/**
 * URL Form Handler
 * Handles the submission of the URL form using AJAX to prevent page refreshes
 */

document.addEventListener('DOMContentLoaded', function() {
    // Get form elements
    const urlForm = document.getElementById('urlForm');
    const urlInput = document.getElementById('urlInput');
    const loadingIndicator = document.getElementById('loading');
    const resultsSection = document.getElementById('results-section');
    const errorContainer = document.getElementById('errorContainer');
    const errorMessage = document.getElementById('errorMessage');
    const errorDetails = document.getElementById('errorDetails');
    const dismissErrorBtn = document.getElementById('dismissError');
    
    console.log('URL Form Handler initialized');
    
    // Add event listener to the form
    if (urlForm) {
        console.log('URL form found, adding submit handler');
        
        urlForm.addEventListener('submit', function(e) {
            e.preventDefault();
            console.log('Form submission intercepted');
            
            const url = urlInput.value.trim();
            if (!url) {
                console.log('Empty URL, aborting');
                return;
            }
            
            // Clear any previous errors
            hideError();
            
            // Show loading indicator
            if (loadingIndicator) {
                loadingIndicator.style.display = 'block';
            }
            
            // Hide results section if visible
            if (resultsSection) {
                resultsSection.style.display = 'none';
            }
            
            console.log('Analyzing URL:', url);
            
            // Prepare the request data
            const requestData = {
                url: url
            };
            
            // Make AJAX request
            fetch('/predict', {
                method: 'POST',
                headers: {
                    'Content-Type': 'application/json'
                },
                body: JSON.stringify(requestData)
            })
            .then(response => {
                if (!response.ok) {
                    throw new Error(`HTTP error! Status: ${response.status}`);
                }
                console.log('Response received:', response.status);
                return response.json().catch(error => {
                    console.error('Error parsing JSON response:', error);
                    throw new Error('Invalid JSON response from server');
                });
            })
            .then(data => {
                console.log('Analysis result:', data);
                
                // Hide loading indicator
                if (loadingIndicator) {
                    loadingIndicator.style.display = 'none';
                }
                
                // Enhanced error detection: Check for error status or missing required fields
                if (data.status === "error" || (!data.score && !data.fraud_score)) {
                    console.error('Server error or incomplete data:', data);
                    let errorMsg = data.message || 'Incomplete data received from server';
                    let detailMsg = data.traceback || 'The response is missing required fields';
                    
                    if (data.error) {
                        errorMsg = data.error;
                    }
                    
                    showError(errorMsg, detailMsg);
                    return;
                }
                
                // Make sure we have the minimum data needed to display results
                try {
                    // Display results using the displayResults function
                    if (window.displayResults && typeof window.displayResults.displayAllResults === 'function') {
                        window.displayResults.displayAllResults(data);
                        
                        // Show the results section
                        if (resultsSection) {
                            resultsSection.style.display = 'block';
                            resultsSection.scrollIntoView({ behavior: 'smooth' });
                        }
                    } else {
                        console.error('displayResults function not available');
                        // Update analyzed URL in the results
                        const analyzedUrlElement = document.getElementById('analyzed-url');
                        if (analyzedUrlElement) {
                            analyzedUrlElement.textContent = url;
                        }
                        
                        // If displayResults is not available, show the results section at minimum
                        if (resultsSection) {
                            resultsSection.style.display = 'block';
                            resultsSection.scrollIntoView({ behavior: 'smooth' });
                        }
                    }
                } catch (displayError) {
                    console.error('Error displaying results:', displayError);
                    showError('Error displaying results', 'An error occurred while rendering the analysis results. Please try again.');
                }
            })
            .catch(error => {
                console.error('Error analyzing URL:', error);
                
                // Hide loading indicator
                if (loadingIndicator) {
                    loadingIndicator.style.display = 'none';
                }
                
                // More detailed error message
                let errorDetails = 'Please check your connection and try again';
                if (error.message) {
                    errorDetails = `Error details: ${error.message}`;
                }
                
                // Show error message
                showError('An error occurred while analyzing the URL', errorDetails);
            });
        });
    } else {
        console.warn('URL form not found in the document');
    }
    
