/**
 * SCADA vs DWG Manifest Comparison Tool
 * Main JavaScript functionality
 */

document.addEventListener('DOMContentLoaded', function() {
    // Initialize Bootstrap components
    initializeBootstrapComponents();
    
    // Add search/filter functionality to tables
    initializeTableFilters();
    
    // Add copy to clipboard functionality
    initializeClipboardCopy();
    
    // Handle form submissions to prevent resubmission prompts
    initializeFormHandlers();
});

/**
 * Initialize form handlers to prevent resubmission prompts
 */
function initializeFormHandlers() {
    // Handle main comparison form
    const comparisonForm = document.querySelector('form[action*="compare"]');
    if (comparisonForm) {
        comparisonForm.addEventListener('submit', function(e) {
            e.preventDefault();
            const formData = new FormData(this);
            
            // Show loading indicator
            const submitBtn = this.querySelector('button[type="submit"]');
            const originalBtnText = submitBtn.innerHTML;
            submitBtn.disabled = true;
            submitBtn.innerHTML = 'Processing...';
            
            fetch(this.action, {
                method: 'POST',
                body: formData,
                redirect: 'manual'
            })
            .then(response => {
                if (response.type === 'opaqueredirect') {
                    // Server redirected, follow the redirect
                    window.location.href = response.url || '/';
                    return;
                }
                return response.text();
            })
            .then(html => {
                if (html) {
                    // If we got HTML back and not a redirect, handle it
                    // This is a fallback in case redirect didn't work
                    window.location.reload();
                }
            })
            .catch(error => {
                console.error('Error:', error);
                alert('An error occurred during form submission. Please try again.');
                submitBtn.disabled = false;
                submitBtn.innerHTML = originalBtnText;
            });
        });
    }
    
    // Handle update files form
    const updateForm = document.querySelector('form[action*="update_files"]');
    if (updateForm) {
        updateForm.addEventListener('submit', function(e) {
            e.preventDefault();
            const formData = new FormData(this);
            
            // Show loading indicator
            const submitBtn = this.querySelector('button[type="submit"]');
            const originalBtnText = submitBtn.innerHTML;
            submitBtn.disabled = true;
            submitBtn.innerHTML = 'Updating...';
            
            fetch(this.action, {
                method: 'POST',
                body: formData,
                redirect: 'manual'
            })
            .then(response => {
                if (response.type === 'opaqueredirect') {
                    // Server redirected, follow the redirect
                    window.location.href = response.url || '/';
                    return;
                }
                return response.text();
            })
            .then(html => {
                if (html) {
                    // If we got HTML back and not a redirect, handle it
                    window.location.reload();
                }
            })
            .catch(error => {
                console.error('Error:', error);
                alert('An error occurred during update. Please try again.');
                submitBtn.disabled = false;
                submitBtn.innerHTML = originalBtnText;
            });
        });
    }
    
    // Handle delete comparison form (the one created dynamically in the results page)
    document.addEventListener('submit', function(e) {
        if (e.target.action && e.target.action.includes('delete_comparison')) {
            e.preventDefault();
            
            fetch(e.target.action, {
                method: 'POST',
                redirect: 'manual'
            })
            .then(response => {
                if (response.type === 'opaqueredirect') {
                    window.location.href = response.url || '/';
                    return;
                }
                return response.text();
            })
            .then(html => {
                if (html) {
                    window.location.href = '/';
                }
            })
            .catch(error => {
                console.error('Error:', error);
                alert('An error occurred while deleting the comparison. Please try again.');
            });
        }
    });
}

/**
 * Initialize Bootstrap components like tabs
 */
function initializeBootstrapComponents() {
    // Initialize tabs if they exist
    const tabEls = document.querySelectorAll('button[data-bs-toggle="tab"]');
    if (tabEls.length > 0) {
        tabEls.forEach(tabEl => {
            new bootstrap.Tab(tabEl);
        });
        
