//========================================================================
// Joystick input test
// Copyright (c) Camilla Löwy <elmindreda@glfw.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, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
//    claim that you wrote the original software. If you use this software
//    in a product, an acknowledgment in the product documentation would
//    be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such, and must not
//    be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source
//    distribution.
//
//========================================================================
//
// This test displays the state of every button and axis of every connected
// joystick and/or gamepad
//
//========================================================================

#include <glad/glad.h>
#include <GLFW/glfw3.h>

#define NK_IMPLEMENTATION
#define NK_INCLUDE_FIXED_TYPES
#define NK_INCLUDE_FONT_BAKING
#define NK_INCLUDE_DEFAULT_FONT
#define NK_INCLUDE_DEFAULT_ALLOCATOR
#define NK_INCLUDE_VERTEX_BUFFER_OUTPUT
#define NK_INCLUDE_STANDARD_VARARGS
#define NK_BUTTON_TRIGGER_ON_RELEASE
#include <nuklear.h>

#define NK_GLFW_GL2_IMPLEMENTATION
#include <nuklear_glfw_gl2.h>

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

#ifdef _MSC_VER
#define strdup(x) _strdup(x)
#endif

static GLFWwindow* window;
static int joysticks[GLFW_JOYSTICK_LAST + 1];
static int joystick_count = 0;

static void error_callback(int error, const char* description)
{
    fprintf(stderr, "Error: %s\n", description);
}

static void joystick_callback(int jid, int event)
{
    if (event == GLFW_CONNECTED)
        joysticks[joystick_count++] = jid;
    else if (event == GLFW_DISCONNECTED)
    {
        int i;

        for (i = 0;  i < joystick_count;  i++)
        {
            if (joysticks[i] == jid)
                break;
        }

        for (i = i + 1;  i < joystick_count;  i++)
            joysticks[i - 1] = joysticks[i];

        joystick_count--;
    }

    if (!glfwGetWindowAttrib(window, GLFW_FOCUSED))
        glfwRequestWindowAttention(window);
}

static void drop_callback(GLFWwindow* window, int count, const char** paths)
{
    int i;

    for (i = 0;  i < count;  i++)
    {
        long size;
        char* text;
        FILE* stream = fopen(paths[i], "rb");
        if (!stream)
            continue;

        fseek(stream, 0, SEEK_END);
        size = ftell(stream);
        fseek(stream, 0, SEEK_SET);

        text = malloc(size + 1);
        text[size] = '\0';
        if (fread(text, 1, size, stream) == size)
            glfwUpdateGamepadMappings(text);

        free(text);
        fclose(stream);
    }
}

static const char* joystick_label(int jid)
{
    static char label[1024];
    snprintf(label, sizeof(label), "%i: %s", jid + 1, glfwGetJoystickName(jid));
    return label;
}

static void hat_widget(struct nk_context* nk, unsigned char state)
{
    float radius;
    struct nk_rect area;
    struct nk_vec2 center;

    if (nk_widget(&area, nk) == NK_WIDGET_INVALID)
        return;

    center = nk_vec2(area.x + area.w / 2.f, area.y + area.h / 2.f);
    radius = NK_MIN(area.w, area.h) / 2.f;

    nk_stroke_circle(nk_window_get_canvas(nk),
                     nk_rect(center.x - radius,
                             center.y - radius,
                             radius * 2.f,
                             radius * 2.f),
                     1.f,
                     nk_rgb(175, 175, 175));

    if (state)
    {
        const float angles[] =
        {
            0.f,           0.f,
            NK_PI * 1.5f,  NK_PI * 1.75f,
            NK_PI,         0.f,
            NK_PI * 1.25f, 0.f,
            NK_PI * 0.5f,  NK_PI * 0.25f,
            0.f,           0.f,
            NK_PI * 0.75f, 0.f,
        };
        const float cosa = nk_cos(angles[state]);
        const float sina = nk_sin(angles[state]);
        const struct nk_vec2 p0 = nk_vec2(0.f, -radius);
        const struct nk_vec2 p1 = nk_vec2( radius / 2.f, -radius / 3.f);
        const struct nk_vec2 p2 = nk_vec2(-radius / 2.f, -radius / 3.f);

        nk_fill_triangle(nk_window_get_canvas(nk),
                            center.x + cosa * p0.x + sina * p0.y,
                            center.y + cosa * p0.y - sina * p0.x,
                            center.x + cosa * p1.x + sina * p1.y,
                            center.y + cosa * p1.y - sina * p1.x,
                            center.x + cosa * p2.x + sina * p2.y,
                            center.y + cosa * p2.y - sina * p2.x,
                            nk_rgb(175, 175, 175));
    }
}

int main(void)
{
    int jid, hat_buttons = GLFW_FALSE;
    struct nk_context* nk;
    struct nk_font_atlas* atlas;

    memset(joysticks, 0, sizeof(joysticks));

    glfwSetErrorCallback(error_callback);

    if (!glfwInit())
        exit(EXIT_FAILURE);

    glfwWindowHint(GLFW_SCALE_TO_MONITOR, GLFW_TRUE);

    window = glfwCreateWindow(800, 600, "Joystick Test", NULL, NULL);
    if (!window)
    {
        glfwTerminate();
        exit(EXIT_FAILURE);
    }

    glfwMakeContextCurrent(window);
    gladLoadGLLoader((GLADloadproc) glfwGetProcAddress);
    glfwSwapInterval(1);

