server.ts

import express, { Request, Response } from "express";
import path from "path";
import { GoogleGenAI, Type } from "@google/genai";
import dotenv from "dotenv";

dotenv.config();

const app = express();
const PORT = process.env.PORT || 3000;

app.use(express.json());

// Initialize Google Gen AI client server-side
function getGeminiClient(): GoogleGenAI | null {
  const apiKey = process.env.GEMINI_API_KEY;
  if (!apiKey) {
    console.warn("GEMINI_API_KEY is not set in environment. Using smart catalog engine fallback.");
    return null;
  }
  return new GoogleGenAI({
    apiKey,
    httpOptions: {
      headers: {
        'User-Agent': 'aistudio-build',
      },
    },
  });
}

// Health check endpoint
app.get("/api/health", (req: Request, res: Response) => {
  res.json({
    status: "ok",
    hasGeminiKey: Boolean(process.env.GEMINI_API_KEY),
    time: new Date().toISOString(),
  });
});

// Generate party plan endpoint
app.post("/api/planner/generate", async (req: Request, res: Response) => {
  try {
    const {
      occasion,
      occasionTitle,
      themeDescription,
      guestCount = 20,
      targetBudget = 10000,
      dietary = 'pure_veg',
      venue = 'home_living_room',
      durationHours = 4,
      specialRequests = '',
      ecoFriendly = true,
      city = 'Bengaluru'
    } = req.body;

    const ai = getGeminiClient();

    if (!ai) {
      // Return structured fallback response if no API key
      return res.json({
        source: 'catalog_engine',
        data: generateSmartCatalogPlan({
          occasion,
          occasionTitle,
          themeDescription,
          guestCount,
          targetBudget,
          dietary,
          venue,
          durationHours,
          specialRequests,
          ecoFriendly,
          city
        })
      });
    }

    const systemPrompt = `You are IndianMart's Chief AI Party Planning Concierge in India.
Your mission is to generate a comprehensive, realistic, and budget-conscious grocery & party supply shopping list for Indian hosts.
All prices must be in Indian Rupees (₹ INR).
Always consider:
1. Indian tastes, brands (Haldiram's, Amul, Paper Boat, MTR, Tata Sampann, Rooh Afza, Bikanervala, EcoVeda areca leaf plates).
2. Dietary preferences: ${dietary} (if pure_veg or jain, strictly no meat/egg/onion/garlic where applicable).
3. Guest count: ${guestCount} people. Ensure portion sizes and quantities are mathematically sufficient.
4. Total Budget: ₹${targetBudget}. The total cost of all recommended items should align closely with this target budget (within ±10%).
5. Eco-friendly: ${ecoFriendly ? 'Prioritize biodegradable areca palm leaf plates, wooden cutlery and compostable bags' : 'Standard tableware'}.
6. City/Region: ${city}.

Categories to cover:
- 'food_snacks' (appetizers, samosas, tikka, chips, dips, chaat)
- 'main_course' (biryani trays, gravies, rotis/naans, rice)
- 'beverages' (chai, coolers, soft drinks, mocktails, juices)
- 'sweets_desserts' (mithai, gulab jamun, ice cream, kaju katli)
- 'decor_lighting' (marigold garlands, fairy rice lights, diyas, balloons)
- 'tableware_essentials' (plates, cups, spoons, napkins, trash bags)
- 'games_favors' (housie/tambola, cards, return gifts)

Include realistic item prices in INR, appropriate pack sizes, and smart alternatives where a host could save money.`;

    const userPrompt = `Please plan an event shopping list for:
Event: ${occasionTitle || occasion}
Theme: ${themeDescription || 'Festive Indian Gathering'}
Guests: ${guestCount}
Target Budget: ₹${targetBudget}
Dietary: ${dietary}
Venue: ${venue}
Duration: ${durationHours} hours
Special Requests: ${specialRequests || 'None'}
Eco-friendly tableware: ${ecoFriendly ? 'Yes' : 'No'}
City: ${city}`;

