// Import Firebase functions
import { initializeApp } from 'https://www.gstatic.com/firebasejs/11.6.1/firebase-app.js';
import { getAuth, onAuthStateChanged, signInAnonymously, signInWithCustomToken, signOut, GoogleAuthProvider, GithubAuthProvider, signInWithPopup, updateProfile } from 'https://www.gstatic.com/firebasejs/11.6.1/firebase-auth.js';
import { getFirestore, doc, getDoc, setDoc, deleteDoc } from 'https://www.gstatic.com/firebasejs/11.6.1/firebase-firestore.js';

// Main application logic
document.addEventListener('DOMContentLoaded', async () => {
    try {
        console.log('App initialized');
        
        const firebaseConfig = JSON.parse(typeof __firebase_config !== 'undefined' ? __firebase_config : '{}');
        const appId = typeof __app_id !== 'undefined' ? __app_id : 'default-app-id';

        const app = initializeApp(firebaseConfig);
        const db = getFirestore(app);
        const auth = getAuth(app);
        
        // Set log level for debugging
        // Note: setLogLevel is not available in the modular SDK, using console.log instead
        console.log("Firebase Initialized. Waiting for auth...");

        // --- App State & Firebase Globals ---
        let userId, agentConfigDocRef;
        let isProfileSidebarOpen = false;
        let testChatHistory = []; // State for test chat

        const defaultAppState = {
            agentName: "Creative Writer",
            description: "A helpful assistant for Python code.",
            instructions: "You are a helpful AI assistant...",
            modelConfig: {
                selectedModel: 'llama3-70b',
                apiKeys: { 'qhy-pro': '', 'gemini-2.5': '' }
            },
            knowledge: {
                prioritize: false,
                urls: ['https://qhy.sync/docs/main']
            },
            capabilities: {
                codeInterpreter: false,
                imageGenerator: true
            },
            prompts: [
                { title: "Explain a concept", message: "\"Explain quantum computing...\"" },
                { title: "Write some code", message: "\"Write a Python function...\"" }
            ],
            bio: "",
            displayName: "",
            photoURL: ""
        };

        let appState = { ...defaultAppState };
        
        // --- DOM Selectors ---
        let agentNameInput, agentDescriptionInput, agentInstructionsInput,
            listenInstructionsBtn, ttsPlayer,
            modelConfigContainer, knowledgeListContainer, knowledgeEmptyState,
            knowledgeUrlInput, addKnowledgeUrlBtn, prioritizeKnowledgeToggle,
            codeInterpreterToggle, testCodeInterpreterBtn,
            imageGeneratorToggle, testImageGenBtn,
            promptListContainer, promptEmptyState, addPromptBtn, 
            saveChangesBtn, deleteAgentBtn, suggestNameBtn, 
            suggestDescriptionBtn, generateInstructionsBtn, suggestPromptsBtn, 
            loadingModal, loadingMessage, promptModal, promptModalTitle, 
            promptModalCloseBtn, promptModalCancelBtn, promptModalForm, 
            promptModalSaveBtn, promptModalEditIndex, promptModalTitleInput, 
            promptModalMessageInput, deleteAgentModal, deleteAgentCancelBtn, 
            deleteAgentConfirmBtn,
            // UI Elements
            menuBtn, profileToggleBtn, profileHeaderIcon, profileHeaderImg,
            profileSidebar, sidebarOverlay, profileSidebarCloseBtn,
            profileImgPreview, profileImgUrlInput, profileDisplayNameInput,
            profileBioInput, suggestBioBtn, saveProfileBtn, googleSigninBtn, 
            githubSigninBtn, signOutBtn, socialLoginContainer, signOutContainer,
            geminiSettingsModal, geminiSettingsCloseBtn, geminiSettingsSaveBtn,
            // Test Agent Elements
            testAgentBtn, testAgentModal, testAgentCloseBtn, testAgentHistory,
            testAgentForm, testAgentInput,
            // Image Gen Modal Elements
            imageGenModal, imageGenCloseBtn, imageGenForm, imageGenInput, 
            imageGenResultContainer, imageGenSpinner, imageGenResult, imageGenError,
            // NEW: Code Test Modal Elements
            codeTestModal, codeTestCloseBtn, codeTestGenerateBtn, 
            codeTestResultContainer, codeTestSpinner, codeTestResult;

        /**
         * Assign all DOM elements to their variables.
         */
        function selectDOMElements() {
            // Wait for custom elements to be fully loaded
            const waitForElements = setInterval(() => {
                // Try to get elements from main content and custom components
                const mainContent = document.getElementById('main-content');
                const sidebar = document.querySelector('custom-sidebar');
                const navbar = document.querySelector('custom-navbar');
                const modals = document.querySelector('custom-modals');
                
