/*
 * SPDX-FileCopyrightText: 2021-2024 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: CC0-1.0
 */

#include <cstdio>
#include <unistd.h>
#include <sys/lock.h>

#include "main.h"

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_timer.h"
#include "esp_lcd_panel_io.h"
#include "esp_lcd_panel_ops.h"
#include "esp_err.h"
#include "esp_log.h"
#include "driver/i2c_master.h"
#include "lvgl.h"
#include "esp_lcd_panel_vendor.h"

#define I2C_BUS_PORT  0
#define LVGL_TICK_PERIOD_MS    5
#define LVGL_TASK_STACK_SIZE   (4 * 1024)
#define LVGL_TASK_PRIORITY     2
#define LVGL_PALETTE_SIZE      8

static const char *TAG = "lcd-panel";

// https://www.digikey.com/en/products/detail/winstar-display/WEA012864DWPP3N00003/20533255
// According to SSD1306 datasheet
// Bit number used to represent command and parameter
#define SCREEN_WIDTH           128  // OLED display width, in pixels
#define SCREEN_HEIGHT          64  // OLED display height, in pixels
#define LCD_H_RES              SCREEN_WIDTH
#define LCD_V_RES              SCREEN_HEIGHT
#define I2C_HW_ADDR            0x3C
#define LCD_PIXEL_CLOCK_HZ     (400 * 1000)
#define LCD_CMD_BITS           8
#define LCD_PARAM_BITS         8

// Pin may vary based on your schematic
#define PIN_SDA                GPIO_NUM_21
#define PIN_SCL                GPIO_NUM_22
#define PIN_RST                -1

// To use LV_COLOR_FORMAT_I1, we need an extra buffer to hold the converted data
static uint8_t oled_buffer[LCD_H_RES * LCD_V_RES / 8];
// LVGL library is not thread-safe, this example will call LVGL APIs from different tasks, so use a mutex to protect it
static _lock_t lvgl_api_lock;

static bool example_notify_lvgl_flush_ready(esp_lcd_panel_io_handle_t io_panel,
                                            esp_lcd_panel_io_event_data_t *edata,
                                            void *user_ctx)
{
  auto *disp = (lv_display_t *) user_ctx;
  lv_display_flush_ready(disp);
  return false;
}

static void example_lvgl_flush_cb(lv_display_t *disp, const lv_area_t *area,
                                  uint8_t *px_map)
{
  auto panel_handle = (esp_lcd_panel_handle_t) lv_display_get_user_data(disp);

  // This is necessary because LVGL reserves 2 x 4 bytes in the buffer, as these are assumed to be used as a palette. Skip the palette here
  // More information about the monochrome, please refer to https://docs.lvgl.io/9.2/porting/display.html#monochrome-displays
  px_map += LVGL_PALETTE_SIZE;

  uint16_t hor_res = lv_display_get_physical_horizontal_resolution(disp);
  int x1 = area->x1;
  int x2 = area->x2;
  int y1 = area->y1;
  int y2 = area->y2;

  for (int y = y1; y <= y2; y++) {
    for (int x = x1; x <= x2; x++) {
      /* The order of bits is MSB first
                  MSB           LSB
         bits      7 6 5 4 3 2 1 0
         pixels    0 1 2 3 4 5 6 7
                  Left         Right
      */
      bool chroma_color = (px_map[(hor_res >> 3) * y + (x >> 3)] &
                           1 << (7 - x % 8));

      /* Write to the buffer as required for the display.
      * It writes only 1-bit for monochrome displays mapped vertically.*/
      uint8_t *buf = oled_buffer + hor_res * (y >> 3) + (x);
      if (chroma_color) {
        (*buf) &= ~(1 << (y % 8));
      } else {
        (*buf) |= (1 << (y % 8));
      }
    }
  }
  // pass the draw buffer to the driver
  ESP_ERROR_CHECK(
      esp_lcd_panel_draw_bitmap(panel_handle, x1, y1, x2 + 1, y2 + 1,
                                oled_buffer));
}

static void example_increase_lvgl_tick(void *arg)
{
  /* Tell LVGL how many milliseconds has elapsed */
  lv_tick_inc(LVGL_TICK_PERIOD_MS);
}

static void example_lvgl_port_task(void *arg)
{
  ESP_LOGI(TAG, "Starting LVGL task");
  uint32_t time_till_next_ms = 0;
  while (1) {
    _lock_acquire(&lvgl_api_lock);
    time_till_next_ms = lv_timer_handler();
    _lock_release(&lvgl_api_lock);
    usleep(1000 * time_till_next_ms);
  }
}

void setup()
{
  ESP_LOGI(TAG, "Initialize I2C bus");
  i2c_master_bus_handle_t i2c_bus = nullptr;
  i2c_master_bus_config_t bus_config = {
      .i2c_port = I2C_BUS_PORT,
      .sda_io_num = PIN_SDA,
      .scl_io_num = PIN_SCL,
      .clk_source = I2C_CLK_SRC_DEFAULT,
      .glitch_ignore_cnt = 7,
      .flags {
          .enable_internal_pullup = true,
      },
  };
  ESP_ERROR_CHECK(i2c_new_master_bus(&bus_config, &i2c_bus));

