#include "p_serial_mgr.h"
#include "putil.h"
#include "stm32l4xx_hal_def.h"
#include "stm32l4xx_hal_uart.h"

#define NUM_BUFFERS (10)

uint8_t sbuffer[NUM_BUFFERS][MAX_MESSAGE_LEN];
uint8_t active_buffer = 0;

uint8_t rxb[MAX_MESSAGE_LEN];
// this protocol is very similar to the digi api v2 (inspired from)
// [0]{1} Start delimiter 0x7E
// [1]{1} Source Address
// [2]{1} Destination Address
// [3]{1} Length Byte (of non-delimited framebuffer)
// [4-n]{n} frame data
// [n+1]{1} checksum
// Escape bytes are 0x7D, only frame data can be escaped
// Escaped bytes are followed by the byte to be escaped XOR'd with 0x20
// 0x7D and 0x7E need to be escaped (within the frame data)

typedef enum serial_state_t
{
	SS_IDLE = 0,  // waiting
	SS_START = 1, // get start byte, interrupt after 4 more bytes
	SS_ERR = 2
} serial_state_t;

static UART_HandleTypeDef *_serial_huart_inst = NULL;

static uint8_t rxc = '\0';
static serial_state_t sstate = SS_IDLE;

static void p_serial_mgr_flush()
{
	HAL_UART_Receive(_serial_huart_inst, sbuffer[active_buffer], MAX_MESSAGE_LEN, 10);
}
void UART1_RxCpltCallback(UART_HandleTypeDef *huart)
{
	PDEBUG("%c", sbuffer[active_buffer][0]);
	p_serial_mgr_start();
	return;
	if (sstate == SS_IDLE && sbuffer[active_buffer][0] == 0x7E)
	{
		sstate = SS_START;
	}
	else
	{
		sstate = SS_ERR;
	}
}

void p_serial_mgr_init(UART_HandleTypeDef *huart)
{
	_serial_huart_inst = huart;
	_serial_huart_inst->RxCpltCallback = UART1_RxCpltCallback;
}
void p_serial_mgr_service(void)
{
	if (sstate == SS_START)
	{
		while (HAL_UART_Receive(_serial_huart_inst, &sbuffer[active_buffer][1], MAX_MESSAGE_LEN - 2, 20) != HAL_OK) {}
		for (int ind = 0; ind < 24; ind++)
		{
			PDEBUG("[%d]: 0x%02x\n", ind, sbuffer[active_buffer][ind]);
		}
		PDEBUG("\n\n");
		memset(sbuffer[active_buffer], 0, MAX_MESSAGE_LEN);
		active_buffer = (active_buffer + 1) % NUM_BUFFERS;
		uint8_t sendbuffer[9] = {0x7E, DEVICE_ADDR, MASTER_ADDR, 4, 0x01, 0x02, 0x03, 0x04, 0xFF};
		// HAL_UART_Transmit(_serial_huart_inst, sendbuffer, 9, 10);
		p_serial_mgr_start();
	}
	else if (sstate == SS_ERR)
	{
		PDEBUG("MISSED BYTE 0x%02x\n", sbuffer[active_buffer][0]);
		p_serial_mgr_start();
	}
}

void p_serial_mgr_start()
{
	sstate = SS_IDLE;
	volatile HAL_StatusTypeDef ret = HAL_UART_Receive_IT(_serial_huart_inst, &sbuffer[active_buffer][0], 1);
	asm volatile("nop");
}