// ==========================================
// 1. CONFIGURATION & CREDENTIALS
// ==========================================
const WHATSAPP_TOKEN = 'YOUR_META_TOKEN'; 
const WHATSAPP_PHONE_ID = '1013222271877801';
const VERIFY_TOKEN = 'eye_center_verify_token_123'; 
const GROQ_API_KEY = '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'; 
const PHP_DASHBOARD_URL = 'https://yourdomain.com/api/whatsapp_lead.php'; 
const PHP_API_SECRET = 'wa_api_key_eyecenter_2026_123456789';

// ==========================================
// 2. SYSTEM PROMPT (The Intelligent Brain)
// ==========================================
const SYSTEM_PROMPT = `# Role & Persona
You are Sarah, the virtual WhatsApp receptionist for "The Eye Center" in Clifton, Karachi.
Your tone is warm, professional, and concise. Mirror the user's language (English or Roman Urdu).

# DOCTOR SCHEDULES & KNOWLEDGE BASE
Use this data to answer inquiries if a patient explicitly asks "What time does Doctor X sit?".
- Dr. Mahnaz Naveed Shah: Tue, Wed, Fri (09:00 AM to 12:00 PM)
- Dr. Ali Zia: Mon, Wed, Thu, Sat (10:00 AM to 12:00 PM) | Tue, Fri (03:30 PM to 05:00 PM)
- Dr. Shahyan Shadmani: Mon (12:00 PM to 02:00 PM)
- Dr. Syeda Aisha Bokhari: Mon, Tue, Wed, Thu, Fri (01:30 PM to 04:00 PM)
- Dr. M. Saeed Iqbal: Tue, Thu (05:00 PM to 06:30 PM) | Sat (01:00 PM to 03:00 PM)
- Dr. Shahab Ul Hasan Siddique: Mon, Wed, Sat (03:30 PM to 05:30 PM)
- Dr. Uzma Naz: Tue, Fri (09:00 AM to 05:00 PM) | Thu (02:00 PM to 04:00 PM) | Sat (09:00 PM to 12:00 PM)
- Dr. Saliha Naz: Tue, Thu (04:30 PM to 06:00 PM)
- Dr. M. Omer Hassan: Tue, Thu, Sat (02:30 PM to 04:30 PM)
- Dr. Zeeshan Kamil: Thu (05:00 PM to 06:30 PM) | Sat (06:00 PM to 07:30 PM)
- Dr. Hina Nawaz: Mon, Wed, Fri (03:30 PM to 05:30 PM)

Hours: Mon-Sat, 9:00 AM to 6:00 PM. Sunday is CLOSED.
Address: First Floor, GPC 13 Rojhan Street, Block 5, Clifton, Karachi.

# INTERACTIVE UI RULES (STRICT)
To show options, you MUST use one of these two formats at the very end of your message:
1. For 1 to 3 short options: Use [BUTTONS: Option 1 | Option 2 | Option 3]
2. For 4 to 10 options: Use [LIST: Menu Title | Item 1 | Item 2 | Item 3 | Item 4]
Never exceed 20 characters for a button/list item.

# SCENARIO 1: BOOK TENTATIVE APPOINTMENT
Guide them step-by-step. Ask ONE question at a time. No buttons for data entry.
1. "Please type your First and Last name."
2. "Please type your cell phone number."
3. "Which doctor would you like to see? [LIST: View Doctors | Dr. Mahnaz | Dr. Ali Zia | Not Sure]" (If 'Not Sure', ask their symptoms).
4. SUGGEST DAYS (CRITICAL RULE): Look at the chosen doctor's schedule. Calculate the NEXT available sitting day based on the current date provided by the system. Say: "Dr. [Name] is available on [Valid Days]. Would you like to request [Next Available Day] or another valid day?" 
   --> STRICT FORBIDDEN ACTION: DO NOT mention or offer specific times during this step. Only offer the DAY.
5. SHIFT PREFERENCE: Once a valid day is chosen, DO NOT ASK FOR A SPECIFIC TIME. Ask: "Do you prefer a Morning or Evening slot on that day? Our staff will call you to confirm the exact time."

Once all details are collected, read them back cleanly:
"Please confirm your tentative booking request:
👤 Name: [Name]
📱 Phone: [Phone]
👨‍⚕️ Doctor: [Doctor]
📅 Requested Day & Shift: [Day, Morning/Evening]
[BUTTONS: Yes Confirm | Edit Details]"

If they click 'Yes Confirm', trigger the 'submit_patient_lead' tool.

# SCENARIO 2: TALK TO HUMAN
If asked for a real person, reply: "I have notified our team. A representative will reply to you here shortly. 😊" (Stop asking questions).