  ESP_LOGI(TAG, "Install panel IO");
  esp_lcd_panel_io_handle_t io_handle = nullptr;
  esp_lcd_panel_io_i2c_config_t io_config = {
      .dev_addr = I2C_HW_ADDR,
      .control_phase_bytes = 1,               // According to SSD1306 datasheet
      .dc_bit_offset = 6,                     // According to SSD1306 datasheet
      .lcd_cmd_bits = LCD_CMD_BITS,           // According to SSD1306 datasheet
      .lcd_param_bits = LCD_CMD_BITS,         // According to SSD1306 datasheet
      .scl_speed_hz = LCD_PIXEL_CLOCK_HZ,
  };
  ESP_ERROR_CHECK(esp_lcd_new_panel_io_i2c(i2c_bus, &io_config, &io_handle));

  ESP_LOGI(TAG, "Install SSD1306 panel driver");
  esp_lcd_panel_handle_t panel_handle = nullptr;
  esp_lcd_panel_dev_config_t panel_config = {
      .reset_gpio_num = PIN_RST,
      .bits_per_pixel = 1,
  };
  esp_lcd_panel_ssd1306_config_t ssd1306_config = {
      .height = LCD_V_RES,
  };
  panel_config.vendor_config = &ssd1306_config;
  ESP_ERROR_CHECK(
      esp_lcd_new_panel_ssd1306(io_handle, &panel_config, &panel_handle));

  ESP_ERROR_CHECK(esp_lcd_panel_reset(panel_handle));
  ESP_ERROR_CHECK(esp_lcd_panel_init(panel_handle));
  ESP_ERROR_CHECK(esp_lcd_panel_disp_on_off(panel_handle, true));

  ESP_LOGI(TAG, "Initialize LVGL");
  lv_init();
  // create a lvgl display
  lv_display_t *display = lv_display_create(LCD_H_RES, LCD_V_RES);
  // associate the i2c panel handle to the display
  lv_display_set_user_data(display, panel_handle);
  // create draw buffer
  void *buf = nullptr;
  ESP_LOGI(TAG, "Allocate separate LVGL draw buffers");
  // LVGL reserves 2 x 4 bytes in the buffer, as these are assumed to be used as a palette.
  size_t draw_buffer_sz = LCD_H_RES * LCD_V_RES / 8 + LVGL_PALETTE_SIZE;
  buf = heap_caps_calloc(1, draw_buffer_sz,
                         MALLOC_CAP_INTERNAL | MALLOC_CAP_8BIT);
  assert(buf);

  // LVGL9 suooprt new monochromatic format.
  lv_display_set_color_format(display, LV_COLOR_FORMAT_I1);
  // initialize LVGL draw buffers
  lv_display_set_buffers(display, buf, nullptr, draw_buffer_sz,
                         LV_DISPLAY_RENDER_MODE_FULL);
  lv_display_set_rotation(display, LV_DISPLAY_ROTATION_90);
  // set the callback which can copy the rendered image to an area of the display
  lv_display_set_flush_cb(display, example_lvgl_flush_cb);

  ESP_LOGI(TAG,
           "Register io panel event callback for LVGL flush ready notification");
  const esp_lcd_panel_io_callbacks_t cbs = {
      .on_color_trans_done = example_notify_lvgl_flush_ready,
  };
  /* Register done callback */
  ESP_ERROR_CHECK(
      esp_lcd_panel_io_register_event_callbacks(io_handle, &cbs, display));

  ESP_LOGI(TAG, "Use esp_timer as LVGL tick timer");
  const esp_timer_create_args_t lvgl_tick_timer_args = {
      .callback = &example_increase_lvgl_tick,
      .name = "lvgl_tick"
  };
  esp_timer_handle_t lvgl_tick_timer = nullptr;
  ESP_ERROR_CHECK(esp_timer_create(&lvgl_tick_timer_args, &lvgl_tick_timer));
  ESP_ERROR_CHECK(esp_timer_start_periodic(lvgl_tick_timer,
                                           LVGL_TICK_PERIOD_MS * 1000));

  ESP_LOGI(TAG, "Create LVGL task");
  xTaskCreate(example_lvgl_port_task, "LVGL", LVGL_TASK_STACK_SIZE,
              nullptr, LVGL_TASK_PRIORITY, nullptr);

  ESP_LOGI(TAG, "Display LVGL Scroll Text");
  // Lock the mutex due to the LVGL APIs are not thread-safe
  _lock_acquire(&lvgl_api_lock);

  // UI function
  {
    lv_obj_t *scr = lv_display_get_screen_active(display);
    lv_obj_t *label = lv_label_create(scr);
    // Circular scroll
    lv_label_set_long_mode(label,
                           LV_LABEL_LONG_WRAP);
    lv_label_set_text(label,
                      "Hello hello hello hello hello hello hello hello.");
    // Size of the screen
    // if you use rotation 90 or 270 use lv_display_get_vertical_resolution
    lv_obj_set_width(label, lv_display_get_horizontal_resolution(display));
    lv_obj_align(label, LV_ALIGN_TOP_MID, 0, 0);
  }

  _lock_release(&lvgl_api_lock);
}

void loop() { }