    // Error handling functions
    function showError(message, details = '') {
        if (errorContainer && errorMessage && errorDetails) {
            errorMessage.textContent = message || 'An error occurred';
            errorDetails.textContent = details || 'Please try again or check your connection';
            errorContainer.style.display = 'block';
            
            // Auto-scroll to error message
            errorContainer.scrollIntoView({ behavior: 'smooth' });
        } else {
            console.error('Error message elements not found');
            alert(message || 'An error occurred');
        }
    }
    
    function hideError() {
        if (errorContainer) {
            errorContainer.style.display = 'none';
        }
    }
    
    // Add event listener to dismiss error button
    if (dismissErrorBtn) {
        dismissErrorBtn.addEventListener('click', hideError);
    }
    
    // Add connection test functionality
    // Check for test button in error message
    const testConnectionBtn = document.createElement('button');
    testConnectionBtn.id = 'testConnectionBtn';
    testConnectionBtn.className = 'btn btn-outline-primary btn-sm ms-2';
    testConnectionBtn.textContent = 'Test Connection';
    testConnectionBtn.style.marginLeft = '8px';
    
    // Add it to the error container if it exists
    if (errorContainer && !document.getElementById('testConnectionBtn')) {
        const errorActions = document.createElement('div');
        errorActions.className = 'error-actions';
        errorActions.style.marginTop = '15px';
        errorActions.style.display = 'flex';
        errorActions.style.justifyContent = 'flex-end';
        
        errorActions.appendChild(testConnectionBtn);
        
        if (dismissErrorBtn) {
            dismissErrorBtn.style.marginLeft = '8px';
            errorActions.appendChild(dismissErrorBtn);
        }
        
        errorContainer.appendChild(errorActions);
    }
    
    // Add event listener for connection test
    testConnectionBtn.addEventListener('click', function() {
        console.log('Testing connection to backend...');
        
        // Show a small loading indicator in the button
        testConnectionBtn.innerHTML = '<span class="spinner-border spinner-border-sm" role="status" aria-hidden="true"></span> Testing...';
        testConnectionBtn.disabled = true;
        
        // Test basic connection with simple GET request
        fetch('/debug-connection')
            .then(response => response.json())
            .then(data => {
                console.log('Connection test GET result:', data);
                
                // Now try a POST request with actual payload
                return fetch('/debug-connection', {
                    method: 'POST',
                    headers: {
                        'Content-Type': 'application/json'
                    },
                    body: JSON.stringify({test: true, timestamp: new Date().toISOString()})
                });
            })
            .then(response => response.json())
            .then(data => {
                console.log('Connection test POST result:', data);
                
                // Show success message
                testConnectionBtn.innerHTML = '<i class="fas fa-check"></i> Connection OK';
                testConnectionBtn.className = 'btn btn-success btn-sm ms-2';
                
                // Reset after a delay
                setTimeout(() => {
                    testConnectionBtn.textContent = 'Test Connection';
                    testConnectionBtn.className = 'btn btn-outline-primary btn-sm ms-2';
                    testConnectionBtn.disabled = false;
                    
                    // Update error message
                    errorMessage.textContent = 'Connection to server is working';
                    errorDetails.textContent = 'Try submitting your URL again. If the error persists, the issue may be with processing your specific URL.';
                }, 2000);
            })
            .catch(error => {
                console.error('Connection test failed:', error);
                
                // Show error
                testConnectionBtn.innerHTML = '<i class="fas fa-times"></i> Failed';
                testConnectionBtn.className = 'btn btn-danger btn-sm ms-2';
                
                // Reset after a delay
                setTimeout(() => {
                    testConnectionBtn.textContent = 'Test Connection';
                    testConnectionBtn.className = 'btn btn-outline-primary btn-sm ms-2';
                    testConnectionBtn.disabled = false;
                    
                    // Update error message with more details
                    errorMessage.textContent = 'Connection to server failed';
                    errorDetails.textContent = `Error details: ${error.message}. Please check your network connection or server status.`;
                }, 2000);
            });
    });
});