/**
 * AniWorld - UI Utilities Module
 *
 * Toast notifications, loading overlays, and
 * common UI helper functions.
 *
 * Dependencies: constants.js
 */

var AniWorld = window.AniWorld || {};

AniWorld.UI = (function() {
    'use strict';

    const DEFAULTS = AniWorld.Constants.DEFAULTS;

    /**
     * Show a toast notification
     * @param {string} message - The message to display
     * @param {string} type - 'info', 'success', 'warning', or 'error'
     * @param {number} duration - Duration in milliseconds (optional)
     */
    function showToast(message, type, duration) {
        type = type || 'info';
        duration = duration || DEFAULTS.TOAST_DURATION;

        const container = document.getElementById('toast-container');
        if (!container) {
            console.warn('Toast container not found');
            return;
        }

        const toast = document.createElement('div');
        toast.className = 'toast ' + type;
        toast.setAttribute('data-testid', 'toast');
        toast.innerHTML = 
            '<div style="display: flex; justify-content: space-between; align-items: center;">' +
                '<span>' + escapeHtml(message) + '</span>' +
                '<button onclick="this.parentElement.parentElement.remove()" ' +
                    'style="background: none; border: none; color: var(--color-text-secondary); ' +
                    'cursor: pointer; padding: 0; margin-left: 1rem;">' +
                    '<i class="fas fa-times"></i>' +
                '</button>' +
            '</div>';

        container.appendChild(toast);

        // Auto-remove after duration
        setTimeout(function() {
            if (toast.parentElement) {
                toast.remove();
            }
        }, duration);
    }

    /**
     * Show loading overlay
     */
    function showLoading() {
        const overlay = document.getElementById('loading-overlay');
        if (overlay) {
            overlay.classList.remove('hidden');
        }
    }

    /**
     * Hide loading overlay
     */
    function hideLoading() {
        const overlay = document.getElementById('loading-overlay');
        if (overlay) {
            overlay.classList.add('hidden');
        }
    }

    /**
     * Escape HTML to prevent XSS
     * @param {string} text - The text to escape
     * @returns {string} Escaped HTML
     */
    function escapeHtml(text) {
        if (text === null || text === undefined) return '';
        const div = document.createElement('div');
        div.textContent = text;
        return div.innerHTML;
    }

    /**
     * Format bytes to human readable string
     * @param {number} bytes - Number of bytes
     * @param {number} decimals - Decimal places (default 2)
     * @returns {string} Formatted string like "1.5 MB"
     */
    function formatBytes(bytes, decimals) {
        decimals = decimals || 2;
        if (bytes === 0) return '0 Bytes';

        const k = 1024;
        const sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB'];
        const i = Math.floor(Math.log(bytes) / Math.log(k));

        return parseFloat((bytes / Math.pow(k, i)).toFixed(decimals)) + ' ' + sizes[i];
    }

    /**
     * Format duration in seconds to human readable string
     * @param {number} seconds - Duration in seconds
     * @returns {string} Formatted string like "1h 30m"
     */
    function formatDuration(seconds) {
        if (!seconds || seconds <= 0) return '---';

        if (seconds < 60) {
            return Math.round(seconds) + 's';
        } else if (seconds < 3600) {
            const minutes = Math.round(seconds / 60);
            return minutes + 'm';
        } else if (seconds < 86400) {
            const hours = Math.floor(seconds / 3600);
            const minutes = Math.round((seconds % 3600) / 60);
            return hours + 'h ' + minutes + 'm';
        } else {
            const days = Math.floor(seconds / 86400);
            const hours = Math.round((seconds % 86400) / 3600);
            return days + 'd ' + hours + 'h';
        }
    }

    /**
     * Format ETA (alias for formatDuration)
     * @param {number} seconds - ETA in seconds
     * @returns {string} Formatted ETA string
     */
    function formatETA(seconds) {
        return formatDuration(seconds);
    }

    /**
     * Format date to locale string
     * @param {string|Date} date - Date to format
     * @returns {string} Formatted date string
     */
    function formatDate(date) {
        if (!date) return '';
        const d = new Date(date);
        return d.toLocaleString();
    }

    /**
     * Get display name for anime/series object
     * Returns name if available, otherwise key or folder
     * @param {Object} anime - Anime/series object
     * @returns {string} Display name
     */
    function getDisplayName(anime) {
        if (!anime) return '';
        const name = anime.name || '';
        const trimmedName = name.trim();
        if (trimmedName) {
            return trimmedName;
        }
        return anime.key || anime.folder || '';
    }

    /**
     * Calculate duration between two timestamps
     * @param {string} startTime - Start timestamp
     * @param {string} endTime - End timestamp
     * @returns {string} Formatted duration
     */
    function calculateDuration(startTime, endTime) {
        const start = new Date(startTime);
        const end = new Date(endTime);
        const diffMs = end - start;

        const minutes = Math.floor(diffMs / (1000 * 60));
        const seconds = Math.floor((diffMs % (1000 * 60)) / 1000);

        return minutes + 'm ' + seconds + 's';
    }

    /**
     * Show a confirmation modal
     * @param {string} title - Modal title
     * @param {string} message - Modal message
     * @returns {Promise<boolean>} Resolves to true if confirmed, false if cancelled
     */
    function showConfirmModal(title, message) {
        return new Promise(function(resolve) {
            const modal = document.getElementById('confirm-modal');
            if (!modal) {
                resolve(window.confirm(message));
                return;
            }

            document.getElementById('confirm-title').textContent = title;
            document.getElementById('confirm-message').textContent = message;
            modal.classList.remove('hidden');

            function handleConfirm() {
                cleanup();
                resolve(true);
            }

            function handleCancel() {
                cleanup();
                resolve(false);
            }

            function cleanup() {
                document.getElementById('confirm-ok').removeEventListener('click', handleConfirm);
                document.getElementById('confirm-cancel').removeEventListener('click', handleCancel);
                modal.classList.add('hidden');
            }

            document.getElementById('confirm-ok').addEventListener('click', handleConfirm);
            document.getElementById('confirm-cancel').addEventListener('click', handleCancel);
        });
    }

    /**
     * Hide the confirmation modal
     */
    function hideConfirmModal() {
        const modal = document.getElementById('confirm-modal');
        if (modal) {
            modal.classList.add('hidden');
        }
    }

    // Public API
    return {
        showToast: showToast,
        showLoading: showLoading,
        hideLoading: hideLoading,
        escapeHtml: escapeHtml,
        formatBytes: formatBytes,
        formatDuration: formatDuration,
        formatETA: formatETA,
        formatDate: formatDate,
        getDisplayName: getDisplayName,
        calculateDuration: calculateDuration,
        showConfirmModal: showConfirmModal,
        hideConfirmModal: hideConfirmModal
    };
})();