// Loading management
export class LoadingManager {
    constructor() {
        this.overlay = document.getElementById('loading-overlay');
        this.progressBar = this.overlay.querySelector('.progress-bar');
        this.statusText = this.overlay.querySelector('.loading-status');
        this.detailsContainer = null; // Will be created when needed
    }

    show(message = 'Loading...', progress = 0) {
        this.overlay.style.display = 'flex';
        this.setProgress(progress);
        this.setStatus(message);
        
        // Remove any existing details container
        this.removeDetailsContainer();
    }

    hide() {
        this.overlay.style.display = 'none';
        this.reset();
        this.removeDetailsContainer();
    }

    setProgress(percent) {
        this.progressBar.style.width = `${percent}%`;
        this.progressBar.setAttribute('aria-valuenow', percent);
    }

    setStatus(message) {
        this.statusText.textContent = message;
    }

    reset() {
        this.setProgress(0);
        this.setStatus('');
        this.removeDetailsContainer();
    }

    // Create a details container for enhanced progress display
    createDetailsContainer() {
        // Remove existing container if any
        this.removeDetailsContainer();
        
        // Create new container
        this.detailsContainer = document.createElement('div');
        this.detailsContainer.className = 'progress-details-container';
        
        // Insert after the main progress bar
        const loadingContent = this.overlay.querySelector('.loading-content');
        if (loadingContent) {
            loadingContent.appendChild(this.detailsContainer);
        }
        
        return this.detailsContainer;
    }
    
    // Remove details container
    removeDetailsContainer() {
        if (this.detailsContainer) {
            this.detailsContainer.remove();
            this.detailsContainer = null;
        }
    }
    
    // Show enhanced progress for downloads
    showDownloadProgress(totalItems = 1) {
        this.show('Preparing download...', 0);
        
        // Create details container
        const detailsContainer = this.createDetailsContainer();
        
        // Create current item progress
        const currentItemContainer = document.createElement('div');
        currentItemContainer.className = 'current-item-progress';
        
        const currentItemLabel = document.createElement('div');
        currentItemLabel.className = 'current-item-label';
        currentItemLabel.textContent = 'Current file:';
        
        const currentItemBar = document.createElement('div');
        currentItemBar.className = 'current-item-bar-container';
        
        const currentItemProgress = document.createElement('div');
        currentItemProgress.className = 'current-item-bar';
        currentItemProgress.style.width = '0%';
        
        const currentItemPercent = document.createElement('span');
        currentItemPercent.className = 'current-item-percent';
        currentItemPercent.textContent = '0%';
        
        currentItemBar.appendChild(currentItemProgress);
        currentItemContainer.appendChild(currentItemLabel);
        currentItemContainer.appendChild(currentItemBar);
        currentItemContainer.appendChild(currentItemPercent);
        
        // Create overall progress elements if multiple items
        let overallLabel = null;
        if (totalItems > 1) {
            overallLabel = document.createElement('div');
            overallLabel.className = 'overall-progress-label';
            overallLabel.textContent = `Overall progress (0/${totalItems} complete):`;
            detailsContainer.appendChild(overallLabel);
        }
        
        // Add current item progress to container
        detailsContainer.appendChild(currentItemContainer);
        
        // Return update function
        return (currentProgress, currentIndex = 0, currentName = '') => {
            // Update current item progress
            currentItemProgress.style.width = `${currentProgress}%`;
            currentItemPercent.textContent = `${Math.floor(currentProgress)}%`;
            
            // Update current item label if name provided
            if (currentName) {
                currentItemLabel.textContent = `Downloading: ${currentName}`;
            }
            
            // Update overall label if multiple items
            if (totalItems > 1 && overallLabel) {
                overallLabel.textContent = `Overall progress (${currentIndex}/${totalItems} complete):`;
                
                // Calculate and update overall progress
                const overallProgress = Math.floor((currentIndex + currentProgress/100) / totalItems * 100);
                this.setProgress(overallProgress);
            } else {
                // Single item, just update main progress
                this.setProgress(currentProgress);
            }
        };
    }

    async showWithProgress(callback, options = {}) {
        const { initialMessage = 'Processing...', completionMessage = 'Complete' } = options;
        
        try {
            this.show(initialMessage);
            await callback(this);
            this.setProgress(100);
            this.setStatus(completionMessage);
            await new Promise(resolve => setTimeout(resolve, 500));
        } finally {
            this.hide();
        }
    }

    showSimpleLoading(message = 'Loading...') {
        this.overlay.style.display = 'flex';
        this.progressBar.style.display = 'none';
        this.setStatus(message);
    }

    restoreProgressBar() {
        this.progressBar.style.display = 'block';
    }
}