# STRICT RULES
- NEVER confirm an exact time (e.g., 3:00 PM) during booking. Only record Morning/Evening preferences.
- NEVER give medical advice.
- KEEP MESSAGES SHORT.`;

// ==========================================
// 3. WEBHOOK VERIFICATION (GET)
// ==========================================
function doGet(e) {
  if (e.parameter['hub.mode'] === 'subscribe' && e.parameter['hub.verify_token'] === VERIFY_TOKEN) {
    return ContentService.createTextOutput(e.parameter['hub.challenge']);
  }
  return ContentService.createTextOutput("Verification failed");
}

// ==========================================
// 4. MAIN PROCESSOR (POST)
// ==========================================
function doPost(e) {
  try {
    const data = JSON.parse(e.postData.contents);
    if (!data.entry || !data.entry[0].changes[0].value.messages) return ContentService.createTextOutput("OK");
    
    const msgData = data.entry[0].changes[0].value.messages[0];
    const senderPhone = msgData.from;
    const messageId = msgData.id;
    
    // DEDUPLICATION: Prevent Meta Timeout Death Loops
    const cache = CacheService.getScriptCache();
    if (cache.get(messageId)) return ContentService.createTextOutput("OK - Duplicate");
    cache.put(messageId, 'true', 300); // Lock for 5 mins

    let userMessage = "";

    // -- MESSAGE PARSING & MEDIA HANDLING --
    if (msgData.type === 'text') {
      userMessage = msgData.text.body;
    } 
    else if (msgData.type === 'interactive') {
      userMessage = msgData.interactive.type === 'button_reply' 
        ? msgData.interactive.button_reply.title 
        : msgData.interactive.list_reply.title;
    } 
    else if (msgData.type === 'audio') {
      userMessage = transcribeAudio(msgData.audio.id);
    } 
    else if (msgData.type === 'image' || msgData.type === 'document') {
      userMessage = "[SYSTEM NOTE: The patient sent an image/document. Tell them you cannot view images yet and ask them to type their issue or send a voice note.]";
    } 
    else {
      return ContentService.createTextOutput("OK");
    }

    // -- RESET SWITCH --
    if (userMessage.toLowerCase().trim() === 'reset' || userMessage.toLowerCase().trim() === 'restart') {
      cache.remove(senderPhone + '_history');
      sendWhatsAppMessage(senderPhone, "Welcome to The Eye Center! How can I help you? [BUTTONS: Book Appointment | General Inquiry | Talk to Human]");
      return ContentService.createTextOutput("SUCCESS");
    }

    // -- CHAT HISTORY & GROQ LLM --
    let history = getChatHistory(senderPhone);
    history.push({ "role": "user", "content": userMessage });

    let groqResponse = callGroq(history);
    let replyText = "";

    // -- TOOL EXECUTION (DASHBOARD ROUTING) --
    if (groqResponse.tool_calls) {
      const toolCall = groqResponse.tool_calls[0];
      const args = JSON.parse(toolCall.function.arguments);
      
      // Send to Dashboard
      sendToDashboard(args, history);
      
      history.push(groqResponse); 
      history.push({ "role": "tool", "tool_call_id": toolCall.id, "content": "Dashboard updated successfully." });
      
      replyText = callGroq(history).content; 
    } else {
      replyText = groqResponse.content;
    }

    // Update Memory & Reply
    history.push({ "role": "assistant", "content": replyText });
    saveChatHistory(senderPhone, history);
    sendWhatsAppMessage(senderPhone, replyText);
    
    return ContentService.createTextOutput("SUCCESS");
  } catch (error) {
    console.error(error);
    return ContentService.createTextOutput("ERROR");
  }
}

// ==========================================
// 5. WHATSAPP UI GENERATOR (BUTTONS VS LISTS)
// ==========================================
function sendWhatsAppMessage(to, text) {
  const url = `https://graph.facebook.com/v19.0/${WHATSAPP_PHONE_ID}/messages`;
  let payload = { "messaging_product": "whatsapp", "to": to };

  const buttonMatch = text.match(/\[BUTTONS:\s*(.+?)\]/);
  const listMatch = text.match(/\[LIST:\s*(.+?)\]/);
  
  if (listMatch) {
    // GENERATE LIST (For 4-10 options)
    const items = listMatch[1].split('|').map(b => b.trim());
    const menuTitle = items.shift().substring(0, 20); 
    const cleanText = text.replace(listMatch[0], '').trim(); 
    
    const rows = items.slice(0, 10).map((label, index) => ({
      "id": `list_${index}`, "title": label.substring(0, 24)
    }));

    payload.type = "interactive";
    payload.interactive = {
      "type": "list",
      "body": { "text": cleanText || "Please select an option:" },
      "action": {
        "button": menuTitle,
        "sections": [{ "title": "Available Options", "rows": rows }]
      }
    };
  } 
  else if (buttonMatch) {
    // GENERATE BUTTONS (Max 3)
    const labels = buttonMatch[1].split('|').map(b => b.trim()).slice(0, 3);
    const cleanText = text.replace(buttonMatch[0], '').trim(); 
    
    const buttons = labels.map((label, index) => ({
      "type": "reply",
      "reply": { "id": `btn_${index}`, "title": label.substring(0, 20) }
    }));

    payload.type = "interactive";
    payload.interactive = {
      "type": "button",
      "body": { "text": cleanText || "Choose an option:" },
      "action": { "buttons": buttons }
    };
  } 
  else {
    // NORMAL TEXT
    payload.type = "text";
    payload.text = { "body": text };
  }

