// Gestión de tema (light/dark)
function initTheme() {
    const savedTheme = localStorage.getItem('theme') || 'light';
    if (savedTheme === 'dark') {
        document.documentElement.classList.add('dark');
    } else {
        document.documentElement.classList.remove('dark');
    }
}

function toggleTheme() {
    const isDark = document.documentElement.classList.contains('dark');
    if (isDark) {
        document.documentElement.classList.remove('dark');
        localStorage.setItem('theme', 'light');
    } else {
        document.documentElement.classList.add('dark');
        localStorage.setItem('theme', 'dark');
    }
}

// Gestión de sesión de usuario
function getUserSession() {
    let session = localStorage.getItem('userSession');
    if (!session) {
        session = 'user_' + Math.random().toString(36).substr(2, 9) + '_' + Date.now();
        localStorage.setItem('userSession', session);
    }
    return session;
}

// Notificación tipo toast
function showToast(message, type = 'success') {
    const toast = document.getElementById('toast');
    const toastMessage = document.getElementById('toastMessage');
    toastMessage.textContent = message;
    toast.classList.remove('bg-green-500', 'bg-red-500', 'bg-blue-500');
    if (type === 'success') {
        toast.classList.add('bg-green-500');
    } else if (type === 'error') {
        toast.classList.add('bg-red-500');
    } else if (type === 'info') {
        toast.classList.add('bg-blue-500');
    }
    toast.classList.remove('translate-x-full');
    setTimeout(() => {
        toast.classList.add('translate-x-full');
    }, 3000);
}

// Tooltip personalizado
let tooltipTimeout;
function showCustomTooltip(target, text) {
    let tooltip = document.getElementById('custom-tooltip');
    if (!tooltip) {
        tooltip = document.createElement('div');
        tooltip.id = 'custom-tooltip';
        tooltip.className = 'custom-tooltip';
        document.body.appendChild(tooltip);
    }
    tooltip.textContent = text;
    const rect = target.getBoundingClientRect();
    tooltip.style.top = (window.scrollY + rect.bottom + 4) + 'px';
    tooltip.style.left = (window.scrollX + rect.left) + 'px';
    tooltip.classList.add('visible');
    clearTimeout(tooltipTimeout);
}
function hideCustomTooltip() {
    const tooltip = document.getElementById('custom-tooltip');
    if (tooltip) {
        tooltip.classList.remove('visible');
        tooltipTimeout = setTimeout(() => {
            tooltip.remove();
        }, 200);
    }
}

// Formateo de tamaño de archivo
function formatFileSize(bytes) {
    if (bytes === 0) return '0 Bytes';
    const k = 1024;
    const sizes = ['Bytes', 'KB', 'MB', 'GB'];
    const i = Math.floor(Math.log(bytes) / Math.log(k));
    return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i];
}

// Formateo de fecha
function formatDate(dateString) {
    const date = new Date(dateString);
    return date.toLocaleDateString() + ' ' + date.toLocaleTimeString();
}

// Tiempo restante
function getTimeRemaining(expirationDate) {
    const now = new Date();
    const expiry = new Date(expirationDate);
    const diff = expiry - now;
    if (diff <= 0) return 'Expired';
    const hours = Math.floor(diff / (1000 * 60 * 60));
    const minutes = Math.floor((diff % (1000 * 60 * 60)) / (1000 * 60));
    if (hours > 0) {
        return `${hours}h ${minutes}m remaining`;
    } else {
        return `${minutes}m remaining`;
    }
}

