontrollers[0];
    } else {
        gamecontroller = NULL;
    }
    UpdateWindowTitle();
}

static SDL_Texture *
LoadTexture(SDL_Renderer *renderer, const char *file, SDL_bool transparent)
{
    SDL_Surface *temp = NULL;
    SDL_Texture *texture = NULL;

    temp = SDL_LoadBMP(file);
    if (temp == NULL) {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't load %s: %s", file, SDL_GetError());
    } else {
        /* Set transparent pixel as the pixel at (0,0) */
        if (transparent) {
            if (temp->format->BytesPerPixel == 1) {
                SDL_SetColorKey(temp, SDL_TRUE, *(Uint8 *)temp->pixels);
            }
        }

        texture = SDL_CreateTextureFromSurface(renderer, temp);
        if (!texture) {
            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't create texture: %s\n", SDL_GetError());
        }
    }
    if (temp) {
        SDL_FreeSurface(temp);
    }
    return texture;
}

static Uint16 ConvertAxisToRumble(Sint16 axis)
{
    /* Only start rumbling if the axis is past the halfway point */
    const Sint16 half_axis = (Sint16)SDL_ceil(SDL_JOYSTICK_AXIS_MAX / 2.0f);
    if (axis > half_axis) {
        return (Uint16)(axis - half_axis) * 4;
    } else {
        return 0;
    }
}

void
loop(void *arg)
{
    SDL_Event event;
    int i;
    SDL_bool showing_front = SDL_TRUE;

    while (SDL_PollEvent(&event)) {
        switch (event.type) {
        case SDL_CONTROLLERDEVICEADDED:
            SDL_Log("Game controller device %d added.\n", (int) SDL_JoystickGetDeviceInstanceID(event.cdevice.which));
            AddController(event.cdevice.which, SDL_TRUE);
            break;

        case SDL_CONTROLLERDEVICEREMOVED:
            SDL_Log("Game controller device %d removed.\n", (int) event.cdevice.which);
            DelController(event.cdevice.which);
            break;

        case SDL_CONTROLLERTOUCHPADDOWN:
        case SDL_CONTROLLERTOUCHPADMOTION:
        case SDL_CONTROLLERTOUCHPADUP:
            SDL_Log("Controller touchpad %d finger %d %s %.2f, %.2f, %.2f\n",
                event.ctouchpad.touchpad,
                event.ctouchpad.finger,
                (event.type == SDL_CONTROLLERTOUCHPADDOWN ? "pressed at" :
                (event.type == SDL_CONTROLLERTOUCHPADUP ? "released at" :
                "moved to")),
                event.ctouchpad.x,
                event.ctouchpad.y,
                event.ctouchpad.pressure);
            break;

        case SDL_CONTROLLERSENSORUPDATE:
            SDL_Log("Controller sensor %s: %.2f, %.2f, %.2f\n",
                event.csensor.sensor == SDL_SENSOR_ACCEL ? "accelerometer" :
                event.csensor.sensor == SDL_SENSOR_GYRO ? "gyro" : "unknown",
                event.csensor.data[0],
                event.csensor.data[1],
                event.csensor.data[2]);
            break;

        case SDL_CONTROLLERAXISMOTION:
            if (event.caxis.value <= (-SDL_JOYSTICK_AXIS_MAX / 2) || event.caxis.value >= (SDL_JOYSTICK_AXIS_MAX / 2)) {
                SetController(event.caxis.which);
            }
            SDL_Log("Controller axis %s changed to %d\n", SDL_GameControllerGetStringForAxis((SDL_GameControllerAxis)event.caxis.axis), event.caxis.value);
            break;

        case SDL_CONTROLLERBUTTONDOWN:
        case SDL_CONTROLLERBUTTONUP:
            if (event.type == SDL_CONTROLLERBUTTONDOWN) {
                SetController(event.cbutton.which);
            }
            SDL_Log("Controller button %s %s\n", SDL_GameControllerGetStringForButton((SDL_GameControllerButton)event.cbutton.button), event.cbutton.state ? "pressed" : "released");
            break;

        case SDL_KEYDOWN:
            if (event.key.keysym.sym != SDLK_ESCAPE) {
                break;
            }
            /* Fall through to signal quit */
        case SDL_QUIT:
            done = SDL_TRUE;
            break;
        default:
            break;
        }
    }

    if (gamecontroller) {
        /* Show the back of the controller if the paddles are being held */
        for (i = SDL_CONTROLLER_BUTTON_PADDLE1; i <= SDL_CONTROLLER_BUTTON_PADDLE4; ++i) {
            if (SDL_GameControllerGetButton(gamecontroller, (SDL_GameControllerButton)i) == SDL_PRESSED) {
                showing_front = SDL_FALSE;
                break;
            }
        }
    }