                if (mainContent) {
                    // Existing Elements
                    agentNameInput = document.getElementById('agent-name');
                    agentDescriptionInput = document.getElementById('agent-description');
                    agentInstructionsInput = document.getElementById('agent-instructions');
                    listenInstructionsBtn = document.getElementById('listen-instructions-btn');
                    modelConfigContainer = document.getElementById('model-config-container');
                    knowledgeListContainer = document.getElementById('knowledge-list-container');
                    knowledgeEmptyState = document.getElementById('knowledge-empty-state');
                    knowledgeUrlInput = document.getElementById('knowledge-url-input');
                    addKnowledgeUrlBtn = document.getElementById('add-knowledge-url-btn');
                    prioritizeKnowledgeToggle = document.getElementById('prioritize-knowledge');
                    codeInterpreterToggle = document.getElementById('code-interpreter');
                    testCodeInterpreterBtn = document.getElementById('test-code-interpreter-btn');
                    imageGeneratorToggle = document.getElementById('image-generator');
                    testImageGenBtn = document.getElementById('test-image-gen-btn');
                    promptListContainer = document.getElementById('prompt-list-container');
                    promptEmptyState = document.getElementById('prompt-empty-state');
                    addPromptBtn = document.getElementById('add-prompt-btn');
                    saveChangesBtn = document.getElementById('save-changes-btn');
                    deleteAgentBtn = document.getElementById('delete-agent-btn');
                    suggestNameBtn = document.getElementById('suggest-name-btn');
                    suggestDescriptionBtn = document.getElementById('suggest-description-btn');
                    generateInstructionsBtn = document.getElementById('generate-instructions-btn');
                    suggestPromptsBtn = document.getElementById('suggest-prompts-btn');
                    
                    // Test Agent Elements
                    testAgentBtn = document.getElementById('test-agent-btn');
                    testAgentHistory = document.getElementById('test-agent-history');
                    testAgentForm = document.getElementById('test-agent-form');
                    testAgentInput = document.getElementById('test-agent-input');
                    testAgentModal = document.getElementById('test-agent-modal');
                    testAgentCloseBtn = document.getElementById('test-agent-close-btn');
                    
                    // Image Gen Modal Elements
                    imageGenModal = document.getElementById('image-gen-modal');
                    imageGenCloseBtn = document.getElementById('image-gen-close-btn');
                    imageGenForm = document.getElementById('image-gen-form');
                    imageGenInput = document.getElementById('image-gen-input');
                    imageGenResultContainer = document.getElementById('image-gen-result-container');
                    imageGenSpinner = document.getElementById('image-gen-spinner');
                    imageGenResult = document.getElementById('image-gen-result');
                    imageGenError = document.getElementById('image-gen-error');

                    // NEW: Code Test Modal Elements
                    codeTestModal = document.getElementById('code-test-modal');
                    codeTestCloseBtn = document.getElementById('code-test-close-btn');
                    codeTestGenerateBtn = document.getElementById('code-test-generate-btn');
                    codeTestResultContainer = document.getElementById('code-test-result-container');
                    codeTestSpinner = document.getElementById('code-test-spinner');
                    codeTestResult = document.getElementById('code-test-result');
                    
                    // Modals
                    loadingModal = document.getElementById('loading-modal');
                    loadingMessage = document.getElementById('loading-message');
                    promptModal = document.getElementById('prompt-modal');
                    promptModalTitle = document.getElementById('prompt-modal-title');
                    promptModalCloseBtn = document.getElementById('prompt-modal-close-btn');
                    promptModalCancelBtn = document.getElementById('prompt-modal-cancel-btn');
                    promptModalForm = document.getElementById('prompt-modal-form');
                    promptModalSaveBtn = document.getElementById('prompt-modal-save-btn');
                    promptModalEditIndex = document.getElementById('prompt-modal-edit-index');
                    promptModalTitleInput = document.getElementById('prompt-modal-title-input');
                    promptModalMessageInput = document.getElementById('prompt-modal-message-input');
                    deleteAgentModal = document.getElementById('delete-agent-modal');
                    deleteAgentCancelBtn = document.getElementById('delete-agent-cancel-btn');
                    deleteAgentConfirmBtn = document.getElementById('delete-agent-confirm-btn');
                    geminiSettingsModal = document.getElementById('gemini-settings-modal');
                    geminiSettingsCloseBtn = document.getElementById('gemini-settings-close-btn');
                    geminiSettingsSaveBtn = document.getElementById('gemini-settings-save-btn');
                }
                
                if (navbar && navbar.shadowRoot) {
                    menuBtn = navbar.shadowRoot.querySelector('#menu-btn');
                    profileToggleBtn = navbar.shadowRoot.querySelector('#profile-toggle-btn');
                    profileHeaderIcon = navbar.shadowRoot.querySelector('#profile-header-icon');
                    profileHeaderImg = navbar.shadowRoot.querySelector('#profile-header-img');
                }
                
                if (sidebar && sidebar.shadowRoot) {
                    profileSidebar = sidebar.shadowRoot.querySelector('#profile-sidebar');
                    sidebarOverlay = sidebar.shadowRoot.querySelector('#sidebar-overlay');
                    profileSidebarCloseBtn = sidebar.shadowRoot.querySelector('#profile-sidebar-close-btn');
                    profileImgPreview = sidebar.shadowRoot.querySelector('#profile-img-preview');
                    profileImgUrlInput = sidebar.shadowRoot.querySelector('#profile-img-url-input');
                    profileDisplayNameInput = sidebar.shadowRoot.querySelector('#profile-display-name-input');
                    profileBioInput = sidebar.shadowRoot.querySelector('#profile-bio-input');
                    suggestBioBtn = sidebar.shadowRoot.querySelector('#suggest-bio-btn');
                    saveProfileBtn = sidebar.shadowRoot.querySelector('#save-profile-btn');
                    googleSigninBtn = sidebar.shadowRoot.querySelector('#google-signin-btn');
                    githubSigninBtn = sidebar.shadowRoot.querySelector('#github-signin-btn');
                    signOutBtn = sidebar.shadowRoot.querySelector('#sign-out-btn');
                    socialLoginContainer = sidebar.shadowRoot.querySelector('#social-login-container');
                    signOutContainer = sidebar.shadowRoot.querySelector('#sign-out-container');
                }
                
