document.addEventListener("DOMContentLoaded", () => {
    // --- Element Selectors ---
    const userInput = document.getElementById("user-input");
    const sendButton = document.getElementById("send-button");
    const chatHistory = document.getElementById("chat-history");
    const menuItems = document.querySelectorAll(".menu-item");
    const convoRecord = document.getElementById("convo-record");

    // Modal Elements
    const patientModal = document.getElementById("patient-modal");
    const patientForm = document.getElementById("patient-form");
    const patientIdInput = document.getElementById("patient-id-input");

    // Track session for backend context
    let currentSessionId = window.activeSessionId || null;
    let similarSearchActive = false; // --- NEW: Toggle state for similar search

    // --- NEW: Function to control chat input state ---
    function setChatInputDisabled(disabled) {
        if (userInput) {
            userInput.disabled = disabled;
            userInput.placeholder = disabled ? "Please start a patient session first..." : "Ask Swift Query AI...";
        }
        if (sendButton) {
            sendButton.disabled = disabled;
            sendButton.classList.toggle('bg-gray-400', disabled);
            sendButton.classList.toggle('bg-primary', !disabled);
            sendButton.classList.toggle('hover:bg-orange-600', !disabled);
        }
    }

    // --- Feature Handlers (MODIFIED) ---
    const featureHandlers = {
        "chat-feature": () => {
            if (similarSearchActive) {
                // If similar search was active, turn it off
                toggleSimilarSearch(document.getElementById('similar-cases-feature'));
            }
            if (userInput) userInput.focus();
        },
        "similar-cases-feature": (event) => {
            if (!window.activePatientId) {
                appendMessage("Please start a patient session to find similar cases.", "ai", new Date());
                return;
            }
            // NEW: Toggle the similar search mode
            toggleSimilarSearch(event.currentTarget);
        },
        "patient-search-feature": () => {
            if (patientModal) {
                patientModal.classList.remove("hidden");
                if (patientIdInput) setTimeout(() => patientIdInput.focus(), 100);
            }
        },
        "clear-chat-feature": () => {
            const greeting = chatHistory.firstChild;
            chatHistory.innerHTML = '';
            if(greeting) chatHistory.appendChild(greeting);
            appendMessage("Local chat view cleared.", "ai", new Date());
        },
        "history-feature": () => {
            loadHistoryList();
        }
    };

    // --- NEW: Toggle function for Similar Search ---
    function toggleSimilarSearch(buttonElement) {
        similarSearchActive = !similarSearchActive;
        if (!userInput || !buttonElement) return;

        if (similarSearchActive) {
            userInput.value = "/similar ";
            userInput.focus();
            buttonElement.classList.add("active"); // Add visual indicator
            appendMessage("**Similar Case Search Activated.**\nPlease describe the symptoms or conditions to find matching cases.", "ai", new Date());
        } else {
            if (userInput.value.startsWith("/similar ")) {
                userInput.value = "";
            }
            buttonElement.classList.remove("active");
            appendMessage("**Similar Case Search Deactivated.**", "ai", new Date());
        }
    }

    // --- Event Listeners ---
    menuItems.forEach(item => {
        if (item.tagName === 'A' && !item.href.includes('logout')) {
            item.addEventListener("click", (e) => {
                if (featureHandlers[item.id]) {
                    e.preventDefault();
                    // Don't deactivate similar search button when it's clicked
                    if (item.id !== 'similar-cases-feature') {
                        const activeItem = document.querySelector(".menu-item.active");
                        if (activeItem) activeItem.classList.remove("active");
                        item.classList.add("active");
                    }
                    featureHandlers[item.id](e);
                }
            });
        }
    });

    if (patientForm) {
        patientForm.addEventListener("submit", (e) => {
            e.preventDefault();
            const pid = patientIdInput.value.trim();
            if (pid) {
                if (patientModal) patientModal.classList.add("hidden");
                startPatientSession(pid);
            }
        });
    }

