#pragma once

#include <Arduino.h>
#include "config.h"
#include "data_model.h"

constexpr size_t LORA_MAX_PAYLOAD = 230;
constexpr size_t LORA_FRAME_HEADER_LEN = 3; // msg_kind + dev_id_short
constexpr size_t LORA_FRAME_CRC_LEN = 2;
constexpr size_t LORA_ACK_DOWN_PAYLOAD_LEN = 7; // flags(1) + batch_id(2) + epoch_utc(4)
static_assert(LORA_ACK_DOWN_PAYLOAD_LEN == 7, "ACK_DOWN payload must remain 7 bytes");

constexpr size_t lora_frame_size(size_t payload_len) {
  return LORA_FRAME_HEADER_LEN + payload_len + LORA_FRAME_CRC_LEN;
}

enum class LoraMsgKind : uint8_t {
  BatchUp = 0,
  AckDown = 1
};

struct LoraPacket {
  LoraMsgKind msg_kind;
  uint16_t device_id_short;
  uint8_t payload[LORA_MAX_PAYLOAD];
  size_t payload_len;
  int16_t rssi_dbm;
  float snr_db;
};

void lora_init();
bool lora_send(const LoraPacket &pkt);
bool lora_receive(LoraPacket &pkt, uint32_t timeout_ms);
RxRejectReason lora_get_last_rx_reject_reason();
bool lora_get_last_rx_signal(int16_t &rssi_dbm, float &snr_db);
void lora_idle();
void lora_sleep();
void lora_receive_continuous();
bool lora_receive_window(LoraPacket &pkt, uint32_t timeout_ms);
uint32_t lora_airtime_ms(size_t packet_len);