/*
 * SPDX-FileCopyrightText: 2022 atanisoft (github.com/atanisoft)
 *
 * SPDX-License-Identifier: MIT
 */

#include <driver/gpio.h>
#include <driver/ledc.h>
#include <driver/spi_master.h>
#include <esp_err.h>
#include <esp_freertos_hooks.h>
#include <esp_log.h>
#include <esp_lcd_panel_io.h>
#include <esp_lcd_panel_vendor.h>
#include <esp_lcd_panel_ops.h>
#include <esp_lcd_ili9488.h>
#include <esp_timer.h>
#include <freertos/FreeRTOS.h>
#include <freertos/task.h>
#include <lvgl.h>
#include <stdio.h>
#include "sdkconfig.h"

// Uncomment the following line to enable using double buffering of LVGL color
// data.
// #define USE_DOUBLE_BUFFERING 1

static const char *TAG = "lcd_driver";

#define DISPLAY_HORIZONTAL_PIXELS 320
#define DISPLAY_VERTICAL_PIXELS 480
#define DISPLAY_COMMAND_BITS 8
#define DISPLAY_PARAMETER_BITS 8
#define DISPLAY_REFRESH_HZ 40000000
#define DISPLAY_SPI_QUEUE_LEN 10
#define SPI_MAX_TRANSFER_SIZE 32768

#define TFT_PIN_MOSI GPIO_NUM_17
#define TFT_PIN_MISO GPIO_NUM_18
#define TFT_PIN_CLK GPIO_NUM_16
#define TFT_PIN_CS GPIO_NUM_NC
#define TFT_PIN_DC GPIO_NUM_15
#define TFT_PIN_RESET GPIO_NUM_8

#define TFT_INVERT_COLOR false

// Default to 50 lines of color data
#define LV_BUFFER_SIZE DISPLAY_HORIZONTAL_PIXELS * 50
#define LVGL_UPDATE_PERIOD_MS 5

#define BACKLIGHT_LEDC_MODE LEDC_LOW_SPEED_MODE
#define BACKLIGHT_LEDC_CHANNEL LEDC_CHANNEL_0
#define BACKLIGHT_LEDC_TIMER LEDC_TIMER_1
#define BACKLIGHT_LEDC_TIMER_RESOLUTION LEDC_TIMER_10_BIT
#define BACKLIGHT_LEDC_FRQUENCY 5000

static esp_lcd_panel_io_handle_t lcd_io_handle = NULL;
static esp_lcd_panel_handle_t lcd_handle = NULL;

static lv_disp_draw_buf_t lv_disp_buf;
static lv_disp_drv_t lv_disp_drv;
static lv_disp_t *lv_display = NULL;
static lv_color_t *lv_buf_1 = NULL;
static lv_color_t *lv_buf_2 = NULL;
static lv_obj_t *meter = NULL;
static lv_style_t style_screen;

static void update_meter_value(void *indic, int32_t v)
{
    lv_meter_set_indicator_end_value(meter, (lv_meter_indicator_t*)indic, v);
}

static bool notify_lvgl_flush_ready(esp_lcd_panel_io_handle_t panel_io,
    esp_lcd_panel_io_event_data_t *edata, void *user_ctx)
{
    lv_disp_drv_t *disp_driver = (lv_disp_drv_t *)user_ctx;
    lv_disp_flush_ready(disp_driver);
    return false;
}

static void lvgl_flush_cb(lv_disp_drv_t *drv, const lv_area_t *area, lv_color_t *color_map)
{
    esp_lcd_panel_handle_t panel_handle = (esp_lcd_panel_handle_t) drv->user_data;

    int offsetx1 = area->x1;
    int offsetx2 = area->x2;
    int offsety1 = area->y1;
    int offsety2 = area->y2;
    esp_lcd_panel_draw_bitmap(panel_handle, offsetx1, offsety1, offsetx2 + 1, offsety2 + 1, color_map);
}

static void IRAM_ATTR lvgl_tick_cb(void *param)
{
	lv_tick_inc(LVGL_UPDATE_PERIOD_MS);
}

