// Data models
class Dish {
    constructor(name) {
        this.id = this.generateUUID();
        this.name = name;
        this.createdAt = new Date().toISOString();
    }
    
    generateUUID() {
        return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
            const r = Math.random() * 16 | 0;
            const v = c === 'x' ? r : (r & 0x3 | 0x8);
            return v.toString(16);
        });
    }
}

class History {
    constructor(dishId) {
        this.id = this.generateUUID();
        this.dishId = dishId;
        this.selectedAt = new Date().toISOString();
    }
    
    generateUUID() {
        return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
            const r = Math.random() * 16 | 0;
            const v = c === 'x' ? r : (r & 0x3 | 0x8);
            return v.toString(16);
        });
    }
}

// App state
let dishes = [];
let history = [];

// DOM Elements
const welcomeScreen = document.getElementById('welcome-screen');
const dishesScreen = document.getElementById('dishes-screen');
const homeScreen = document.getElementById('home-screen');
const resultScreen = document.getElementById('result-screen');

const addFirstDishBtn = document.getElementById('add-first-dish-btn');
const dishInput = document.getElementById('dish-input');
const addDishBtn = document.getElementById('add-dish-btn');
const dishesList = document.getElementById('dishes-list');
const randomBtn = document.getElementById('random-btn');
const selectedDish = document.getElementById('selected-dish');
const cookBtn = document.getElementById('cook-btn');
const anotherBtn = document.getElementById('another-btn');
const manageDishesBtn = document.getElementById('manage-dishes-btn');
const backToHomeBtn = document.getElementById('back-to-home-btn');
const backToHomeResultBtn = document.getElementById('back-to-home-result-btn');

// Initialize app
function init() {
    loadData();
    setupEventListeners();
    
    if (dishes.length === 0) {
        showScreen('welcome');
    } else {
        showScreen('home');
    }
}

// Event listeners
function setupEventListeners() {
    addFirstDishBtn.addEventListener('click', () => {
        showScreen('dishes');
        dishInput.focus();
    });
    
    addDishBtn.addEventListener('click', addDish);
    dishInput.addEventListener('keypress', (e) => {
        if (e.key === 'Enter') addDish();
    });
    
    randomBtn.addEventListener('click', getRandomDish);
    cookBtn.addEventListener('click', () => showScreen('home'));
    anotherBtn.addEventListener('click', getRandomDish);
    
    manageDishesBtn.addEventListener('click', () => {
        showScreen('dishes');
        renderDishesList();
    });
    
    backToHomeBtn.addEventListener('click', () => {
        if (dishes.length === 0) {
            showScreen('welcome');
        } else {
            showScreen('home');
        }
    });
    
    backToHomeResultBtn.addEventListener('click', () => showScreen('home'));
}

// Screen management
function showScreen(screen) {
    welcomeScreen.classList.add('hidden');
    dishesScreen.classList.add('hidden');
    homeScreen.classList.add('hidden');
    resultScreen.classList.add('hidden');
    
    switch(screen) {
        case 'welcome':
            welcomeScreen.classList.remove('hidden');
            break;
        case 'dishes':
            dishesScreen.classList.remove('hidden');
            renderDishesList();
            break;
        case 'home':
            homeScreen.classList.remove('hidden');
            break;
        case 'result':
            resultScreen.classList.remove('hidden');
            break;
    }
}

// Dish management
function addDish() {
    const name = dishInput.value.trim();
    if (!name) return;
    
    const dish = new Dish(name);
    dishes.push(dish);
    saveData();
    
    dishInput.value = '';
    renderDishesList();
    
    if (dishes.length === 1) {
        showScreen('home');
    }
}

function editDish(id) {
    const dish = dishes.find(d => d.id === id);
    if (!dish) return;
    
    const newName = prompt('Введите новое название:', dish.name);
    if (newName && newName.trim()) {
        dish.name = newName.trim();
        saveData();
        renderDishesList();
    }
}

function deleteDish(id) {
    if (!confirm('Вы уверены, что хотите удалить это блюдо?')) return;
    
    dishes = dishes.filter(d => d.id !== id);
    history = history.filter(h => h.dishId !== id);
    saveData();
    renderDishesList();
    
    if (dishes.length === 0) {
        showScreen('welcome');
    }
}

// Random selection with 3-day repeat protection
function getRandomDish() {
    if (dishes.length === 0) {
        showScreen('welcome');
        return;
    }
    
    const threeDaysAgo = new Date();
    threeDaysAgo.setDate(threeDaysAgo.getDate() - 3);
    
    const recentDishIds = history
        .filter(h => new Date(h.selectedAt) > threeDaysAgo)
        .map(h => h.dishId);
    
    let availableDishes = dishes.filter(d => !recentDishIds.includes(d.id));
    
    if (availableDishes.length === 0) {
        availableDishes = dishes;
    }
    
    const randomIndex = Math.floor(Math.random() * availableDishes.length);
    const selected = availableDishes[randomIndex];
    
    const historyEntry = new History(selected.id);
    history.push(historyEntry);
    saveData();
    
    selectedDish.textContent = selected.name;
    showScreen('result');
}

// Render functions
function renderDishesList() {
    dishesList.innerHTML = '';
    
    if (dishes.length === 0) {
        dishesList.innerHTML = '<p style="text-align: center; color: #666;">Пока нет блюд. Добавьте первое!</p>';
        return;
    }
    
    dishes.forEach(dish => {
        const dishElement = document.createElement('div');
        dishElement.className = 'dish-item';
        dishElement.innerHTML = `
            <span class="dish-name">${dish.name}</span>
            <div class="dish-actions">
                <button onclick="editDish('${dish.id}')">Изменить</button>
                <button class="delete-btn" onclick="deleteDish('${dish.id}')">Удалить</button>
            </div>
        `;
        dishesList.appendChild(dishElement);
    });
}

// Local storage
function saveData() {
    localStorage.setItem('whatToCookDishes', JSON.stringify(dishes));
    localStorage.setItem('whatToCookHistory', JSON.stringify(history));
}

function loadData() {
    const savedDishes = localStorage.getItem('whatToCookDishes');
    const savedHistory = localStorage.getItem('whatToCookHistory');
    
    if (savedDishes) dishes = JSON.parse(savedDishes);
    if (savedHistory) history = JSON.parse(savedHistory);
}

// Initialize app when DOM is loaded
document.addEventListener('DOMContentLoaded', init);