#include "multi_converter_units.h"

#define MULTI_CONVERTER_CHAR_OVERFLOW        '#'
#define MULTI_CONVERTER_MAX_SUPORTED_INT     999999999

#define multi_converter_unit_set_overflow(b) for (int _i = 0; _i < MULTI_CONVERTER_NUMBER_DIGITS; _i++) b[_i] = MULTI_CONVERTER_CHAR_OVERFLOW;

//
// DEC / HEX / BIN conversion
// 
void multi_converter_unit_dec_hex_bin_convert(MultiConverterState* const multi_converter_state) {

	char dest[MULTI_CONVERTER_NUMBER_DIGITS];

	int i = 0;
	uint8_t overflow = 0;
	
	int a = 0;
	int r = 0;
	uint8_t f = 1;

	switch(multi_converter_state->unit_type_orig) {
		default:
			break;
		case UnitTypeDec: {
			a = atoi(multi_converter_state->buffer_orig);
			f = (multi_converter_state->unit_type_dest == UnitTypeHex ? 16 : 2);

			break;
		}
		case UnitTypeHex:
			a = strtol(multi_converter_state->buffer_orig, NULL, 16);
			f = (multi_converter_state->unit_type_dest == UnitTypeDec ? 10 : 2);

			break;
		case UnitTypeBin:
			a = strtol(multi_converter_state->buffer_orig, NULL, 2);
			f = (multi_converter_state->unit_type_dest == UnitTypeDec ? 10 : 16);

			break;
	}

	while (a > 0) {
		r = a % f;
		dest[i] = r + (r < 10 ? '0' : ('A' - 10) );
		a /= f;
		if (i++ >= MULTI_CONVERTER_NUMBER_DIGITS) {
			overflow = 1;
			break;
		}
	}

	if (overflow) {
		multi_converter_unit_set_overflow(multi_converter_state->buffer_dest);
	} else {
		// copy DEST (reversed) to destination and append empty chars at the end
		for (int j = 0; j < MULTI_CONVERTER_NUMBER_DIGITS; j++) {
			if (i >= 1) multi_converter_state->buffer_dest[j] = dest[--i];
			else multi_converter_state->buffer_dest[j] = ' ';
		}
	}

}

uint8_t multi_converter_unit_dec_hex_bin_allowed(MultiConverterUnitType unit_type) {
	return (unit_type == UnitTypeDec || unit_type == UnitTypeHex || unit_type == UnitTypeBin);
}

//
// CEL / FAR / KEL
//
void multi_converter_unit_temperature_convert(MultiConverterState* const multi_converter_state) {

	double a = strtof(multi_converter_state->buffer_orig, NULL);
	uint8_t overflow = 0;

	switch(multi_converter_state->unit_type_orig) {
		default:
			break;
		case UnitTypeCelsius:
			if (multi_converter_state->unit_type_dest == UnitTypeFahernheit) {
				// celsius to fahrenheit
				a = (a * ((double) 1.8)) + 32;
			} else { // UnitTypeKelvin
				a += ((double) 273.15);
			}

			break;
		case UnitTypeFahernheit:
			// fahrenheit to celsius, always
			a = (a - 32) / ((double) 1.8);
				if (multi_converter_state->unit_type_dest == UnitTypeKelvin) {
				// if kelvin, add
				a += ((double) 273.15);
			}

			break;
		case UnitTypeKelvin:
			// kelvin to celsius, always
			a -= ((double) 273.15);
				if (multi_converter_state->unit_type_dest == UnitTypeFahernheit) {
				// if fahernheit, convert
				a = (a * ((double) 1.8)) + 32;
			}

			break;
	}	

	if (overflow) {
		multi_converter_unit_set_overflow(multi_converter_state->buffer_dest);
	} else {

		int ret = snprintf(multi_converter_state->buffer_dest, MULTI_CONVERTER_NUMBER_DIGITS + 1, "%.3lf", a);

		if (ret < 0) multi_converter_unit_set_overflow(multi_converter_state->buffer_dest);
	}

}

uint8_t multi_converter_unit_temperature_allowed(MultiConverterUnitType unit_type) {
	return (unit_type == UnitTypeCelsius || unit_type == UnitTypeFahernheit || unit_type == UnitTypeKelvin);
}

//
// KM / M / CM / MILES / FEET / INCHES
//

void multi_converter_unit_distance_convert(MultiConverterState* const multi_converter_state) {
	double a = strtof(multi_converter_state->buffer_orig, NULL);
	uint8_t overflow = 0;

