terranodo/angular-search

/*eslint angular/di: [2,"array"]*/
(function () {
    angular
    .module('SolrHeatmapApp')
    .factory('NumberService', [function () {

        // Converts an integer into its most compact representation
        function compactInteger(input, decimals) {
            decimals = decimals || 0;
            decimals = Math.max(decimals, 0);
            var number = parseInt(input, 10);
            var signString = number < 0 ? '-' : '';
            var unsignedNumber = Math.abs(number);
            var unsignedNumberString = String(unsignedNumber);
            var numberLength = unsignedNumberString.length;
            var numberLengths = [13, 10, 7, 4];
            var bigNumPrefixes = ['T', 'B', 'M', 'k'];

              // small numbers
            if (unsignedNumber < 1000) {
                // return `${ signString }${ unsignedNumberString }`;
                return signString + unsignedNumberString;
            }

            // really big numbers
            if (numberLength > numberLengths[0] + 3) {
                return number.toExponential(decimals).replace('e+', 'x10^');
            }

            // 999 < unsignedNumber < 999,999,999,999,999
            var length;
            for (var i = 0; i < numberLengths.length; i++) {
                var _length = numberLengths[i];
                if (numberLength >= _length) {
                    length = _length;
                    break;
                }
            }

            var decimalIndex = numberLength - length + 1;
            var unsignedNumberCharacterArray = unsignedNumberString.split('');

            var wholePartArray = unsignedNumberCharacterArray.slice(0, decimalIndex);
            var decimalPartArray = unsignedNumberCharacterArray.slice(
                decimalIndex, decimalIndex + decimals + 1);

            var wholePart = wholePartArray.join('');

              // pad decimalPart if necessary
            var decimalPart = decimalPartArray.join('');
            if (decimalPart.length < decimals) {
                decimalPart += Array(decimals - decimalPart.length + 1).join('0');
            }

            var output;
            if (decimals === 0) {
                output = signString + wholePart + bigNumPrefixes[numberLengths.indexOf(length)];
            } else {
                var outputNumber = Number(wholePart + '.' + decimalPart).toFixed(decimals);
                output = signString + outputNumber + bigNumPrefixes[numberLengths.indexOf(length)];
            }

            return output;
        }

        return {
            compactInteger: compactInteger
        };
    }]);
})();