/* time-predictor.js */

function predict_time()
{
	//alert("predict time");
	var given_distance = document.getElementById("given_distance").value;
	if( given_distance == null || given_distance == "" ) alert("Please enter the distance you have a time for.");
	var given_units = document.getElementById("given_units").value;
	if( given_units == "km" ) given_distance = given_distance * 1000;
	if( given_units == "miles" ) given_distance = given_distance * 1609.344;
	
	var given_time = document.getElementById("given_hours").value * 3600
		+ document.getElementById("given_minutes").value * 60
		+ document.getElementById("given_seconds").value * 1;
		
	if( given_time < 1 ) alert("Please enter the time you completed the distance in.");

	var target_distance = document.getElementById("target_distance").value;
	if( target_distance == null || target_distance == "" ) alert("Please enter the distance you wish to predict your time for.");
	var target_units = document.getElementById("target_units").value;
	if( target_units == "km" ) target_distance = target_distance * 1000;
	if( target_units == "miles" ) target_distance = target_distance * 1609.344;
	
	if( ( given_distance != null && given_distance != "" ) && (given_time > 0) && (target_distance != null && target_distance != "") )
	{
		var predicted_time = given_time * Math.pow(target_distance/given_distance, 1.06);
		var predicted_hours = Math.floor( predicted_time / 3600 );
		predicted_time = predicted_time - predicted_hours * 3600;
		var predicted_minutes = Math.floor( predicted_time / 60 );
		predicted_time = predicted_time - predicted_minutes * 60;
		var predicted_seconds = Math.round( predicted_time );

		//alert("predicted_time = " + predicted_hours + ":" + predicted_minutes + ":" + predicted_seconds );
		document.getElementById("predict_hours").value = predicted_hours;
		document.getElementById("predict_minutes").value = predicted_minutes;
		document.getElementById("predict_seconds").value = predicted_seconds;
	}
}

function calculate_calories()
{
	//alert
	var distance = document.getElementById("calorie_distance").value;
	var distance_units = document.getElementById("calorie_distance_units").value;
	var distance_factor = 1;
	if( distance_units == "miles" ) distance_factor = 1.609344;
	var weight = document.getElementById("calorie_weight").value;
	var weight_units = document.getElementById("calorie_weight_units").value;
	var weight_factor = 1;
	if( weight_units == "pounds" ) weight_factor = 0.4535;
	var calories = Math.round( weight * weight_factor * distance * distance_factor * 1.036 );
	document.getElementById("calories_burned").value = calories;
}