units.service.js

var service = {}, 

// unit model
// 'singular': 'USD 1 Millon',
// 'plural': 'USD 1 Millon',
// 'abbr': '$1M',
// // also can be true and template would assume to be `abbr`  
// // (for sbackwards compat)
// 'prefix': '$', 
// 'postfix': 'M'


// LABEL for mapping
unitTypes = {
    'electricDemand': [{
        'singular' : 'Kilowatt',
        'plural' : 'Kilowatts',
        'abbr' : 'kW',
        'LABEL': 'KILOWATTS'
    }, {
        'singular': 'Megawatt',
        'plural': 'Megawatts',
        'abbr': 'MW',
        'LABEL': 'MEGAWATTS'
    }, {
        'singular': 'Gigawatt',
        'plural': 'Gigawatts',
        'abbr': 'GW',
        'LABEL': 'GIGAWATTS'
    }, {
        'singular': 'Terawatt',
        'plural': 'Terawatts',
        'abbr': 'TW',
        'LABEL': 'TERAWATTS'
    },
    {
        'singular' : 'Petawatt',
        'plural' : 'Petawatts',
        'abbr' : 'PW',
        'LABEL': 'PETAWATT'
    }],

    'steamDemand': [{
        'singular': 'Pounds per hour',
        'plural': 'Pounds per hour',
        'abbr': 'lbs/hr',
        'LABEL': 'POUNDS_PER_HOUR'
    }],

    'usage': [{
        'singular': 'Kilowatt hour',
        'plural': 'Kilowatt hours',
        'abbr': 'kWh',
        'LABEL': 'KILOWATT_HOURS'
    }, {
        'singular': 'Megawatts hour',
        'plural': 'Megawatt hours',
        'abbr': 'MWh',
        'LABEL': 'MEGAWATT_HOURS'
    }, {
        'singular': 'Gigawatt hour',
        'plural': 'Gigawatt hours',
        'abbr': 'GWh',
        'LABEL': 'GIGAWATT_HOURS'
    }, {
        'singular' : 'Terawatt hour',
        'plural' : 'Terawatt hours',
        'abbr' : 'TWh',
        'LABEL': 'TERAWATT_HOURS'
    },
    {
        'singular' : 'Petawatt hour',
        'plural' : 'Petawatt hours',
        'abbr' : 'PWh',
        'LABEL': 'PETAWATT_HOURS'
    }],

    'price': [{
        'singular': 'Dollar per MWh',
        'plural': 'Dollars per MWh',
        'abbr': '$/MWh',
        'prefix': true,
        'LABEL': 'DOLLAR_PER_MWH'
    }, {
        'singular': 'Dollar per GWh',
        'plural': 'Dollars per GWh',
        'abbr': '$/GWh',
        'prefix': true,
        'LABEL': 'DOLLAR_PER_GWH'
    }, {
        'singular': 'Dollar per TWh',
        'plural': 'Dollars per TWh',
        'abbr': '$/TWh',
        'prefix': true,
        'LABEL': 'DOLLAR_PER_TWH'
    }],

    'cost': [{
        'singular': 'USD',
        'plural': 'USD',
        'abbr': '$',
        'prefix': true,
        'LABEL': 'USD'
    },
    null,
    {
        'singular': 'USD 1 Millon',
        'plural': 'USD 1 Millon',
        'abbr': '$1M',
        'prefix': '$',
        'postfix': 'M',
        'LABEL': 'USD'
    }] 
},
labels = {
    legend: {
        'demand': 'Load in',
        'usage': 'Load in',
        'price': 'LMP in',
        'cost': 'Cost in'
    }
};
 // cause electric is default
unitTypes.demand = unitTypes.electricDemand;

// use param.type to get units
function getUnitsByType( type, all ){
// todo: if already augmented then pass in returned type?
return (all) ? unitTypes[type] : unitTypes[type][0];
}

function getLabelsByType( labelType, type ){
// todo: if already augmented then pass in returned type?
return labels[labelType][type];
}

// use param.type to get units,
// check again value to augment units
// for better display
function factory( baseValue, type, forcePower ){
var negative = 1,
    power,
    divisor,
    unitType;

if ( angular.isString(baseValue) ){
    baseValue = parseFloat(baseValue);
}

negative = Math.sign( baseValue );
if (negative === -1) {
    // make it a positive for now
    baseValue = Math.abs( baseValue );
}

if (forcePower !== undefined) {
    power = forcePower; 
} else {
    power = Math.floor( Math.log10(baseValue) );
}

if (type && unitTypes[type]) {
    if (power >= 12 && unitTypes[type][4]) {
        // peta
        unitType = unitTypes[type][4];
        divisor = Math.pow(10,12);
    } else if (power >= 9 && unitTypes[type][3]) {
        // tera
        unitType = unitTypes[type][3];
        divisor = Math.pow(10,9);
    } else if (power >= 6 && unitTypes[type][2]) {
        // giga
        unitType = unitTypes[type][2];
        divisor = Math.pow(10,6);
    } else if (power >= 3 && unitTypes[type][1]) {
        // mega
        unitType = unitTypes[type][1];
        divisor = Math.pow(10,3);
    } else {
        // kilo
        unitType = unitTypes[type][0] || false;
        divisor = 1;
    } 
}

var t = {
    units: unitType,
    divisor: divisor,
    negative: negative,
    power: power,
    eval: function( value ){
        var v = value / divisor;

        if ( v === 0 && type !== 'cost' ) { // 0.00 === 0
            return v.toFixed( 0 );
        }else{
            return v.toFixed( 2 );
        }
    }
};

return t;
}

function translateValue( value, type, forcePower ){
var t = factory( value, type, forcePower );

t.display = t.eval( value );

return t;
}

service.factory = factory;
service.labels = labels;
service.getUnitsByType = getUnitsByType;
service.translateValue = translateValue;
service.getLabelsByType = getLabelsByType;

return service;