(function() {
    'use strict';
    // Event handling

    // Set up all event listeners
    function setupEventListeners() {
        // Header buttons
        document.getElementById('addDirectoryBtn').addEventListener('click', () => window.app.modules.directory.addDirectory());
        document.getElementById('refreshHeaderBtn').addEventListener('click', () => window.app.modules.directory.refreshDirectories());
    
        // Content area buttons
        document.getElementById('filterSelectedBtn').addEventListener('click', () => window.app.modules.app.toggleFilterSelected());
        document.getElementById('downloadSelectedBtn').addEventListener('click', () => window.app.modules.export.downloadSelected());
        document.getElementById('exportCsvBtn').addEventListener('click', () => window.app.modules.export.exportCSV());
    
        // Search and filter inputs
        document.getElementById('groupingFilter').addEventListener('input', (e) => {
            window.app.groupingFilter = e.target.value;
            e.target.classList.toggle('filter-active', e.target.value.length > 0);
            window.app.modules.app.updateUI();
            window.app.modules.filtering.applyFilters();
            window.app.modules.urlState.push();
        });

        document.getElementById('transmittalFilter').addEventListener('input', (e) => {
            window.app.transmittalFilter = e.target.value;
            e.target.classList.toggle('filter-active', e.target.value.length > 0);
            window.app.modules.app.updateUI();
            window.app.modules.filtering.applyFilters(); // Re-filter files when transmittal filter changes
            window.app.modules.urlState.push();
        });
    
        // Select All Grouping Folders checkbox
        document.getElementById('selectAllGroupingCheckbox').addEventListener('change', (e) => {
            window.app.selectAllGroupingFolders = e.target.checked;
            window.app.modules.app.renderGroupingFolders();
            window.app.modules.app.renderTransmittalFolders();
            window.app.modules.filtering.applyFilters();
        });
    
        // Folder type toggle bar — global click delegation
        document.addEventListener('click', (e) => {
            const btn = e.target.closest('.folder-type-toggle');
            if (btn) {
                const type = btn.getAttribute('data-type');
                if (type) window.app.modules.app.toggleFolderType(type);
            }
        });
    
        // Select All Transmittals checkbox
        document.getElementById('selectAllTransmittalsCheckbox').addEventListener('change', (e) => {
            window.app.selectAllTransmittals = e.target.checked;
            window.app.modules.app.renderTransmittalFolders();
            window.app.modules.filtering.applyFilters();
        });
    
        // Modifier filter dropdown
        document.getElementById('modifierFilterBtn').addEventListener('click', () => window.app.modules.app.toggleModifierDropdown());
        document.getElementById('modifierSelectAll').addEventListener('change', (e) => {
            window.app.modules.app.toggleAllModifiers(e.target.checked);
        });
    
        // Close modifier dropdown when clicking outside
        document.addEventListener('click', (e) => {
            const container = document.querySelector('.modifier-filter-container');
            const dropdown = document.getElementById('modifierFilterDropdown');
            if (container && dropdown && !container.contains(e.target)) {
                dropdown.classList.add('hidden');
            }
        });
    
        // Select all visible files checkbox
        document.getElementById('selectAllVisibleCheckbox').addEventListener('change', (e) => {
            e.stopPropagation();
            window.app.modules.table.toggleSelectAllVisible(e.target.checked);
        });
        
        // Reset filters button
        document.getElementById('resetFiltersBtn').addEventListener('click', () => window.app.modules.filtering.clearFilters());
    
        // Column filters — delegated from thead
        const thead = document.querySelector('thead');
        if (thead) {
            thead.addEventListener('input', (e) => {
                if (e.target.matches('.column-filter[data-filter-field]')) {
                    const field = e.target.getAttribute('data-filter-field');
                    const raw = e.target.value.trim();
                    window.app.columnFilters[field] = raw;
                    window.app.columnFilterASTs[field] = zddc.filter.parse(raw);
                    