                // Audio player
                ttsPlayer = document.getElementById('tts-player');
                
                if (agentNameInput && menuBtn && profileToggleBtn) {
                    clearInterval(waitForElements);
                    console.log('DOM elements ready');
                    attachEventListeners();
                    initializeAppUI();
                }
            }, 100);
        }

        // --- Render Functions ---

        /** Initializes the UI from the current appState */
        function initializeAppUI() {
            if (!agentNameInput) {
                console.warn("DOM elements not ready, skipping UI init.");
                return; // Guard clause
            }

            // 1. Populate Agent Config Form
            agentNameInput.value = appState.agentName;
            agentDescriptionInput.value = appState.description;
            agentInstructionsInput.value = appState.instructions;
            prioritizeKnowledgeToggle.checked = appState.knowledge.prioritize;
            
            // Handle Code Interpreter Toggle and Test Button
            codeInterpreterToggle.checked = appState.capabilities.codeInterpreter;
            if (appState.capabilities.codeInterpreter) {
                testCodeInterpreterBtn.disabled = false;
                testCodeInterpreterBtn.classList.remove('btn-disabled', 'text-slate-400');
                testCodeInterpreterBtn.classList.add('text-indigo-600', 'hover:bg-indigo-50');
            } else {
                testCodeInterpreterBtn.disabled = true;
                testCodeInterpreterBtn.classList.add('btn-disabled', 'text-slate-400');
                testCodeInterpreterBtn.classList.remove('text-indigo-600', 'hover:bg-indigo-50');
            }
            
            // Handle Image Generator Toggle and Test Button
            imageGeneratorToggle.checked = appState.capabilities.imageGenerator;
            if (appState.capabilities.imageGenerator) {
                testImageGenBtn.disabled = false;
                testImageGenBtn.classList.remove('btn-disabled', 'text-slate-400');
                testImageGenBtn.classList.add('text-indigo-600', 'hover:bg-indigo-50');
            } else {
                testImageGenBtn.disabled = true;
                testImageGenBtn.classList.add('btn-disabled', 'text-slate-400');
                testImageGenBtn.classList.remove('text-indigo-600', 'hover:bg-indigo-50');
            }

            if (appState.modelConfig?.selectedModel) {
                 const modelInput = document.querySelector(`input[name="model-selection"][value="${appState.modelConfig.selectedModel}"]`);
                 if (modelInput) modelInput.checked = true;
            }
            document.getElementById('api-key-qhy-pro-input').value = appState.modelConfig?.apiKeys?.['qhy-pro'] || '';
            document.getElementById('api-key-gemini-2.5-input').value = appState.modelConfig?.apiKeys?.['gemini-2.5'] || '';
            
            renderModelConfig();
            renderKnowledgeList();
            renderPromptList();

            // 2. Populate Profile Sidebar
            const currentUser = auth.currentUser;
            const displayName = currentUser?.displayName || appState.displayName || '';
            const photoURL = currentUser?.photoURL || appState.photoURL || '';
            const bio = appState.bio || '';

            if (profileDisplayNameInput) profileDisplayNameInput.value = displayName;
            if (profileImgUrlInput) profileImgUrlInput.value = photoURL;
            if (profileBioInput) profileBioInput.value = bio;

            // Update image previews
            updateImagePreviews(photoURL);

            // 3. Update Auth-dependent UI
            if (currentUser && saveProfileBtn) {
                if (currentUser.isAnonymous) {
                    if (socialLoginContainer) socialLoginContainer.classList.remove('hidden');
                    if (signOutContainer) signOutContainer.classList.add('hidden');
                    saveProfileBtn.classList.add('btn-disabled');
                    saveProfileBtn.disabled = true;
                    saveProfileBtn.title = "Sign in to save profile";
                } else {
                    if (socialLoginContainer) socialLoginContainer.classList.add('hidden');
                    if (signOutContainer) signOutContainer.classList.remove('hidden');
                    saveProfileBtn.classList.remove('btn-disabled');
                    saveProfileBtn.disabled = false;
                    saveProfileBtn.title = "";
                }
            }
        }
        
        function updateImagePreviews(url) {
            const validUrl = url && (url.startsWith('http') || url.startsWith('data:image'));
            const userIconSvg = `<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M19 21v-2a4 4 0 0 0-4-4H9a4 4 0 0 0-4 4v2"></path><circle cx="12" cy="7" r="4"></circle></svg>`;
            
            if (profileHeaderImg && profileHeaderIcon) {
                if (validUrl) {
                    profileHeaderImg.src = url;
                    profileHeaderImg.classList.remove('hidden');
                    profileHeaderIcon.classList.add('hidden');
                } else {
                    profileHeaderImg.classList.add('hidden');
                    profileHeaderIcon.classList.remove('hidden');
                }
            }
            
