/**
 * ================================================================================
 * Text Classification Dataset - Main JavaScript
 * ================================================================================
 * Project: Text Classification Dataset
 * Category: Text Data / NLP
 * 
 * Author: Molla Samser
 * Designer & Tester: Rima Khatun
 * Website: https://rskworld.in
 * Email: help@rskworld.in | support@rskworld.in
 * Phone: +91 93305 39277
 * 
 * Copyright (c) 2026 RSK World - All Rights Reserved
 * 
 * Created: December 2026
 * ================================================================================
 */

(function() {
    'use strict';

    // ===== DOM Elements =====
    const header = document.querySelector('.header');
    const mobileMenuBtn = document.querySelector('.mobile-menu-btn');
    const navLinks = document.querySelector('.nav-links');
    const backToTopBtn = document.querySelector('.back-to-top');
    const tabBtns = document.querySelectorAll('.tab-btn');
    const tabContents = document.querySelectorAll('.tab-content');
    const statNumbers = document.querySelectorAll('.stat-number');

    // ===== Initialize =====
    document.addEventListener('DOMContentLoaded', function() {
        initMobileMenu();
        initSmoothScroll();
        initTabs();
        initBackToTop();
        initScrollAnimations();
        initStatCounters();
        initCategoryChart();
    });

    // ===== Mobile Menu =====
    function initMobileMenu() {
        if (mobileMenuBtn && navLinks) {
            mobileMenuBtn.addEventListener('click', function() {
                navLinks.classList.toggle('active');
                this.classList.toggle('active');
            });

            // Close menu when clicking on a link
            navLinks.querySelectorAll('a').forEach(link => {
                link.addEventListener('click', function() {
                    navLinks.classList.remove('active');
                    mobileMenuBtn.classList.remove('active');
                });
            });
        }
    }

    // ===== Smooth Scroll =====
    function initSmoothScroll() {
        document.querySelectorAll('a[href^="#"]').forEach(anchor => {
            anchor.addEventListener('click', function(e) {
                e.preventDefault();
                const targetId = this.getAttribute('href');
                const target = document.querySelector(targetId);
                
                if (target) {
                    const headerHeight = header ? header.offsetHeight : 0;
                    const targetPosition = target.getBoundingClientRect().top + window.pageYOffset - headerHeight;
                    
                    window.scrollTo({
                        top: targetPosition,
                        behavior: 'smooth'
                    });
                }
            });
        });
    }

    // ===== Tabs =====
    function initTabs() {
        tabBtns.forEach(btn => {
            btn.addEventListener('click', function() {
                const targetTab = this.dataset.tab;
                
                // Update buttons
                tabBtns.forEach(b => b.classList.remove('active'));
                this.classList.add('active');
                
                // Update content
                tabContents.forEach(content => {
                    content.classList.remove('active');
                    if (content.id === targetTab) {
                        content.classList.add('active');
                    }
                });
            });
        });
    }

    // ===== Back to Top Button =====
    function initBackToTop() {
        if (backToTopBtn) {
            window.addEventListener('scroll', function() {
                if (window.pageYOffset > 500) {
                    backToTopBtn.classList.add('visible');
                } else {
                    backToTopBtn.classList.remove('visible');
                }
            });

            backToTopBtn.addEventListener('click', function() {
                window.scrollTo({
                    top: 0,
                    behavior: 'smooth'
                });
            });
        }
    }

    // ===== Scroll Animations =====
    function initScrollAnimations() {
        const observerOptions = {
            threshold: 0.1,
            rootMargin: '0px 0px -50px 0px'
        };

        const observer = new IntersectionObserver(function(entries) {
            entries.forEach(entry => {
                if (entry.isIntersecting) {
                    entry.target.classList.add('animate-in');
                    observer.unobserve(entry.target);
                }
            });
        }, observerOptions);

        // Observe elements
        document.querySelectorAll('.overview-card, .feature-item, .tech-card, .download-card, .step').forEach(el => {
            el.style.opacity = '0';
            el.style.transform = 'translateY(30px)';
            el.style.transition = 'opacity 0.6s ease, transform 0.6s ease';
            observer.observe(el);
        });
    }