                    // Add/remove filter-active class based on non-empty value
                    if (raw) {
                        e.target.classList.add('filter-active');
                    } else {
                        e.target.classList.remove('filter-active');
                    }
                    
                    window.app.modules.filtering.applyFilters();
                    window.app.modules.urlState.push();
                }
            });
            thead.addEventListener('keydown', (e) => {
                if (!e.target.matches('.column-filter[data-filter-field]')) return;
                if (e.key === 'Escape') {
                    e.target.value = '';
                    e.target.classList.remove('filter-active');
                    const field = e.target.getAttribute('data-filter-field');
                    window.app.columnFilters[field] = '';
                    window.app.columnFilterASTs[field] = null;
                    window.app.modules.filtering.applyFilters();
                    window.app.modules.urlState.push();
                    e.preventDefault();
                } else if (e.key === 'Enter') {
                    e.preventDefault();
                    const inputs = Array.from(thead.querySelectorAll('.column-filter'));
                    const idx = inputs.indexOf(e.target);
                    if (idx !== -1) {
                        inputs[(idx + 1) % inputs.length].focus();
                    }
                }
            });
            thead.addEventListener('click', (e) => {
                if (e.target.matches('.column-filter')) {
                    e.stopPropagation();
                }
            });
        }
    
        // Table sorting
        document.querySelectorAll('.sortable').forEach(th => {
            th.querySelector('.th-content').addEventListener('click', () => {
                const field = th.getAttribute('data-field');
                window.app.modules.table.sortTable(field);
            });
        });
    
        // Initialize column resize
        window.app.modules.table.initializeColumnResize();
    
        // Modal close buttons
        document.querySelectorAll('.modal-close').forEach(btn => {
            btn.addEventListener('click', closeModal);
        });
    
        // Modal backdrop clicks
        document.querySelectorAll('.modal-backdrop').forEach(backdrop => {
            backdrop.addEventListener('click', closeModal);
        });
    
        // Drop modal buttons
        const dropModal = document.getElementById('dropModal');
        dropModal.querySelector('.modal-cancel').addEventListener('click', closeModal);
        dropModal.querySelector('.modal-confirm').addEventListener('click', () => window.app.modules.dragDrop.confirmTransmittal());
    
        // Drag and drop (local mode only — requires write access)
        if (window.app.sourceMode === 'local') {
            window.app.modules.dragDrop.setupDragAndDrop();
        }
    
        // Multi-select for folders
        setupFolderMultiSelect();
    
        // Date group toggle handlers
        setupDateGroupToggles();
    
        // Grouping section collapse toggle
        setupGroupingToggle();
    
        // Resizable panes
        setupResizablePanes();
    
        // Keyboard shortcuts
        document.addEventListener('keydown', handleKeyboardShortcuts);
    }



    // Handle grouping filter
    function handleGroupingFilter(e) {
        window.app.groupingFilter = e.target.value;
        window.app.modules.app.renderGroupingFolders();
        // Re-render transmittal folders as they depend on grouping selection
        window.app.modules.app.renderTransmittalFolders();
        // Re-filter files based on updated folder selections
        window.app.modules.filtering.applyFilters();
    }

    // Handle transmittal filter
    function handleTransmittalFilter(e) {
        window.app.transmittalFilter = e.target.value;
        window.app.modules.app.renderTransmittalFolders();
        // Re-filter files based on updated folder selections
        window.app.modules.filtering.applyFilters();
    }

    // Close modal
    function closeModal(e) {
        const modal = e.target.closest('.modal');
        if (modal) {
            modal.classList.add('hidden');
        }
    }

    // Handle keyboard shortcuts
    function handleKeyboardShortcuts(e) {
        // Escape closes modals
        if (e.key === 'Escape') {
            document.querySelectorAll('.modal:not(.hidden)').forEach(modal => {
                modal.classList.add('hidden');
            });
        }
    
        // Ctrl+A selects all visible files
        if (e.ctrlKey && e.key === 'a' && e.target.tagName !== 'INPUT') {
            e.preventDefault();
            toggleSelectAll();
        }
    