    // --- Recording Logic ---
    let mediaRecorder = null;
    let audioChunks = [];

    window.startRecording = async function () {
        if (!navigator.mediaDevices || !navigator.mediaDevices.getUserMedia) return;
        try {
            const stream = await navigator.mediaDevices.getUserMedia({ audio: true });
            mediaRecorder = new MediaRecorder(stream);
            audioChunks = [];
            mediaRecorder.ondataavailable = (event) => {
                if (event.data.size > 0) audioChunks.push(event.data);
            };
            mediaRecorder.onstop = async () => {
                const audioBlob = new Blob(audioChunks, { type: 'audio/mp3' });
                appendMessage("Processing recording... ⏳", "ai", new Date());
                const formData = new FormData();
                formData.append("audio", audioBlob, "recording.mp3");
                formData.append("patient_id", window.activePatientId);

                try {
                    const response = await fetch("/doctor/upload_recording", { method: "POST", body: formData });
                    const result = await response.json();
                    if (result.success) {
                        appendMessage(`### 🎙️ Recording Saved\n\n**Processed Note:**\n${result.data.processed_note}`, "ai", new Date());
                    } else {
                        appendMessage(`❌ Recording failed: ${result.error}`, "ai", new Date());
                    }
                } catch (err) {
                    console.error(err);
                    appendMessage("❌ Error uploading recording.", "ai", new Date());
                }
                stream.getTracks().forEach(track => track.stop());
            };
            mediaRecorder.start();
            appendMessage("🎙️ **Recording Started...**", "ai", new Date());
            if (convoRecord) convoRecord.checked = true;
        } catch (err) {
            console.error("Microphone access denied:", err);
            if (convoRecord) convoRecord.checked = false;
            alert("Microphone access is required to record.");
        }
    };

    window.stopRecording = function () {
        if (mediaRecorder && mediaRecorder.state !== "inactive") {
            mediaRecorder.stop();
            appendMessage("⏹️ **Recording Stopped.** Processing...", "ai", new Date());
            if (convoRecord) convoRecord.checked = false;
        }
    };

    if (convoRecord) {
        convoRecord.addEventListener("change", async () => {
            if (!window.activePatientId) {
                convoRecord.checked = false;
                alert("Please start a patient session before starting a recording.");
                return;
            }
            if (convoRecord.checked) await window.startRecording();
            else window.stopRecording();
        });
    }

    // --- Core Chat Functions ---
    if (sendButton) sendButton.addEventListener("click", sendMessage);
    if (userInput) {
        userInput.addEventListener("keypress", (e) => {
            if (e.key === "Enter" && !e.shiftKey) {
                e.preventDefault();
                sendMessage();
            }
        });
        userInput.addEventListener("input", function () {
            this.style.height = "50px";
            this.style.height = `${Math.min(this.scrollHeight, 200)}px`;
        });
    }

    function startPatientSession(patientId) {
        setChatInputDisabled(true);
        if (chatHistory) chatHistory.innerHTML = '';
        appendMessage(`Starting session for Patient ID: ${patientId}... This may take a moment.`, "ai", new Date());

        fetch(`/doctor/start_session/${patientId}`, {
            method: "POST",
            headers: { "Content-Type": "application/json" },
        })
        .then(res => res.json())
        .then(data => {
            if (data.success) {
                appendMessage(`Session for patient ${data.patient_id} is ready. Reloading dashboard...`, "ai", new Date());
                setTimeout(() => window.location.reload(), 500);
            } else {
                console.error("Error starting session:", data.error);
                appendMessage(`Failed to start session: ${data.error}`, "ai", new Date());
                setChatInputDisabled(false);
            }
        })
        .catch(err => {
            console.error("Network error starting session:", err);
            appendMessage("A network error occurred while starting the session.", "ai", new Date());
            setChatInputDisabled(false);
        });
    }

    function loadHistoryList() {
        chatHistory.innerHTML = '';
        appendMessage("Loading history sessions...", "ai", new Date());

        fetch("/api/history")
            .then(res => res.json())
            .then(data => {
                chatHistory.innerHTML = '';
                if (data.history && data.history.length > 0) {
                    appendMessage("### Select a Past Session to Resume:", "ai", new Date());
                    const list = document.createElement("div");
                    list.className = "flex flex-col gap-2 mt-2";
                    data.history.forEach(item => {
                        const btn = document.createElement("button");
                        btn.className = "bg-white p-3 rounded-lg shadow-sm hover:bg-orange-50 text-left border border-gray-200 transition-colors w-full group";
                        btn.innerHTML = `<div class='font-bold text-primary flex justify-between'><span>${item.title || 'Untitled'}</span><i class="fas fa-chevron-right text-gray-300 group-hover:text-primary transition-colors"></i></div><div class='text-xs text-gray-500 mt-1'><i class="far fa-clock mr-1"></i> ${item.display_time || 'Unknown date'}</div>`;
                        btn.onclick = () => window.loadHistoryItem(item.type || 'chat', item.session_id);
                        list.appendChild(btn);
                    });
                    const container = document.createElement("div");
                    container.className = "w-full max-w-lg mb-4";
                    container.appendChild(list);
                    chatHistory.appendChild(container);
                    chatHistory.scrollTop = chatHistory.scrollHeight;
                } else {
                    appendMessage("No past sessions found.", "ai", new Date());
                }
            })
            .catch(err => {
                console.error(err);
                appendMessage("Failed to load history.", "ai", new Date());
            });
    }