    const response = await ai.models.generateContent({
      model: "gemini-3.7-flash",
      contents: userPrompt,
      config: {
        systemInstruction: systemPrompt,
        responseMimeType: "application/json",
        responseSchema: {
          type: Type.OBJECT,
          properties: {
            eventName: { type: Type.STRING },
            eventSummary: { type: Type.STRING },
            budgetAnalysis: {
              type: Type.OBJECT,
              properties: {
                status: { type: Type.STRING, description: "within_budget, over_budget, or under_budget" },
                totalCost: { type: Type.NUMBER },
                difference: { type: Type.NUMBER },
                tip: { type: Type.STRING }
              },
              required: ["status", "totalCost", "difference", "tip"]
            },
            items: {
              type: Type.ARRAY,
              items: {
                type: Type.OBJECT,
                properties: {
                  id: { type: Type.STRING },
                  name: { type: Type.STRING },
                  brand: { type: Type.STRING },
                  category: { 
                    type: Type.STRING, 
                    description: "food_snacks, main_course, beverages, sweets_desserts, decor_lighting, tableware_essentials, or games_favors" 
                  },
                  unitPrice: { type: Type.NUMBER, description: "Price in INR ₹" },
                  quantity: { type: Type.INTEGER },
                  unitSize: { type: Type.STRING, description: "e.g. 500g pack, 1L bottle, Pack of 25" },
                  portionsPerUnit: { type: Type.STRING, description: "e.g. Serves 6-8 guests" },
                  isEssential: { type: Type.BOOLEAN },
                  tags: { 
                    type: Type.ARRAY, 
                    items: { type: Type.STRING } 
                  },
                  alternative: {
                    type: Type.OBJECT,
                    properties: {
                      name: { type: Type.STRING },
                      unitPrice: { type: Type.NUMBER },
                      savingAmount: { type: Type.NUMBER },
                      reason: { type: Type.STRING }
                    },
                    required: ["name", "unitPrice", "savingAmount", "reason"]
                  }
                },
                required: ["id", "name", "category", "unitPrice", "quantity", "unitSize", "isEssential", "tags"]
              }
            },
            hostChecklist: {
              type: Type.ARRAY,
              items: { type: Type.STRING },
              description: "5-7 high value preparation checklist tasks for the host"
            },
            timelineGuide: {
              type: Type.ARRAY,
              items: {
                type: Type.OBJECT,
                properties: {
                  time: { type: Type.STRING, description: "e.g. T-3 Hours, T-1 Hour, 00:00 (Party Start), +2 Hours (Dinner)" },
                  activity: { type: Type.STRING }
                },
                required: ["time", "activity"]
              }
            }
          },
          required: ["eventName", "eventSummary", "budgetAnalysis", "items", "hostChecklist", "timelineGuide"]
        }
      }
    });

    const parsedData = JSON.parse(response.text || "{}");
    return res.json({
      source: 'gemini_ai',
      data: parsedData
    });

  } catch (error: any) {
    console.error("Gemini generation error:", error);
    // Fallback to catalog generator
    return res.json({
      source: 'catalog_fallback',
      error: error.message,
      data: generateSmartCatalogPlan(req.body)
    });
  }
});

// Auto-Optimize Budget endpoint
app.post("/api/planner/optimize", async (req: Request, res: Response) => {
  try {
    const { items, targetBudget, mode = 'balance_exact' } = req.body;
    const ai = getGeminiClient();

    if (!ai) {
      return res.json({
        success: true,
        source: 'rule_optimizer',
        recommendations: optimizeItemsRuleBased(items, targetBudget, mode)
      });
    }

    const currentTotal = items.reduce((acc: number, item: any) => acc + (item.unitPrice * item.quantity), 0);

    const prompt = `You are a budget optimization engine for IndianMart India.
The host has a target budget of ₹${targetBudget}.
Current cart total is ₹${currentTotal}.
Mode requested: ${mode} (options: balance_exact, trim_overage, upgrade_premium).
Current items: ${JSON.stringify(items.map((it: any) => ({
      id: it.id,
      name: it.name,
      category: it.category,
      unitPrice: it.unitPrice,
      quantity: it.quantity,
      isEssential: it.isEssential
    })))}

Provide optimization advice and suggested quantity modifications or item swaps to bring the cart as close as possible to the target budget (₹${targetBudget}) without compromising core hospitality.`;

    const response = await ai.models.generateContent({
      model: "gemini-3.7-flash",
      contents: prompt,
      config: {
        responseMimeType: "application/json",
        responseSchema: {
          type: Type.OBJECT,
          properties: {
            optimizationSummary: { type: Type.STRING },
            newTotalEstimate: { type: Type.NUMBER },
            adjustments: {
              type: Type.ARRAY,
              items: {
                type: Type.OBJECT,
                properties: {
                  itemId: { type: Type.STRING },
                  itemName: { type: Type.STRING },
                  recommendedQuantity: { type: Type.INTEGER },
                  reason: { type: Type.STRING },
                  suggestedSwap: {
                    type: Type.OBJECT,
                    properties: {
                      swapName: { type: Type.STRING },
                      swapPrice: { type: Type.NUMBER },
                      netSavings: { type: Type.NUMBER }
                    }
                  }
                },
                required: ["itemId", "itemName", "recommendedQuantity", "reason"]
              }
            }
          },
          required: ["optimizationSummary", "newTotalEstimate", "adjustments"]
        }
      }
    });