        // F5 refreshes
        if (e.key === 'F5') {
            e.preventDefault();
            window.app.modules.directory.refreshDirectories();
        }
    }

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

    // Multi-select handling for folder lists
    function setupFolderMultiSelect() {
        let lastSelectedGroupingIndex = -1;
        let lastSelectedTransmittalIndex = -1;
    
        // Handle grouping folders
        const groupingList = document.getElementById('groupingFoldersList');
        groupingList.addEventListener('click', (e) => {
            const result = handleFolderClick(e, window.app.selectedGroupingFolders, lastSelectedGroupingIndex);
            if (result !== undefined) {
                lastSelectedGroupingIndex = result;
                // Turn off "Select All" mode when user manually selects
                if (window.app.selectAllGroupingFolders) {
                    window.app.selectAllGroupingFolders = false;
                    document.getElementById('selectAllGroupingCheckbox').checked = false;
                }
                // Update selection state first
                window.app.modules.app.updateFolderSelectionState('groupingFoldersList');
                // Then update transmittal folder list based on new selection
                window.app.modules.app.renderTransmittalFolders();
                window.app.modules.filtering.applyFilters(); // Re-filter files
                // Check presets dirty state
                if (window.app.modules.presets) {
                    window.app.modules.presets.checkDirty();
                }
                // Reset transmittal index since list may have changed
                lastSelectedTransmittalIndex = -1;
            }
        });
    
        // Handle transmittal folders
        const transmittalList = document.getElementById('transmittalFoldersList');
        transmittalList.addEventListener('click', (e) => {
            const result = handleFolderClick(e, window.app.selectedTransmittalFolders, lastSelectedTransmittalIndex);
            if (result !== undefined) {
                lastSelectedTransmittalIndex = result;
                // Turn off "Select All" mode when user manually selects
                if (window.app.selectAllTransmittals) {
                    window.app.selectAllTransmittals = false;
                    document.getElementById('selectAllTransmittalsCheckbox').checked = false;
                }
                // Update selection state without rebuilding DOM
                window.app.modules.app.updateFolderSelectionState('transmittalFoldersList');
                window.app.modules.filtering.applyFilters(); // Update file display
            }
        });
    
        // Handle Ctrl+A for folder lists
        groupingList.addEventListener('keydown', (e) => {
            if (e.ctrlKey && e.key === 'a') {
                e.preventDefault();
                selectAllVisibleFolders('grouping');
            }
        });
    
        transmittalList.addEventListener('keydown', (e) => {
            if (e.ctrlKey && e.key === 'a') {
                e.preventDefault();
                selectAllVisibleFolders('transmittal');
            }
        });
    
        // Make lists focusable
        groupingList.setAttribute('tabindex', '0');
        transmittalList.setAttribute('tabindex', '0');
    }

    /**
     * Handle folder click with multi-select support (Shift/Ctrl)
     * @param {Event} e - Click event
     * @param {Set} selectedSet - Set of selected folder paths
     * @param {number} lastIndex - Index of last clicked item
     * @returns {number|undefined} Current index if valid click, undefined otherwise
     */
    function handleFolderClick(e, selectedSet, lastIndex) {
        const folderItem = e.target.closest('.folder-item');
        if (!folderItem) return undefined;
    
        const path = folderItem.getAttribute('data-path');
        if (!path) return undefined;
    
        const container = folderItem.parentElement;
        const items = Array.from(container.children);
        const currentIndex = items.indexOf(folderItem);
    
        if (e.shiftKey && lastIndex !== -1 && lastIndex < items.length) {
            // Shift+click: select range from last to current
            e.preventDefault();
            const start = Math.min(lastIndex, currentIndex);
            const end = Math.max(lastIndex, currentIndex);
        