    window.loadHistoryItem = function (type, id) {
        chatHistory.innerHTML = '';
        appendMessage("Restoring...", "ai", new Date());
        currentSessionId = (type === 'chat') ? id : null;

        fetch(`/api/history/${type}/${id}`)
            .then(res => res.json())
            .then(data => {
                chatHistory.innerHTML = '';
                if (data.messages && data.messages.length > 0) {
                    data.messages.forEach(msg => appendMessage(msg.content, msg.sender, msg.timestamp || new Date()));
                    if (type === 'chat') appendMessage("--- Session Restored ---", "ai", new Date());
                } else {
                    appendMessage("Item is empty.", "ai", new Date());
                }
            })
            .catch(err => {
                console.error(err);
                appendMessage("Failed to restore item.", "ai", new Date());
            });
    };

    function sendMessage() {
        if (!userInput || userInput.disabled) return;
        const message = userInput.value.trim();
        if (message === "") return;

        appendMessage(message, "user", new Date());
        userInput.value = "";
        userInput.style.height = "50px";
        
        fetchAIResponse(message);

        // NEW: Deactivate similar search after sending the query
        if (similarSearchActive) {
            toggleSimilarSearch(document.getElementById('similar-cases-feature'));
        }
    }

    async function fetchAIResponse(message) {
        if (!window.activePatientId || !currentSessionId) {
            appendMessage("Cannot send message. No active patient session.", "ai", new Date());
            return;
        }

        try {
            const response = await fetch("/api/chat", {
                method: "POST",
                headers: { "Content-Type": "application/json" },
                body: JSON.stringify({ message: message, session_id: currentSessionId }),
            });
            const data = await response.json();
            appendMessage(data.response, "ai", new Date());
        } catch (error) {
            console.error("Error fetching AI response:", error);
            appendMessage("Sorry, I'm having trouble connecting to the AI service.", "ai", new Date());
        }
    }
    
    function appendMessage(message, sender, timestamp) {
        if (!chatHistory) return;

        const messageWrapper = document.createElement("div");
        messageWrapper.classList.add("flex", "flex-col", sender === "user" ? "items-end" : "items-start", "mb-4", "animate-fade-in");

        const bubble = document.createElement("div");
        bubble.classList.add("rounded-lg", "p-3", "max-w-lg", "shadow-sm", "text-sm", "md:text-base");

        if (sender === "user") {
            bubble.classList.add("bg-primary", "text-white");
            bubble.innerText = message;
        } else {
            bubble.classList.add("bg-white", "text-text-dark", "prose", "prose-orange", "prose-sm");
            const rawHtml = marked.parse(message);
            bubble.innerHTML = DOMPurify.sanitize(rawHtml);
        }

        let timeStr = "";
        try {
            if (timestamp instanceof Date) {
                timeStr = timestamp.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' });
            } else if (typeof timestamp === 'string') {
                timeStr = new Date(timestamp).toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' });
            }
        } catch (e) { /* Ignore */ }

        const meta = document.createElement("div");
        meta.classList.add("text-xs", "text-gray-400", "mt-1", "mx-1");
        meta.innerText = timeStr;

        messageWrapper.appendChild(bubble);
        messageWrapper.appendChild(meta);

        chatHistory.appendChild(messageWrapper);
        chatHistory.scrollTop = chatHistory.scrollHeight;
    }

    // --- INITIALIZATION on Page Load ---
    if (window.activePatientId) {
        console.log(`Session active for patient ${window.activePatientId}`);
        setChatInputDisabled(false); // ENABLE chat
        if (userInput) userInput.focus();

        if (window.activeSessionId && chatHistory.children.length <= 1) { 
             console.log("Loading active session history:", window.activeSessionId);
             loadHistoryItem('chat', window.activeSessionId);
        }
    } else {
        console.log("No active patient session.");
        setChatInputDisabled(true); // DISABLE chat by default
    }
});