/**
 * UI Components Module
 * Reusable UI components and utilities
 */

class UIComponents {
    constructor() {
        this.loadingElement = document.getElementById('loading');
        this.successMessageElement = document.getElementById('successMessage');
    }

    /**
     * Show loading spinner
     * @param {string} message - Custom loading message
     */
    showLoading(message = 'Finding challenges...') {
        if (this.loadingElement) {
            // Update loading message
            const loadingText = this.loadingElement.querySelector('p');
            if (loadingText) {
                loadingText.textContent = message;
            }
            
            this.loadingElement.style.display = 'flex';
        }
    }

    /**
     * Hide loading spinner
     */
    hideLoading() {
        if (this.loadingElement) {
            this.loadingElement.style.display = 'none';
        }
    }

    /**
     * Show success message
     * @param {string} message - Success message
     * @param {number} duration - Duration to show message (ms)
     */
    showSuccessMessage(message, duration = 4000) {
        if (this.successMessageElement) {
            const messageSpan = this.successMessageElement.querySelector('span');
            if (messageSpan) {
                messageSpan.textContent = message;
            }
            
            this.successMessageElement.style.display = 'flex';
            
            // Auto-hide after duration
            setTimeout(() => {
                this.successMessageElement.style.display = 'none';
            }, duration);
        }
    }

    /**
     * Show error message
     * @param {string} message - Error message
     * @param {number} duration - Duration to show message (ms)
     */
    showError(message, duration = 3000) {
        // Create a temporary error message
        const errorDiv = document.createElement('div');
        errorDiv.style.cssText = `
            position: fixed;
            top: 2rem;
            left: 50%;
            transform: translateX(-50%);
            background: var(--danger-color);
            color: white;
            padding: 1rem 2rem;
            border-radius: var(--border-radius);
            box-shadow: var(--shadow-lg);
            z-index: 1000;
            animation: slideIn 0.3s ease-out;
        `;
        errorDiv.innerHTML = `<i class="fas fa-exclamation-triangle"></i> ${message}`;
        
        document.body.appendChild(errorDiv);
        
        setTimeout(() => {
            errorDiv.remove();
        }, duration);
    }

    /**
     * Show info message
     * @param {string} message - Info message
     * @param {number} duration - Duration to show message (ms)
     */
    showInfoMessage(message, duration = 3000) {
        const infoDiv = document.createElement('div');
        infoDiv.style.cssText = `
            position: fixed;
            top: 2rem;
            left: 50%;
            transform: translateX(-50%);
            background: var(--primary-color);
            color: white;
            padding: 1rem 2rem;
            border-radius: var(--border-radius);
            box-shadow: var(--shadow-lg);
            z-index: 1000;
            animation: slideIn 0.3s ease-out;
        `;
        infoDiv.innerHTML = `<i class="fas fa-info-circle"></i> ${message}`;
        
        document.body.appendChild(infoDiv);
        
        setTimeout(() => {
            infoDiv.remove();
        }, duration);
    }

    /**
     * Create a modal
     * @param {string} title - Modal title
     * @param {string} content - Modal content (HTML)
     * @param {Array} buttons - Array of button objects {text, class, onclick}
     */
    createModal(title, content, buttons = []) {
        const modal = document.createElement('div');
        modal.className = 'modal';
        modal.style.display = 'flex';
        
        const modalContent = `
            <div class="modal-content">
                <div class="modal-header">
                    <h3><i class="fas fa-info-circle"></i> ${title}</h3>
                    <button class="close-btn">&times;</button>
                </div>
                <div class="modal-body">
                    ${content}
                </div>
                <div class="modal-footer">
                    ${buttons.map(btn => 
                        `<button class="btn ${btn.class || 'btn-secondary'}" data-action="${btn.action || ''}">${btn.text}</button>`
                    ).join('')}
                </div>
            </div>
        `;
        
        modal.innerHTML = modalContent;
        document.body.appendChild(modal);
        
        // Add event listeners
        const closeBtn = modal.querySelector('.close-btn');
        closeBtn.addEventListener('click', () => this.closeModal(modal));
        
