const foodSearch = document.querySelector("#food-search");
const searchEntries = document.querySelector("#search-entries");
const foodMenu = document.querySelector("#food-menu");
const menuTable = document.querySelector("#menu-table");

const summaryEnergy = document.querySelector("#summary-energy");
const summaryFat = document.querySelector("#summary-fat");
const summaryCarbs = document.querySelector("#summary-carbs");
const summarySugar = document.querySelector("#summary-sugar");
const summaryProteins = document.querySelector("#summary-proteins");
const summaryAlc = document.querySelector("#summary-alc");

const alcDensity = 0.789;

updateSummary();
initFoodList();
foodSearch.addEventListener("input", onFoodSearched);
if (foodSearch.value != "") onFoodSearched();

function initFoodList() {
	const dataList = document.querySelector("#food-list");

	for (let food of foods) {
		const option = document.createElement("option");
		option.setAttribute("value", food.name);
		dataList.appendChild(option);
	}
}

function onFoodSearched() {
	const food = foodSearch.value;
	const foodLC = food.toLowerCase();

	if (food == "") {
		createSearchEntries([]);
		return;
	}

	const foodsCopy = structuredClone(foods);

	foodsCopy.sort((a, b) => {
		const aNameLC = a.name.toLowerCase();
		const bNameLC = b.name.toLowerCase();

		const ainc = aNameLC.includes(foodLC);
		const binc = bNameLC.includes(foodLC);
		if (ainc && binc) {
			return 0;
		} else if (ainc) {
			return -1;
		} else if (binc) {
			return 1;
		}

		const distA = levenshtein(foodLC, aNameLC);
		const distB = levenshtein(foodLC, bNameLC);
		return distA - distB;
	})

	const maxDist = 10;
	let maxAmount = 10;
	let amount = 0;
	for (let f of foodsCopy) {
		const fnameLC = f.name.toLowerCase();
		if (fnameLC.includes(foodLC)) {
			amount++;
			maxAmount++;
			continue;
		}
		const dist = levenshtein(foodLC, fnameLC);
		if (dist >= maxDist) break;
		amount++;
	}

	createSearchEntries(foodsCopy.slice(0, Math.min(amount, maxAmount, 30)));
}

async function createSearchEntries(foods) {
	const nodes = [];
	for (let food of foods) {
		const node = await JST.load("search-entry");
		node.querySelector(".search-entry-name").textContent = food.name;
		node.querySelector(".search-entry").addEventListener("click", () => addMenuItem(food));
		nodes.push(node);
	}
	searchEntries.replaceChildren(...nodes);
}

async function addMenuItem(food) {
	const alreadyAddedMenuItem = document.querySelector(`#food-menu .menu-item[data-food-name="${food.name}"]`);
	if (alreadyAddedMenuItem !== null) {
		alreadyAddedMenuItem.style.animation = "highlight 0.25s linear";
		setTimeout(() => alreadyAddedMenuItem.style.animation = "", 250);
		return;
	}

	const node = await JST.load("menu-item");

	const nodeRoot = node.querySelector(".menu-item");
	const itemName = node.querySelector(".menu-item-name");
	const itemKcal = node.querySelector(".menu-item-kcal");
	const itemUnit = node.querySelector(".menu-item-unit");
	const itemAmount = node.querySelector(".menu-item-amount");
	const kcalAmount = node.querySelector(".menu-item-energy");
	const fatAmount = node.querySelector(".menu-item-fat");
	const carbsAmount = node.querySelector(".menu-item-carbs");
	const sugarAmount = node.querySelector(".menu-item-sugar");
	const proteinsAmount = node.querySelector(".menu-item-proteins");
	const alcAmount = node.querySelector(".menu-item-alc");
	const score = node.querySelector(".menu-item-score");

	const nutritions100 = calculateKcal(food, 100);

	nodeRoot.setAttribute("data-food-name", food.name);

	itemName.textContent = food.name;
	itemKcal.textContent = `${formatValue(nutritions100.kcal)} kcal/100${food.unit}`;
	itemUnit.textContent = food.unit;

	fatAmount.textContent = `${food.fat}g`;
	carbsAmount.textContent = `${food.carbs}g`;
	proteinsAmount.textContent = `${food.proteins}g`;

	score.textContent = nutritions100.score.toFixed(1);
	score.classList.add(getScoreColor(nutritions100.score, food.unit));