// Progreso de subida
let uploadStartTime = 0;
let uploadedBytes = 0;
function updateProgress(loaded, total, isDone = false) {
    const percent = isDone ? 100 : Math.round((loaded / total) * 100);
    const progressBar = document.getElementById('progressBar');
    const progressPercent = document.getElementById('progressPercent');
    const uploadSpeed = document.getElementById('uploadSpeed');
    const timeRemaining = document.getElementById('timeRemaining');
    progressBar.style.width = percent + '%';
    progressPercent.textContent = percent + '%';
    if (isDone) {
        uploadSpeed.textContent = '';
        timeRemaining.textContent = '';
        return;
    }
    const elapsed = (Date.now() - uploadStartTime) / 1000;
    const speed = loaded / elapsed;
    const speedMB = (speed / (1024 * 1024)).toFixed(2);
    uploadSpeed.textContent = `${speedMB} MB/s`;
    if (speed > 0) {
        const remaining = (total - loaded) / speed;
        const minutes = Math.floor(remaining / 60);
        const seconds = Math.floor(remaining % 60);
        timeRemaining.textContent = `${minutes}:${seconds.toString().padStart(2, '0')} remaining`;
    }
}

// Manejo de selección de archivo
function handleFileSelection(file) {
    const fileInfo = document.getElementById('file-info');
    const fileName = document.getElementById('file-name');
    const fileSize = document.getElementById('file-size');
    const maxFileSizeMB = window.maxFileSizeMB || 16;
    if (file) {
        if (file.size > maxFileSizeMB * 1024 * 1024) {
            showToast(`File size exceeds the allowed limit (${maxFileSizeMB} MB)`, 'error');
            clearFileSelection();
            return;
        }
        fileName.textContent = file.name;
        fileName.classList.add('truncate');
        fileName.setAttribute('data-tooltip', file.name);
        fileSize.textContent = formatFileSize(file.size);
        fileInfo.classList.remove('hidden');
    } else {
        fileInfo.classList.add('hidden');
    }
}

function clearFileSelection() {
    const fileInput = document.getElementById('file-upload');
    const fileInfo = document.getElementById('file-info');
    fileInput.value = '';
    fileInfo.classList.add('hidden');
}

// Cargar archivos del usuario
async function loadUserFiles() {
    const userSession = getUserSession();
    try {
        const response = await fetch(`/files/${userSession}`);
        const files = await response.json();
        const filesList = document.getElementById('filesList');
        const noFiles = document.getElementById('noFiles');
        if (files.length === 0) {
            filesList.innerHTML = '';
            noFiles.classList.remove('hidden');
        } else {
            noFiles.classList.add('hidden');
            filesList.innerHTML = files.map(file => `
                <div class="border border-gray-200 dark:border-gray-600 rounded-lg p-4 hover:bg-gray-50 dark:hover:bg-gray-700 transition-colors animate-slide-up">
                    <div class="flex items-center justify-between">
                        <div class="flex-1">
                            <div class="flex items-center space-x-3">
                                <div class="flex-shrink-0">
                                    <svg class="w-8 h-8 text-gray-400 dark:text-gray-500" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                                        <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 12h6m-6 4h6m2 5H7a2 2 0 01-2-2V5a2 2 0 012-2h5.586a1 1 0 01.707.293l5.414 5.414a1 1 0 01.293.707V19a2 2 0 01-2 2z"></path>
                                    </svg>
                                </div>
                                <div class="flex-1 min-w-0">
                                    <p class="text-sm font-medium text-gray-900 dark:text-white truncate file-tooltip" data-tooltip="${file.original_filename}">${file.original_filename}</p>
                                    <p class="text-xs text-gray-500 dark:text-gray-400">${formatFileSize(file.file_size)} • Uploaded ${formatDate(file.upload_date)}</p>
                                </div>
                            </div>
                        </div>
                        <div class="flex items-center space-x-2">
                            <div class="text-right">
                                <p class="text-xs text-gray-500 dark:text-gray-400 file-remaining-time" data-expiration="${file.expiration_date}">${getTimeRemaining(file.expiration_date)}</p>
                            </div>
                            <a href="${file.download_url}" class="inline-flex items-center px-3 py-1 text-xs font-medium text-blue-600 dark:text-blue-400 bg-blue-100 dark:bg-blue-900/30 hover:bg-blue-200 dark:hover:bg-blue-900/50 rounded-full transition-colors" target="_blank">
                                Download
                            </a>
                            <button onclick="copyDownloadUrl('${file.download_url}')" class="inline-flex items-center px-3 py-1 text-xs font-medium text-gray-700 dark:text-gray-200 bg-gray-100 dark:bg-gray-700 hover:bg-gray-200 dark:hover:bg-gray-600 rounded-full transition-colors">
                                Copy Link
                            </button>
                            <button onclick="deleteFile('${file.id}')" class="inline-flex items-center px-3 py-1 text-xs font-medium text-red-600 dark:text-red-400 bg-red-100 dark:bg-red-900/30 hover:bg-red-200 dark:hover:bg-red-900/50 rounded-full transition-colors">
                                Delete
                            </button>
                        </div>
                    </div>
                </div>
            `).join('');
        }
        document.querySelectorAll('.file-tooltip').forEach(el => {
            el.addEventListener('mouseenter', function(e) {
                showCustomTooltip(e.target, e.target.getAttribute('data-tooltip'));
            });
            el.addEventListener('mouseleave', hideCustomTooltip);
        });
        updateRemainingTimes();
    } catch (error) {
        showToast('Error loading files', 'error');
    }
}