        // Add event listener for tab change to persist active tab
        tabEls.forEach(tab => {
            tab.addEventListener('shown.bs.tab', function (event) {
                // Store the currently active tab in local storage
                localStorage.setItem('activeTab', event.target.id);
            });
        });
        
        // Restore active tab from localStorage if available
        const activeTabId = localStorage.getItem('activeTab');
        if (activeTabId) {
            const activeTab = document.getElementById(activeTabId);
            if (activeTab) {
                new bootstrap.Tab(activeTab).show();
            }
        }
    }
}

/**
 * Add search/filter functionality to tables
 */
function initializeTableFilters() {
    // Create filter inputs for each table that needs filtering
    const tableContainers = document.querySelectorAll('.table-container');
    
    tableContainers.forEach((container, index) => {
        const table = container.querySelector('table');
        if (!table) return;
        
        // Make the table the first element in a new structure
        const originalHTML = container.innerHTML;
        container.innerHTML = '';
        
        // Create a wrapper for the sticky elements
        const stickyHeader = document.createElement('div');
        stickyHeader.className = 'sticky-table-header';
        
        // Create filter input
        const filterDiv = document.createElement('div');
        filterDiv.className = 'table-filter-container d-flex justify-content-between align-items-center';
        
        // Create the left side with search input
        const searchGroup = document.createElement('div');
        searchGroup.className = 'input-group';
        searchGroup.style.flexBasis = '80%';
        
        const filterInput = document.createElement('input');
        filterInput.type = 'text';
        filterInput.className = 'form-control table-filter';
        filterInput.placeholder = 'Filter items...';
        filterInput.setAttribute('data-table-index', index);
        
        const filterClearBtn = document.createElement('button');
        filterClearBtn.className = 'btn btn-outline-secondary';
        filterClearBtn.innerHTML = '×';
        filterClearBtn.type = 'button';
        
        searchGroup.appendChild(filterInput);
        searchGroup.appendChild(filterClearBtn);
        
        // Add the search group to the filter container
        filterDiv.appendChild(searchGroup);
        
        // The copy button will be added by initializeClipboardCopy()
        stickyHeader.appendChild(filterDiv);
        
        // Create a scrollable content div
        const scrollableContent = document.createElement('div');
        scrollableContent.className = 'scrollable-table-content';
        scrollableContent.innerHTML = originalHTML;
        
        // Add both elements to the container
        container.appendChild(stickyHeader);
        container.appendChild(scrollableContent);
        
        // Fix for header width issue - ensure the table has a consistent width
        // and the header cells match the body cells
        window.addEventListener('load', function() {
            const tableHeader = scrollableContent.querySelector('thead');
            const tableBody = scrollableContent.querySelector('tbody');
            
            if (tableHeader && tableBody) {
                // Ensure equal cell widths
                const headerCells = tableHeader.querySelectorAll('th');
                const firstRowCells = tableBody.querySelector('tr') ? 
                                      tableBody.querySelector('tr').querySelectorAll('td') : null;
                
                if (headerCells.length > 0 && firstRowCells && firstRowCells.length > 0) {
                    // Set explicit widths on header cells based on first row
                    for (let i = 0; i < headerCells.length && i < firstRowCells.length; i++) {
                        const width = firstRowCells[i].offsetWidth;
                        headerCells[i].style.minWidth = width + 'px';
                    }
                }
            }
        });
        
        // Add event listeners
        filterInput.addEventListener('input', function() {
            // Get the table from the scrollable content
            const tableInContent = scrollableContent.querySelector('table');
            filterTable(tableInContent, this.value);
        });
        
        filterClearBtn.addEventListener('click', function() {
            filterInput.value = '';
            const tableInContent = scrollableContent.querySelector('table');
            filterTable(tableInContent, '');
        });
    });
}

/**
 * Filter table rows based on input
 */
function filterTable(table, filterText) {
    const tbody = table.querySelector('tbody');
    if (!tbody) return;
    
    const rows = tbody.querySelectorAll('tr');
    const lowerFilterText = filterText.toLowerCase();
    
    rows.forEach(row => {
        const text = row.textContent.toLowerCase();
        if (text.includes(lowerFilterText)) {
            row.style.display = '';
        } else {
            row.style.display = 'none';
        }
    });
    