            if (!e.ctrlKey) {
                selectedSet.clear();
            }
        
            for (let i = start; i <= end; i++) {
                const itemPath = items[i]?.getAttribute('data-path');
                if (itemPath) {
                    selectedSet.add(itemPath);
                }
            }
        } else if (e.ctrlKey || e.metaKey) {
            // Ctrl+click: toggle individual selection
            e.preventDefault();
            if (selectedSet.has(path)) {
                selectedSet.delete(path);
            } else {
                selectedSet.add(path);
            }
        } else {
            // Regular click: clear and select single item
            selectedSet.clear();
            selectedSet.add(path);
        }
    
        return currentIndex;
    }

    /**
     * Toggle expand/collapse state of a grouping folder
     * @param {string} path - Folder path to toggle
     * @param {boolean} recursive - If true, also toggle all descendants
     */
    function toggleGroupingFolder(path, recursive) {
        const isCurrentlyCollapsed = window.app.collapsedGroupingFolders.has(path);
    
        if (recursive) {
            // Get all descendant folder paths
            const descendants = window.app.groupingFolders
                .filter(f => f.path.startsWith(path + '/'))
                .map(f => f.path);
        
            if (isCurrentlyCollapsed) {
                // Expand this folder and all descendants
                window.app.collapsedGroupingFolders.delete(path);
                descendants.forEach(p => window.app.collapsedGroupingFolders.delete(p));
            } else {
                // Collapse this folder and all descendants
                window.app.collapsedGroupingFolders.add(path);
                descendants.forEach(p => window.app.collapsedGroupingFolders.add(p));
            }
        } else {
            // Just toggle this folder
            if (isCurrentlyCollapsed) {
                window.app.collapsedGroupingFolders.delete(path);
            } else {
                window.app.collapsedGroupingFolders.add(path);
            }
        }
    
        window.app.modules.app.renderGroupingFolders();
    }

    // Select all visible folders
    function selectAllVisibleFolders(folderType) {
        const container = folderType === 'grouping' ? 
            document.getElementById('groupingFoldersList') : 
            document.getElementById('transmittalFoldersList');
    
        const selectedSet = folderType === 'grouping' ? 
            window.app.selectedGroupingFolders : 
            window.app.selectedTransmittalFolders;
    
        selectedSet.clear();
    
        const items = container.querySelectorAll('.folder-item');
        items.forEach(item => {
            const path = item.getAttribute('data-path');
            if (path) {
                selectedSet.add(path);
            }
        });
    
        if (folderType === 'grouping') {
            // Update UI to reflect grouping changes
            window.app.modules.app.updateUI();
            window.app.modules.filtering.applyFilters();
        } else {
            // For transmittal folders, just update selection state
            window.app.modules.app.updateFolderSelectionState('transmittalFoldersList');
            window.app.modules.filtering.applyFilters();
        }
    }

    // Setup date group toggle handlers
    function setupDateGroupToggles() {
        // Toggle all dates button
        const toggleAllBtn = document.getElementById('toggleAllDatesBtn');
        if (toggleAllBtn) {
            toggleAllBtn.addEventListener('click', toggleAllDateGroups);
        }
    
        // Individual date group headers (using event delegation)
        const transmittalList = document.getElementById('transmittalFoldersList');
        transmittalList.addEventListener('click', (e) => {
            const header = e.target.closest('.date-group-header');
            if (header) {
                const date = header.getAttribute('data-date');
                if (date) {
                    toggleDateGroup(date);
                }
            }
        });
    }

    // Toggle a single date group
    function toggleDateGroup(date) {
        if (window.app.collapsedDateGroups.has(date)) {
            window.app.collapsedDateGroups.delete(date);
        } else {
            window.app.collapsedDateGroups.add(date);
        }
        window.app.modules.app.renderTransmittalFolders();
        updateToggleAllIcon();
    }

    // Toggle all date groups
    function toggleAllDateGroups() {
        const headers = document.querySelectorAll('.date-group-header');
        const allDates = Array.from(headers).map(h => h.getAttribute('data-date')).filter(Boolean);
    