    const parsed = JSON.parse(response.text || "{}");
    return res.json({
      success: true,
      source: 'gemini_ai',
      recommendations: parsed
    });
  } catch (err: any) {
    console.error("Optimizer error:", err);
    return res.json({
      success: true,
      source: 'rule_fallback',
      recommendations: optimizeItemsRuleBased(req.body.items, req.body.targetBudget, req.body.mode)
    });
  }
});

// IndianMart Assistant Chatbot Endpoint
app.post("/api/chat", async (req: Request, res: Response) => {
  try {
    const {
      message,
      history = [],
      eventContext = {},
      cartContext = {}
    } = req.body;

    if (!message || typeof message !== 'string') {
      return res.status(400).json({ error: "Message is required" });
    }

    const ai = getGeminiClient();

    if (!ai) {
      // Fallback rule-based response
      return res.json({
        source: 'smart_fallback',
        reply: generateAssistantFallbackReply(message, eventContext, cartContext),
        quickReplies: [
          "How much food for my guest count?",
          "Suggest budget Jain snacks",
          "What drinks pair best with Biryani?",
          "Add extra gulab jamun to my list"
        ]
      });
    }

    const systemInstruction = `You are the "IndianMart Assistant", an expert, warm, and highly practical AI retail party concierge for IndianMart India.
You help Indian hosts plan, budget, shop, and execute unforgettable parties and gatherings (Diwali, Bollywood Karaoke, Chai Chaat, Biryani feasts, Birthdays, Housewarmings, Cricket watch parties).

Guidelines:
1. Always speak politely with Indian hospitality context (use terms like "Namaste", "Host", "chai", "mithai", "chaat", "portions").
2. Always calculate and quote currency in Indian Rupees (₹ INR).
3. Offer precise portion estimation formulas when asked (e.g. 150-180g cooked biryani/pulao per adult, 2-3 snack pieces per person, 250ml beverage/mocktail per person, 1.5 pieces of mithai per person, 1 areca palm plate set per person + 15% buffer).
4. Be mindful of dietary constraints (Pure Veg, Jain without onion/garlic/root veg, Halal/Non-veg, Vegan, Eggless).
5. If the user asks for item recommendations or additions, mention realistic Indian retail brands (Haldiram's, Paper Boat, Amul, Tata Sampann, Bikaji, Bikanervala, Rooh Afza, Catch, Britannia, Epigamia, etc.) with approximate ₹ prices.
6. Provide helpful quick response suggestions for the customer to continue the conversation.

Current Customer Context:
- Occasion: ${eventContext.occasionTitle || 'Party'}
- Guest Count: ${eventContext.guestCount || 20} Guests
- City: ${eventContext.city || 'Bengaluru'}
- Dietary: ${eventContext.dietary || 'pure_veg'}
- Target Budget: ₹${eventContext.targetBudget || 10000}
- Current Cart Total: ₹${cartContext.totalSpend || 0} (${cartContext.itemCount || 0} items in list)

Return a structured JSON with:
- "reply": Markdown formatted string with clear, friendly explanation and advice.
- "suggestedItems": (Optional array of items if recommending new products to add to cart, with id, name, brand, category, unitPrice, unitSize, quantity, isEssential, tags).
- "quickReplies": (Array of 3-4 short question strings the user might ask next).`;

    // Construct conversation contents
    const contents: any[] = [];
    
    // Add recent history (up to last 6 turns)
    const recentHistory = history.slice(-6);
    for (const msg of recentHistory) {
      contents.push({
        role: msg.role === 'assistant' ? 'model' : 'user',
        parts: [{ text: msg.content }]
      });
    }

