#pragma once
#include "freertos/FreeRTOS.h"
#include "freertos/semphr.h"
#include "esp_lcd_touch_gt911.h"
#include "common/semaphore_guard.h"
#include <vector>
#include <atomic>

// Refresh mode configuration
#define PARTIAL_REFRESH_THRESHOLD 10  // Full refresh every N partial refreshes
#define DISPLAY_WIDTH 800
#define DISPLAY_HEIGHT 480

// forward declarations
class EInkDisplayHandler;

struct RefreshArea {
public:
  RefreshArea(int32_t x_start, int32_t y_start, int32_t x_end, int32_t y_end)
    : x1(x_start), y1(y_start), x2(x_end), y2(y_end) { }
  int32_t x1;
  int32_t y1;
  int32_t x2;
  int32_t y2;
  // reset to empty area
  void reset() {
    x1 = y1 = x2 = y2 = 0;
  }
  // expand area to include another area
  void expand_to_include(const RefreshArea& other) {
    expand_to_include(other.x1, other.y1, other.x2, other.y2);
  }
  void expand_to_include(int32_t x1, int32_t y1, int32_t x2, int32_t y2) {
    const bool force_update = is_empty();
    if (x1 < this->x1 || force_update) this->x1 = x1;
    if (y1 < this->y1 || force_update) this->y1 = y1;
    if (x2 > this->x2 || force_update) this->x2 = x2;
    if (y2 > this->y2 || force_update) this->y2 = y2;
  }
  bool is_empty() const {
    return (x1 == 0 && y1 == 0 && x2 == 0 && y2 == 0);
  }
  uint32_t area() const {
    if (is_empty()) return 0;
    return (x2 - x1 + 1) * (y2 - y1 + 1);
  }
};

class EInkDisplayHandler {
public:
  EInkDisplayHandler();
  virtual ~EInkDisplayHandler();

  esp_err_t init_devices(EventGroupHandle_t system_event_group = nullptr);


  esp_err_t refresh_display(void);
  esp_err_t full_write(const uint8_t* framebuffer, const bool white_basemap = true);
  esp_err_t partial_refresh(const uint8_t* framebuffer, const RefreshArea& area);
  esp_err_t clear_display(void);
  esp_err_t deep_sleep_display(void);
  // Request a full refresh on next flush
  void request_full_refresh(void);

  // Check if display is busy (refreshing)
  bool is_busy(void) const;
  void wait_for_idle(void) const;

  esp_lcd_touch_handle_t get_touch_handle() const { return tp_handle_; }

protected:
  esp_err_t epd_write_cmd(const uint8_t cmd, uint32_t transaction_id);
  esp_err_t epd_write_data(const uint8_t data, uint32_t transaction_id);
  esp_err_t epd_write_cmd_with_data(const uint8_t cmd, std::vector<uint8_t>& data, uint32_t transaction_id);
  esp_err_t transfer_spi_data(const uint8_t* data, const size_t& length, uint32_t transaction_id);

private:

  esp_err_t init_display_pins_(void);
  esp_err_t epd_init_(void); // full fast refresh init
  esp_err_t epd_init_partial_(void); // partial refresh init (standalone)
  esp_err_t epd_init_partial_internal_(uint32_t transaction_id); // partial refresh init (within existing transaction)
  esp_err_t init_touch_(void);
  esp_err_t dangerous_epd_write_cmd_without_lock_(const uint8_t cmd);
  esp_err_t dangerous_epd_write_data_without_lock_(const uint8_t data);

  esp_err_t begin_transaction_(TickType_t timeout, uint32_t& out_id);
  esp_err_t end_transaction_(void);
  // given a transaction ID, wait for current transaction to complete. The transaction ID will determine if the wait is needed.
  esp_err_t wait_for_transaction_end_(TickType_t timeout, uint32_t awaiting_transaction_id, SemaphoreGuard& out_transaction_guard);

  friend class TransactionGuard;

  uint32_t partial_refresh_count_ = 0;
  bool force_full_refresh_ = false;
  std::atomic<bool> is_deep_sleep_ { false };

  SemaphoreHandle_t spi_mutex_ = nullptr;
  SemaphoreHandle_t spi_transaction_mutex_ = nullptr;
  SemaphoreHandle_t refresh_mutex_ = nullptr;
  uint32_t spi_transaction_id = 0; // For tracking SPI transactions
  spi_device_handle_t spi_ = nullptr;
  esp_lcd_panel_io_handle_t tp_io_handle_ = nullptr;
  esp_lcd_touch_handle_t tp_handle_ = nullptr;
};


class TransactionGuard {
public:
  TransactionGuard(EInkDisplayHandler& handler, TickType_t timeout = portMAX_DELAY)
    : handler_(handler) { }
  ~TransactionGuard() { if (transaction_id_) handler_.end_transaction_(); }

  esp_err_t begin(TickType_t timeout = portMAX_DELAY) {
    esp_err_t err = handler_.begin_transaction_(timeout, transaction_id_);
    return err;
  }
  uint32_t transaction_id() const { return transaction_id_; }
  bool is_active() const { return transaction_id_ != 0; }
private:
  // delete copy constructor and assignment operator
  TransactionGuard(const TransactionGuard&) = delete;
  TransactionGuard& operator=(const TransactionGuard&) = delete;
  EInkDisplayHandler& handler_;
  uint32_t transaction_id_ = 0;
};