#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <3ds.h>
#include "lvgl.h"
#include "lv_ctr_disp.h"
#include "lv_ctr_indev.h"


static lv_obj_t * cursor;
static lv_obj_t * label;
static lv_obj_t * label2;
static lv_obj_t * fps_label;
static lv_obj_t * keypad_label;


long unsigned int sys_tick(void)
{
    long unsigned int tick = (long unsigned int)osGetTime();
    return tick;
}

void sys_init(void)
{
    gfxInitDefault();
}

void sys_free(void)
{
    gfxExit();
}

void sys_log(lv_log_level_t level, const char * buf)
{
    (level);
    svcOutputDebugString(buf, strlen(buf)-1);
}

static void ui_timer_cb(lv_timer_t * t)
{
    LV_UNUSED(t);

    lv_indev_t * indev = lv_indev_get_next(NULL);

    while (indev) {
        if (lv_indev_get_type(indev) == LV_INDEV_TYPE_POINTER) {
            lv_point_t p;
            lv_indev_get_point(indev, &p);

            if (lv_indev_get_state(indev) == LV_INDEV_STATE_PRESSED) {
                lv_obj_set_pos(cursor, p.x - 5, p.y - 5);
                lv_obj_clear_flag(cursor, LV_OBJ_FLAG_HIDDEN);

                lv_label_set_text_fmt(label2,
                    "x: %d\ny: %d",
                    p.x,
                    p.y);
            }
            else {
                lv_obj_add_flag(cursor, LV_OBJ_FLAG_HIDDEN);
            }
        }
        if (lv_indev_get_type(indev) == LV_INDEV_TYPE_KEYPAD) {
            uint32_t key = lv_indev_get_key(indev);
            uint32_t state = lv_indev_get_state(indev);
            const char * txt = "None";

            switch(key) {
                case LV_KEY_UP:
                    txt = "UP";
                    break;
                case LV_KEY_DOWN:
                    txt = "DOWN";
                    break;
                case LV_KEY_LEFT:
                    txt = "LEFT";
                    break;
                case LV_KEY_RIGHT:
                    txt = "RIGHT";
                    break;
                case LV_KEY_ENTER:
                    txt = "A";
                    break;
                case LV_KEY_ESC:
                    txt = "B";
                    break;
                case LV_KEY_PREV:
                    txt = "L";
                    break;
                case LV_KEY_NEXT:
                    txt = "R";
                    break;
                default:
                    txt = "None";
                    break;
            }

            if (state == LV_INDEV_STATE_PRESSED)
                lv_label_set_text_fmt(keypad_label, "Pressed: %s", txt);
            else
                lv_label_set_text_fmt(keypad_label, "Released", txt);
        }
        indev = lv_indev_get_next(indev);
    }
}

static void switch_event_cb(lv_event_t * e)
{
    lv_obj_t * sw = lv_event_get_target(e);

    if (lv_obj_has_state(sw, LV_STATE_CHECKED))
        lv_label_set_text_fmt(label, "ON");
    else
        lv_label_set_text_fmt(label, "OFF");
}

static void fps_tick(void)
{
    static u32 frames = 0;
    static u64 last = 0;

    u64 now = osGetTime();

    frames++;

    if (now - last >= 1000) {

        lv_label_set_text_fmt(fps_label,
            "FPS: %lu",
            frames);

        frames = 0;
        last = now;
    }
}

static void ui_prepare(void)
{
    /* Container START */
    lv_obj_t * cont = lv_obj_create(lv_screen_active());

    /* Container layout */
    lv_obj_set_size(cont, 220, 120);
    lv_obj_center(cont);

    lv_obj_set_layout(cont, LV_LAYOUT_FLEX);
    lv_obj_set_flex_flow(cont, LV_FLEX_FLOW_COLUMN);
    lv_obj_set_flex_align(cont,
        LV_FLEX_ALIGN_CENTER,
        LV_FLEX_ALIGN_CENTER,
        LV_FLEX_ALIGN_CENTER);

    /* Optional cleaner look */
    lv_obj_set_style_pad_all(cont, 16, 0);
    lv_obj_set_style_pad_row(cont, 12, 0);

    /* Label */
    label = lv_label_create(cont);
    lv_label_set_text(label, "Hello world");

    /* Switch */
    lv_obj_t * sw = lv_switch_create(cont);
    lv_obj_center(sw);
    lv_obj_add_event_cb(sw,
        switch_event_cb,
        LV_EVENT_VALUE_CHANGED,
        NULL);
    /* Container END */
    
    /* Cursor */
    cursor = lv_obj_create(lv_screen_active());
    lv_obj_set_size(cursor, 10, 10);
    lv_obj_set_style_radius(cursor, LV_RADIUS_CIRCLE, 0);
    lv_obj_set_style_bg_color(cursor, lv_palette_main(LV_PALETTE_RED), 0);
    lv_obj_set_style_border_width(cursor, 0, 0);

    /* Coord label */
    label2 = lv_label_create(lv_screen_active());
    lv_obj_align(label2, LV_ALIGN_TOP_LEFT, 4, 4);
    
    /* Keypad label */
    keypad_label = lv_label_create(lv_screen_active());
    lv_obj_align(keypad_label, LV_ALIGN_TOP_LEFT, 4, 36);
    
    /* FPS label */
    fps_label = lv_label_create(lv_screen_active());
    lv_obj_align(fps_label,
        LV_ALIGN_BOTTOM_LEFT,
        4,
        -4);
    
    /* Main loop UI update timer */
    lv_timer_create(ui_timer_cb, 16, NULL);
    
    /* Dummy group to make indev happy */
    lv_group_t * group = lv_group_create();
    lv_indev_set_group(lv_ctr_indev_get_keypad(), group);
    
    lv_obj_invalidate(lv_screen_active());
}

int main(int argc, char* argv[])
{
    sys_init();
    lv_init();
    lv_log_register_print_cb(sys_log);
    lv_tick_set_cb(sys_tick);
    lv_ctr_disp_init();
    lv_ctr_indev_init();

    ui_prepare();

    // Main loop
    while (aptMainLoop())
    {
        // scan HID inputs
        hidScanInput();

        // call LVGL timer handler
        u64 start = osGetTime();
        lv_timer_handler();
        u64 end = osGetTime();
        lv_label_set_text_fmt(fps_label, "render: %llums", end - start);

        // evacuate the dance floor!
        u32 kDown = hidKeysDown();
        if (kDown & KEY_START)
            break; // break in order to return to hbmenu
    }

    sys_free();
    return 0;
}