        // If all are collapsed, expand all. Otherwise, collapse all.
        const allCollapsed = allDates.length > 0 && allDates.every(date => window.app.collapsedDateGroups.has(date));
    
        if (allCollapsed) {
            // Expand all
            window.app.collapsedDateGroups.clear();
        } else {
            // Collapse all
            allDates.forEach(date => window.app.collapsedDateGroups.add(date));
        }
    
        window.app.modules.app.renderTransmittalFolders();
        updateToggleAllIcon();
    }

    // Update the toggle all icon based on current state
    function updateToggleAllIcon() {
        const icon = document.getElementById('toggleAllDatesIcon');
        if (!icon) return;
    
        const headers = document.querySelectorAll('.date-group-header');
        const allDates = Array.from(headers).map(h => h.getAttribute('data-date')).filter(Boolean);
        const allCollapsed = allDates.length > 0 && allDates.every(date => window.app.collapsedDateGroups.has(date));
    
        icon.textContent = allCollapsed ? '▶' : '▼';
    }

    // Setup grouping section collapse toggle
    function setupGroupingToggle() {
        const toggleBtn = document.getElementById('toggleGroupingBtn');
        const groupingSection = document.getElementById('groupingSection');
        const icon = document.getElementById('toggleGroupingIcon');
    
        if (toggleBtn && groupingSection && icon) {
            toggleBtn.addEventListener('click', () => {
                groupingSection.classList.toggle('collapsed');
                icon.textContent = groupingSection.classList.contains('collapsed') ? '▶' : '▼';
            });
        }
    }

    // Setup resizable panes
    function setupResizablePanes() {
        // Resize nav sections (vertical divider between grouping and transmittal)
        const navSectionsHandle = document.querySelector('[data-resize="nav-sections"]');
        if (navSectionsHandle) {
            let isResizing = false;
            let startY = 0;
            let startHeight = 0;
            let groupingSection = null;
        
            navSectionsHandle.addEventListener('mousedown', (e) => {
                isResizing = true;
                startY = e.clientY;
                groupingSection = document.getElementById('groupingSection');
                startHeight = groupingSection.offsetHeight;
                navSectionsHandle.classList.add('resizing');
                e.preventDefault();
            });
        
            document.addEventListener('mousemove', (e) => {
                if (!isResizing) return;
            
                const deltaY = e.clientY - startY;
                const newHeight = startHeight + deltaY;
            
                // Set min/max heights
                if (newHeight >= 100 && newHeight <= window.innerHeight - 250) {
                    groupingSection.style.flex = 'none';
                    groupingSection.style.height = newHeight + 'px';
                }
            });
        
            document.addEventListener('mouseup', () => {
                if (isResizing) {
                    isResizing = false;
                    navSectionsHandle.classList.remove('resizing');
                }
            });
        }
    
        // Resize nav pane (horizontal divider between nav and content)
        const navPaneHandle = document.querySelector('[data-resize="nav-pane"]');
        if (navPaneHandle) {
            let isResizing = false;
            let startX = 0;
            let startWidth = 0;
            let navPane = null;
        
            navPaneHandle.addEventListener('mousedown', (e) => {
                isResizing = true;
                startX = e.clientX;
                navPane = document.getElementById('navigationPane');
                startWidth = navPane.offsetWidth;
                navPaneHandle.classList.add('resizing');
                e.preventDefault();
            });
        
            document.addEventListener('mousemove', (e) => {
                if (!isResizing) return;
            
                const deltaX = e.clientX - startX;
                const newWidth = startWidth + deltaX;
            
                // Set min/max widths
                if (newWidth >= 200 && newWidth <= window.innerWidth - 400) {
                    navPane.style.width = newWidth + 'px';
                }
            });
        
            document.addEventListener('mouseup', () => {
                if (isResizing) {
                    isResizing = false;
                    navPaneHandle.classList.remove('resizing');
                }
            });
        }
    }

    window.app.modules.events = {
        setupEventListeners,
        handleFolderClick,
        toggleGroupingFolder,
        selectAllVisibleFolders,
        setupDateGroupToggles,
        toggleDateGroup,
        toggleAllDateGroups,
        updateToggleAllIcon,
        setupGroupingToggle,
        setupResizablePanes
    };

})();