// --- Helper function for quick prompts ---
function quickPrompt(prompt) {
    const userInput = document.getElementById('user-input');
    if (userInput) {
        userInput.value = prompt;
        sendMessage();
    } else {
        window.logToScreen('ERROR: User input field not found for quickPrompt.');
    }
}

// --- Main function to send messages to the AI ---
async function sendMessage() {
    const userInput = document.getElementById('user-input');
    const chatMessages = document.getElementById('chat-messages');

    if (!userInput || !chatMessages) {
        window.logToScreen('ERROR: Cannot find chat UI elements.');
        return;
    }
    
    const userMessageText = userInput.value.trim();
    if (userMessageText === '') return;

    // 1. Add user's message to the chat window
    const userBubble = document.createElement('div');
    userBubble.className = 'chat-bubble user-bubble p-4 w-3/4 ml-auto mb-4 fade-in';
    userBubble.innerHTML = `<p>${userMessageText}</p>`;
    chatMessages.appendChild(userBubble);
    chatMessages.scrollTop = chatMessages.scrollHeight;
    userInput.value = '';

    // 2. Prepare the AI's response bubble (will be filled in as the stream arrives)
    const aiBubble = document.createElement('div');
    aiBubble.className = 'chat-bubble ai-bubble p-4 w-3/4 fade-in';
    const aiParagraph = document.createElement('p');
    aiBubble.appendChild(aiParagraph);
    chatMessages.appendChild(aiBubble);
    chatMessages.scrollTop = chatMessages.scrollHeight;


    // 3. Start the fetch process and log everything
    window.logToScreen('sendMessage triggered. Preparing to fetch...');

    try {
        // IMPORTANT: Replace this with your actual Cloudflare Worker URL
        const workerUrl = 'https://stream-ai-backend.your-username.workers.dev'; 
        window.logToScreen(`Fetching from: ${workerUrl}`);

        const response = await fetch(workerUrl, {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
            },
            body: JSON.stringify({ prompt: userMessageText }),
        });

        window.logToScreen(`Fetch response received. Status: ${response.status} ${response.statusText}`);

        if (!response.ok) {
            const errorText = await response.text();
            window.logToScreen(`Error response body: ${errorText}`);
            throw new Error(`Network response was not ok: ${response.statusText}`);
        }
        
        // 4. Handle the streaming response
        const reader = response.body.getReader();
        const decoder = new TextDecoder();
        window.logToScreen('Stream starting...');

        while (true) {
            const { done, value } = await reader.read();
            if (done) {
                window.logToScreen('Stream finished.');
                break;
            }
            const chunk = decoder.decode(value, { stream: true });
            aiParagraph.textContent += chunk; // Append chunk to the AI's paragraph
            chatMessages.scrollTop = chatMessages.scrollHeight; // Keep scrolling
        }
        
    } catch (error) {
        // Log the error and display a message in the UI
        window.logToScreen(`FETCH FAILED: ${error.message}`);
        aiParagraph.textContent = "Sorry, an error occurred. Check the debug console for details.";
        aiParagraph.style.color = 'red';
    }
}


// --- Initialization function for the chat module ---
export function initChat() {
    const sendBtn = document.getElementById('send-btn');
    const userInput = document.getElementById('user-input');

    if (sendBtn && userInput) {
        sendBtn.addEventListener('click', sendMessage);
        userInput.addEventListener('keypress', (e) => {
            if (e.key === 'Enter') {
                sendMessage();
            }
        });

        // Make quickPrompt globally accessible for the inline HTML onclick attributes
        window.quickPrompt = quickPrompt;
    } else {
        // Use the logger in case the elements don't exist
        if (window.logToScreen) {
            window.logToScreen("ERROR: Could not find 'send-btn' or 'user-input' to initialize chat.");
        }
    }
}