#include <Arduino.h>
#include <FreeRTOS.h>
#include <task.h>
#include <semphr.h>
#include <queue.h>
#include <lvgl.h>
#include <ILI9341_t3.h>
#include <XPT2046_Touchscreen.h>

// --- ピン定義 ---
#define TFT_DC      9
#define TFT_CS      10
#define TFT_RST     8
#define TOUCH_CS    7

// --- グローバルリソース ---
ILI9341_t3 tft = ILI9341_t3(TFT_CS, TFT_DC, TFT_RST);
XPT2046_Touchscreen ts(TOUCH_CS);
SemaphoreHandle_t xSPIMutex;
QueueHandle_t xTouchQueue;

// キャンバス設定 (320x240)
#define CANVAS_WIDTH 320
#define CANVAS_HEIGHT 240


// DMAMEMを使用してTeensy 4.1の外部RAMに配置
#define CANVAS_BUF_SIZE (CANVAS_WIDTH * CANVAS_HEIGHT * 2)
DMAMEM static uint8_t canvas_buf[CANVAS_BUF_SIZE];

lv_obj_t * canvas;
lv_obj_t * btn;
lv_obj_t * label;
int current_hue_start = 0; 

// LVGL描画用中間バッファ
#define DRAW_BUF_SIZE (320 * 20)
static uint16_t draw_buf[DRAW_BUF_SIZE]; 

// --- グラデーション描画関数 ---
void draw_background_gradient(int hue_offset) {
    for (int y = 0; y < CANVAS_HEIGHT; y++) {
        // USB保護のための休憩
        if (y % 10 == 0) vTaskDelay(pdMS_TO_TICKS(1)); 

        for (int x = 0; x < CANVAS_WIDTH; x++) {
            int h = (hue_offset + (x * 360 / CANVAS_WIDTH)) % 360;
            int v = 100 - (y * 100 / CANVAS_HEIGHT);
            
            // 安全なピクセル書き込み関数を使用
            lv_color_t color = lv_color_hsv_to_rgb(h, 100, v);
            lv_canvas_set_px(canvas, x, y, color, LV_OPA_COVER);
        }
    }
    lv_obj_invalidate(canvas);
}

void my_disp_flush(lv_display_t * disp, const lv_area_t * area, uint8_t * px_map) {
    if (xSemaphoreTake(xSPIMutex, portMAX_DELAY) == pdTRUE) {
        tft.writeRect(area->x1, area->y1, lv_area_get_width(area), lv_area_get_height(area), (uint16_t *)px_map);
        xSemaphoreGive(xSPIMutex);
    }
    lv_display_flush_ready(disp);
}

void my_touch_read(lv_indev_t * indev, lv_indev_data_t * data) {
    if (ts.touched()) {
        TS_Point p = ts.getPoint();
        data->point.x = map(p.x, 200, 3800, 0, 320);
        data->point.y = map(p.y, 200, 3800, 0, 240);
        data->state = LV_INDEV_STATE_PRESSED;
    } else {
        data->state = LV_INDEV_STATE_RELEASED;
    }
}

static void btn_event_cb(lv_event_t * e) {
    if(lv_event_get_code(e) == LV_EVENT_CLICKED) {
        uint8_t dummy = 1;
        xQueueSend(xTouchQueue, &dummy, 0);
    }
}

void TaskGUI(void *pvParameters) {
    tft.begin();
    tft.setRotation(3);
    ts.begin();
    ts.setRotation(1);

    lv_init();
    lv_tick_set_cb((uint32_t (*)(void))millis); 

    lv_display_t * disp = lv_display_create(320, 240);
    lv_display_set_flush_cb(disp, my_disp_flush);
    lv_display_set_buffers(disp, (void*)draw_buf, NULL, sizeof(draw_buf), LV_DISPLAY_RENDER_MODE_PARTIAL);

    lv_indev_t * indev = lv_indev_create();
    lv_indev_set_type(indev, LV_INDEV_TYPE_POINTER);
    lv_indev_set_read_cb(indev, my_touch_read);

    lv_obj_t * scr = lv_screen_active();

    // キャンバス作成とバッファ紐付け
    canvas = lv_canvas_create(scr);
    // 第5引数はフォーマットを明示的に指定
    lv_canvas_set_buffer(canvas, canvas_buf, CANVAS_WIDTH, CANVAS_HEIGHT, LV_COLOR_FORMAT_RGB565);
    
    // 初回描画
    draw_background_gradient(0);
    lv_obj_align(canvas, LV_ALIGN_CENTER, 0, 0);

    // ボタン設定
    btn = lv_button_create(scr);
    lv_obj_set_size(btn, 240, 60);
    lv_obj_center(btn);
    lv_obj_set_style_bg_color(btn, lv_color_black(), 0);
    lv_obj_set_style_bg_opa(btn, LV_OPA_COVER, 0);
    lv_obj_set_style_border_color(btn, lv_color_white(), 0);
    lv_obj_set_style_border_width(btn, 2, 0);
    lv_obj_add_event_cb(btn, btn_event_cb, LV_EVENT_ALL, NULL); 

    label = lv_label_create(btn);
    lv_label_set_text(label, "Hello Teensy4.1!!");
    lv_obj_set_style_text_color(label, lv_color_white(), 0);
    lv_obj_center(label);

    uint8_t received_event;
    uint32_t last_sync_time = millis();

    for (;;) {
        lv_timer_handler();

        uint32_t now = millis();
        if (now - last_sync_time >= 1000) {
            if (xQueueReceive(xTouchQueue, &received_event, 0) == pdTRUE) {
                current_hue_start = (current_hue_start + 36) % 360;
                draw_background_gradient(current_hue_start);
            }
            last_sync_time = now;
        }
        vTaskDelay(pdMS_TO_TICKS(5)); 
    }
}

void setup() {
    Serial.begin(115200);
    xTouchQueue = xQueueCreate(10, sizeof(uint8_t));
    xSPIMutex = xSemaphoreCreateMutex();

    if (xTouchQueue != NULL) {
        xTaskCreate(TaskGUI, "GUI_TASK", 12288, NULL, 3, NULL);
    }
    vTaskStartScheduler();
}

void loop() {}