class PresentationController {
    constructor() {
        this.currentSlide = 1;
        this.totalSlides = 12;
        this.slides = document.querySelectorAll('.slide');
        this.prevBtn = document.getElementById('prevBtn');
        this.nextBtn = document.getElementById('nextBtn');
        this.currentSlideSpan = document.getElementById('currentSlide');
        this.totalSlidesSpan = document.getElementById('totalSlides');
        this.isTransitioning = false;
        
        this.init();
    }

    init() {
        // Set total slides
        this.totalSlidesSpan.textContent = this.totalSlides;
        
        // Add event listeners
        this.prevBtn.addEventListener('click', () => this.previousSlide());
        this.nextBtn.addEventListener('click', () => this.nextSlide());
        
        // Keyboard navigation
        document.addEventListener('keydown', (e) => this.handleKeyboard(e));
        
        // Initialize first slide
        this.showSlide(1);
        
        // Initialize progress bar
        this.initProgressBar();
        
        console.log('Presentation initialized with', this.totalSlides, 'slides');
    }

    initProgressBar() {
        // Create and add progress bar
        const progressBar = document.createElement('div');
        progressBar.className = 'progress-bar';
        progressBar.innerHTML = '<div class="progress-fill"></div>';
        document.body.insertBefore(progressBar, document.body.firstChild);
        
        this.progressBar = progressBar;
        this.updateProgress();
    }

    showSlide(slideNumber) {
        if (slideNumber < 1 || slideNumber > this.totalSlides || this.isTransitioning) {
            return;
        }

        this.isTransitioning = true;

        // Hide all slides
        this.slides.forEach(slide => {
            slide.classList.remove('active', 'exiting');
            slide.style.opacity = '0';
            slide.style.visibility = 'hidden';
            slide.style.transform = 'translateX(50px)';
        });

        // Update current slide
        this.currentSlide = slideNumber;

        // Show target slide with a small delay to ensure clean transition
        setTimeout(() => {
            const targetSlide = document.querySelector(`[data-slide="${slideNumber}"]`);
            if (targetSlide) {
                targetSlide.style.visibility = 'visible';
                targetSlide.classList.add('active');
                
                // Force a repaint
                targetSlide.offsetHeight;
                
                targetSlide.style.opacity = '1';
                targetSlide.style.transform = 'translateX(0)';
            }

            // Update UI elements
            this.updateButtonStates();
            this.updateSlideCounter();
            this.updateProgress();

            // Allow next transition after animation completes
            setTimeout(() => {
                this.isTransitioning = false;
            }, 450);
        }, 50);
    }

    nextSlide() {
        if (this.currentSlide < this.totalSlides && !this.isTransitioning) {
            this.showSlide(this.currentSlide + 1);
        }
    }

    previousSlide() {
        if (this.currentSlide > 1 && !this.isTransitioning) {
            this.showSlide(this.currentSlide - 1);
        }
    }

    updateButtonStates() {
        // Update previous button
        this.prevBtn.disabled = (this.currentSlide === 1);
        
        // Update next button
        this.nextBtn.disabled = (this.currentSlide === this.totalSlides);
    }

    updateSlideCounter() {
        this.currentSlideSpan.textContent = this.currentSlide;
    }

    updateProgress() {
        if (this.progressBar) {
            const progressFill = this.progressBar.querySelector('.progress-fill');
            const percentage = (this.currentSlide / this.totalSlides) * 100;
            progressFill.style.width = `${percentage}%`;
        }
    }

    handleKeyboard(e) {
        // Prevent default behavior for navigation keys
        if (['ArrowLeft', 'ArrowRight', 'Home', 'End'].includes(e.key)) {
            e.preventDefault();
        }

        switch(e.key) {
            case 'ArrowLeft':
                this.previousSlide();
                break;
            case 'ArrowRight':
                this.nextSlide();
                break;
            case 'Home':
                this.showSlide(1);
                break;
            case 'End':
                this.showSlide(this.totalSlides);
                break;
            case 'f':
            case 'F':
                this.toggleFullscreen();
                break;
            case 'Escape':
                this.exitFullscreen();
                break;
        }
    }

    toggleFullscreen() {
        if (!document.fullscreenElement) {
            document.documentElement.requestFullscreen().catch(err => {
                console.log(`Error attempting to enable fullscreen: ${err.message}`);
            });
        } else {
            document.exitFullscreen();
        }
    }

    exitFullscreen() {
        if (document.fullscreenElement) {
            document.exitFullscreen();
        }
    }
}

// Touch/swipe support for mobile
class TouchHandler {
    constructor(controller) {
        this.controller = controller;
        this.touchStartX = 0;
        this.touchEndX = 0;
        this.minSwipeDistance = 50;
        
        this.init();
    }

    init() {
        const slidesContainer = document.getElementById('slidesContainer');
        
        slidesContainer.addEventListener('touchstart', (e) => {
            this.touchStartX = e.changedTouches[0].screenX;
        }, { passive: true });
        
        slidesContainer.addEventListener('touchend', (e) => {
            this.touchEndX = e.changedTouches[0].screenX;
            this.handleSwipe();
        }, { passive: true });
    }

    handleSwipe() {
        const diffX = this.touchStartX - this.touchEndX;
        
        if (Math.abs(diffX) > this.minSwipeDistance) {
            if (diffX > 0) {
                // Swipe left - next slide
                this.controller.nextSlide();
            } else {
                // Swipe right - previous slide
                this.controller.previousSlide();
            }
        }
    }
}

// Simple hover effects without problematic animations
function addHoverEffects() {
    const style = document.createElement('style');
    style.textContent = `
        .tech-card:hover,
        .company-card:hover,
        .use-case-card:hover,
        .challenge-card:hover,
        .trend-item:hover,
        .takeaway-card:hover {
            background: rgba(255, 255, 255, 0.15) !important;
            cursor: pointer;
        }
    `;
    document.head.appendChild(style);
}

// Initialize presentation when DOM is loaded
document.addEventListener('DOMContentLoaded', function() {
    // Prevent scrolling and ensure proper viewport
    document.body.style.overflow = 'hidden';
    document.body.style.margin = '0';
    document.body.style.padding = '0';
    document.documentElement.style.overflow = 'hidden';
    
    // Initialize the presentation controller
    const presentation = new PresentationController();
    
    // Add touch support
    new TouchHandler(presentation);
    
    // Add simple hover effects
    addHoverEffects();
    
    // Prevent default scrolling behavior
    document.addEventListener('wheel', (e) => {
        e.preventDefault();
    }, { passive: false });
    
    // Prevent arrow key scrolling
    document.addEventListener('keydown', (e) => {
        if (['ArrowUp', 'ArrowDown', 'ArrowLeft', 'ArrowRight', 'Space'].includes(e.key)) {
            e.preventDefault();
        }
    });
    
    // Handle window resize
    window.addEventListener('resize', () => {
        // Force a repaint to handle responsive changes
        const activeSlide = document.querySelector('.slide.active');
        if (activeSlide) {
            activeSlide.style.height = '100%';
        }
    });
    
    console.log('Presentation ready');
});

// Export controller for debugging
window.PresentationController = PresentationController;