#ifndef EVSE_LINK_FRAMING_H_
#define EVSE_LINK_FRAMING_H_

#include <stdint.h>
#include <stdbool.h>
#include "driver/uart.h"

// UART baud/buffer configuration
#define UART_BAUDRATE 9600
#define UART_RX_BUF_SIZE 256

// Select EVSE-Link physical layer at compile time.
// 0 = production RS485: UART2 GPIO17/16 + RTS/DE GPIO2
// 1 = emergency/internal UART TTL: UART1 GPIO21/22, no RS485/RTS
#ifndef EVSE_LINK_USE_UART_TTL
#define EVSE_LINK_USE_UART_TTL 0
#endif

#if EVSE_LINK_USE_UART_TTL

#define UART_PORT UART_NUM_1
#define TX_PIN 21
#define RX_PIN 22
#define RTS_PIN UART_PIN_NO_CHANGE
#define EVSE_LINK_UART_MODE UART_MODE_UART
#define EVSE_LINK_PHY_NAME "UART_TTL"

#else

#define UART_PORT UART_NUM_2
#define TX_PIN 17
#define RX_PIN 16
#define RTS_PIN 2
#define EVSE_LINK_UART_MODE UART_MODE_RS485_HALF_DUPLEX
#define EVSE_LINK_PHY_NAME "RS485"

#endif
// Frame delimiters
#define MAGIC_START 0x7E
#define MAGIC_END 0x7F

// Maximum payload (excluding sequence byte)
#define EVSE_LINK_MAX_PAYLOAD 254

// Callback type for when a full frame is received
typedef void (*evse_link_frame_cb_t)(uint8_t src, uint8_t dest,
                                     const uint8_t *payload, uint8_t len);

// Initialize framing module (mutex, UART driver, etc.)
void evse_link_framing_init(void);

// Send a framed payload to `dest` with length `len`
// Includes source address in the header
bool evse_link_framing_send(uint8_t dest, uint8_t src,
                            const uint8_t *payload, uint8_t len);

// Feed a received byte into the framing parser
void evse_link_framing_recv_byte(uint8_t byte);

// Register a callback for complete frames
void evse_link_framing_register_cb(evse_link_frame_cb_t cb);

#endif // EVSE_LINK_FRAMING_H_