            if (profileImgPreview) {
                if (validUrl) {
                    profileImgPreview.src = url;
                    profileImgPreview.classList.remove('bg-slate-200', 'text-slate-400');
                    profileImgPreview.innerHTML = '';
                } else {
                    profileImgPreview.src = '';
                    profileImgPreview.classList.add('bg-slate-200', 'text-slate-400');
                    profileImgPreview.innerHTML = userIconSvg;
                }
            }
        }
        
        function renderKnowledgeList() {
            if (!knowledgeListContainer) return;
            
            const items = knowledgeListContainer.querySelectorAll('.knowledge-item');
            items.forEach(item => item.remove());
            const urls = appState.knowledge?.urls || [];
            
            if (knowledgeEmptyState) {
                if (urls.length === 0) {
                    knowledgeEmptyState.classList.remove('hidden');
                } else {
                    knowledgeEmptyState.classList.add('hidden');
                }
            }
            
            urls.forEach((url, index) => {
                const div = document.createElement('div');
                div.className = 'knowledge-item flex items-center justify-between rounded-md border border-slate-200 bg-white p-3';
                div.innerHTML = `<span class="text-sm text-slate-800 truncate" title="${url}">${url}</span><button class="ml-4 flex-shrink-0 p-1 text-slate-400 hover:text-red-600 rounded-full hover:bg-red-50" data-index="${index}"><svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="pointer-events-none"><polyline points="3 6 5 6 21 6"></polyline><path d="M19 6v14a2 2 0 0 1-2 2H7a2 2 0 0 1-2-2V6m3 0V4a2 2 0 0 1 2-2h4a2 2 0 0 1 2 2v2"></path><line x1="10" y1="11" x2="10" y2="17"></line><line x1="14" y1="11" x2="14" y2="17"></line></svg></button>`;
                knowledgeListContainer.appendChild(div);
            });
        }
        
        function renderPromptList() {
            if (!promptListContainer) return;
            
            const items = promptListContainer.querySelectorAll('.prompt-item');
            items.forEach(item => item.remove());
            const prompts = appState.prompts || [];
            
            if (promptEmptyState) {
                if (prompts.length === 0) {
                    promptEmptyState.classList.remove('hidden');
                } else {
                    promptEmptyState.classList.add('hidden');
                }
            }
            
            prompts.forEach((prompt, index) => {
                const div = document.createElement('div');
                div.className = 'prompt-item rounded-md border border-slate-200 p-4';
                div.innerHTML = `<div class="flex justify-between items-center mb-2"><p class="text-sm font-semibold text-slate-800">${prompt.title}</p><div><button class="edit-prompt-btn p-1 text-slate-400 hover:text-slate-700 rounded-full hover:bg-slate-100" data-index="${index}"><svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="pointer-events-none"><path d="M11 4H4a2 2 0 0 0-2 2v14a2 2 0 0 0 2 2h14a2 2 0 0 0 2-2v-7"></path><path d="M18.5 2.5a2.121 2.121 0 0 1 3 3L12 15l-4 1 1-4 9.5-9.5z"></path></svg></button><button class="delete-prompt-btn ml-1 p-1 text-slate-400 hover:text-red-600 rounded-full hover:bg-red-50" data-index="${index}"><svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="pointer-events-none"><polyline points="3 6 5 6 21 6"></polyline><path d="M19 6v14a2 2 0 0 1-2 2H7a2 2 0 0 1-2-2V6m3 0V4a2 2 0 0 1 2-2h4a2 2 0 0 1 2 2v2"></path></svg></button></div></div><p class="text-sm text-slate-600 bg-slate-50 p-3 rounded">${prompt.message}</p>`;
                promptListContainer.appendChild(div);
            });
        }
        
        function renderModelConfig() {
            const qhyProEl = document.getElementById('api-key-qhy-pro');
            const geminiEl = document.getElementById('api-key-gemini-2.5');
            
            if (qhyProEl) qhyProEl.classList.add('hidden');
            if (geminiEl) geminiEl.classList.add('hidden');
            
            const selected = appState.modelConfig?.selectedModel;
            if (selected === 'qhy-pro' && qhyProEl) {
                qhyProEl.classList.remove('hidden');
            } else if (selected === 'gemini-2.5' && geminiEl) {
                geminiEl.classList.remove('hidden');
            }
        }
        
        function renderTestChatMessage(sender, text) {
            if (!testAgentHistory) return;
            
            const messageDiv = document.createElement('div');
            messageDiv.className = `chat-message ${sender} mb-2`;
            let html = text.replace(/\*\*(.*?)\*\*/g, '<strong>$1</strong>');
            html = html.replace(/`(.*?)`/g, '<code class="bg-slate-200 px-1 py-0.5 rounded text-sm">$1</code>');
            html = html.replace(/\n/g, '<br>');
            messageDiv.innerHTML = html;
            testAgentHistory.appendChild(messageDiv);
            testAgentHistory.scrollTop = testAgentHistory.scrollHeight;
        }
        
        function setChatTyping(isTyping) {
            if (!testAgentHistory) return;
            
            let typingEl = document.getElementById('typing-indicator');
            if (isTyping) {
                if (!typingEl) {
                    typingEl = document.createElement('div');
                    typingEl.id = 'typing-indicator';
                    typingEl.className = 'chat-message model typing';
                    typingEl.textContent = 'typing...';
                    testAgentHistory.appendChild(typingEl);
                    testAgentHistory.scrollTop = testAgentHistory.scrollHeight;
                }
            } else {
                if (typingEl) {
                    typingEl.remove();
                }
            }
        }

