/*
 * Project: Arrow
 * Author: 	curiousmuch
 * Description: This project is an APRS transceiver based on the ESP32 and CC1200.
 * TODO: Refactor Code to isolate into seperate components
 * TODO: Isolate BT_SPP.C functionality
 * TODO: Isolate KISS.C functionality
 * TODO: Remove any dependancies on Direwolf.
 * TODO: Transfer DSP functions to APRS folder
 * TODO: Abstract includes to be nicer (#include aprs.h) for example
 * TODO: Isolate CC1200 functions from other parts / maybe integrate most of TX scheme into task.
 */

/* Standard Includes */
#include <stdio.h>

/* ESP-IDF */
#include "sdkconfig.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/semphr.h"
#include "freertos/ringbuf.h"
#include "nvs.h"
#include "nvs_flash.h"
#include "esp_log.h"


/* Application Specific */
#include "bt_spp.h"
#include "board.h"
#include "radio.h"
#include "kiss.h"
#include "fcs_calc.h"


/* Data Structures */
typedef struct {
	uint8_t tnc_number;
	uint8_t tx_delay;
	uint8_t P;
	uint8_t slot_time;
	uint8_t full_duplex;
	uint8_t tx_tail;
} tnc_settings_t;

/* Public Variables */
tnc_settings_t tnc_settings;

uint8_t ax25_rx_buf[1024];
RingbufHandle_t ax25_tx_buf;

/* Functions and Main */

/* Radio Callback Functions */
// callback function for when radio rx'd AX25 packet
// unblocks task on other core and packet to another buffer
// so we can continue processing
void radio_rx_ax25_cb(uint8_t *frame, uint32_t len)
{
	ESP_LOGV("AX25 CB", "We Here");
	// unblock receive task on CPU0

}

/* KISS callback Functions */
void kiss_tx_cb(uint8_t *frame, uint32_t len)
{
	// send data to UART / via bluetooth
	bt_spp_tx(frame, len);
}

void kiss_rx_cb(uint8_t *frame, uint32_t len)
{
	uint8_t data_byte;
	data_byte = frame[0] & 0x0F;	// tnc_number information

	// process dataframe
	if (data_byte == KISS_DATAFRAME)
	{
		// feed packet to ring buffer
		uint32_t fcs = fcs_calc(&frame[1], len-1);
		frame[len] = fcs & 0xFF;
		frame[len+1] = fcs>>8 & 0xFF;
		xRingbufferSend(ax25_tx_buf, &frame[1], ((len+1)*sizeof(uint8_t)),10/portTICK_PERIOD_MS);
	}
	else // assume command
	{
		switch(data_byte)
		{
			case KISS_CMD_TXDELAY:
				ESP_LOGI("TNC", "updated tx delay");
				tnc_settings.tx_delay = frame[1];
				break;
			case KISS_CMD_P:
				ESP_LOGI("TNC", "updated persistance");
				tnc_settings.P = frame[1];
				break;
			case KISS_CMD_SLOTTIME:
				ESP_LOGI("TNC", "updated slot time");
				tnc_settings.slot_time = frame[1];
				break;
			case KISS_CMD_TXTAIL:
				ESP_LOGI("TNC", "updated tx tail");
				tnc_settings.tx_tail = frame[1];
				break;
			case KISS_CMD_FULLDUPLEX:
				ESP_LOGI("TNC", "updated duplex setting");
				tnc_settings.full_duplex = frame[1];
				break;
			case KISS_CMD_SETHARDWARE:
				ESP_LOGI("TNC", "updated hardware settings");
				break;
			case KISS_CMD_RETURN:
				ESP_LOGI("TNC", "wtf is return");
				break;
			default:
				ESP_LOGE("KISS", "unknown data byte");
		}

		// reload for parameter changes to take effect
	}
}

/* TNC Tasks */
// schedules transmissions based on p-persistance
// settings and carrier sense from radio a
// TODO: Latch CS during slot time?

void tnc_task(void *para)
{
	radio_packet_rx(NULL);
	uint8_t *packet;
	size_t packet_size;
	while(1)
	{
		// indicate RX
		enable_green_led();
		disable_red_led();

		// check ring buffer for packet
		packet = xRingbufferReceive(ax25_tx_buf, &packet_size, portMAX_DELAY);

		if (packet != NULL)
		{
			uint8_t P;
			// wait based on persistance algorithm
			while (1)
			{
				if (!radio_get_cs())
				{
					P = (uint8_t) esp_random();
					if (P <= tnc_settings.P)
					{
						break;
					}
					else
					{
						vTaskDelay(tnc_settings.slot_time * 10 / portTICK_PERIOD_MS);
					}
				}
				taskYIELD(); // make sure to yield for RX'ing task
			}

			// indicate TX
			enable_red_led();
			disable_green_led();

			// dump all the packets in the buffer
			while(packet != NULL)
			{
				radio_packet_tx(packet, packet_size, NULL);
				vRingbufferReturnItem(ax25_tx_buf, (void *)packet);
				packet = xRingbufferReceive(ax25_tx_buf, &packet_size, 0);
			}
		}
		else
		{
			printf("Why we here \n");
		}
		// setup again for reception
		radio_packet_rx(NULL);
	}
}

void IRAM_ATTR app_main()
{
	// Initialize Flash
	esp_err_t ret = nvs_flash_init();
	if (ret == ESP_ERR_NVS_NO_FREE_PAGES || ret == ESP_ERR_NVS_NEW_VERSION_FOUND) {
		ESP_ERROR_CHECK(nvs_flash_erase());
		ret = nvs_flash_init();
	}
	ESP_ERROR_CHECK( ret );

	// Board IO Initialize
	board_init();

	// Load Settings from Flash


	// Radio Task Initialize
	ax25_param_t ax25_param;

	ax25_param.tx_tail = 10;
	ax25_param.tx_delay = 10;
	ax25_param.sample_rate = 13200;
	ax25_param.symbol0_freq = 1200;
	ax25_param.symbol1_freq = 2200;
	ax25_param.rx_cb = radio_rx_ax25_cb;
	ax25_param.rx_buf = ax25_rx_buf;
	ax25_param.rx_buf_len = sizeof(ax25_rx_buf) / sizeof(ax25_rx_buf[0]);
	ax25_param.cpu_core = 1;

	radio_init(AX25, &ax25_param);

	// Kiss Decoder and Encoder
	kiss_init(0, kiss_tx_cb, kiss_rx_cb);


	// BLE and SPP
	bt_spp_init();

	// Inter-Task Communication
	ax25_tx_buf = xRingbufferCreate(1028, RINGBUF_TYPE_NOSPLIT);

	// Tasks
	xTaskCreatePinnedToCore(tnc_task, "tnc task", 1024*4, 0, 2, NULL, 1);

}