// Variables para el modal de eliminación
let fileIdToDelete = null;

function openDeleteModal(fileId) {
    fileIdToDelete = fileId;
    document.getElementById('deleteModal').classList.remove('hidden');
}

function closeDeleteModal() {
    fileIdToDelete = null;
    document.getElementById('deleteModal').classList.add('hidden');
}

// Eliminar archivo (ahora solo ejecuta si se confirma en el modal)
async function confirmDeleteFile() {
    if (!fileIdToDelete) return;
    const userSession = getUserSession();
    try {
        const response = await fetch(`/delete/${fileIdToDelete}`, {
            method: 'DELETE',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ user_session: userSession })
        });
        const result = await response.json();
        if (result.success) {
            showToast('File deleted successfully');
            loadUserFiles();
        } else {
            showToast(result.error || 'Error deleting file', 'error');
        }
    } catch (error) {
        showToast('Error deleting file: ' + error.message, 'error');
    } finally {
        closeDeleteModal();
    }
}

// Reemplazar deleteFile para abrir el modal
window.deleteFile = openDeleteModal;

// Eventos del modal
function setupDeleteModalEvents() {
    document.getElementById('cancelDeleteBtn').addEventListener('click', closeDeleteModal);
    document.getElementById('confirmDeleteBtn').addEventListener('click', confirmDeleteFile);
    // Cerrar modal con Escape
    document.addEventListener('keydown', function(e) {
        if (e.key === 'Escape') closeDeleteModal();
    });
}

