// FlowFlex - Main JavaScript
class FlowFlexApp {
    constructor() {
        this.currentFeed = 'trending';
        this.posts = [];
        this.seenPosts = new Set();
        this.userPreferences = this.getUserPreferences();
        this.isLoading = false;
        this.page = 1;
        
        this.init();
    }

    init() {
        this.bindEvents();
        this.loadInitialFeed();
        this.setupIntersectionObserver();
        this.checkAuthStatus();
    }
    bindEvents() {
        // Feed filter buttons
        document.querySelectorAll('.feed-filter-btn').forEach(btn => {
            btn.addEventListener('click', (e) => {
                this.switchFeed(e.target.closest('.feed-filter-btn').dataset.filter);
        });

        // Like button functionality
        document.addEventListener('click', (e) => {
            if (e.target.closest('.like-btn')) {
                this.handleLike(e.target.closest('.like-btn'));
        });

        // Save post functionality
        document.addEventListener('click', (e) => {
            if (e.target.closest('.save-btn')) {
                this.handleSave(e.target.closest('.save-btn'));
        }

        // Post interaction tracking
        document.addEventListener('click', (e) => {
            const postCard = e.target.closest('.post-card');
            if (postCard) {
                this.trackPostInteraction(postCard.dataset.postId);
        }

        // Auth modal triggers
        document.addEventListener('click', (e) => {
            if (e.target.closest('[data-auth-trigger]')) {
                this.showAuthModal();
            }
        });
    }
switchFeed(feedType) {
        // Update active button
        document.querySelectorAll('.feed-filter-btn').forEach(btn => {
            btn.classList.remove('active', 'bg-primary-500', 'text-white');
            btn.classList.add('bg-gray-200', 'text-gray-700');
        });

        const activeBtn = document.querySelector(`[data-filter="${feedType}"]`);
        activeBtn.classList.remove('bg-gray-200', 'text-gray-700');
        activeBtn.classList.add('active', 'bg-primary-500', 'text-white');

        this.currentFeed = feedType;
        this.page = 1;
        this.posts = [];
        this.loadFeed();
    }

    async loadInitialFeed() {
        await this.loadFeed();
    }

    async loadFeed() {
        if (this.isLoading) return;

        this.isLoading = true;
        this.showLoading();

        try {
            // Simulate API call with timeout
            await new Promise(resolve => setTimeout(resolve, 1000));
            
            const newPosts = await this.fetchPosts(this.currentFeed, this.page);
            const filteredPosts = this.filterDuplicatePosts(newPosts);
            
            if (filteredPosts.length > 0) {
                this.posts = [...this.posts, ...filteredPosts];
                this.renderPosts(filteredPosts);
                this.page++;
            } else {
                this.showEmptyState();
            }
        } catch (error) {
            console.error('Error loading feed:', error);
            this.showError('Failed to load posts. Please try again.');
        } finally {
            this.isLoading = false;
            this.hideLoading();
        }
    }

    async fetchPosts(feedType, page = 1) {
        // Using Unsplash API for demo posts (real implementation would use your backend)
        const accessKey = 'YOUR_UNSPLASH_ACCESS_KEY'; // Replace with actual key
        const endpoints = {
            trending: `https://api.unsplash.com/photos?page=${page}&per_page=9&order_by=popular`,
            following: `https://api.unsplash.com/photos?page=${page}&per_page=9&order_by=latest`,
            discover: `https://api.unsplash.com/photos/random?count=9`,
            personalized: `https://api.unsplash.com/photos?page=${page}&per_page=9`
        };

        // For demo purposes, we'll use mock data
        return this.generateMockPosts(9);
    }

    generateMockPosts(count) {
        const categories = ['nature', 'technology', 'travel', 'food', 'architecture', 'people'];
        const users = [
            { name: 'Alex Johnson', username: 'alexj', followers: 1243 },
            { name: 'Sarah Miller', username: 'sarahm', followers: 856 },
            { name: 'Mike Chen', username: 'mikec', followers: 2107 },
            { name: 'Emma Davis', username: 'emmad', followers: 932 },
            { name: 'James Wilson', username: 'jamesw', followers: 1541 }
        ];

        return Array.from({ length: count }, (_, i) => {
            const user = users[Math.floor(Math.random() * users.length)];
            const category = categories[Math.floor(Math.random() * categories.length)];
            const postId = `post_${Date.now()}_${i}`;
            
