export function arrays_equal(arr1, arr2) {
	if(arr1.length !== arr2.length) return false;
	let are_equal = true;
	arr1.map((d, i) => {
		if(arr2[i] !== d) are_equal = false;
	});
	return are_equal;
}

function limitColor(r){
	if (r > 255) return 255;
	else if (r < 0) return 0;
	return r;
}

export function lightenDarkenColor(col, amt) {
	let usePound = false;
	if (col[0] == "#") {
		col = col.slice(1);
		usePound = true;
	}
	let num = parseInt(col,16);
	let r = limitColor((num >> 16) + amt);
	let b = limitColor(((num >> 8) & 0x00FF) + amt);
	let g = limitColor((num & 0x0000FF) + amt);
	return (usePound?"#":"") + (g | (b << 8) | (r << 16)).toString(16);
}

/**
 * Shuffles array in place. ES6 version
 * @param {Array} a items An array containing the items.
 */
export function shuffle(array) {
	// Awesomeness: https://bost.ocks.org/mike/shuffle/
	// https://stackoverflow.com/a/2450976/6495043
	// https://stackoverflow.com/questions/6274339/how-can-i-shuffle-an-array?noredirect=1&lq=1

	for (let i = array.length - 1; i > 0; i--) {
		let j = Math.floor(Math.random() * (i + 1));
		[array[i], array[j]] = [array[j], array[i]];
	}

	return array;
}

export function get_string_width(string, char_width) {
	return (string+"").length * char_width;
}

export function get_bar_height_and_y_attr(y_top, zero_line, total_height) {
	let height, y;
	if (y_top <= zero_line) {
		height = zero_line - y_top;
		y = y_top;

		// In case of invisible bars
		if(height === 0) {
			height = total_height * 0.01;
			y -= height;
		}
	} else {
		height = y_top - zero_line;
		y = zero_line;

		// In case of invisible bars
		if(height === 0) {
			height = total_height * 0.01;
		}
	}

	return [height, y];
}

export function divide_if_more_than_five(number) {
	return (number < 5) ? number : number / 2;
}

export function calc_whole_parts(value, divisor) {
	return Math.ceil(value / divisor);
}

export function make_even(number) {
	return (number % 2 !== 0) ? ++number : number;
}

export function calc_part_size(value) {
	// take care of fractions
	return Math.pow(10, ((value+"").length - 1));
}

export function calc_upper_bound(value) {

}

export function calc_intervals(start, interval_size, count) {
	let intervals = [];
	for(var i = 0; i <= count; i++){
		intervals.push(start);
		start += interval_size;
	}
	return intervals;
}

// export function