    /* blank screen, set up for drawing this frame. */
    SDL_SetRenderDrawColor(screen, 0xFF, 0xFF, 0xFF, SDL_ALPHA_OPAQUE);
    SDL_RenderClear(screen);
    SDL_RenderCopy(screen, showing_front ? background_front : background_back, NULL, NULL);

    if (gamecontroller) {
        /* Update visual controller state */
        for (i = 0; i < SDL_CONTROLLER_BUTTON_TOUCHPAD; ++i) {
            if (SDL_GameControllerGetButton(gamecontroller, (SDL_GameControllerButton)i) == SDL_PRESSED) {
                SDL_bool on_front = (i < SDL_CONTROLLER_BUTTON_PADDLE1 || i > SDL_CONTROLLER_BUTTON_PADDLE4);
                if (on_front == showing_front) {
                    const SDL_Rect dst = { button_positions[i].x, button_positions[i].y, 50, 50 };
                    SDL_RenderCopyEx(screen, button, NULL, &dst, 0, NULL, SDL_FLIP_NONE);
                }
            }
        }

        if (showing_front) {
            for (i = 0; i < SDL_CONTROLLER_AXIS_MAX; ++i) {
                const Sint16 deadzone = 8000;  /* !!! FIXME: real deadzone */
                const Sint16 value = SDL_GameControllerGetAxis(gamecontroller, (SDL_GameControllerAxis)(i));
                if (value < -deadzone) {
                    const SDL_Rect dst = { axis_positions[i].x, axis_positions[i].y, 50, 50 };
                    const double angle = axis_positions[i].angle;
                    SDL_RenderCopyEx(screen, axis, NULL, &dst, angle, NULL, SDL_FLIP_NONE);
                } else if (value > deadzone) {
                    const SDL_Rect dst = { axis_positions[i].x, axis_positions[i].y, 50, 50 };
                    const double angle = axis_positions[i].angle + 180.0;
                    SDL_RenderCopyEx(screen, axis, NULL, &dst, angle, NULL, SDL_FLIP_NONE);
                }
            }
        }

        /* Update LED based on left thumbstick position */
        {
            Sint16 x = SDL_GameControllerGetAxis(gamecontroller, SDL_CONTROLLER_AXIS_LEFTX);
            Sint16 y = SDL_GameControllerGetAxis(gamecontroller, SDL_CONTROLLER_AXIS_LEFTY);

            if (!set_LED) {
                set_LED = (x < -8000 || x > 8000 || y > 8000);
            }
            if (set_LED) {
                Uint8 r, g, b;

                if (x < 0) {
                    r = (Uint8)(((int)(~x) * 255) / 32767);
                    b = 0;
                } else {
                    r = 0;
                    b = (Uint8)(((int)(x) * 255) / 32767);
                }
                if (y > 0) {
                    g = (Uint8)(((int)(y) * 255) / 32767);
                } else {
                    g = 0;
                }

                SDL_GameControllerSetLED(gamecontroller, r, g, b);
            }
        }

        /* Update rumble based on trigger state */
        {
            Sint16 left = SDL_GameControllerGetAxis(gamecontroller, SDL_CONTROLLER_AXIS_TRIGGERLEFT);
            Sint16 right = SDL_GameControllerGetAxis(gamecontroller, SDL_CONTROLLER_AXIS_TRIGGERRIGHT);
            Uint16 low_frequency_rumble = ConvertAxisToRumble(left);
            Uint16 high_frequency_rumble = ConvertAxisToRumble(right);
            SDL_GameControllerRumble(gamecontroller, low_frequency_rumble, high_frequency_rumble, 250);
        }

        /* Update trigger rumble based on thumbstick state */
        {
            Sint16 left = SDL_GameControllerGetAxis(gamecontroller, SDL_CONTROLLER_AXIS_LEFTY);
            Sint16 right = SDL_GameControllerGetAxis(gamecontroller, SDL_CONTROLLER_AXIS_RIGHTY);
            Uint16 left_rumble = ConvertAxisToRumble(~left);
            Uint16 right_rumble = ConvertAxisToRumble(~right);

            SDL_GameControllerRumbleTriggers(gamecontroller, left_rumble, right_rumble, 250);
        }
    }

    SDL_RenderPresent(screen);

#ifdef __EMSCRIPTEN__
    if (done) {
        emscripten_cancel_main_loop();
    }
#endif
}

int
main(int argc, char *argv[])
{
    int i;
    int controller_count = 0;
    int controller_index = 0;
    char guid[64];

    SDL_SetHint(SDL_HINT_ACCELEROMETER_AS_JOYSTICK, "0");
    SDL_SetHint(SDL_HINT_JOYSTICK_HIDAPI_PS4_RUMBLE, "1");
    SDL_SetHint(SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS, "1");

    /* Enable standard application logging */
    SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);

    /* Initialize SDL (Note: video is required to start event loop) */
    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_JOYSTICK | SDL_INIT_GAMECONTROLLER ) < 0) {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't initialize SDL: %s\n", SDL_GetError());
        return 1;
    }
    
    SDL_GameControllerAddMappingsFromFile("gamecontrollerdb.txt");