            return {
                id: postId,
                user: user,
                image: `http://static.photos/${category}/640x360/${i + 1}`,
                caption: this.generateMockCaption(category),
                likes: Math.floor(Math.random() * 1000),
                comments: Math.floor(Math.random() * 50),
                shares: Math.floor(Math.random() * 20),
                timestamp: new Date(Date.now() - Math.random() * 7 * 24 * 60 * 60 * 1000), // Within last 7 days
                category: category,
                engagement: Math.random() * 100
            };
        });
    }

    generateMockCaption(category) {
        const captions = {
            nature: ['Beautiful sunset at the beach! 🌅', 'Morning hike in the mountains 🏔️', 'Peaceful forest walk 🌲'],
            technology: ['Working on some exciting new projects! 💻', 'Tech conference was amazing! 🚀', 'Latest gadget unboxing 📱'],
            travel: ['Exploring new places! ✈️', 'Cultural experience of a lifetime 🌍', 'Travel dreams coming true 🗺️'],
            food: ['Delicious homemade meal! 🍽️', 'Food photography session 📸', 'Trying out new recipes 👨‍🍳'],
            architecture: ['Modern architecture never fails to impress! 🏛️', 'Historical building tour 🏰', 'Architectural marvels 🏗️'],
            people: ['Great time with friends! 👥', 'Community event was fantastic! 🎉', 'Networking and making connections 🤝']
        };

        const categoryCaptions = captions[category] || ['Great day! 😊'];
        return categoryCaptions[Math.floor(Math.random() * categoryCaptions.length)];
    }

    filterDuplicatePosts(newPosts) {
        return newPosts.filter(post => !this.seenPosts.has(post.id));
    }

    renderPosts(posts) {
        const feedContainer = document.getElementById('feed-container');
        const emptyState = document.getElementById('empty-state');
        
        if (posts.length === 0 && this.posts.length === 0) {
            this.showEmptyState();
            return;
        }

        emptyState.classList.add('hidden');
        
        posts.forEach(post => {
            this.seenPosts.add(post.id);
            const postElement = this.createPostElement(post);
            feedContainer.appendChild(postElement);
        });
    }

    createPostElement(post) {
        const postDiv = document.createElement('div');
        postDiv.className = 'post-card bg-white rounded-xl shadow-sm overflow-hidden fade-in';
        postDiv.dataset.postId = post.id;
        
        const timeAgo = this.getTimeAgo(post.timestamp);
        
        postDiv.innerHTML = `
            <div class="relative">
                <img src="${post.image}" alt="Post image" class="w-full h-48 object-cover">
                <button class="save-btn absolute top-3 right-3 p-2 bg-white/80 backdrop-blur-sm rounded-full hover:bg-white transition-colors duration-200">
                    <i data-feather="bookmark" class="w-4 h-4 text-gray-600"></i>
                </button>
            </div>
            <div class="p-4">
                <div class="flex items-center justify-between mb-3">
                    <div class="flex items-center space-x-3">
                        <img src="http://static.photos/people/40x40/${Math.floor(Math.random() * 100)}" alt="${post.user.name}" class="w-8 h-8 rounded-full">
                        <div>
                            <h4 class="font-semibold text-gray-900 text-sm">${post.user.name}</h4>
                            <p class="text-gray-500 text-xs">@${post.user.username}</p>
                        </div>
                    </div>
                    <span class="text-xs text-gray-400">${timeAgo}</span>
                </div>
                
                <p class="text-gray-700 mb-4 text-sm">${post.caption}</p>
                
                <div class="flex items-center justify-between text-gray-500">
                    <div class="flex items-center space-x-4">
                        <button class="like-btn flex items-center space-x-1 text-sm hover:text-red-500 transition-colors duration-200">
                        <i data-feather="heart" class="w-4 h-4"></i>
                        <span>${post.likes}</span>
                    </button>
                    <button class="flex items-center space-x-1 text-sm hover:text-blue-500 transition-colors duration-200">
                        <i data-feather="message-circle" class="w-4 h-4"></i>
                        <span>${post.comments}</span>
                    </button>
                    <button class="flex items-center space-x-1 text-sm hover:text-green-500 transition-colors duration-200">
                        <i data-feather="share-2" class="w-4 h-4"></i>
                        <span>${post.shares}</span>
                    </button>
                </div>
            </div>
        `;
        
        return postDiv;
    }

    handleLike(likeBtn) {
        const heartIcon = likeBtn.querySelector('i');
        const likesCount = likeBtn.querySelector('span');
        
        likeBtn.classList.add('like-animation');
        setTimeout(() => likeBtn.classList.remove('like-animation'), 600);
        
