#include <stdio.h>
#include <inttypes.h>
#include <stdexcept>
#include "sdkconfig.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_chip_info.h"
#include "esp_flash.h"
#include "esp_system.h"
#include "esp_log.h"

//
#include "common/constants.h"
#include "common/queue_defs.h"
#include "io/nvs_handler.h"
#include "info/info.h"
#include "display/eink_display_handler.h"
#include "ui/ui_handler.h"
#include "ui/app_registry.h"
#include "ui/apps/shutdown_app.h"
#include "ui/apps/discord_app.h"
#include "ui/apps/mtr_app.h"
#include <tick/lv_tick.h>
#include "esp_lvgl_port.h"
#include "lvgl.h"
#include "network.h"
#include <esp_task_wdt.h>

// nvs storage namespaces, 15 characters max
#define DEFAULT_STORAGE_NAMESPACE "storage"
#define WIFI_CREDENTIALS_STORAGE_NAMESPACE "wifi_cred"
#define TAG "Main"

extern "C" void app_main(void);

void init_queues(
  QueueHandle_t& touch_queue,
  EventGroupHandle_t& system_event_group,
  EventGroupHandle_t& system_lifecycle_event_group
);


void app_main(void) {
  display_chip_info();

  QueueHandle_t touch_event_queue = NULL;
  EventGroupHandle_t system_event_group = NULL, system_lifecycle_event_group = NULL;

  init_queues(touch_event_queue, system_event_group, system_lifecycle_event_group);
  if (touch_event_queue == NULL || system_event_group == NULL || system_lifecycle_event_group == NULL) {
    ESP_LOGE("Main", "Failed to create one or more queues/event groups");
    vTaskDelay(5000 / portTICK_PERIOD_MS);
    return esp_restart();
  }
  ESP_LOGI(TAG, "Queues initialized.\n");

  // Initialize LVGL
  const lvgl_port_cfg_t lvgl_cfg = ESP_LVGL_PORT_INIT_CONFIG();
  esp_err_t err = lvgl_port_init(&lvgl_cfg);
  if (err != ESP_OK) {
    ESP_LOGE(TAG, "LVGL port initialization failed: %s", esp_err_to_name(err));
    vTaskDelay(5000 / portTICK_PERIOD_MS);
    return esp_restart();
  }
  ESP_LOGI(TAG, "LVGL port initialized successfully.\n");

  SemaphoreHandle_t lvgl_mutex = xSemaphoreCreateMutex();
  if (lvgl_mutex == NULL) {
    ESP_LOGE("Main", "Failed to create LVGL mutex");
    vTaskDelay(5000 / portTICK_PERIOD_MS);
    return esp_restart();
  }
  //
  // KVStorageHandler* kv_storage_handler = new NVSStorageHandler(
  //   DEFAULT_STORAGE_NAMESPACE
  // );

  // auto wifi_handler = std::make_unique<WifiHandler>(
  //   std::unique_ptr<KVStorageHandler>(new NVSStorageHandler(WIFI_CREDENTIALS_STORAGE_NAMESPACE))
  // );
  // NetworkHandler* network_handler = new NetworkHandler(std::move(wifi_handler));
  EInkDisplayHandler* display_handler = new EInkDisplayHandler();
  //
  // kv_storage_handler->init(system_event_group);
  // network_handler->init(system_event_group);

  // Initialize display and touch
  display_handler->init_devices(system_event_group);
  display_handler->clear_display();
  // ESP_LOGV(TAG, "Starting touch task...\n");
  // display_handler->start_touch_task();
  // ESP_LOGV(TAG, "Touch task started.\n");
  //
  // LVGL tick timer
  // auto lvgl_tick_timer_callback = [](TimerHandle_t xTimer) {
  //   lv_tick_inc(5);
  //   };
  // TickType_t lvgl_tick_period = pdMS_TO_TICKS(5);
  // if (lvgl_tick_period == 0) {
  //   lvgl_tick_period = 1; // ensure at least 1 tick to avoid FreeRTOS assert
  // }
  // ESP_LOGV(TAG, "Creating LVGL tick timer with period %u ticks...\n", (unsigned)lvgl_tick_period);
  // TimerHandle_t lvgl_tick_timer = xTimerCreate(
  //   "lvgl_tick_timer",
  //   lvgl_tick_period,
  //   pdTRUE,
  //   NULL,
  //   lvgl_tick_timer_callback
  // );
  // if (lvgl_tick_timer == NULL) {
  //   ESP_LOGE("Main", "Failed to create LVGL tick timer");
  //   vTaskDelay(5000 / portTICK_PERIOD_MS);
  //   return esp_restart();
  // }
  // ESP_LOGV(TAG, "Starting LVGL tick timer...\n");
  // xTimerStart(lvgl_tick_timer, 0);