void initialize_spi()
{
    ESP_LOGI(TAG, "Initializing SPI bus (MOSI:%d, MISO:%d, CLK:%d)",
             TFT_PIN_MOSI, TFT_PIN_MISO, TFT_PIN_CLK);
    spi_bus_config_t bus =
    {
        .mosi_io_num = TFT_PIN_MOSI,
        .miso_io_num = TFT_PIN_MISO,
        .sclk_io_num = TFT_PIN_CLK,
        .quadwp_io_num = GPIO_NUM_NC,
        .quadhd_io_num = GPIO_NUM_NC,
        .data4_io_num = GPIO_NUM_NC,
        .data5_io_num = GPIO_NUM_NC,
        .data6_io_num = GPIO_NUM_NC,
        .data7_io_num = GPIO_NUM_NC,
        .max_transfer_sz = SPI_MAX_TRANSFER_SIZE,
        .flags = SPICOMMON_BUSFLAG_SCLK | SPICOMMON_BUSFLAG_MISO |
                 SPICOMMON_BUSFLAG_MOSI | SPICOMMON_BUSFLAG_MASTER,
        .intr_flags = ESP_INTR_FLAG_LOWMED | ESP_INTR_FLAG_IRAM
    };

    ESP_ERROR_CHECK(spi_bus_initialize(SPI2_HOST, &bus, SPI_DMA_CH_AUTO));
}

void initialize_display()
{
    const esp_lcd_panel_io_spi_config_t io_config = 
    {
        .cs_gpio_num = TFT_PIN_CS,
        .dc_gpio_num = TFT_PIN_DC,
        .spi_mode = 0,
        .pclk_hz = DISPLAY_REFRESH_HZ,
        .trans_queue_depth = DISPLAY_SPI_QUEUE_LEN,
        .on_color_trans_done = notify_lvgl_flush_ready,
        .user_ctx = &lv_disp_drv,
        .lcd_cmd_bits = DISPLAY_COMMAND_BITS,
        .lcd_param_bits = DISPLAY_PARAMETER_BITS,
        .flags =
        {
            .dc_low_on_data = 0,
            .octal_mode = 0,
            .lsb_first = 0
        }
    };

    const esp_lcd_panel_dev_config_t lcd_config = 
    {
        .reset_gpio_num = TFT_PIN_RESET,
        .color_space = ESP_LCD_COLOR_SPACE_BGR,
        .bits_per_pixel = 18,
        .flags =
        {
            .reset_active_high = 0
        },
        .vendor_config = NULL
    };

    ESP_ERROR_CHECK(
        esp_lcd_new_panel_io_spi((esp_lcd_spi_bus_handle_t)SPI2_HOST, &io_config, &lcd_io_handle)); 

    ESP_ERROR_CHECK(esp_lcd_new_panel_ili9488(lcd_io_handle, &lcd_config, LV_BUFFER_SIZE, &lcd_handle));

    ESP_ERROR_CHECK(esp_lcd_panel_reset(lcd_handle));
    ESP_ERROR_CHECK(esp_lcd_panel_init(lcd_handle));
    ESP_ERROR_CHECK(esp_lcd_panel_invert_color(lcd_handle, false));
    ESP_ERROR_CHECK(esp_lcd_panel_swap_xy(lcd_handle, false));
    ESP_ERROR_CHECK(esp_lcd_panel_mirror(lcd_handle, true, false));
    ESP_ERROR_CHECK(esp_lcd_panel_set_gap(lcd_handle, 0, 0));
#if ESP_IDF_VERSION < ESP_IDF_VERSION_VAL(5, 0, 0)
    ESP_ERROR_CHECK(esp_lcd_panel_disp_off(lcd_handle, false));
#else
    ESP_ERROR_CHECK(esp_lcd_panel_disp_on_off(lcd_handle, true));
#endif
}

void initialize_lvgl()
{
    ESP_LOGI(TAG, "Initializing LVGL");
    lv_init();
    ESP_LOGI(TAG, "Allocating %zu bytes for LVGL buffer", LV_BUFFER_SIZE * sizeof(lv_color_t));
    lv_buf_1 = (lv_color_t *)heap_caps_malloc(LV_BUFFER_SIZE * sizeof(lv_color_t), MALLOC_CAP_DMA);
#if USE_DOUBLE_BUFFERING
    ESP_LOGI(TAG, "Allocating %zu bytes for second LVGL buffer", LV_BUFFER_SIZE * sizeof(lv_color_t));
    lv_buf_2 = (lv_color_t *)heap_caps_malloc(LV_BUFFER_SIZE * sizeof(lv_color_t), MALLOC_CAP_DMA);
#endif
    ESP_LOGI(TAG, "Creating LVLG display buffer");
    lv_disp_draw_buf_init(&lv_disp_buf, lv_buf_1, lv_buf_2, LV_BUFFER_SIZE);