    // Update counter if there is one
    const cardHeader = table.closest('.card').querySelector('.card-header h5');
    if (cardHeader) {
        const originalText = cardHeader.getAttribute('data-original-text');
        if (!originalText) {
            cardHeader.setAttribute('data-original-text', cardHeader.textContent);
        }
        
        if (filterText) {
            const visibleRowCount = [...rows].filter(row => row.style.display !== 'none').length;
            const matches = cardHeader.textContent.match(/\((\d+)\)/);
            if (matches && matches[1]) {
                cardHeader.textContent = cardHeader.textContent.replace(
                    `(${matches[1]})`, 
                    `(${visibleRowCount} of ${matches[1]})`
                );
            }
        } else if (originalText) {
            cardHeader.textContent = originalText;
        }
    }
}

/**
 * Add ability to copy table contents to clipboard
 */
function initializeClipboardCopy() {
    const tableContainers = document.querySelectorAll('.table-container');
    
    tableContainers.forEach(container => {
        // Find the filter container in the sticky header
        const filterContainer = container.querySelector('.table-filter-container');
        if (!filterContainer) return;
        
        // Create copy button
        const copyBtn = document.createElement('button');
        copyBtn.className = 'btn btn-primary ms-2 copy-btn';
        copyBtn.innerHTML = '<i class="bi bi-clipboard"></i> Copy';
        
        // Insert button into the filter container
        filterContainer.appendChild(copyBtn);
        
        // Add event listener
        copyBtn.addEventListener('click', function() {
            // Find the table in the scrollable content
            const scrollableContent = container.querySelector('.scrollable-table-content');
            const table = scrollableContent ? scrollableContent.querySelector('table') : container.querySelector('table');
            if (!table) return;
            
            let text = '';
            const rows = table.querySelectorAll('tbody tr');
            
            rows.forEach(row => {
                if (row.style.display !== 'none') {
                    const cells = row.querySelectorAll('td');
                    cells.forEach(cell => {
                        text += cell.textContent.trim() + '\t';
                    });
                    text += '\n';
                }
            });
            
            copyToClipboard(text);
            
            // Visual feedback
            const originalText = copyBtn.innerHTML;
            copyBtn.innerHTML = '<i class="bi bi-check"></i> Copied!';
            copyBtn.classList.add('btn-success');
            copyBtn.classList.remove('btn-primary');
            
            setTimeout(() => {
                copyBtn.innerHTML = originalText;
                copyBtn.classList.remove('btn-success');
                copyBtn.classList.add('btn-primary');
            }, 1500);
        });
    });
}

/**
 * Helper function to copy text to clipboard
 */
function copyToClipboard(text) {
    // Create a temporary textarea
    const textarea = document.createElement('textarea');
    textarea.value = text;
    textarea.setAttribute('readonly', '');
    textarea.style.position = 'absolute';
    textarea.style.left = '-9999px';
    document.body.appendChild(textarea);
    
    // Select and copy
    textarea.select();
    document.execCommand('copy');
    
    // Clean up
    document.body.removeChild(textarea);
}

/**
 * Handle file upload previews and validation
 */
document.querySelectorAll('input[type="file"]').forEach(fileInput => {
    fileInput.addEventListener('change', function(e) {
        const fileName = e.target.files[0]?.name;
        const fileLabel = fileInput.nextElementSibling;
        
        if (fileName) {
            // Show the filename
            if (fileLabel) {
                fileLabel.textContent = fileName;
            }
            
            // Basic validation for Excel files
            if (!fileName.endsWith('.xlsx') && !fileName.endsWith('.xls')) {
                alert('Please upload a valid Excel file (.xlsx or .xls)');
                fileInput.value = '';
                if (fileLabel) {
                    fileLabel.textContent = 'Choose file';
                }
            }
        }
    });
});