  //
  ESP_LOGI(TAG, "Waiting for system to be ready...\n");
  xEventGroupWaitBits(
    system_event_group,
    // DISPLAY_READY_BIT | STORAGE_READY_BIT | NETWORK_READY_BIT,
    DISPLAY_READY_BIT,
    // do not clear on exit, require explicit reset
    pdFALSE,
    pdTRUE,
    portMAX_DELAY
  );
  ESP_LOGI(TAG, "System is ready. Starting main application...\n");

  // Register apps with AppRegistry by creating their descriptors
  // Each descriptor will create and register the app instance
  // DemoAppDescriptor* demo_descriptor = new DemoAppDescriptor();
  // ShutdownAppDescriptor* shutdown_descriptor = new ShutdownAppDescriptor();
  // DiscordAppDescriptor::instance(); // Use singleton pattern for Discord app
  // MtrAppDescriptor* mtr_descriptor = new MtrAppDescriptor();

  // Pass network handler to MtrApp so it can fetch arrival data
  // MtrApp* mtr_app = dynamic_cast<MtrApp*>(mtr_descriptor->get_app_instance());
  // if (mtr_app) {
  //   mtr_app->set_network_handler(network_handler);
  // }

  // ESP_LOGI(TAG, "Apps registered with AppRegistry\n");

  // Initialize UI Handler (will render app icons from registry)
  // UIHandler ui_handler;
  // if (ui_handler.init() != ESP_OK) {
  //   ESP_LOGE(TAG, "Failed to initialize UI handler");
  //   vTaskDelay(5000 / portTICK_PERIOD_MS);
  //   return esp_restart();
  // }
  // ESP_LOGI(TAG, "UI handler initialized successfully\n");
  // ESP_LOGI(TAG, "Main screen displayed with app icons. Tap an icon to launch an app.\n");

  // Run checkerboard draw in its own FreeRTOS task to avoid watchdog triggers
  struct CheckerboardTaskParams {
    EInkDisplayHandler* display_handler;
  };
  auto checkerboard_task_fn = [](void* pvParameters) {
    CheckerboardTaskParams* params = static_cast<CheckerboardTaskParams*>(pvParameters);
    if (params != nullptr && params->display_handler != nullptr) {
      // Add this task to the watchdog timer
      esp_err_t wdt_err = esp_task_wdt_add(NULL);
      if (wdt_err != ESP_OK) {
        ESP_LOGW(TAG, "Failed to add checkerboard task to watchdog: %s", esp_err_to_name(wdt_err));
      }

      EInkDisplayHandler* display_handler = params->display_handler;
      const size_t DISPLAY_BUFFER_SIZE = DISPLAY_WIDTH * DISPLAY_HEIGHT / 8;
      uint8_t* framebuffer = new uint8_t[DISPLAY_BUFFER_SIZE];
      if (framebuffer == nullptr) {
        ESP_LOGE(TAG, "Failed to allocate framebuffer for checkerboard task");
        if (wdt_err == ESP_OK) {
          esp_task_wdt_delete(NULL);
        }
        vTaskDelete(NULL);
        return;
      }
      // Create checkerboard pattern
      for (size_t y = 0; y < DISPLAY_HEIGHT; y++) {
        for (size_t x = 0; x < DISPLAY_WIDTH; x++) {
          size_t byte_index = (y * DISPLAY_WIDTH + x) / 8;
          size_t bit_index = 7 - (x % 8);
          bool is_white = ((x / 20) % 2) == ((y / 20) % 2);
          if (is_white) {
            framebuffer[byte_index] |= (1 << bit_index); // Set bit to 1 for white
          } else {
            framebuffer[byte_index] &= ~(1 << bit_index); // Clear bit to 0 for black
          }
        }
        // Yield and reset watchdog periodically
        if (y % 50 == 0) {
          if (wdt_err == ESP_OK) {
            esp_task_wdt_reset();
          }
          vTaskDelay(1 / portTICK_PERIOD_MS);
        }
      }
      // Perform full write to display
      esp_err_t err = display_handler->full_write(framebuffer);
      if (err != ESP_OK) {
        ESP_LOGE(TAG, "Checkerboard full write failed: %s", esp_err_to_name(err));
      } else {
        ESP_LOGI(TAG, "Checkerboard pattern displayed successfully.");
      }
      delete[] framebuffer;