    // Add animation class styles
    const style = document.createElement('style');
    style.textContent = `
        .animate-in {
            opacity: 1 !important;
            transform: translateY(0) !important;
        }
    `;
    document.head.appendChild(style);

    // ===== Stat Counters =====
    function initStatCounters() {
        const observerOptions = {
            threshold: 0.5
        };

        const observer = new IntersectionObserver(function(entries) {
            entries.forEach(entry => {
                if (entry.isIntersecting) {
                    animateCounter(entry.target);
                    observer.unobserve(entry.target);
                }
            });
        }, observerOptions);

        statNumbers.forEach(stat => {
            observer.observe(stat);
        });
    }

    function animateCounter(element) {
        const target = parseInt(element.dataset.target);
        const duration = 2000;
        const step = target / (duration / 16);
        let current = 0;

        const updateCounter = () => {
            current += step;
            if (current < target) {
                element.textContent = Math.floor(current).toLocaleString();
                requestAnimationFrame(updateCounter);
            } else {
                element.textContent = target.toLocaleString();
            }
        };

        updateCounter();
    }

    // ===== Category Chart =====
    function initCategoryChart() {
        const chartCanvas = document.getElementById('categoryChart');
        
        if (chartCanvas && typeof Chart !== 'undefined') {
            const ctx = chartCanvas.getContext('2d');
            
            new Chart(ctx, {
                type: 'doughnut',
                data: {
                    labels: ['Technology', 'Sports', 'Politics', 'Entertainment', 'Business', 'Science'],
                    datasets: [{
                        data: [1800, 1600, 1500, 1700, 1650, 1750],
                        backgroundColor: [
                            '#3b82f6',
                            '#22c55e',
                            '#8b5cf6',
                            '#ec4899',
                            '#f59e0b',
                            '#06b6d4'
                        ],
                        borderWidth: 0,
                        hoverOffset: 10
                    }]
                },
                options: {
                    responsive: true,
                    maintainAspectRatio: false,
                    plugins: {
                        legend: {
                            position: 'bottom',
                            labels: {
                                color: '#a5a3b8',
                                font: {
                                    family: "'Source Sans 3', sans-serif",
                                    size: 12
                                },
                                padding: 15
                            }
                        },
                        tooltip: {
                            backgroundColor: '#231d3a',
                            titleColor: '#f8fafc',
                            bodyColor: '#a5a3b8',
                            borderColor: '#352d54',
                            borderWidth: 1,
                            padding: 12,
                            callbacks: {
                                label: function(context) {
                                    const label = context.label || '';
                                    const value = context.parsed || 0;
                                    const total = context.dataset.data.reduce((a, b) => a + b, 0);
                                    const percentage = ((value / total) * 100).toFixed(1);
                                    return `${label}: ${value.toLocaleString()} (${percentage}%)`;
                                }
                            }
                        }
                    },
                    cutout: '60%'
                }
            });
        }
    }

    // ===== Header Scroll Effect =====
    let lastScroll = 0;
    
    window.addEventListener('scroll', function() {
        const currentScroll = window.pageYOffset;
        
        if (header) {
            if (currentScroll > 100) {
                header.style.background = 'rgba(15, 10, 31, 0.95)';
                header.style.boxShadow = '0 4px 20px rgba(0, 0, 0, 0.3)';
            } else {
                header.style.background = 'rgba(15, 10, 31, 0.8)';
                header.style.boxShadow = 'none';
            }
        }
        
        lastScroll = currentScroll;
    });

    // ===== Copy Code Snippets =====
    document.querySelectorAll('.code-snippet').forEach(snippet => {
        snippet.addEventListener('click', function() {
            const code = this.querySelector('code').textContent;
            navigator.clipboard.writeText(code.replace(/<br>/g, '\n')).then(() => {
                // Show feedback
                const originalBg = this.style.borderColor;
                this.style.borderColor = '#22c55e';
                setTimeout(() => {
                    this.style.borderColor = originalBg;
                }, 1000);
            });
        });

        snippet.style.cursor = 'pointer';
        snippet.title = 'Click to copy';
    });

    // ===== Preloader (optional) =====
    window.addEventListener('load', function() {
        document.body.classList.add('loaded');
    });

})();