/**
 * HAProxy Logs Management
 * Pagination and dynamic loading of logs
 */

document.addEventListener('DOMContentLoaded', function() {
    let currentPage = 1;
    let perPage = 50;
    let totalLogs = parseInt(document.getElementById('total_count').textContent);
    
    const logsContainer = document.getElementById('logs_container');
    const perPageSelect = document.getElementById('logs_per_page');
    const refreshBtn = document.getElementById('refresh_logs_btn');
    const prevBtn = document.getElementById('prev_btn');
    const nextBtn = document.getElementById('next_btn');
    const loadAllBtn = document.getElementById('load_all_btn');
    const loadedSpan = document.getElementById('loaded_count');
    const currentPageSpan = document.getElementById('current_page');
    const totalPagesSpan = document.getElementById('total_pages');
    
    // Event Listeners
    perPageSelect.addEventListener('change', function(e) {
        perPage = parseInt(e.target.value);
        currentPage = 1;
        loadLogs();
    });
    
    refreshBtn.addEventListener('click', function() {
        currentPage = 1;
        loadLogs();
    });
    
    prevBtn.addEventListener('click', function() {
        if (currentPage > 1) {
            currentPage--;
            loadLogs();
        }
    });
    
    nextBtn.addEventListener('click', function() {
        const totalPages = Math.ceil(totalLogs / perPage);
        if (currentPage < totalPages) {
            currentPage++;
            loadLogs();
        }
    });
    
    loadAllBtn.addEventListener('click', function() {
        perPage = totalLogs;
        currentPage = 1;
        if (perPageSelect.querySelector(`option[value="${totalLogs}"]`)) {
            perPageSelect.value = totalLogs;
        }
        loadLogs();
    });
    
    /**
     * Load logs from API with pagination
     */
    function loadLogs() {
        console.log(`[Logs] Loading page ${currentPage} with ${perPage} per page`);
        
        fetch('/api/logs', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
            },
            body: JSON.stringify({
                page: currentPage,
                per_page: perPage
            })
        })
        .then(response => response.json())
        .then(data => {
            if (data.success) {
                renderLogs(data.logs);
                updatePagination(data);
                console.log(`[Logs] Successfully loaded page ${data.page}/${Math.ceil(data.total / data.per_page)}`);
            } else {
                showError(data.error || 'Unknown error');
            }
        })
        .catch(error => {
            console.error('[Logs] Error loading logs:', error);
            showError('Failed to load logs. Please try again.');
        });
    }
    
    /**
     * Render logs in the table
     */
    function renderLogs(logs) {
        if (!logs || logs.length === 0) {
            logsContainer.innerHTML = '<tr><td class="text-center text-muted py-4"><i class="bi bi-inbox"></i> No logs available</td></tr>';
            return;
        }
        
        logsContainer.innerHTML = logs.map(entry => `
            <tr>
                <td>
                    <small style="font-family: monospace; color: #666;">
                        <i class="bi bi-clock text-muted me-1"></i>${escapeHtml(entry.timestamp || 'N/A')}<br>
                        <span class="text-muted">${escapeHtml(entry.source || 'N/A')}</span><br>
                        <code style="color: #333; word-break: break-all; display: block; margin-top: 4px;">
                            ${escapeHtml(entry.message || 'N/A')}
                        </code>
                    </small>
                </td>
            </tr>
        `).join('');
    }
    
    /**
     * Update pagination controls
     */
    function updatePagination(data) {
        const totalPages = Math.ceil(data.total / data.per_page);
        loadedSpan.textContent = data.logs.length;
        currentPageSpan.textContent = data.page;
        totalPagesSpan.textContent = totalPages;
        
        // Disable/enable navigation buttons
        prevBtn.disabled = data.page === 1;
        nextBtn.disabled = !data.has_more;
    }
    
    /**
     * Show error message
     */
    function showError(message) {
        logsContainer.innerHTML = `
            <tr>
                <td class="text-center">
                    <div class="alert alert-danger mb-0">
                        <i class="bi bi-exclamation-triangle me-2"></i>${escapeHtml(message)}
                    </div>
                </td>
            </tr>
        `;
    }
    
    /**
     * Escape HTML to prevent XSS
     */
    function escapeHtml(text) {
        const map = {
            '&': '&amp;',
            '<': '&lt;',
            '>': '&gt;',
            '"': '&quot;',
            "'": '&#039;'
        };
        return text.replace(/[&<>"']/g, m => map[m]);
    }
    
    // Initial load
    loadLogs();
});