        // --- Modal & Sidebar Functions ---

        function showModal(modalEl) {
            if (!modalEl) return;
            modalEl.classList.remove('opacity-0', 'pointer-events-none');
            const content = modalEl.querySelector('.modal-content');
            if (content) content.classList.remove('-translate-y-10');
        }
        
        function hideModal(modalEl) {
            if (!modalEl) return;
            modalEl.classList.add('opacity-0', 'pointer-events-none');
            const content = modalEl.querySelector('.modal-content');
            if (content) content.classList.add('-translate-y-10');
        }
        
        function showLoading(message = "Generating...") {
            if (loadingMessage) loadingMessage.textContent = message;
            if (loadingModal) showModal(loadingModal);
        }
        
        function hideLoading() {
            if (loadingModal) hideModal(loadingModal);
        }
        
        function showPromptModal(mode = 'add', index = -1) {
            if (!promptModal || !promptModalTitle || !promptModalSaveBtn || 
                !promptModalEditIndex || !promptModalTitleInput || !promptModalMessageInput) return;
                
            if (mode === 'edit' && index > -1) {
                const prompt = appState.prompts[index];
                promptModalTitle.textContent = 'Edit Prompt';
                promptModalSaveBtn.textContent = 'Save Changes';
                promptModalEditIndex.value = index;
                promptModalTitleInput.value = prompt.title;
                promptModalMessageInput.value = prompt.message;
            } else {
                promptModalTitle.textContent = 'Add New Prompt';
                promptModalSaveBtn.textContent = 'Save Prompt';
                if (promptModalForm) promptModalForm.reset();
                promptModalEditIndex.value = -1;
            }
            showModal(promptModal);
        }
        
        function toggleProfileSidebar() {
            isProfileSidebarOpen = !isProfileSidebarOpen;
            const sidebar = document.querySelector('custom-sidebar');
            if (sidebar && sidebar.shadowRoot) {
                const profileSidebar = sidebar.shadowRoot.querySelector('#profile-sidebar');
                const sidebarOverlay = sidebar.shadowRoot.querySelector('#sidebar-overlay');
                
                if (profileSidebar && sidebarOverlay) {
                    if (isProfileSidebarOpen) {
                        profileSidebar.classList.add('open');
                        sidebarOverlay.classList.remove('opacity-0', 'pointer-events-none');
                    } else {
                        profileSidebar.classList.remove('open');
                        sidebarOverlay.classList.add('opacity-0', 'pointer-events-none');
                    }
                }
            }
        }
        
        function openTestAgentModal() {
            testChatHistory = []; // Reset history
            if (testAgentHistory) testAgentHistory.innerHTML = ''; // Clear UI
            renderTestChatMessage('model', 'Hi! I\'m ready to test. My instructions are set. Ask me anything.');
            if (testAgentModal) showModal(testAgentModal);
        }
        
        function openImageGenModal() {
            if (imageGenInput) imageGenInput.value = '';
            if (imageGenResult) {
                imageGenResult.src = '';
                imageGenResult.alt = '';
            }
            if (imageGenError) imageGenError.textContent = '';
            if (imageGenResultContainer) imageGenResultContainer.classList.remove('loading');
            if (imageGenResult) imageGenResult.classList.add('hidden');
            if (imageGenError) imageGenError.classList.add('hidden');
            if (imageGenModal) showModal(imageGenModal);
        }

        // NEW: Open Code Test Modal
        function openCodeTestModal() {
            if (codeTestResultContainer) codeTestResultContainer.classList.remove('loading');
            if (codeTestResult) codeTestResult.textContent = '// Click "Generate Example" to see a code snippet...';
            if (codeTestSpinner) codeTestSpinner.style.display = 'none';
            if (codeTestResult) codeTestResult.style.display = 'block';
            if (codeTestModal) showModal(codeTestModal);
        }
        
        // --- Gemini API Callers ---
        
        // Text Generation
        async function callGeminiApi(payload, maxRetries = 5) {
            const apiKey = ""; // In a real app, this would come from environment variables
            const apiUrl = `https://generativelanguage.googleapis.com/v1beta/models/gemini-2.5-flash-preview-09-2025:generateContent?key=${apiKey}`;
            let attempt = 0, delay = 1000;
            
            while (attempt < maxRetries) {
                try {
                    const response = await fetch(apiUrl, { 
                        method: 'POST', 
                        headers: { 'Content-Type': 'application/json' }, 
                        body: JSON.stringify(payload) 
                    });
                    
                    if (response.status === 429 || response.status >= 500) {
                        throw new Error(`API Error: ${response.status}`);
                    }
                    
