console.loggerName = 'js.lib';
console.log('Load lib module');


function compare(a, b, operator) {
    // Hint: a = currentState, b = targetState
    let logMsg = '';
    let returnValue = undefined;
    try {
        logMsg = `Quantity comparison of ${a}, ${b} with operator ${operator}`;
        switch (operator)  {
            case '==':
                returnValue = a.equal(b);
                break;
            case '!=':
                returnValue = !a.equal(b);
                break;
            case '<' :
                returnValue = a.lessThan(b);
                break;
            case '<=':
                returnValue = a.lessThanOrEqual(b);
                break;
            case '>' :
                returnValue = a.greaterThan(b);
                break;
            case '>=':
                returnValue = a.greaterThanOrEqual(b);
                break;
            default:
                console.error(`${operator} is no valid operator`);
                return;
        }
    } catch(e) {
        logMsg = `Standard comparison of ${a}, ${b} with operator ${operator}`;
        switch (operator) {
            case '==':
                returnValue = (a == b);
                break;
            case '!=':
                returnValue = !(a == b);
                break;
            case '<' :
                returnValue = (a < b);
                break;
            case '<=':
                returnValue = (a <= b);
                break;
            case '>' :
                returnValue = (a > b);
                break;
            case '>=':
                returnValue = (a >= b);
                break;
        }        
    }

    console.debug(logMsg);
    return returnValue;
}

function convertValue(value) {
    console.debug('Converting value ' + value + ' of type ' + typeof value);
    if(typeof value === 'string') {
        if(value.includes(' ')) {
            let logMsg = '';
            let returnValue;
            try {
                logMsg = 'Quantity: ' + value;
                returnValue = Quantity(value);
            } catch(e) {
                logMsg = 'Not a Quantity but has a space, leaving as a string: ' + value;
                returnValue = value;
            } finally {
                console.debug(logMsg);
                return returnValue;
            }
        } else if(!isNaN(value)) {
            console.debug('Number: ' + value)
            return Number.parseFloat(value);
        } else if(value == 'UnDefType' || value == 'NULL' || value == 'UNDEF') {
            console.debug('UnDefType: ' + value);
            return 'UnDefType';
        }
        console.debug('String: ' + value);
        return value;
    } else if(value instanceof DecimalType || value instanceof PercentType) {
        console.debug('DecimalType or PercentType: ' + value);
        return value.floatValue();
    } else if(value instanceof QuantityType) {
        console.debug('QuantityType: ' + value);
        return Quantity(value);
    } else {
        console.debug('String: ' + value);
        return value.toString();
    }
}

function distanceFrom(locationA, locationB) {
    let lat1 = (locationA.split(',')[0]) * (Math.PI / 180);
    let lon1 = (locationA.split(',')[1]) * (Math.PI / 180);
    let lat2 = (locationB.split(',')[0]) * (Math.PI / 180);
    let lon2 = (locationB.split(',')[1]) * (Math.PI / 180);
    
	if ((lat1 == lat2) && (lon1 == lon2)) {
		return 0;
	}

    // Haversine formula
    let dlon = lon2 - lon1;
    let dlat = lat2 - lat1;
    let a = Math.pow(Math.sin(dlat / 2), 2)
                + Math.cos(lat1) * Math.cos(lat2)
                * Math.pow(Math.sin(dlon / 2),2);          
    let c = 2 * Math.asin(Math.sqrt(a));
  
    // Radius of earth in meters
    let r = 6371000;
    
    // calculate the result
    let result = `${(c * r).toFixed()} m`
    
    console.debug(`Calculated distance between ${locationA} and ${locationB} is ${result}`);
    return result;
}


module.exports = {
    compare,
    convertValue,
    distanceFrom
};