// Inicialización de eventos
function setupEventListeners() {
    // Tema
    document.getElementById('themeToggle').addEventListener('click', toggleTheme);
    // Selección de archivo
    document.getElementById('file-upload').addEventListener('change', function(e) {
        const file = e.target.files[0];
        handleFileSelection(file);
    });
    // Limpiar selección
    document.getElementById('clear-file').addEventListener('click', clearFileSelection);
    // Subida de archivo
    document.getElementById('uploadForm').addEventListener('submit', async function(e) {
        e.preventDefault();
        const fileInput = document.getElementById('file-upload');
        const file = fileInput.files[0];
        const duration = document.getElementById('duration').value;
        const uploadBtn = document.getElementById('uploadBtn');
        const uploadBtnText = document.getElementById('uploadBtnText');
        const uploadProgress = document.getElementById('uploadProgress');
        const maxFileSizeMB = window.maxFileSizeMB || 16;
        if (!file) {
            showToast('Please select a file', 'error');
            return;
        }
        if (file.size > maxFileSizeMB * 1024 * 1024) {
            showToast(`File size exceeds the allowed limit (${maxFileSizeMB} MB)`, 'error');
            clearFileSelection();
            return;
        }
        uploadBtn.disabled = true;
        uploadBtnText.textContent = 'Uploading...';
        uploadProgress.classList.remove('hidden');
        uploadStartTime = Date.now();
        uploadedBytes = 0;
        const formData = new FormData();
        formData.append('file', file);
        formData.append('user_session', getUserSession());
        formData.append('duration_hours', duration);
        let waitingTimeout, errorTimeout;
        try {
            const xhr = new XMLHttpRequest();
            xhr.upload.addEventListener('progress', function(e) {
                if (e.lengthComputable) {
                    updateProgress(e.loaded, e.total);
                }
            });
            xhr.addEventListener('load', function() {
                clearTimeout(waitingTimeout);
                clearTimeout(errorTimeout);
                updateProgress(file.size, file.size, true);
                document.getElementById('uploadSpeed').textContent = '';
                document.getElementById('timeRemaining').textContent = '';
                document.getElementById('waitingServer')?.remove();
                if (xhr.status === 200) {
                    const result = JSON.parse(xhr.responseText);
                    if (result.success) {
                        showToast('File uploaded successfully!');
                        clearFileSelection();
                        loadUserFiles();
                    } else {
                        showToast(result.error || 'Error uploading file', 'error');
                    }
                } else {
                    showToast('Error uploading file', 'error');
                }
            });
            xhr.addEventListener('error', function() {
                clearTimeout(waitingTimeout);
                clearTimeout(errorTimeout);
                document.getElementById('waitingServer')?.remove();
                showToast('Network error while uploading', 'error');
            });
            xhr.upload.addEventListener('load', function() {
                // Barra llegó a 100%, pero aún esperando respuesta
                updateProgress(file.size, file.size, true);
                let waiting = document.getElementById('waitingServer');
                if (!waiting) {
                    waiting = document.createElement('div');
                    waiting.id = 'waitingServer';
                    waiting.className = 'text-xs text-blue-600 dark:text-blue-400 mt-2 flex items-center gap-2';
                    waiting.innerHTML = '<svg class="animate-spin h-4 w-4 mr-1 inline" viewBox="0 0 24 24"><circle class="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" stroke-width="4" fill="none"></circle><path class="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8v8z"></path></svg>Waiting for server confirmation...';
                    uploadProgress.appendChild(waiting);
                }
                // Si pasan 60s tras barra 100%, mostrar advertencia
                waitingTimeout = setTimeout(() => {
                    waiting.textContent = 'The upload is taking longer than expected. Please check your connection.';
                }, 60000);
                // Si pasan 2 minutos, mostrar error y permitir reintentar
                errorTimeout = setTimeout(() => {
                    waiting.remove();
                    showToast('Upload failed: server did not respond. Please try again.', 'error');
                    uploadBtn.disabled = false;
                    uploadBtnText.textContent = 'Upload File';
                    uploadProgress.classList.add('hidden');
                }, 120000);
            });
            xhr.open('POST', '/upload');
            xhr.send(formData);
        } catch (error) {
            showToast('Error uploading file: ' + error.message, 'error');
        } finally {
            setTimeout(() => {
                uploadBtn.disabled = false;
                uploadBtnText.textContent = 'Upload File';
                uploadProgress.classList.add('hidden');
            }, 1000);
        }
    });
    // Refrescar lista
    document.getElementById('refreshBtn').addEventListener('click', loadUserFiles);
}

document.addEventListener('DOMContentLoaded', function() {
    initTheme();
    setupEventListeners();
    setupDeleteModalEvents();
    loadUserFiles();
    setInterval(updateRemainingTimes, 60000);
});

function updateRemainingTimes() {
    document.querySelectorAll('.file-remaining-time').forEach(el => {
        const expiration = el.getAttribute('data-expiration');
        el.textContent = getTimeRemaining(expiration);
    });
} 

window.copyDownloadUrl = function(url) {
    navigator.clipboard.writeText(url).then(() => {
        showToast('Download link copied!');
    }, () => {
        showToast('Failed to copy link', 'error');
    });
}