                    if (!response.ok) { 
                        const errorResult = await response.json(); 
                        console.error("Gemini API Error:", errorResult); 
                        throw new Error(`Gemini API Error: ${errorResult.error?.message || response.statusText}`); 
                    }
                    
                    const result = await response.json();
                    const candidate = result.candidates?.[0];
                    
                    if (!candidate) throw new Error("Invalid API response: No candidates found.");
                    
                    if (payload.generationConfig?.responseMimeType === "application/json") {
                        const text = candidate.content?.parts?.[0]?.text;
                        if (!text) throw new Error("Invalid API response: No text part found for JSON.");
                        return text;
                    }
                    
                    const text = candidate.content?.parts?.[0]?.text;
                    if (typeof text !== 'string') throw new Error("Invalid API response: No text content found.");
                    return text;
                } catch (error) {
                    console.warn(`Gemini API call attempt ${attempt + 1} failed: ${error.message}`);
                    attempt++;
                    if (attempt >= maxRetries) throw new Error(`Gemini API failed after ${maxRetries} attempts: ${error.message}`);
                    await new Promise(resolve => setTimeout(resolve, delay));
                    delay *= 2;
                }
            }
        }
        
        // Image Generation
        async function callImagenApi(userPrompt, maxRetries = 5) {
            const apiKey = ""; // API key is handled by the environment
            const apiUrl = `https://generativelanguage.googleapis.com/v1beta/models/imagen-3.0-generate-002:predict?key=${apiKey}`;
            
            const payload = { 
                instances: { prompt: userPrompt }, 
                parameters: { "sampleCount": 1 } 
            };
            
            let attempt = 0, delay = 1000;
            while (attempt < maxRetries) {
                try {
                    const response = await fetch(apiUrl, {
                        method: 'POST',
                        headers: { 'Content-Type': 'application/json' },
                        body: JSON.stringify(payload)
                    });

                    if (response.status === 429 || response.status >= 500) {
                        throw new Error(`API Error: ${response.status}`);
                    }
                    
                    if (!response.ok) {
                        const errorResult = await response.json();
                        console.error("Imagen API Error:", errorResult);
                        throw new Error(`Imagen API Error: ${errorResult.error?.message || response.statusText}`);
                    }
                    
                    const result = await response.json();
                    
                    if (result.predictions && result.predictions.length > 0 && result.predictions[0].bytesBase64Encoded) {
                        return `data:image/png;base64,${result.predictions[0].bytesBase64Encoded}`;
                    } else {
                        throw new Error("Invalid API response: No image data found.");
                    }

                } catch (error) {
                    console.warn(`Imagen API call attempt ${attempt + 1} failed: ${error.message}`);
                    attempt++;
                    if (attempt >= maxRetries) {
                        throw new Error(`Imagen API failed after ${maxRetries} attempts: ${error.message}`);
                    }
                    await new Promise(resolve => setTimeout(resolve, delay));
                    delay *= 2;
                }
            }
        }
        
        // NEW: TTS Generation
        async function callTtsApi(textToSpeak, maxRetries = 5) {
            const apiKey = "";
            const apiUrl = `https://generativelanguage.googleapis.com/v1beta/models/gemini-2.5-flash-preview-tts:generateContent?key=${apiKey}`;
            
            const payload = {
                contents: [{
                    parts: [{ text: textToSpeak }]
                }],
                generationConfig: {
                    responseModalities: ["AUDIO"],
                    speechConfig: {
                        voiceConfig: {
                            prebuiltVoiceConfig: { voiceName: "Kore" } // Using 'Kore' voice
                        }
                    }
                },
                model: "gemini-2.5-flash-preview-tts"
            };

            let attempt = 0, delay = 1000;
            while (attempt < maxRetries) {
                try {
                    const response = await fetch(apiUrl, {
                        method: 'POST',
                        headers: { 'Content-Type': 'application/json' },
                        body: JSON.stringify(payload)
                    });

                    if (response.status === 429 || response.status >= 500) throw new Error(`API Error: ${response.status}`);
                    if (!response.ok) { 
                        const errorResult = await response.json(); 
                        console.error("TTS API Error:", errorResult); 
                        throw new Error(`TTS API Error: ${errorResult.error?.message || response.statusText}`); 
                    }
                    
                    const result = await response.json();
                    const part = result?.candidates?.[0]?.content?.parts?.[0];
                    const audioData = part?.inlineData?.data;
                    const mimeType = part?.inlineData?.mimeType;

                    if (audioData && mimeType && mimeType.startsWith("audio/")) {
                        const sampleRate = parseInt(mimeType.match(/rate=(\d+)/)[1], 10) || 24000;
                        return { audioData, sampleRate };
                    } else {
                        throw new Error("Invalid API response: No audio data found.");
                    }
                } catch (error) {
                    console.warn(`TTS API call attempt ${attempt + 1} failed: ${error.message}`);
                    attempt++;
                    if (attempt >= maxRetries) throw new Error(`TTS API failed after ${maxRetries} attempts: ${error.message}`);
                    await new Promise(resolve => setTimeout(resolve, delay));
                    delay *= 2;
                }
            }
        }
        
