#pragma once

#ifdef USE_ESP32

#include <driver/uart.h>
#include "esphome/core/component.h"
#include "uart_component.h"
#ifdef USE_UART_WAKE_LOOP_ON_RX
#include <driver/uart_select.h>
#endif

namespace esphome::uart {

/// ESP-IDF UART driver wrapper.
///
/// Thread safety: All public methods must only be called from the main loop.
/// The ESP-IDF UART driver API does not guarantee thread safety, and ESPHome's
/// peek byte state (has_peek_/peek_byte_) is not synchronized.
class IDFUARTComponent final : public UARTComponent, public Component {
 public:
  // User provided, not "= default": `new(p) IDFUARTComponent()` would zero-fill .bss that is already zero.
  IDFUARTComponent() {}
  void setup() override;
  void dump_config() override;
  float get_setup_priority() const override { return setup_priority::BUS; }

  void set_rx_full_threshold(size_t rx_full_threshold) override;
  void set_rx_timeout(size_t rx_timeout) override;

  void write_array(const uint8_t *data, size_t len) override;

  bool peek_byte(uint8_t *data) override;
  bool read_array(uint8_t *data, size_t len) override;

  size_t available() override;
  size_t available_for_write() override;
  UARTFlushResult flush() override;

  void set_flush_timeout(uint32_t flush_timeout_ms) override { this->flush_timeout_ms_ = flush_timeout_ms; }

  /// TX ring buffer size for the driver; 0 leaves TX unbuffered so write_array() blocks until
  /// the FIFO has taken everything.
  void set_tx_buffer_size(size_t tx_buffer_size) { this->tx_buffer_size_ = tx_buffer_size; }

  void set_clock_source(uart_sclk_t clock_source) { this->clock_source_ = static_cast<uint8_t>(clock_source); }

  uint8_t get_hw_serial_number() { return this->uart_num_; }

  /// Discard everything received so far: the peek cache and the driver's RX buffer.
  void flush_input() {
    this->has_peek_ = false;
    uart_flush_input(this->uart_num_);
  }

  /**
   * Load the UART with the current settings.
   * @param dump_config (Optional, default `true`): True for displaying new settings or
   * false to change it quitely
   *
   * Example:
   * ```cpp
   * id(uart1).load_settings();
   * ```
   *
   * This will load the current UART interface with the latest settings (baud_rate, parity, etc).
   */
  void load_settings(bool dump_config) override;
  using UARTComponent::load_settings;  // also bring in the no-arg overload for convenience

  /**
   * Apply the current framing (baud rate, parity, data/stop bits) to the installed
   * driver in place, without the delete/reinstall of load_settings(). Tasks blocked in
   * the driver survive and the ring buffers are kept, but both hardware FIFOs are
   * flushed: a frame in flight reaches the peer truncated and bytes not yet out of the
   * RX FIFO are dropped. No lock is taken: quiesce writers first if that matters.
   * rx_full_threshold is not rescaled (call set_rx_full_threshold_ms() first if it
   * should follow the baud rate); a rollback restores the value from the last accepted
   * configuration, undoing a standalone set_rx_full_threshold() made since. Without an
   * installed driver this is a full load_settings(false) instead.
   *
   * @return ESP_OK once the new framing is live (a line-setting error after that only
   * logs). On rejection (unreachable baud rate) the previous framing is restored and
   * the driver's error returned; if the restore fails too the component is marked
   * failed. ESP_ERR_INVALID_STATE if already failed; ESP_FAIL if the fallback
   * load_settings() fails.
   */
  esp_err_t apply_settings_live();

  void on_shutdown() override;

 protected:
  void check_logger_conflict() override;
  uint32_t line_inversion_mask_();
  // Re-applies what uart_param_config() resets: inversion, RX threshold/timeout, mode.
  esp_err_t apply_line_settings_();
  uart_port_t uart_num_{UART_NUM_MAX};
  uart_config_t get_config_();

  struct Framing {
    uint32_t baud_rate;
    uint8_t data_bits;
    uint8_t stop_bits;
    UARTParityOptions parity;
    size_t rx_full_threshold;  // sized for the baud rate, so rolled back with it
  };
  Framing framing_() const {
    return {this->baud_rate_, this->data_bits_, this->stop_bits_, this->parity_, this->rx_full_threshold_};
  }
  void set_framing_(const Framing &framing);
  // Last framing the driver accepted; baud_rate 0 means none yet.
  Framing last_good_framing_{};

  bool has_peek_{false};
  uint8_t peek_byte_{0};
  uint8_t clock_source_{UART_SCLK_DEFAULT};  ///< uart_sclk_t stored in a byte; the IDF values are all small.
  uint32_t flush_timeout_ms_{0};             ///< 0 means wait indefinitely (portMAX_DELAY).
  size_t tx_buffer_size_{0};

#ifdef USE_UART_WAKE_LOOP_ON_RX
  // ISR callback for UART RX data notification — wakes the main loop directly.
  static void uart_rx_isr_callback(uart_port_t uart_num, uart_select_notif_t uart_select_notif, BaseType_t *task_woken);
#endif  // USE_UART_WAKE_LOOP_ON_RX
};

}  // namespace esphome::uart
#endif  // USE_ESP32