    /* Print information about the mappings */
    if (argv[1] && SDL_strcmp(argv[1], "--mappings") == 0) {
        SDL_Log("Supported mappings:\n");
        for (i = 0; i < SDL_GameControllerNumMappings(); ++i) {
            char *mapping = SDL_GameControllerMappingForIndex(i);
            if (mapping) {
                SDL_Log("\t%s\n", mapping);
                SDL_free(mapping);
            }
        }
        SDL_Log("\n");
    }

    /* Print information about the controller */
    for (i = 0; i < SDL_NumJoysticks(); ++i) {
        const char *name;
        const char *description;

        SDL_JoystickGetGUIDString(SDL_JoystickGetDeviceGUID(i),
                                  guid, sizeof (guid));

        if (SDL_IsGameController(i)) {
            controller_count++;
            name = SDL_GameControllerNameForIndex(i);
            switch (SDL_GameControllerTypeForIndex(i)) {
            case SDL_CONTROLLER_TYPE_XBOX360:
                description = "XBox 360 Controller";
                break;
            case SDL_CONTROLLER_TYPE_XBOXONE:
                description = "XBox One Controller";
                break;
            case SDL_CONTROLLER_TYPE_PS3:
                description = "PS3 Controller";
                break;
            case SDL_CONTROLLER_TYPE_PS4:
                description = "PS4 Controller";
                break;
            case SDL_CONTROLLER_TYPE_NINTENDO_SWITCH_PRO:
                description = "Nintendo Switch Pro Controller";
                break;
            case SDL_CONTROLLER_TYPE_VIRTUAL:
                description = "Virtual Game Controller";
                break;
            default:
                description = "Game Controller";
                break;
            }
            AddController(i, SDL_FALSE);
        } else {
            name = SDL_JoystickNameForIndex(i);
            description = "Joystick";
        }
        SDL_Log("%s %d: %s (guid %s, VID 0x%.4x, PID 0x%.4x, player index = %d)\n",
            description, i, name ? name : "Unknown", guid,
            SDL_JoystickGetDeviceVendor(i), SDL_JoystickGetDeviceProduct(i), SDL_JoystickGetDevicePlayerIndex(i));
    }
    SDL_Log("There are %d game controller(s) attached (%d joystick(s))\n", controller_count, SDL_NumJoysticks());

    /* Create a window to display controller state */
    window = SDL_CreateWindow("Game Controller Test", SDL_WINDOWPOS_CENTERED,
                              SDL_WINDOWPOS_CENTERED, SCREEN_WIDTH,
                              SCREEN_HEIGHT, 0);
    if (window == NULL) {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't create window: %s\n", SDL_GetError());
        return 2;
    }

    screen = SDL_CreateRenderer(window, -1, 0);
    if (screen == NULL) {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't create renderer: %s\n", SDL_GetError());
        SDL_DestroyWindow(window);
        return 2;
    }

    SDL_SetRenderDrawColor(screen, 0x00, 0x00, 0x00, SDL_ALPHA_OPAQUE);
    SDL_RenderClear(screen);
    SDL_RenderPresent(screen);

    /* scale for platforms that don't give you the window size you asked for. */
    SDL_RenderSetLogicalSize(screen, SCREEN_WIDTH, SCREEN_HEIGHT);

    background_front = LoadTexture(screen, "controllermap.bmp", SDL_FALSE);
    background_back = LoadTexture(screen, "controllermap_back.bmp", SDL_FALSE);
    button = LoadTexture(screen, "button.bmp", SDL_TRUE);
    axis = LoadTexture(screen, "axis.bmp", SDL_TRUE);

    if (!background_front || !background_back || !button || !axis) {
        SDL_DestroyRenderer(screen);
        SDL_DestroyWindow(window);
        return 2;
    }
    SDL_SetTextureColorMod(button, 10, 255, 21);
    SDL_SetTextureColorMod(axis, 10, 255, 21);

    /* !!! FIXME: */
    /*SDL_RenderSetLogicalSize(screen, background->w, background->h);*/

    if (argv[1] && *argv[1] != '-') {
        controller_index = SDL_atoi(argv[1]);
    }
    if (controller_index < num_controllers) {
        gamecontroller = gamecontrollers[controller_index];
    } else {
        gamecontroller = NULL;
    }
    UpdateWindowTitle();

    /* Loop, getting controller events! */
#ifdef __EMSCRIPTEN__
    emscripten_set_main_loop_arg(loop, NULL, 0, 1);
#else
    while (!done) {
        loop(NULL);
    }
#endif

    SDL_DestroyRenderer(screen);
    SDL_DestroyWindow(window);
    SDL_QuitSubSystem(SDL_INIT_VIDEO | SDL_INIT_JOYSTICK | SDL_INIT_GAMECONTROLLER);

    return 0;
}

#else

int
main(int argc, char *argv[])
{
    SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "SDL compiled without Joystick support.\n");
    return 1;
}

#endif

/* vi: set ts=4 sw=4 expandtab: */