    ESP_LOGI(TAG, "Initializing %dx%d display", DISPLAY_HORIZONTAL_PIXELS, DISPLAY_VERTICAL_PIXELS);
    lv_disp_drv_init(&lv_disp_drv);
    lv_disp_drv.hor_res = DISPLAY_HORIZONTAL_PIXELS;
    lv_disp_drv.ver_res = DISPLAY_VERTICAL_PIXELS;
    lv_disp_drv.flush_cb = lvgl_flush_cb;
    lv_disp_drv.draw_buf = &lv_disp_buf;
    lv_disp_drv.user_data = lcd_handle;
    lv_display = lv_disp_drv_register(&lv_disp_drv);

    ESP_LOGI(TAG, "Creating LVGL tick timer");
    const esp_timer_create_args_t lvgl_tick_timer_args =
    {
        .callback = &lvgl_tick_cb,
        .name = "lvgl_tick"
    };
    esp_timer_handle_t lvgl_tick_timer = NULL;
    ESP_ERROR_CHECK(esp_timer_create(&lvgl_tick_timer_args, &lvgl_tick_timer));
    ESP_ERROR_CHECK(esp_timer_start_periodic(lvgl_tick_timer, LVGL_UPDATE_PERIOD_MS * 1000));
}

void create_demo_ui()
{
    lv_obj_t *scr = lv_disp_get_scr_act(NULL);

    // Set the background color of the display to black.
    lv_style_init(&style_screen);
    lv_style_set_bg_color(&style_screen, lv_color_black());
    lv_obj_add_style(lv_scr_act(), &style_screen, LV_STATE_DEFAULT);

    // Create a meter which can be animated.
    meter = lv_meter_create(scr);
    lv_obj_center(meter);
    lv_obj_set_size(meter, 200, 200);

    // Add a scale first
    lv_meter_scale_t *scale = lv_meter_add_scale(meter);
    lv_meter_set_scale_ticks(meter, scale, 41, 2, 10, lv_palette_main(LV_PALETTE_GREY));
    lv_meter_set_scale_major_ticks(meter, scale, 8, 4, 15, lv_color_black(), 10);

    lv_meter_indicator_t *indic;

    // Add a blue arc to the start
    indic = lv_meter_add_arc(meter, scale, 3, lv_palette_main(LV_PALETTE_BLUE), 0);
    lv_meter_set_indicator_start_value(meter, indic, 0);
    lv_meter_set_indicator_end_value(meter, indic, 20);

    // Make the tick lines blue at the start of the scale
    indic = lv_meter_add_scale_lines(meter, scale, lv_palette_main(LV_PALETTE_BLUE), lv_palette_main(LV_PALETTE_BLUE), false, 0);
    lv_meter_set_indicator_start_value(meter, indic, 0);
    lv_meter_set_indicator_end_value(meter, indic, 20);

    // Add a red arc to the end
    indic = lv_meter_add_arc(meter, scale, 3, lv_palette_main(LV_PALETTE_RED), 0);
    lv_meter_set_indicator_start_value(meter, indic, 80);
    lv_meter_set_indicator_end_value(meter, indic, 100);

    // Make the tick lines red at the end of the scale
    indic = lv_meter_add_scale_lines(meter, scale, lv_palette_main(LV_PALETTE_RED), lv_palette_main(LV_PALETTE_RED), false, 0);
    lv_meter_set_indicator_start_value(meter, indic, 80);
    lv_meter_set_indicator_end_value(meter, indic, 100);

    // Add a needle line indicator
    indic = lv_meter_add_needle_line(meter, scale, 4, lv_palette_main(LV_PALETTE_GREY), -10);

    // Create an animation to set the value
    lv_anim_t a;
    lv_anim_init(&a);
    lv_anim_set_exec_cb(&a, update_meter_value);
    lv_anim_set_var(&a, indic);
    lv_anim_set_values(&a, 0, 100);
    lv_anim_set_time(&a, 2000);
    lv_anim_set_repeat_delay(&a, 100);
    lv_anim_set_playback_time(&a, 500);
    lv_anim_set_playback_delay(&a, 100);
    lv_anim_set_repeat_count(&a, LV_ANIM_REPEAT_INFINITE);
    lv_anim_start(&a);
}

void init_tft() {
    initialize_spi();
    initialize_display();
    initialize_lvgl();

    ESP_LOGI(TAG, "TFT initialization Successful");
}