// Smooth scrolling for navigation links
document.querySelectorAll('a[href^="#"]').forEach(anchor => {
    anchor.addEventListener('click', function (e) {
        e.preventDefault();
        const target = document.querySelector(this.getAttribute('href'));
        if (target) {
            target.scrollIntoView({
                behavior: 'smooth',
                block: 'start'
            });
        }
    });
});

// Navbar scroll effect
window.addEventListener('scroll', function() {
    const navbar = document.querySelector('.navbar');
    if (window.scrollY > 50) {
        navbar.style.background = 'rgba(255, 255, 255, 0.98)';
        navbar.style.boxShadow = '0 5px 20px rgba(15, 23, 42, 0.1)';
    } else {
        navbar.style.background = 'rgba(255, 255, 255, 0.95)';
        navbar.style.boxShadow = 'none';
    }
});

// Mobile menu toggle
const hamburger = document.querySelector('.hamburger');
const navMenu = document.querySelector('.nav-menu');

hamburger?.addEventListener('click', function() {
    navMenu.classList.toggle('active');
    this.classList.toggle('active');
});

// Animate circular progress rings on scroll
const observerOptions = {
    threshold: 0.3,
    rootMargin: '0px'
};

const observer = new IntersectionObserver(function(entries) {
    entries.forEach(entry => {
        if (entry.isIntersecting) {
            const techIcons = entry.target.querySelectorAll('.tech-icon');
            techIcons.forEach((icon, index) => {
                const skill = icon.getAttribute('data-skill');
                const circle = icon.querySelector('.progress-ring-circle');
                const circumference = 2 * Math.PI * 40; // radius = 40
                const offset = circumference - (skill / 100) * circumference;

                setTimeout(() => {
                    circle.style.strokeDashoffset = offset;
                }, index * 100);
            });
        }
    });
}, observerOptions);

const skillsSection = document.querySelector('.skills');
if (skillsSection) {
    observer.observe(skillsSection);
}

// Interactive hover effects for tech icons
document.addEventListener('DOMContentLoaded', function() {
    const techIcons = document.querySelectorAll('.tech-icon');

    techIcons.forEach(icon => {
        const skill = icon.getAttribute('data-skill');
        const circle = icon.querySelector('.progress-ring-circle');
        const percentage = icon.querySelector('.percentage');
        const circumference = 2 * Math.PI * 40; // radius = 40

        // Set initial state
        circle.style.strokeDasharray = circumference;
        circle.style.strokeDashoffset = circumference;

        icon.addEventListener('mouseenter', function() {
            const offset = circumference - (skill / 100) * circumference;
            circle.style.strokeDashoffset = offset;
            percentage.textContent = skill + '%';
        });

        icon.addEventListener('mouseleave', function() {
            circle.style.strokeDashoffset = circumference;
        });
    });
});

// Animate elements on scroll
const animateOnScroll = () => {
    const elements = document.querySelectorAll('.timeline-item, .project-card, .stat-card');
    
    elements.forEach(element => {
        const elementTop = element.getBoundingClientRect().top;
        const elementBottom = element.getBoundingClientRect().bottom;
        
        if (elementTop < window.innerHeight && elementBottom > 0) {
            element.style.opacity = '1';
            element.style.transform = 'translateY(0)';
        }
    });
};

window.addEventListener('scroll', animateOnScroll);
window.addEventListener('load', animateOnScroll);

// Character-by-character streaming effect for specific lines
const streamingElement = document.getElementById('streaming-text');
if (streamingElement) {
    const textLines = [
        'Hi, nice to meet you!',
        "I'm Tran Bao Ngoc",
        'A passionate AI developer',
        'I love Python 🐍',
        'I love researching AI 🤖',
        'I love playing games 🎮'
    ];

    let currentLineIndex = 0;
    let currentCharIndex = 0;
    let isDeleting = false;
    let typingSpeed = 45;
    let deleteSpeed = 25;

    function typewriterEffect() {
        const currentLine = textLines[currentLineIndex];

        if (!isDeleting) {
            // Typing characters
            if (currentCharIndex <= currentLine.length) {
                streamingElement.innerHTML = currentLine.substring(0, currentCharIndex);
                currentCharIndex++;

                if (currentCharIndex > currentLine.length) {
                    // Finished typing line, pause then start deleting
                    setTimeout(() => {
                        isDeleting = true;
                        typewriterEffect();
                    }, 1800); // Pause for 1.8 seconds
                } else {
                    setTimeout(typewriterEffect, typingSpeed + Math.random() * 20);
                }
            }
        } else {
            // Deleting characters
            if (currentCharIndex > 0) {
                currentCharIndex--;
                streamingElement.innerHTML = currentLine.substring(0, currentCharIndex);
                setTimeout(typewriterEffect, deleteSpeed);
            } else {
                // Finished deleting, move to next line
                isDeleting = false;
                currentLineIndex = (currentLineIndex + 1) % textLines.length;

                // Pause before starting next line
                setTimeout(typewriterEffect, 500);
            }
        }
    }

    // Start the typewriter effect after a delay
    setTimeout(typewriterEffect, 2000);
}

// Parallax effect for shapes
window.addEventListener('scroll', () => {
    const shapes = document.querySelectorAll('.shape');
    const scrollY = window.pageYOffset;
    
    shapes.forEach((shape, index) => {
        const speed = 0.5 + (index * 0.1);
        shape.style.transform = `translateY(${scrollY * speed}px)`;
    });
});

// Add active class to current navigation item
window.addEventListener('scroll', () => {
    const sections = document.querySelectorAll('section');
    const navLinks = document.querySelectorAll('.nav-link');
    
    let current = '';
    
    sections.forEach(section => {
        const sectionTop = section.offsetTop - 100;
        if (window.pageYOffset >= sectionTop) {
            current = section.getAttribute('id');
        }
    });
    
    navLinks.forEach(link => {
        link.classList.remove('active');
        if (link.getAttribute('href').substring(1) === current) {
            link.classList.add('active');
        }
    });
});

console.log('Portfolio loaded successfully! 🚀');