	node.querySelector(".delete-menu-item").addEventListener("click", () => {
		foodMenu.removeChild(nodeRoot);
		updateSummary();
	});

	const updateFoodValues = () => {
		if (!/^[0-9]+$/.test(itemAmount.value)) {
			return;
		}

		const amount = parseInt(itemAmount.value);
		updateFoodAmount(food, amount, kcalAmount, fatAmount, carbsAmount, sugarAmount, proteinsAmount, alcAmount);
	};

	const evaluateFoodValues = () => {
		if (/^[0-9]+$/.test(itemAmount.value)) {
			return;
		}

		const evaluator = new Worker("evaluator.js");
		evaluator.postMessage(itemAmount.value);
		evaluator.onmessage = e => {
			const amount = Math.max(parseInt(e.data), 0);
			itemAmount.value = amount;
			updateFoodAmount(food, amount, kcalAmount, fatAmount, carbsAmount, sugarAmount, proteinsAmount, alcAmount);
		};
	}

	itemAmount.value = food.avg_amount ?? 100;
	itemAmount.addEventListener("input", updateFoodValues);
	itemAmount.addEventListener("change", evaluateFoodValues);

	foodMenu.appendChild(node);
	updateFoodValues();
}

function updateFoodAmount(food, amount, kcalAmount, fatAmount, carbsAmount, sugarAmount, proteinsAmount, alcAmount) {
	const {fat, carbs, sugar, proteins, alc, kcal} = calculateKcal(food, amount);

	setAmount(kcalAmount, kcal, "kcal");
	setAmount(fatAmount, fat, "g");
	setAmount(carbsAmount, carbs, "g");
	setAmount(sugarAmount, sugar, "g");
	setAmount(proteinsAmount, proteins, "g");
	setAmount(alcAmount, alc, "g");

	updateSummary();
}

function setAmount(element, amount, unit) {
	element.textContent = `${formatValue(amount)}${unit}`;
	element.setAttribute("data-value", amount);
}

function formatValue(value) {
	if (value > 0 && value < 1) {
		return "<1"
	}

	return Math.round(value);
}

function calculateKcal(food, amount) {
	const fat = food.fat / 100 * amount;
	const carbs = food.carbs / 100 * amount;
	const sugar = food.sugar / 100 * amount;
	const proteins = food.proteins / 100 * amount;
	const alc = amount * food.alc / 100;
	const kcal = fat * 9 + carbs * 4 + proteins * 4 + alc * 7;
	const score = kcal / amount;
	return {fat, carbs, sugar, proteins, alc, kcal, score}
}

function updateSummary() {
	const menuItems = foodMenu.querySelectorAll(".menu-item");
	menuTable.style.display = menuItems.length > 0 ? "table" : "none";

	let energy = 0;
	let fat = 0;
	let carbs = 0;
	let sugar = 0;
	let proteins = 0;
	let alc = 0;

	for (let menuItem of menuItems) {
		energy += parseFloat(menuItem.querySelector(".menu-item-energy").getAttribute("data-value"));
		fat += parseFloat(menuItem.querySelector(".menu-item-fat").getAttribute("data-value"));
		carbs += parseFloat(menuItem.querySelector(".menu-item-carbs").getAttribute("data-value"));
		sugar += parseFloat(menuItem.querySelector(".menu-item-sugar").getAttribute("data-value"));
		proteins += parseFloat(menuItem.querySelector(".menu-item-proteins").getAttribute("data-value"));
		alc += parseFloat(menuItem.querySelector(".menu-item-alc").getAttribute("data-value"));
	}

	summaryEnergy.textContent = `${formatValue(energy)}kcal`;
	summaryFat.textContent = `${formatValue(fat)}g`;
	summaryCarbs.textContent = `${formatValue(carbs)}g`;
	summarySugar.textContent = `${formatValue(sugar)}g`;
	summaryProteins.textContent = `${formatValue(proteins)}g`;
	summaryAlc.textContent = `${formatValue(alc)}g`;
}

function getScoreColor(density, unit) {
	switch (unit) {
		case "g": {
			if (density >= 2.4) {
				return "red"
			} else if (density >= 1.6) {
				return "orange"
			} else {
				return "green";
			}
		}

		case "ml": {
			if (density >= 0.1) {
				return "red"
			} else {
				return "green";
			}
		}
	}
}