/**
 * Video Quality Selector
 * Allows users to switch between quality levels
 */

class QualitySelector {
    constructor(videoId, options = {}) {
        this.videoId = videoId;
        this.playerElement = options.playerElement || document.querySelector('video');
        this.containerElement = options.containerElement || document.querySelector('.video-controls');
        this.qualities = [];
        this.currentQuality = 'auto';
        
        this.init();
    }
    
    async init() {
        await this.loadQualities();
        this.render();
        this.attachEventListeners();
    }
    
    async loadQualities() {
        try {
            const response = await fetch(`/api/cdn.php?action=qualities&video_id=${this.videoId}`);
            const data = await response.json();
            
            if (data.success) {
                this.qualities = data.qualities;
                
                // Add "Auto" option
                this.qualities.unshift({
                    quality_label: 'auto',
                    resolution: 'Auto',
                    cdn_url: null
                });
            }
        } catch (error) {
            console.error('Failed to load qualities:', error);
        }
    }
    
    render() {
        if (this.qualities.length <= 1) {
            // No quality options available
            return;
        }
        
        const container = document.createElement('div');
        container.className = 'quality-selector';
        container.innerHTML = `
            <button class="quality-button" id="qualityButton">
                <svg width="20" height="20" viewBox="0 0 20 20" fill="currentColor">
                    <path d="M10 3a7 7 0 100 14 7 7 0 000-14zM2 10a8 8 0 1116 0 8 8 0 01-16 0z"/>
                    <path d="M10 7a3 3 0 100 6 3 3 0 000-6z"/>
                </svg>
                <span id="qualityLabel">Auto</span>
            </button>
            <div class="quality-menu" id="qualityMenu" style="display: none;">
                ${this.renderQualityOptions()}
            </div>
        `;
        
        if (this.containerElement) {
            this.containerElement.appendChild(container);
        } else {
            // Fallback: insert after video player
            this.playerElement.parentNode.insertBefore(container, this.playerElement.nextSibling);
        }
    }
    
    renderQualityOptions() {
        return this.qualities.map(q => `
            <div class="quality-option ${q.quality_label === this.currentQuality ? 'active' : ''}" 
                 data-quality="${q.quality_label}" 
                 data-url="${q.cdn_url || ''}">
                ${q.resolution || q.quality_label}
            </div>
        `).join('');
    }
    
    attachEventListeners() {
        const button = document.getElementById('qualityButton');
        const menu = document.getElementById('qualityMenu');
        
        if (!button || !menu) return;
        
        // Toggle menu
        button.addEventListener('click', (e) => {
            e.stopPropagation();
            const isVisible = menu.style.display === 'block';
            menu.style.display = isVisible ? 'none' : 'block';
        });
        
        // Close menu on outside click
        document.addEventListener('click', () => {
            menu.style.display = 'none';
        });
        
        // Quality selection
        menu.addEventListener('click', (e) => {
            const option = e.target.closest('.quality-option');
            if (option) {
                const quality = option.dataset.quality;
                const url = option.dataset.url;
                
                this.switchQuality(quality, url);
                menu.style.display = 'none';
            }
        });
    }
    
    async switchQuality(quality, url) {
        if (quality === this.currentQuality) return;
        
        const wasPlaying = !this.playerElement.paused;
        const currentTime = this.playerElement.currentTime;
        
        // Update active state
        document.querySelectorAll('.quality-option').forEach(option => {
            option.classList.toggle('active', option.dataset.quality === quality);
        });
        
        // Update label
        const label = document.getElementById('qualityLabel');
        if (label) {
            const selectedQuality = this.qualities.find(q => q.quality_label === quality);
            label.textContent = selectedQuality?.resolution || quality;
        }
        
        if (quality === 'auto') {
            // Auto quality - select best based on connection
            url = await this.selectAutoQuality();
        }
        
        if (!url) {
            console.error('No URL available for quality:', quality);
            return;
        }
        
        // Switch video source
        this.playerElement.src = url;
        this.playerElement.currentTime = currentTime;
        
        if (wasPlaying) {
            this.playerElement.play();
        }
        
        this.currentQuality = quality;
        
        // Save preference
        localStorage.setItem('preferredQuality', quality);
    }
    
    async selectAutoQuality() {
        // Measure connection speed (simplified)
        const connection = navigator.connection || navigator.mozConnection || navigator.webkitConnection;
        
        let selectedQuality = 'original';
        
        if (connection) {
            const effectiveType = connection.effectiveType;
            
            // Map connection type to quality
            if (effectiveType === 'slow-2g' || effectiveType === '2g') {
                selectedQuality = '360p';
            } else if (effectiveType === '3g') {
                selectedQuality = '480p';
            } else if (effectiveType === '4g') {
                selectedQuality = '1080p';
            } else {
                selectedQuality = '720p';
            }
        }
        
        // Find best available quality
        const available = this.qualities.find(q => q.quality_label === selectedQuality);
        
        if (available && available.cdn_url) {
            return available.cdn_url;
        }
        
        // Fallback to highest available
        const highestQuality = this.qualities.filter(q => q.cdn_url).pop();
        return highestQuality?.cdn_url;
    }
    
    restorePreference() {
        const preferred = localStorage.getItem('preferredQuality');
        
        if (preferred && preferred !== 'auto') {
            const quality = this.qualities.find(q => q.quality_label === preferred);
            
            if (quality && quality.cdn_url) {
                this.switchQuality(preferred, quality.cdn_url);
            }
        }
    }
}

// Auto-initialize
document.addEventListener('DOMContentLoaded', () => {
    const videoElement = document.querySelector('video');
    const videoId = new URLSearchParams(window.location.search).get('v');
    
    if (videoElement && videoId) {
        window.qualitySelector = new QualitySelector(videoId, {
            playerElement: videoElement,
            containerElement: document.querySelector('.video-controls')
        });
        
        // Restore user preference after qualities load
        setTimeout(() => {
            if (window.qualitySelector) {
                window.qualitySelector.restorePreference();
            }
        }, 1000);
    }
});