const powerset = arr =>
  arr.reduce((a, v) => a.concat(a.map(r => r.concat(v))), [[]]);
  
powerset([1, 2]); // [[], [1], [2], [1, 2]]

if (process.env.NODE_ENV === "production") {
	app.use(express.static("client/build"));

	app.get("*", (req, res) => {
	res.sendFile(path.resolve(__dirname, "client", "build", "index.html"));
	});
}

const flat = arr => [].concat.apply([], arr.map(a => Array.isArray(a) ? flat(a) : a));
// Or
const flat = arr => arr.reduce((a, b) => Array.isArray(b) ? [...a, ...flat(b)] : [...a, b], []);

// Or
// See the browser compatibility at https://caniuse.com/#feat=array-flat
const flat = arr => arr.flat();

// Example
flat(['cat', ['lion', 'tiger']]);   // ['cat', 'lion', 'tiger']

const arithmeticProgression  = (n, lim) =>
  Array.from({ length: Math.ceil(lim / n) }, (_, i) => (i + 1) * n );
  
arithmeticProgression(5, 25); // [5, 10, 15, 20, 25]

const rectSize = 15; // Size of the color box
        const spacing = 5; // Space between legend items
        let legend = canvas.append('g').attr('class','chart-legend')
        .attr('transform', `translate(${0}, ${height + 3})`);

        // Sample data for the legend
        const legendData = [
            { label: 'low', color: '#1f77b4' },
            { label: 'medium', color: '#ff7f0e' },
            { label: 'high', color: '#2ca02c' },
            { label: 'very high', color: '#2ca02c' }
        ];


        legend.selectAll('g')
            .data(legendData)
            .join('g')
            .attr('class', 'legend-item')
            
            .each(function (d, i) {
                const legendItem = d3.select(this);
                console.log(d.label)
                console.log(d.label?.length)
                let labelWidth = (d.label.length * 5) + 7 + 15
                

                var bbox = legendItem.node().getBBox()
                var width = bbox.width
                console.log(width)
                
                // Add rectangle for color
                legendItem.append('rect')
                    .attr('width', rectSize)
                    .attr('height', rectSize)
                    .attr('fill', d.color);
                    
                    // Add label
                    legendItem.append('text')
                    .attr('x', rectSize + spacing) // Position text to the right of the rectangle
                    .attr('y', rectSize / 2) // Align text vertically with the rectangle
                    .attr('dy', '.35em') // Adjust vertical alignment
                    .attr('text-anchor', 'start') // Align text to the start
                    .text(d.label)
                    .attr('fill', 'black'); // Optional: Text color
                // legendItem.attr('transform', `translate(${i * (rectSize + spacing + labelWidth)}, 0)`) // Position each item horizontally
            });

            const legendItems_spacing = 12
            var legendLength = 0
            legend.selectAll('.legend-item').each(function(d,i) {
              d3.select(this).attr('transform',function() {
                var bbox = d3.select(this).node().getBBox()
                var width = bbox.width
                // if (width == 0) width = (d.text.length * 5) +15  // not in dom yet
                let startingPosition = 0 
                if (i > 0) {
                    startingPosition = legendLength
                }
                legendLength += width + legendItems_spacing
                
                // return `translate(${xx - (width + 30)},0$)`
                return `translate(${startingPosition},0)`
            })
            })

//Retries maxRetries number of times, meaning that if you have 0, then it'll run the function once.
async function retryPromise(promiseFn, maxRetries = 3, delayOffset = 0, delayRandomRange = 0) {
	return new Promise((resolve, reject) => {
		promiseFn()
			.then(resolve, (error) => { //On error
				if (maxRetries <= 0) {
					return reject(error);
				} else {
					if(delayRandomRange * Math.random() + delayOffset < 1.0){
						return retryPromise(promiseFn, maxRetries - 1, delayOffset, delayRandomRange).then(resolve, reject);
					}else{
						return new Promise((resolveTwo, rejectTwo) => {
							setTimeout(() => {
								return retryPromise(promiseFn, maxRetries - 1, delayOffset, delayRandomRange).then(resolveTwo, rejectTwo);
							}, delayRandomRange * Math.random() + delayOffset);
						}).then(resolve, reject);
					}
				}
			});
	});
}

//Tests for that function.

