utils.js

// Utility Functions Module for TLNotes

// ID generation
function generateId() {
    return crypto.randomUUID ? crypto.randomUUID() : Date.now().toString() + Math.random().toString(36).substr(2, 9);
}

// Date utility functions
function getPartialDateTime(dateObj, fallbackTime) {
    if (!dateObj) return fallbackTime;
    const fallbackDate = new Date(fallbackTime);
    const y = dateObj.year ?? fallbackDate.getFullYear();
    const m = dateObj.month ? dateObj.month - 1 : 0;
    const d = dateObj.day || 1;
    return new Date(y, m, d).getTime();
}

function getSortDate(note) {
    if (note.type === 'draft') return note.created;
    let dateObj = null;
    if (note.type === 'event') dateObj = note.date;
    else if (note.type === 'period') dateObj = note.date ? note.date.begin : null;
    else if (note.date && note.date.year) dateObj = note.date;
    return getPartialDateTime(dateObj, note.created);
}

function getEndDate(note) {
    if (note.type !== 'period') return null;
    const endObj = note.date ? note.date.end : null;
    if (!endObj || endObj.year == null) return Infinity;
    const begin = note.date.begin || {};
    const fallbackYear = begin.year ?? new Date(note.created).getFullYear();
    const fallbackTime = new Date(fallbackYear, 0, 1).getTime();
    return getPartialDateTime(endObj, fallbackTime);
}

function getWeek(time) {
    const d = new Date(time);
    d.setHours(0, 0, 0, 0);
    d.setDate(d.getDate() + 3 - (d.getDay() + 6) % 7);
    const week1 = new Date(d.getFullYear(), 0, 4);
    return 1 + Math.round(((d.getTime() - week1.getTime()) / 86400000 + (week1.getDay() + 6) % 7 - 3) / 7);
}

function formatPartialDate(dateObj) {
    if (!dateObj) return '';
    const parts = [];
    if (dateObj.year) parts.push(dateObj.year);
    if (dateObj.month) parts.push(new Date(2000, dateObj.month - 1).toLocaleString('default', { month: 'long' }));
    if (dateObj.day) parts.push(dateObj.day);
    return parts.join(' ') || '';
}

function getDayStart(time) {
    const d = new Date(time);
    d.setHours(0, 0, 0, 0);
    return d.getTime();
}

// HTML and text utilities
function escapeHtml(text) {
    const div = document.createElement('div');
    div.textContent = text;
    return div.innerHTML;
}

function highlightSearch(text, query) {
    if (!query) return escapeHtml(text);
    const escapedText = escapeHtml(text);
    const regex = new RegExp(`(${query.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')})`, 'gi');
    return escapedText.replace(regex, '<span class="search-highlight">$1</span>');
}

// Note sorting and comparison
const typePriority = {
    'period': 0,
    'event': 1,
    'task': 2,
    'dream': 3,
    'idea': 4,
    'dict': 5,
    'draft': 6
};

function compareNotes(a, b) {
    const da = getSortDate(a);
    const db = getSortDate(b);
    const dayA = getDayStart(da);
    const dayB = getDayStart(db);
    if (dayA !== dayB) return dayA - dayB;
    const priA = typePriority[a.type] || 10;
    const priB = typePriority[b.type] || 10;
    if (priA !== priB) return priA - priB;
    return a.created - b.created;
}

// DOM utilities
function scrollToNote(noteId) {
    setTimeout(() => {
        const noteElement = document.querySelector(`[data-note-id="${noteId}"]`);
        if (noteElement) {
            noteElement.scrollIntoView({ behavior: 'smooth', block: 'center' });
            noteElement.classList.add('new-note');
            setTimeout(() => noteElement.classList.remove('new-note'), 2000);
        }
    }, 100);
}

function showView(viewId) {
    // Hide all views
    document.querySelectorAll('.view').forEach(view => {
        view.classList.remove('active');
    });

    // Show selected view
    const targetView = document.getElementById(viewId);
    if (targetView) {
        targetView.classList.add('active');
    }

    // Update nav buttons
    document.querySelectorAll('.nav-btn').forEach(btn => {
        btn.classList.remove('active');
    });
}