        // --- TTS Audio Helpers ---
        
        // NEW: Decodes base64 string to ArrayBuffer
        function base64ToArrayBuffer(base64) {
            const binaryString = window.atob(base64);
            const len = binaryString.length;
            const bytes = new Uint8Array(len);
            for (let i = 0; i < len; i++) {
                bytes[i] = binaryString.charCodeAt(i);
            }
            return bytes.buffer;
        }

        // NEW: Wraps raw PCM data in a WAV header
        function pcmToWav(pcmData, sampleRate) {
            const numChannels = 1;
            const bitsPerSample = 16;
            const byteRate = sampleRate * numChannels * (bitsPerSample / 8);
            const blockAlign = numChannels * (bitsPerSample / 8);
            const dataSize = pcmData.byteLength;
            const fileSize = 36 + dataSize;

            const buffer = new ArrayBuffer(44 + dataSize);
            const view = new DataView(buffer);

            // RIFF header
            writeString(view, 0, 'RIFF');
            view.setUint32(4, fileSize, true);
            writeString(view, 8, 'WAVE');
            
            // fmt chunk
            writeString(view, 12, 'fmt ');
            view.setUint32(16, 16, true); // chunk size
            view.setUint16(20, 1, true);  // audio format (1 = PCM)
            view.setUint16(22, numChannels, true);
            view.setUint32(24, sampleRate, true);
            view.setUint32(28, byteRate, true);
            view.setUint16(32, blockAlign, true);
            view.setUint16(34, bitsPerSample, true);
            
            // data chunk
            writeString(view, 36, 'data');
            view.setUint32(40, dataSize, true);

            // Write PCM data
            new Uint8Array(buffer, 44).set(new Uint8Array(pcmData));

            return new Blob([buffer], { type: 'audio/wav' });
        }
        
        // NEW: Helper for pcmToWav
        function writeString(view, offset, string) {
            for (let i = 0; i < string.length; i++) {
                view.setUint8(offset + i, string.charCodeAt(i));
            }
        }

        /**
         * Loads the agent configuration from Firestore.
         */
        async function loadAgentConfig() {
            if (!agentConfigDocRef) return;
            try {
                const docSnap = await getDoc(agentConfigDocRef);
                if (docSnap.exists()) {
                    console.log("Loaded data from Firestore:", docSnap.data());
                    appState = { ...defaultAppState, ...docSnap.data() };
                } else {
                    console.log("No saved config found, using default.");
                    appState = { ...defaultAppState };
                }
            } catch (error) {
                console.error("Error loading agent config:", error);
                appState = { ...defaultAppState };
            }
        }
        
        // --- Auth Functions ---
        async function signInWithGoogle() {
            const provider = new GoogleAuthProvider();
            try {
                await signInWithPopup(auth, provider);
                toggleProfileSidebar();
            } catch (error) { 
                console.error("Google Sign-In Error:", error); 
            }
        }
        
        async function signInWithGitHub() {
            const provider = new GithubAuthProvider();
            try {
                await signInWithPopup(auth, provider);
                toggleProfileSidebar();
            } catch (error) { 
                console.error("GitHub Sign-In Error:", error); 
            }
        }
        
        async function handleSignOut() {
            try {
                await signOut(auth);
                toggleProfileSidebar();
            } catch (error) { 
                console.error("Sign-Out Error:", error); 
            }
        }
        
        async function handleSaveProfile() {
            const currentUser = auth.currentUser;
            if (!currentUser || currentUser.isAnonymous || 
                !profileDisplayNameInput || !profileImgUrlInput || !profileBioInput || 
                !saveProfileBtn || !agentConfigDocRef) return;
                
            const displayName = profileDisplayNameInput.value.trim();
            const photoURL = profileImgUrlInput.value.trim();
            const bio = profileBioInput.value.trim();
            
            saveProfileBtn.textContent = "Saving...";
            saveProfileBtn.disabled = true;
            saveProfileBtn.classList.add('btn-disabled');
            
            try {
                await updateProfile(currentUser, { displayName, photoURL });
                const profileData = { displayName, photoURL, bio };
                await setDoc(agentConfigDocRef, profileData, { merge: true });
                appState.displayName = displayName;
                appState.photoURL = photoURL;
                appState.bio = bio;
                updateImagePreviews(photoURL);
                saveProfileBtn.textContent = "Profile Saved!";
                saveProfileBtn.classList.add('bg-green-600');
                
                setTimeout(() => {
                    saveProfileBtn.textContent = "Save Profile";
                    saveProfileBtn.disabled = false;
                    saveProfileBtn.classList.remove('btn-disabled', 'bg-green-600');
                }, 2000);
            } catch (error) {
                console.error("Error saving profile:", error);
                saveProfileBtn.textContent = "Save Failed";
                saveProfileBtn.classList.add('bg-red-600');
                
                setTimeout(() => {
                    saveProfileBtn.textContent = "Save Profile";
                    saveProfileBtn.disabled = false;
                    saveProfileBtn.classList.remove('btn-disabled', 'bg-red-600');
                }, 2000);
            }
        }
        