        // Close on background click
        modal.addEventListener('click', (e) => {
            if (e.target === modal) {
                this.closeModal(modal);
            }
        });
        
        // Add button event listeners
        buttons.forEach((btn, index) => {
            const buttonElement = modal.querySelectorAll('.modal-footer .btn')[index];
            if (buttonElement && btn.onclick) {
                buttonElement.addEventListener('click', (e) => {
                    btn.onclick(e, modal);
                });
            }
        });
        
        return modal;
    }

    /**
     * Close modal
     * @param {HTMLElement} modal - Modal element
     */
    closeModal(modal) {
        modal.remove();
    }

    /**
     * Validate form field
     * @param {HTMLElement} field - Form field element
     * @param {Object} rules - Validation rules
     */
    validateField(field, rules) {
        const value = field.value.trim();
        const errors = [];
        
        if (rules.required && !value) {
            errors.push(`${rules.name || 'Field'} is required`);
        }
        
        if (rules.email && value) {
            const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
            if (!emailRegex.test(value)) {
                errors.push('Please enter a valid email address');
            }
        }
        
        if (rules.minLength && value.length < rules.minLength) {
            errors.push(`${rules.name || 'Field'} must be at least ${rules.minLength} characters`);
        }
        
        // Show/hide validation errors
        this.updateFieldValidation(field, errors);
        
        return errors.length === 0;
    }

    /**
     * Update field validation display
     * @param {HTMLElement} field - Form field element
     * @param {Array} errors - Array of error messages
     */
    updateFieldValidation(field, errors) {
        // Remove existing error display
        const existingError = field.parentNode.querySelector('.field-error');
        if (existingError) {
            existingError.remove();
        }
        
        // Add/remove error class
        field.classList.toggle('error', errors.length > 0);
        
        // Add error message if needed
        if (errors.length > 0) {
            const errorDiv = document.createElement('div');
            errorDiv.className = 'field-error';
            errorDiv.style.cssText = `
                color: var(--danger-color);
                font-size: 0.875rem;
                margin-top: 0.25rem;
            `;
            errorDiv.textContent = errors[0]; // Show first error
            field.parentNode.appendChild(errorDiv);
        }
    }

    /**
     * Add loading state to button
     * @param {HTMLElement} button - Button element
     * @param {string} loadingText - Text to show while loading
     */
    addLoadingState(button, loadingText = 'Loading...') {
        const originalText = button.innerHTML;
        button.innerHTML = `<i class="fas fa-spinner fa-spin"></i> ${loadingText}`;
        button.disabled = true;
        
        return () => {
            button.innerHTML = originalText;
            button.disabled = false;
        };
    }

    /**
     * Debounce function calls
     * @param {Function} func - Function to debounce
     * @param {number} wait - Wait time in ms
     */
    debounce(func, wait) {
        let timeout;
        return function executedFunction(...args) {
            const later = () => {
                clearTimeout(timeout);
                func(...args);
            };
            clearTimeout(timeout);
            timeout = setTimeout(later, wait);
        };
    }

    /**
     * Auto-resize textarea
     * @param {HTMLElement} textarea - Textarea element
     */
    autoResizeTextarea(textarea) {
        textarea.style.height = 'auto';
        textarea.style.height = textarea.scrollHeight + 'px';
    }

    /**
     * Add interactive feedback to elements
     * @param {HTMLElement} element - Element to add feedback to
     */
    addInteractiveFeedback(element) {
        element.addEventListener('click', function(e) {
            e.target.style.transform = 'scale(0.98)';
            setTimeout(() => {
                e.target.style.transform = '';
            }, 150);
        });
    }

    /**
     * Format challenge data for display
     * @param {Object} challenge - Challenge object
     */
    formatChallenge(challenge) {
        return {
            name: challenge.name || 'Unknown Challenge',
            description: challenge.description || 'No description available',
            prize: challenge.prize || '$0',
            url: challenge.url || null,
            track: challenge.track || 'General',
            deadline: challenge.deadline || null
        };
    }
}