        const isLiked = heartIcon.style.fill === 'currentColor';
        const currentLikes = parseInt(likesCount.textContent);
        
        if (isLiked) {
            heartIcon.style.fill = 'none';
            likesCount.textContent = currentLikes - 1;
            likesCount.style.color = '';
        } else {
            heartIcon.style.fill = 'currentColor';
            likesCount.textContent = currentLikes + 1;
            likesCount.style.color = '#ef4444';
        }
    }

    handleSave(saveBtn) {
        const bookmarkIcon = saveBtn.querySelector('i');
        const isSaved = bookmarkIcon.style.fill === 'currentColor';
        
        if (isSaved) {
            bookmarkIcon.style.fill = 'none';
        } else {
            bookmarkIcon.style.fill = 'currentColor';
        }
    }

    trackPostInteraction(postId) {
        // Track user engagement for personalization
        const post = this.posts.find(p => p.id === postId);
        if (post) {
            this.updateUserPreferences(post);
        }
    }

    updateUserPreferences(post) {
        if (!this.userPreferences.engagedCategories) {
            this.userPreferences.engagedCategories = {};
        }
        
        this.userPreferences.engagedCategories[post.category] = 
            (this.userPreferences.engagedCategories[post.category] || 0) + 1;
        
        localStorage.setItem('flowflex_preferences', JSON.stringify(this.userPreferences));
    }

    getUserPreferences() {
        const stored = localStorage.getItem('flowflex_preferences');
        return stored ? JSON.parse(stored) : {
            engagedCategories: {},
            preferredFeed: 'trending',
            blockedUsers: []
        };
    }

    getTimeAgo(timestamp) {
        const now = new Date();
        const diff = now - new Date(timestamp);
        const minutes = Math.floor(diff / 60000);
        const hours = Math.floor(diff / 3600000);
        const days = Math.floor(diff / 86400000);
        
        if (days > 0) return `${days}d ago`;
        if (hours > 0) return `${hours}h ago`;
        return `${minutes}m ago`;
    }

    showLoading() {
        document.getElementById('loading').classList.remove('hidden');
    }

    hideLoading() {
        document.getElementById('loading').classList.add('hidden');
    }

    showEmptyState() {
        document.getElementById('feed-container').innerHTML = '';
        document.getElementById('empty-state').classList.remove('hidden');
    }
    showError(message) {
        // Simple error notification
        const errorDiv = document.createElement('div');
        errorDiv.className = 'fixed top-4 right-4 bg-red-500 text-white px-6 py-3 rounded-lg shadow-lg z-50';
        errorDiv.textContent = message;
        document.body.appendChild(errorDiv);
        
        setTimeout(() => {
            errorDiv.remove();
        }, 3000);
    }

    setupIntersectionObserver() {
        const observer = new IntersectionObserver((entries) => {
            entries.forEach(entry => {
                if (entry.isIntersecting && !this.isLoading) {
            this.loadFeed();
        }
    }, {
        rootMargin: '100px'
    });

    observer.observe(document.getElementById('loading'));
    }

    checkAuthStatus() {
        const isLoggedIn = localStorage.getItem('flowflex_user');
        if (!isLoggedIn) {
            // Show login prompt or redirect
            console.log('User not logged in');
        }
    }

    showAuthModal() {
        const authModal = document.querySelector('auth-modal');
        if (authModal) {
            authModal.show();
        }
    }

    // Profile page specific methods
    loadProfilePosts() {
        // Load user's posts for profile page
        const posts = this.generateMockPosts(12);
        this.renderProfilePosts(posts);
    }

    renderProfilePosts(posts) {
        const profileContent = document.getElementById('profile-content');
        if (!profileContent) return;

        posts.forEach(post => {
            const postElement = this.createPostElement(post);
            profileContent.appendChild(postElement);
        });
    }
}
// Initialize the app when DOM is loaded
document.addEventListener('DOMContentLoaded', () => {
    new FlowFlexApp();
});

// Utility function for API calls
async function apiCall(url, options = {}) {
    try {
        const response = await fetch(url, {
            headers: {
                'Authorization': 'Client-ID YOUR_UNSPLASH_ACCESS_KEY',
                'Accept-Version': 'v1'
            },
            ...options
        });
        
        if (!response.ok) {
            throw new Error(`API call failed: ${response.status}`);
        }
        
        return await response.json();
    } catch (error) {
        console.error('API call error:', error);
        throw error;
    }
}