  UrlFetchApp.fetch(url, {
    "method": "post",
    "headers": { "Authorization": "Bearer " + WHATSAPP_TOKEN, "Content-Type": "application/json" },
    "payload": JSON.stringify(payload),
    "muteHttpExceptions": true
  });
}

// ==========================================
// 6. AUDIO PARSING & LLM FUNCTIONS
// ==========================================
function transcribeAudio(mediaId) {
  const mediaMetaUrl = `https://graph.facebook.com/v19.0/${mediaId}`;
  const metaRes = UrlFetchApp.fetch(mediaMetaUrl, { headers: { "Authorization": "Bearer " + WHATSAPP_TOKEN }});
  const mediaUrl = JSON.parse(metaRes.getContentText()).url;
  
  const audioBlob = UrlFetchApp.fetch(mediaUrl, { headers: { "Authorization": "Bearer " + WHATSAPP_TOKEN }}).getBlob();
  
  const formData = {
    "file": audioBlob,
    "model": "whisper-large-v3"
  };
  
  const options = {
    "method": "post",
    "headers": { "Authorization": "Bearer " + GROQ_API_KEY },
    "payload": formData
  };
  
  const whisperRes = UrlFetchApp.fetch("https://api.groq.com/openai/v1/audio/transcriptions", options);
  return JSON.parse(whisperRes.getContentText()).text;
}

function callGroq(messages) {
  // Inject real-time Karachi date awareness into the System Prompt
  const today = new Date().toLocaleString("en-US", { timeZone: "Asia/Karachi", weekday: 'long', year: 'numeric', month: 'long', day: 'numeric' });
  
  if (messages[0].role === "system") {
    // Ensure we don't append the date multiple times if the prompt is re-used
    let basePrompt = messages[0].content.split("# CURRENT SYSTEM CONTEXT")[0].trim();
    messages[0].content = basePrompt + `\n\n# CURRENT SYSTEM CONTEXT\nToday's Date in Karachi is: ${today}. Always use this to calculate "tomorrow", "next week", etc.`;
  }

  const payload = {
    "model": "llama-3.3-70b-versatile",
    "temperature": 0.2,
    "messages": messages,
    "tools": [{
      "type": "function",
      "function": {
        "name": "submit_patient_lead",
        "description": "Call this ONLY when the user clicks 'Yes Confirm' to finalize their booking request.",
        "parameters": {
          "type": "object",
          "properties": {
            "first_name": { "type": "string" },
            "last_name": { "type": "string" },
            "phone_number": { "type": "string" },
            "doctor": { "type": "string" },
            "requested_day_and_shift": { "type": "string", "description": "The confirmed day and shift (e.g., Monday Morning)" }
          },
          "required": ["first_name", "last_name", "phone_number", "doctor", "requested_day_and_shift"]
        }
      }
    }]
  };

  const options = {
    "method": "post",
    "headers": { "Authorization": "Bearer " + GROQ_API_KEY, "Content-Type": "application/json" },
    "payload": JSON.stringify(payload)
  };

  const response = UrlFetchApp.fetch("https://api.groq.com/openai/v1/chat/completions", options);
  return JSON.parse(response.getContentText()).choices[0].message;
}

// ==========================================
// 7. DASHBOARD ROUTING & MEMORY
// ==========================================
function sendToDashboard(args, chatHistory) {
  const payload = {
    source: "whatsapp",
    patient: {
      first_name: args.first_name,
      last_name: args.last_name,
      phone: args.phone_number
    },
    booking: {
      doctor: args.doctor,
      date_time: args.requested_day_and_shift
    },
    full_transcript: chatHistory
  };

  UrlFetchApp.fetch(PHP_DASHBOARD_URL, {
    "method": "post",
    "headers": { "X-API-KEY": PHP_API_SECRET, "Content-Type": "application/json" },
    "payload": JSON.stringify(payload),
    "muteHttpExceptions": true
  });
}

function getChatHistory(phone) {
  const cache = CacheService.getScriptCache();
  const cached = cache.get(phone + '_history');
  if (cached) return JSON.parse(cached);
  return [{ "role": "system", "content": SYSTEM_PROMPT }];
}

function saveChatHistory(phone, history) {
  const cache = CacheService.getScriptCache();
  if (history.length > 15) history = [history[0]].concat(history.slice(-14)); 
  cache.put(phone + '_history', JSON.stringify(history), 21600); // 6 hours
}