/**
 * Main application entry point for arXivCSRAG
 */

document.addEventListener('DOMContentLoaded', () => {
    // Initialize UI and Chat managers
    const uiManager   = new UIManager();
    const chatManager = new ChatManager(uiManager);
    

    // API Keys configuration
    const saveApiKeysBtn = document.getElementById('save-api-keys-btn');
    saveApiKeysBtn.addEventListener('click', async () => {
        const geminiApiKey     = document.getElementById('gemini-api-key').value.trim();
        const huggingfaceToken = document.getElementById('huggingface-token').value.trim();
        
        if (!geminiApiKey || !huggingfaceToken) {
            alert('Please enter both API keys.');
            return;
        }
        
        uiManager.showLoading('Configuring API keys...');
        
        try {
            const response = await ApiService.configureApiKeys(geminiApiKey, huggingfaceToken);
            
            if (response.status === 'success') {
                uiManager.hideModal(uiManager.apiKeysModal);
                alert('API keys configured successfully!');
            } else {
                alert('Failed to configure API keys. Please try again.');
            }
        } catch (error) {
            console.error('Error saving API keys:', error);
            alert('An unexpected error occurred. Please try again.');
        } finally {
            uiManager.hideLoading();
        }
    });
    

    // Paper search functionality
    const searchButton = document.getElementById('search-button');
    searchButton.addEventListener('click', async () => {
        // Get search parameters
        const subjectTags = Array.from(document.getElementById('subject-tags-select').selectedOptions).map(option => option.value);
        const startDate   = document.getElementById('start-date').value;
        const endDate     = document.getElementById('end-date').value;
        const maxResults  = parseInt(document.getElementById('max-results').value) || 10;
        const query       = document.getElementById('search-query').value.trim();
        
        // if (!query) {
        //     alert('Please enter a search query.');
        //     return;
        // }
        
        uiManager.showLoading('Searching for papers...');
        
        try {
            const response = await ApiService.fetchPapers({
                subject_tags: subjectTags.length > 0 ? subjectTags : null,
                start_date  : startDate || null,
                end_date    : endDate || null,
                max_results : maxResults,
                query       : query
            });
            
            if (response.status === 'success') {
                uiManager.renderSearchResults(response.papers);
            } else {
                alert('Failed to fetch papers. Please try again.');
            }
        } catch (error) {
            console.error('Error searching papers:', error);
            alert('An unexpected error occurred. Please try again.');
        } finally {
            uiManager.hideLoading();
        }
    });
    
    
    // Upload paper functionality
    const uploadButton = document.getElementById('upload-button');
    const fileInput = document.getElementById('pdf-upload');
    const fileNameDisplay = document.querySelector('.file-name-display');
    const selectedFileName = document.getElementById('selected-file-name');
    
    // Handle file selection display
    fileInput.addEventListener('change', (event) => {
        const file = fileInput.files[0];
        console.log('File selected:', file ? file.name : 'No file');
        
        if (file) {
            selectedFileName.textContent = file.name;
            fileNameDisplay.classList.add('active');
            uploadButton.classList.add('file-selected');
            uploadButton.innerHTML = '<i class="bi bi-upload"></i> Upload "' + file.name.substring(0, 15) + (file.name.length > 15 ? '...' : '') + '"';
            console.log('File name display should be visible now');
        } else {
            selectedFileName.textContent = 'No file selected';
            fileNameDisplay.classList.remove('active');
            uploadButton.classList.remove('file-selected');
            uploadButton.innerHTML = '<i class="bi bi-upload"></i> Upload PDF';
        }
    });
    
    uploadButton.addEventListener('click', async () => {
        const file = fileInput.files[0];
        
        if (!file) {
            alert('Please select a PDF file to upload.');
            return;
        }
        
        if (file.type !== 'application/pdf') {
            alert('Please select a valid PDF file.');
            return;
        }
        
        uiManager.showLoading('Uploading paper...');
        
        try {
            const response = await ApiService.uploadPaper(file);
            
            if (response.status === 'success') {
                await chatManager.processPaper(response.file_path);
            } else {
                alert('Failed to upload paper. Please try again.');
                uiManager.hideLoading();
            }
        } catch (error) {
            console.error('Error uploading paper:', error);
            alert('An unexpected error occurred. Please try again.');
            uiManager.hideLoading();
        }
    });

    
    // Paper info modal buttons
    document.getElementById('open-arxiv-btn').addEventListener('click', function() {
        const url = this.dataset.url;
        if (url) {
            window.open(url, '_blank');
        }
    });
    
    document.getElementById('view-pdf-btn').addEventListener('click', function() {
        const url = this.dataset.url;
        if (url) {
            window.open(url, '_blank');
        }
    });
    
    document.getElementById('download-pdf-btn').addEventListener('click', function() {
        const paperId = this.dataset.paperId;
        if (paperId) {
            // Create a temporary link to download the file
            uiManager.showLoading('Preparing download...');
            
            ApiService.downloadPaper(paperId)
                .then(response => {
                    if (response.status === 'success') {
                        // Create a link to download the file directly
                        const a = document.createElement('a');
                        a.href = response.file_path;
                        a.download = `${paperId.replace('/', '_')}.pdf`;
                        document.body.appendChild(a);
                        a.click();
                        document.body.removeChild(a);
                    } else {
                        alert('Failed to download paper. Please try again.');
                    }
                })
                .catch(error => {
                    console.error('Error downloading paper:', error);
                    alert('An unexpected error occurred. Please try again.');
                })
                .finally(() => {
                    uiManager.hideLoading();
                });
        }
    });
    
    document.getElementById('chat-with-paper-btn').addEventListener('click', function() {
        const paperId = this.dataset.paperId;
        if (paperId) {
            chatManager.downloadAndProcessPaper(paperId);
        }
    });
    

    // Show API keys modal on first load
    setTimeout(() => {
        uiManager.showModal(uiManager.apiKeysModal);
    }, 500);
});