//Returns a function that will fail numTimes times, then will return aValue
function functionThatReturnsAFunctionThatFailsACoupleTimes(numTimes, aValue){
	return async function(){
		if(numTimes == 0){
			return aValue;
		}
		numTimes--;
		throw false;
	};
}

const SMALL_NUMBER = 10;

function testTest(failNumberOfTimes){

	let functionThatFailsACoupleTimes = functionThatReturnsAFunctionThatFailsACoupleTimes(failNumberOfTimes, true);

	//Test my test
	for(let i = 0; i < (failNumberOfTimes * 2); ++i){
		function evalTest(val){
			let testTestFailedReason = "";
			if(val === undefined){
				testTestFailedReason = "Test test returned undefined for some reason.";
			}
			if((i + 1) > failNumberOfTimes){
				if(val === true){
					//We're good
				}else{
					testTestFailedReason = "Test test didn't return true when it should have.";
				}
			}else{
				if(val === false){
					//We're good
				}else{
					testTestFailedReason = "Test test didn't return false when it should have.";
				}
			}
			testTestFailedReason = testTestFailedReason || "Test test passed test case";
			console.log(testTestFailedReason, "at index", i, "where the function returned", val);
		}
		functionThatFailsACoupleTimes().then(evalTest, evalTest)
	};
}

testTest(SMALL_NUMBER);

let testCaseCounter = 1;

const throwsNoError = [
	(val)=>{
		if(val == true){
			console.log("Passed test case " + (testCaseCounter++));
		}else{
			console.error("Unexpected return value", val);
		}
	},
	()=>{
		console.error("It wasn't supposed to fail!")
	}
]

const throwsError = [
	(val)=>{
		console.error("It wasn't supposed to succeed!", val);
	},
	(val)=>{
		if(val == false){
			console.log("Passed test case " + (testCaseCounter++));
		}else{
			console.error("Unexpected return value", val);
		}
	}
];

//Runs SMALL_NUMBER times, because SMALL_NUMBER - 1 is the number of retries after the first one
let functionThatFailsACoupleTimes = functionThatReturnsAFunctionThatFailsACoupleTimes(SMALL_NUMBER - 1, true);

retryPromise(functionThatFailsACoupleTimes, SMALL_NUMBER - 1).then(...throwsNoError)

functionThatFailsACoupleTimes = functionThatReturnsAFunctionThatFailsACoupleTimes(SMALL_NUMBER - 1, true);

//Runs SMALL_NUMBER - 1 times, because SMALL_NUMBER - 2 is the number of retries after the first one
retryPromise(functionThatFailsACoupleTimes, SMALL_NUMBER - 2).then(...throwsError)

//Testing the delay. You'll have to wait a bit too.

functionThatFailsACoupleTimes = functionThatReturnsAFunctionThatFailsACoupleTimes(SMALL_NUMBER - 1, true);

//Runs SMALL_NUMBER times, because SMALL_NUMBER - 1 is the number of retries after the first one
retryPromise(functionThatFailsACoupleTimes, SMALL_NUMBER - 1, 500, 500).then(...throwsNoError)

functionThatFailsACoupleTimes = functionThatReturnsAFunctionThatFailsACoupleTimes(SMALL_NUMBER - 1, true);

//Runs SMALL_NUMBER - 1 times, because SMALL_NUMBER - 2 is the number of retries after the first one
retryPromise(functionThatFailsACoupleTimes, SMALL_NUMBER - 2, 500, 500).then(...throwsError)