      // Remove task from watchdog before deletion
      if (wdt_err == ESP_OK) {
        esp_task_wdt_delete(NULL);
      }
    } else {
      ESP_LOGE(TAG, "Invalid parameters for checkerboard task");
    }
    vTaskDelete(NULL);
    };
  CheckerboardTaskParams* checker_params = new CheckerboardTaskParams();
  checker_params->display_handler = display_handler;
  BaseType_t res = xTaskCreate(
    checkerboard_task_fn,
    "checkerboard_task",
    8192,
    static_cast<void*>(checker_params),
    tskIDLE_PRIORITY + 1,
    NULL
  );

  if (res != pdPASS) {
    ESP_LOGE(TAG, "Failed to create checkerboard task");
    delete checker_params;
  }

  // wait for shutdown signal
  ESP_LOGI(TAG, "Waiting for shutdown signal...\n");
  EventBits_t bits = xEventGroupWaitBits(
    system_lifecycle_event_group,
    SYSTEM_SHUTDOWN_BIT | SYSTEM_RESTART_BIT,
    // do not clear on exit, require explicit reset
    pdFALSE,
    pdFALSE,
    portMAX_DELAY
  );
  ESP_LOGI(TAG, "Shutdown signal received. Cleaning up...\n");

  // Show shutdown screen using the shutdown descriptor's app instance
  // ShutdownApp* shutdown_app = dynamic_cast<ShutdownApp*>(shutdown_descriptor->get_app_instance());
  // if (shutdown_app) {
  //   ui_handler.switch_app(shutdown_app);
  // }
  vTaskDelay(1000 / portTICK_PERIOD_MS);  // Display shutdown message briefly

  // Cleanup
  // ui_handler.deinit();
  // delete demo_descriptor;
  // delete shutdown_descriptor;
  // delete mtr_descriptor;
  delete display_handler;
  vSemaphoreDelete(lvgl_mutex);
  vEventGroupDelete(system_event_group);
  vQueueDelete(touch_event_queue);
  ESP_LOGI(TAG, "Cleanup complete.\n");

  // handle shutdown or restart
  if (bits & SYSTEM_SHUTDOWN_BIT) {
    // if (shutdown_display_handler != nullptr) {
    //   ESP_LOGI(TAG, "Calling display shutdown handler...\n");
    //   shutdown_display_handler();
    // } else {
    //   ESP_LOGI(TAG, "No display shutdown handler to call.\n");
    // }
    ESP_LOGI(TAG, "System is shutting down.\n");
    fflush(stdout);
    // wait for start bit to be set again if future restart is desired, else expect manual power cycle
    EventBits_t bits = xEventGroupWaitBits(
      system_lifecycle_event_group,
      SYSTEM_START_BIT,
      pdFALSE,
      pdFALSE,
      portMAX_DELAY
    );
    if (bits & SYSTEM_START_BIT) {
      ESP_LOGI(TAG, "SYSTEM_START_BIT received, restarting system.\n");
    } else {
      ESP_LOGW(TAG, "No restart signal received, waiting for manual power cycle.\n");
      while (true) {
        vTaskDelay(portMAX_DELAY);
      }
    }
  } else if (bits & SYSTEM_RESTART_BIT) {
    // if (restart_display_handler != nullptr) {
    //   ESP_LOGI(TAG, "Calling display restart handler...\n");
    //   restart_display_handler();
    // } else {
    //   ESP_LOGI(TAG, "No display restart handler to call.\n");
    // }
    ESP_LOGI(TAG, "System is restarting.\n");
    fflush(stdout);
  } else {
    ESP_LOGW(TAG, "Unknown shutdown signal received. Restarting by default.\n");
    fflush(stdout);
  }

  return esp_restart();
}

void init_queues(
  QueueHandle_t& touch_queue,
  EventGroupHandle_t& system_event_group,
  EventGroupHandle_t& system_lifecycle_event_group
) {
  // Implementation of queue initialization
  touch_queue = xQueueCreate(10, sizeof(touch_event_t));
  system_event_group = xEventGroupCreate();
  system_lifecycle_event_group = xEventGroupCreate();
}