// File operations
function downloadFile(data, filename, type = 'application/json') {
    const blob = new Blob([data], { type });
    const url = URL.createObjectURL(blob);
    const link = document.createElement('a');
    link.href = url;
    link.download = filename;
    document.body.appendChild(link);
    link.click();
    document.body.removeChild(link);
    URL.revokeObjectURL(url);
}

function readFile(file) {
    return new Promise((resolve, reject) => {
        const reader = new FileReader();
        reader.onload = (e) => resolve(e.target.result);
        reader.onerror = (e) => reject(e);
        reader.readAsText(file);
    });
}

// Confirmation dialog utility
function showConfirmDialog(title, message, callback) {
    const dialog = document.getElementById('confirmDialog');
    const titleEl = document.getElementById('confirmTitle');
    const messageEl = document.getElementById('confirmMessage');
    const okBtn = document.getElementById('confirmOk');
    const cancelBtn = document.getElementById('confirmCancel');

    titleEl.textContent = title;
    messageEl.textContent = message;

    // Remove old listeners
    const newOkBtn = okBtn.cloneNode(true);
    const newCancelBtn = cancelBtn.cloneNode(true);
    okBtn.parentNode.replaceChild(newOkBtn, okBtn);
    cancelBtn.parentNode.replaceChild(newCancelBtn, cancelBtn);

    // Add new listeners
    newOkBtn.addEventListener('click', () => {
        dialog.close();
        callback(true);
    });

    newCancelBtn.addEventListener('click', () => {
        dialog.close();
        callback(false);
    });

    dialog.showModal();
}

// Debounce utility
function debounce(func, wait) {
    let timeout;
    return function executedFunction(...args) {
        const later = () => {
            clearTimeout(timeout);
            func(...args);
        };
        clearTimeout(timeout);
        timeout = setTimeout(later, wait);
    };
}

// Validation utilities
function validateNote(note) {
    if (!note.content || note.content.trim() === '') {
        throw new Error('Note content cannot be empty');
    }

    if (!note.type) {
        throw new Error('Note type is required');
    }

    if (!note.id) {
        note.id = generateId();
    }

    if (!note.created) {
        note.created = Date.now();
    }

    note.edited = Date.now();

    return note;
}

// Error handling utilities
function handleError(error, context = '') {
    console.error(`Error ${context}:`, error);

    let message = 'An unexpected error occurred.';
    if (error.message) {
        message = error.message;
    }

    // Show user-friendly error message
    const errorDiv = document.createElement('div');
    errorDiv.style.cssText = `
        position: fixed;
        top: 20px;
        right: 20px;
        background: #f44336;
        color: white;
        padding: 12px 16px;
        border-radius: 4px;
        box-shadow: 0 2px 8px rgba(0,0,0,0.2);
        z-index: 1000;
        max-width: 300px;
        font-size: 14px;
    `;
    errorDiv.textContent = message;

    document.body.appendChild(errorDiv);

    setTimeout(() => {
        if (errorDiv.parentNode) {
            errorDiv.parentNode.removeChild(errorDiv);
        }
    }, 5000);
}

// Success message utility
function showSuccess(message) {
    const successDiv = document.createElement('div');
    successDiv.style.cssText = `
        position: fixed;
        top: 20px;
        right: 20px;
        background: #4CAF50;
        color: white;
        padding: 12px 16px;
        border-radius: 4px;
        box-shadow: 0 2px 8px rgba(0,0,0,0.2);
        z-index: 1000;
        max-width: 300px;
        font-size: 14px;
    `;
    successDiv.textContent = message;

    document.body.appendChild(successDiv);

    setTimeout(() => {
        if (successDiv.parentNode) {
            successDiv.parentNode.removeChild(successDiv);
        }
    }, 3000);
}

// Local storage migration utility (for users upgrading from localStorage version)
function migrateFromLocalStorage() {
    try {
        const oldNotes = localStorage.getItem('tlnotes');
        const oldTrash = localStorage.getItem('tlnotes-trash');

        if (oldNotes || oldTrash) {
            return {
                notes: oldNotes ? JSON.parse(oldNotes) : [],
                trash: oldTrash ? JSON.parse(oldTrash) : []
            };
        }

        return null;
    } catch (error) {
        console.error('Error migrating from localStorage:', error);
        return null;
    }
}

function clearLocalStorageData() {
    try {
        localStorage.removeItem('tlnotes');
        localStorage.removeItem('tlnotes-trash');
        console.log('Old localStorage data cleared');
    } catch (error) {
        console.error('Error clearing localStorage:', error);
    }
}