// Add global error handler
window.addEventListener('error', (event) => {
    console.error('[Ticky Error]', event.message, 'at', event.filename + ':' + event.lineno);
});

class VideoScroller {
    constructor() {
        this.currentIndex = 0;
        this.videos = [];
        this.isLoading = false;
        this.container = document.getElementById('videoContainer');
        this.loadingEl = document.getElementById('loading');
        this.touchStartY = 0;
        this.touchEndY = 0;
        this.isDragging = false;
        this.lastLoadTime = 0;
        this.minLoadInterval = 500;
        
        // Get API URL from current location
        const protocol = window.location.protocol;
        const hostname = window.location.hostname;
        this.apiUrl = `${protocol}//${hostname}:3222`;
        
        this.init();
    }

    async init() {
        this.setupEventListeners();
        await this.loadVideos();
        this.renderVideos();
    }

    setupEventListeners() {
        // Touch events for swipe - prevent default to avoid page scrolling
        document.addEventListener('touchstart', (e) => this.handleTouchStart(e), { passive: false });
        document.addEventListener('touchmove', (e) => e.preventDefault(), { passive: false });
        document.addEventListener('touchend', (e) => this.handleTouchEnd(e), { passive: false });

        // Keyboard navigation
        document.addEventListener('keydown', (e) => this.handleKeydown(e));

        // Infinite scroll - load more when nearing the end
        this.container.addEventListener('scroll', () => this.handleScroll());

        // Mouse wheel
        document.addEventListener('wheel', (e) => this.handleWheel(e), { passive: false });
    }

    handleTouchStart(e) {
        this.touchStartY = e.changedTouches[0].clientY;
        this.isDragging = true;
    }

    handleTouchEnd(e) {
        this.touchEndY = e.changedTouches[0].clientY;
        this.isDragging = false;
        this.handleSwipe();
    }

    handleSwipe() {
        const diff = this.touchStartY - this.touchEndY;
        const minSwipeDistance = 50;

        if (Math.abs(diff) < minSwipeDistance) return;

        if (diff > 0) {
            // Swiped up - next video
            this.nextVideo();
        } else {
            // Swiped down - previous video
            this.prevVideo();
        }
    }

    handleWheel(e) {
        e.preventDefault();
        
        if (e.deltaY > 0) {
            this.nextVideo();
        } else {
            this.prevVideo();
        }
    }

    handleKeydown(e) {
        if (e.key === 'ArrowDown' || e.key === ' ') {
            e.preventDefault();
            this.nextVideo();
        } else if (e.key === 'ArrowUp') {
            e.preventDefault();
            this.prevVideo();
        }
    }

    async loadVideos() {
        try {
            this.showLoading();
            const response = await fetch(`${this.apiUrl}/api/videos?limit=10`);
            const newVideos = await response.json();
            
            if (Array.isArray(newVideos)) {
                this.videos.push(...newVideos);
            }
            
            this.lastLoadTime = Date.now();
        } catch (error) {
            console.error('Error loading videos:', error);
            this.showLoadingError();
        } finally {
            this.hideLoading();
        }
    }

    renderVideos() {
        // Keep only current and adjacent videos in DOM for performance
        const startIndex = Math.max(0, this.currentIndex - 1);
        const endIndex = Math.min(this.videos.length, this.currentIndex + 2);

        // Clear existing videos
        const existingItems = this.container.querySelectorAll('.video-item');
        existingItems.forEach(item => item.remove());

        // Render videos
        for (let i = startIndex; i < endIndex; i++) {
            if (this.videos[i]) {
                this.renderVideo(this.videos[i], i);
            }
        }

        this.updateActiveVideo();
    }

    renderVideo(video, index) {
        const item = document.createElement('div');
        item.className = 'video-item';
        item.dataset.index = index;
        item.style.minHeight = '100vh';

        const videoEl = document.createElement('video');
        videoEl.src = `${this.apiUrl}${video.url}`;
        videoEl.preload = 'auto';
        videoEl.controls = false;
        videoEl.loop = true;
        videoEl.autoplay = index === this.currentIndex;
        videoEl.muted = true;
        videoEl.playsInline = true;
        videoEl.setAttribute('webkit-playsinline', 'webkit-playsinline');
        videoEl.setAttribute('x5-playsinline', 'x5-playsinline');
        videoEl.style.width = '100%';
        videoEl.style.height = '100%';
        videoEl.style.objectFit = 'contain';

        const info = document.createElement('div');
        info.className = 'video-info';
        info.innerHTML = `<div class="video-title">${this.escapeHtml(video.title)}</div>`;

        item.appendChild(videoEl);
        item.appendChild(info);

        // Lazy load: only play current video
        if (index === this.currentIndex) {
            videoEl.play().catch(e => console.log('Play error:', e));
        }

        this.container.appendChild(item);
    }

    updateActiveVideo() {
        const items = this.container.querySelectorAll('.video-item');
        items.forEach(item => {
            const index = parseInt(item.dataset.index);
            const video = item.querySelector('video');
            
            item.classList.remove('active', 'prev', 'next');
            
            if (index === this.currentIndex) {
                item.classList.add('active');
                video.play().catch(e => console.log('Play error:', e));
            } else if (index < this.currentIndex) {
                item.classList.add('prev');
                video.pause();
            } else {
                item.classList.add('next');
                video.pause();
            }
        });

        // Preload next video
        this.preloadNextVideo();
    }

    preloadNextVideo() {
        const nextIndex = this.currentIndex + 1;
        if (nextIndex < this.videos.length && nextIndex > this.currentIndex + 1) {
            // Preload video metadata
            const nextVideo = this.videos[nextIndex];
            if (nextVideo) {
                const img = new Image();
                img.src = `${this.apiUrl}${nextVideo.url}`;
            }
        }
    }

    async nextVideo() {
        if (this.currentIndex < this.videos.length - 1) {
            this.currentIndex++;
            this.renderVideos();
        }

        // Load more videos when near the end
        const now = Date.now();
        if (this.currentIndex > this.videos.length - 3 && 
            now - this.lastLoadTime > this.minLoadInterval && 
            !this.isLoading) {
            await this.loadVideos();
        }
    }

    prevVideo() {
        if (this.currentIndex > 0) {
            this.currentIndex--;
            this.renderVideos();
        }
    }

    handleScroll() {
        // Could be used for horizontal scroll on desktop
    }

    showLoading() {
        this.isLoading = true;
        this.loadingEl.classList.add('show');
        this.loadingEl.innerHTML = '<div class="spinner"></div>';
    }

    hideLoading() {
        this.isLoading = false;
        this.loadingEl.classList.remove('show');
    }

    showLoadingError() {
        this.loadingEl.innerHTML = 'Failed to load videos';
        this.loadingEl.classList.add('show');
        setTimeout(() => this.loadingEl.classList.remove('show'), 3000);
    }

    escapeHtml(text) {
        const div = document.createElement('div');
        div.textContent = text;
        return div.innerHTML;
    }
}

// Initialize on page load
document.addEventListener('DOMContentLoaded', () => {
    new VideoScroller();
});