	switch(multi_converter_state->unit_type_orig) {
		default:
			break;
		case UnitTypeKilometers:
			if (multi_converter_state->unit_type_dest == UnitTypeMeters) a *= ((double) 1000);
			else if (multi_converter_state->unit_type_dest == UnitTypeCentimeters) a *= ((double) 100000);
			else if (multi_converter_state->unit_type_dest == UnitTypeMiles) a *= ((double) 0.6213711);
			else if (multi_converter_state->unit_type_dest == UnitTypeFeet) a *= ((double) 3280.839895013);
			else if (multi_converter_state->unit_type_dest == UnitTypeInches) a *= ((double) 39370.078740157);
			break;
		case UnitTypeMeters:
			if (multi_converter_state->unit_type_dest == UnitTypeKilometers) a /= ((double) 1000);
			else if (multi_converter_state->unit_type_dest == UnitTypeCentimeters) a *= ((double) 100);
			else if (multi_converter_state->unit_type_dest == UnitTypeMiles) a *= ((double) 0.0006213711);
			else if (multi_converter_state->unit_type_dest == UnitTypeFeet) a *= ((double) 3.280839895013);
			else if (multi_converter_state->unit_type_dest == UnitTypeInches) a *= ((double) 39.370078740157);
			break;
		case UnitTypeCentimeters:
			if (multi_converter_state->unit_type_dest == UnitTypeKilometers) a /= ((double) 100000);
			else if (multi_converter_state->unit_type_dest == UnitTypeMeters) a /= ((double) 100);
			else if (multi_converter_state->unit_type_dest == UnitTypeMiles) a *= ((double) 0.000006213711);
			else if (multi_converter_state->unit_type_dest == UnitTypeFeet) a *= ((double) 0.03280839895013);
			else if (multi_converter_state->unit_type_dest == UnitTypeInches) a *= ((double) 0.39370078740157);
			break;

		case UnitTypeMiles:
			if (multi_converter_state->unit_type_dest == UnitTypeKilometers) a *= ((double) 1.609344);
			else if (multi_converter_state->unit_type_dest == UnitTypeMeters) a *= ((double) 1609.344);
			else if (multi_converter_state->unit_type_dest == UnitTypeCentimeters) a *= ((double) 160934.4);
			else if (multi_converter_state->unit_type_dest == UnitTypeFeet) a *= ((double) 5280);
			else if (multi_converter_state->unit_type_dest == UnitTypeInches) a *= ((double) 63360);
			break;
		case UnitTypeFeet:
			if (multi_converter_state->unit_type_dest == UnitTypeKilometers) a *= ((double) 0.0003048);
			else if (multi_converter_state->unit_type_dest == UnitTypeMeters) a *= ((double) 0.3048);
			else if (multi_converter_state->unit_type_dest == UnitTypeCentimeters) a *= ((double) 30.48);
			else if (multi_converter_state->unit_type_dest == UnitTypeMiles) a *= ((double) 0.000189393939394);
			else if (multi_converter_state->unit_type_dest == UnitTypeInches) a *= ((double) 12);
			break;
		case UnitTypeInches:
			if (multi_converter_state->unit_type_dest == UnitTypeKilometers) a *= ((double) 0.0000254);
			else if (multi_converter_state->unit_type_dest == UnitTypeMeters) a *= ((double) 0.0254);
			else if (multi_converter_state->unit_type_dest == UnitTypeCentimeters) a *= ((double) 2.54);
			else if (multi_converter_state->unit_type_dest == UnitTypeMiles) a *= ((double) 0.0000157828282828);
			else if (multi_converter_state->unit_type_dest == UnitTypeFeet) a *= ((double) 0.0833333333333);
			break;

	}

	if (overflow) {
		multi_converter_unit_set_overflow(multi_converter_state->buffer_dest);
	} else {

		int ret = snprintf(multi_converter_state->buffer_dest, MULTI_CONVERTER_NUMBER_DIGITS + 1, "%lf", a);

		if (ret < 0) multi_converter_unit_set_overflow(multi_converter_state->buffer_dest);
	}
}

uint8_t multi_converter_unit_distance_allowed(MultiConverterUnitType unit_type) {
	return (
		unit_type == UnitTypeKilometers || unit_type == UnitTypeMeters || unit_type == UnitTypeCentimeters ||
		unit_type == UnitTypeMiles || unit_type == UnitTypeFeet || unit_type == UnitTypeInches
	);
}

//
// DEG / RAD
//

void multi_converter_unit_angle_convert(MultiConverterState* const multi_converter_state) {
	double a = strtof(multi_converter_state->buffer_orig, NULL);
	uint8_t overflow = 0;

	switch(multi_converter_state->unit_type_orig) {
		default:
			break;
		case UnitTypeDegree:
			if (multi_converter_state->unit_type_dest == UnitTypeRadian) a *= ((double) 0.0174532925199);
			break;

		case UnitTypeRadian:
			if (multi_converter_state->unit_type_dest == UnitTypeDegree) a *= ((double) 57.2957795131);
			break;
	}

	if (overflow) {
		multi_converter_unit_set_overflow(multi_converter_state->buffer_dest);
	} else {

		int ret = snprintf(multi_converter_state->buffer_dest, MULTI_CONVERTER_NUMBER_DIGITS + 1, "%lf", a);

		if (ret < 0) multi_converter_unit_set_overflow(multi_converter_state->buffer_dest);
	}
}

uint8_t multi_converter_unit_angle_allowed(MultiConverterUnitType unit_type) {
	return (unit_type == UnitTypeDegree || unit_type == UnitTypeRadian);
}