#include <avr/io.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "controller.h"
#include "serial.h"

static void handle_set(char *buffer, uint16_t len)
{
	const char *error_msg = "ERR Invalid number for temperature\r\n";
	const char *error_msg2 = "ERR Temperature out of range.\r\n";
	const char *success_msg = "OK Temperature set.\r\n";
	const char *input;
	char *endptr;
	double temperature;

	if (len < 2) {
		serial_send(error_msg, strlen(error_msg), 0);
		return;
	}

	input = buffer + 1;
	temperature = strtod(input, &endptr);
	if (input[0] == '\r' || input[0] == '\n' ||
			(endptr[0] != '\r' && endptr[0] != '\n')) {
		serial_send(error_msg, strlen(error_msg), 0);
		return;
	}

	if (controller_set(temperature)) {
		serial_send(error_msg2, strlen(error_msg2), 0);
		return;
	}

	serial_send(success_msg, strlen(success_msg), 0);
}

static void handle_off(char *buffer, uint16_t len)
{
	const char *success_msg = "OK Powered down.\r\n";
	
	controller_off();
	serial_send(success_msg, strlen(success_msg), 0);
}

static void handle_get(char *buffer, uint16_t len)
{
	char response[128];
	long temp = 10 * controller_get();

	/* printf won't print doubles on avr */
	snprintf(response, sizeof(response), "OK t=%ld.%ld\r\n", temp/10, temp%10);
	serial_send(response, strlen(response), 0);
}

uint16_t serial_rx_cb(char *buffer, uint16_t len)
{
	const char *error_msg = "ERR Unknown command\r\n";
	switch(buffer[len-1]) {
	case '\r':
	case '\n':
		serial_send("\r\n", 2, 0);
		break;
	default:
		/* If we didn't get a line break, just echo and return */
		serial_send(&buffer[len-1], 1, 0);
		return 0;
	}

	switch(buffer[0]) {
	case 's':
	case 'S':
		handle_set(buffer, len);
		break;
	case 'g':
	case 'G':
		handle_get(buffer, len);
		break;
	case 'o':
	case 'O':
		handle_off(buffer, len);
		break;
	default:
		serial_send(error_msg, strlen(error_msg), 0);
	}

	return len;
}