    nk = nk_glfw3_init(window, NK_GLFW3_INSTALL_CALLBACKS);
    nk_glfw3_font_stash_begin(&atlas);
    nk_glfw3_font_stash_end();

    for (jid = GLFW_JOYSTICK_1;  jid <= GLFW_JOYSTICK_LAST;  jid++)
    {
        if (glfwJoystickPresent(jid))
            joysticks[joystick_count++] = jid;
    }

    glfwSetJoystickCallback(joystick_callback);
    glfwSetDropCallback(window, drop_callback);

    while (!glfwWindowShouldClose(window))
    {
        int i, width, height;

        glfwGetWindowSize(window, &width, &height);

        glClear(GL_COLOR_BUFFER_BIT);
        nk_glfw3_new_frame();

        if (nk_begin(nk,
                     "Joysticks",
                     nk_rect(width - 200.f, 0.f, 200.f, (float) height),
                     NK_WINDOW_MINIMIZABLE |
                     NK_WINDOW_TITLE))
        {
            nk_layout_row_dynamic(nk, 30, 1);

            nk_checkbox_label(nk, "Hat buttons", &hat_buttons);

            if (joystick_count)
            {
                for (i = 0;  i < joystick_count;  i++)
                {
                    if (nk_button_label(nk, joystick_label(joysticks[i])))
                        nk_window_set_focus(nk, joystick_label(joysticks[i]));
                }
            }
            else
                nk_label(nk, "No joysticks connected", NK_TEXT_LEFT);
        }

        nk_end(nk);

        for (i = 0;  i < joystick_count;  i++)
        {
            if (nk_begin(nk,
                         joystick_label(joysticks[i]),
                         nk_rect(i * 20.f, i * 20.f, 550.f, 570.f),
                         NK_WINDOW_BORDER |
                         NK_WINDOW_MOVABLE |
                         NK_WINDOW_SCALABLE |
                         NK_WINDOW_MINIMIZABLE |
                         NK_WINDOW_TITLE))
            {
                int j, axis_count, button_count, hat_count;
                const float* axes;
                const unsigned char* buttons;
                const unsigned char* hats;
                GLFWgamepadstate state;

                nk_layout_row_dynamic(nk, 30, 1);
                nk_labelf(nk, NK_TEXT_LEFT, "Hardware GUID %s",
                          glfwGetJoystickGUID(joysticks[i]));
                nk_label(nk, "Joystick state", NK_TEXT_LEFT);

                axes = glfwGetJoystickAxes(joysticks[i], &axis_count);
                buttons = glfwGetJoystickButtons(joysticks[i], &button_count);
                hats = glfwGetJoystickHats(joysticks[i], &hat_count);

                if (!hat_buttons)
                    button_count -= hat_count * 4;

                for (j = 0;  j < axis_count;  j++)
                    nk_slide_float(nk, -1.f, axes[j], 1.f, 0.1f);

                nk_layout_row_dynamic(nk, 30, 12);

                for (j = 0;  j < button_count;  j++)
                {
                    char name[16];
                    snprintf(name, sizeof(name), "%i", j + 1);
                    nk_select_label(nk, name, NK_TEXT_CENTERED, buttons[j]);
                }

                nk_layout_row_dynamic(nk, 30, 8);

                for (j = 0;  j < hat_count;  j++)
                    hat_widget(nk, hats[j]);

                nk_layout_row_dynamic(nk, 30, 1);

                if (glfwGetGamepadState(joysticks[i], &state))
                {
                    int hat = 0;
                    const char* names[GLFW_GAMEPAD_BUTTON_LAST + 1 - 4] =
                    {
                        "A", "B", "X", "Y",
                        "LB", "RB",
                        "Back", "Start", "Guide",
                        "LT", "RT",
                    };

                    nk_labelf(nk, NK_TEXT_LEFT,
                              "Gamepad state: %s",
                              glfwGetGamepadName(joysticks[i]));

                    nk_layout_row_dynamic(nk, 30, 2);

                    for (j = 0;  j <= GLFW_GAMEPAD_AXIS_LAST;  j++)
                        nk_slide_float(nk, -1.f, state.axes[j], 1.f, 0.1f);

                    nk_layout_row_dynamic(nk, 30, GLFW_GAMEPAD_BUTTON_LAST + 1 - 4);

                    for (j = 0;  j <= GLFW_GAMEPAD_BUTTON_LAST - 4;  j++)
                        nk_select_label(nk, names[j], NK_TEXT_CENTERED, state.buttons[j]);

                    if (state.buttons[GLFW_GAMEPAD_BUTTON_DPAD_UP])
                        hat |= GLFW_HAT_UP;
                    if (state.buttons[GLFW_GAMEPAD_BUTTON_DPAD_RIGHT])
                        hat |= GLFW_HAT_RIGHT;
                    if (state.buttons[GLFW_GAMEPAD_BUTTON_DPAD_DOWN])
                        hat |= GLFW_HAT_DOWN;
                    if (state.buttons[GLFW_GAMEPAD_BUTTON_DPAD_LEFT])
                        hat |= GLFW_HAT_LEFT;

                    nk_layout_row_dynamic(nk, 30, 8);
                    hat_widget(nk, hat);
                }
                else
                    nk_label(nk, "Joystick has no gamepad mapping", NK_TEXT_LEFT);
            }

            nk_end(nk);
        }

        nk_glfw3_render(NK_ANTI_ALIASING_ON);

        glfwSwapBuffers(window);
        glfwPollEvents();
    }

    glfwTerminate();
    exit(EXIT_SUCCESS);
}