        // --- AI Feature Handlers ---
        
        async function handleSuggestBio() {
            if (!profileDisplayNameInput || !profileBioInput) return;
            
            const agentRole = profileDisplayNameInput.value.trim();
            if (!agentRole) {
                profileBioInput.placeholder = "Please enter a Display Name first, then click ✨ Suggest.";
                return;
            }
            
            const userQuery = `Based on the following name or role, write a short, professional bio (1-2 sentences). Role: "${agentRole}" Return ONLY the bio text, with no preamble or quotes.`;
            const payload = {
                contents: [{ parts: [{ text: userQuery }] }],
                systemInstruction: { parts: [{ text: "You are a professional profile writer. You return only the bio text." }] }
            };
            
            showLoading("Generating bio...");
            try {
                const generatedText = await callGeminiApi(payload);
                const cleanText = generatedText.replace(/["*]/g, "").trim();
                profileBioInput.value = cleanText;
            } catch (error) {
                console.error(error);
                profileBioInput.value = `Error: ${error.message}`;
            } finally {
                hideLoading();
            }
        }
        
        async function handleTestAgentSend(e) {
            e.preventDefault();
            if (!testAgentInput || !testAgentHistory) return;
            
            const userMessage = testAgentInput.value.trim();
            if (!userMessage) return;
            
            testAgentInput.value = '';
            renderTestChatMessage('user', userMessage);
            setChatTyping(true);
            testChatHistory.push({ role: "user", parts: [{ text: userMessage }] });
            
            let finalSystemInstructions = appState.instructions || "You are a helpful assistant.";
            let payloadTools = [];
            
            if (appState.knowledge.urls.length > 0 && appState.knowledge.prioritize) {
                finalSystemInstructions += `\n\nCRITICAL KNOWLEDGE: You MUST use the provided Google Search tool to find information to answer the user's query. You must prioritize information from these specific websites: ${appState.knowledge.urls.join(', ')}. If the answer cannot be found in those sources, you should state that.`;
                payloadTools.push({ "google_search": {} });
            }
            
            const payload = {
                contents: testChatHistory,
                systemInstruction: { parts: [{ text: finalSystemInstructions }] }
            };
            
            if (payloadTools.length > 0) {
                payload.tools = payloadTools;
            }
            
            try {
                const modelResponse = await callGeminiApi(payload);
                testChatHistory.push({ role: "model", parts: [{ text: modelResponse }] });
                setChatTyping(false);
                renderTestChatMessage('model', modelResponse);
            } catch (error) {
                console.error("Test Agent Chat Error:", error);
                setChatTyping(false);
                renderTestChatMessage('model', `Sorry, an error occurred: ${error.message}`);
            }
        }
        
        async function handleImageGenTest(e) {
            e.preventDefault();
            if (!imageGenInput || !imageGenResultContainer || !imageGenError || 
                !imageGenResult || !imageGenSpinner) return;
                
            const userPrompt = imageGenInput.value.trim();
            if (!userPrompt) return;

            imageGenResultContainer.classList.add('loading');
            imageGenError.textContent = '';
            imageGenError.classList.add('hidden');
            imageGenResult.classList.add('hidden');

            try {
                const imageUrl = await callImagenApi(userPrompt);
                imageGenResult.src = imageUrl;
                imageGenResult.alt = userPrompt;
                imageGenResult.classList.remove('hidden');
            } catch (error) {
                console.error("Image Gen Test Error:", error);
                imageGenError.textContent = `Error: ${error.message}`;
                imageGenError.classList.remove('hidden');
            } finally {
                imageGenResultContainer.classList.remove('loading');
            }
        }
        
        // NEW: Handle TTS for instructions
        async function handleListenInstructions() {
            if (!agentInstructionsInput || !listenInstructionsBtn || !ttsPlayer) return;
            
            const text = agentInstructionsInput.value.trim();
            if (!text) return;
            
            const icon = listenInstructionsBtn.querySelector('svg');
            listenInstructionsBtn.disabled = true;
            if (icon) icon.classList.add('spinner');

            try {
                const { audioData, sampleRate } = await callTtsApi(text);
                const pcmBuffer = base64ToArrayBuffer(audioData);
                const wavBlob = pcmToWav(pcmBuffer, sampleRate);
                const audioUrl = URL.createObjectURL(wavBlob);
                
                ttsPlayer.src = audioUrl;
                ttsPlayer.play();

            } catch (error) {
                console.error("TTS Error:", error);
            } finally {
                listenInstructionsBtn.disabled = false;
                if (icon) icon.classList.remove('spinner');
            }
        }
        
        // NEW: Handle Code Interpreter Test
        async function handleCodeInterpreterTest() {
            if (!codeTestResultContainer || !codeTestSpinner || !codeTestResult) return;
            
            codeTestResultContainer.classList.add('loading');
            codeTestSpinner.style.display = 'flex';
            codeTestResult.style.display = 'none';

            const agentRole = appState.agentName.trim() || "a helpful assistant";
            const userQuery = `You are a code interpreter. Your agent role is "${agentRole}". 
Generate a simple Python code snippet that demonstrates this role.
Return ONLY the Python code, inside \`\`\`python ... \`\`\` tags.`;
            
            const payload = { 
                contents: [{ parts: [{ text: userQuery }] }], 
                systemInstruction: { parts: [{ text: "You are a helpful code generation assistant. You only return code." }] } 
            };
            
            try {
                const generatedText = await callGeminiApi(payload);
                // Clean up markdown fences
                const cleanCode = generatedText.replace(/^