    // Add current user prompt
    contents.push({
      role: 'user',
      parts: [{ text: message }]
    });

    const response = await ai.models.generateContent({
      model: "gemini-3.7-flash",
      contents,
      config: {
        systemInstruction,
        responseMimeType: "application/json",
        responseSchema: {
          type: Type.OBJECT,
          properties: {
            reply: { type: Type.STRING },
            quickReplies: {
              type: Type.ARRAY,
              items: { type: Type.STRING }
            },
            suggestedItems: {
              type: Type.ARRAY,
              items: {
                type: Type.OBJECT,
                properties: {
                  id: { type: Type.STRING },
                  name: { type: Type.STRING },
                  brand: { type: Type.STRING },
                  category: { type: Type.STRING },
                  unitPrice: { type: Type.NUMBER },
                  unitSize: { type: Type.STRING },
                  quantity: { type: Type.INTEGER },
                  isEssential: { type: Type.BOOLEAN },
                  tags: {
                    type: Type.ARRAY,
                    items: { type: Type.STRING }
                  }
                },
                required: ["id", "name", "category", "unitPrice", "unitSize", "quantity"]
              }
            }
          },
          required: ["reply"]
        }
      }
    });

    const parsed = JSON.parse(response.text || "{}");
    return res.json({
      source: 'gemini_ai',
      reply: parsed.reply || "Namaste! I'm here to help you coordinate your party shopping on IndianMart.",
      suggestedItems: parsed.suggestedItems || [],
      quickReplies: parsed.quickReplies || [
        "How much food for my guest count?",
        "Suggest budget Jain snacks",
        "What drinks pair best with Biryani?",
        "How to balance my budget?"
      ]
    });
  } catch (error: any) {
    console.error("Chatbot API error:", error);
    return res.json({
      source: 'fallback_error',
      reply: generateAssistantFallbackReply(req.body.message || '', req.body.eventContext, req.body.cartContext),
      quickReplies: [
        "Estimate food quantities",
        "Show party drink options",
        "Jain snack suggestions",
        "Eco-friendly tableware options"
      ]
    });
  }
});

// Hands-Free Voice Command & Conversational Assistant Endpoint
app.post("/api/voice/process", async (req: Request, res: Response) => {
  try {
    const {
      transcript,
      activeTab = 'define',
      eventDefinition = {},
      items = [],
      currentTotal = 0,
      language = 'en'
    } = req.body;

    if (!transcript || typeof transcript !== 'string') {
      return res.status(400).json({ error: "Speech transcript is required" });
    }

    const ai = getGeminiClient();

    // If Gemini is available, use intelligent conversational and intent reasoning
    if (ai) {
      const languageInstruction = language === 'hi'
        ? 'IMPORTANT: Output the "spokenFeedback" in fluent, natural conversational Hindi (हिन्दी) and "toastMessage" in Hindi.'
        : language === 'bn'
        ? 'IMPORTANT: Output the "spokenFeedback" in fluent, natural conversational Bengali (বাংলা) and "toastMessage" in Bengali.'
        : 'Output the "spokenFeedback" and "toastMessage" in warm, natural conversational Indian English.';

      const systemInstruction = `You are the Voice & Shopping AI Concierge for IndianMart India.
Your job is to understand whatever the user says or asks (in English, Hindi, or Bengali) and respond naturally:
1. If the user asks a question (food portion calculations, snack/sweet ideas, drinks pairings, budget tips, party timeline, delivery info, or greetings), answer their question thoroughly, warmly, and helpfully in "spokenFeedback".
2. If the user gives a command to modify the cart, set event details, navigate, or place an order, include the appropriate action in "actions" AND explain what was done in "spokenFeedback".
3. Always respond strictly in the requested language: ${language === 'hi' ? 'Hindi (हिन्दी)' : language === 'bn' ? 'Bengali (বাংলা)' : 'Indian English'}.

${languageInstruction}

Current App State:
- Active Tab: ${activeTab} ('define', 'review', or 'refine_checkout')
- Occasion: ${eventDefinition.occasionTitle || eventDefinition.occasion || 'Festive Party'}
- Guests: ${eventDefinition.guestCount || 20}
- Target Budget: ₹${eventDefinition.targetBudget || 10000}
- Dietary: ${eventDefinition.dietary || 'pure_veg'}
- Current Cart Total: ₹${currentTotal}
- Current Items in Cart (${items.length}): ${items.map((i: any) => `${i.name} (Qty: ${i.quantity}, ID: ${i.id})`).join(', ')}

Supported Action Types:
1. 'SET_EVENT_FIELD': payload: { field: 'guestCount'|'targetBudget'|'dietary'|'occasion'|'venue'|'city'|'ecoFriendly'|'durationHours', value: any }
2. 'GENERATE_PLAN': payload: {}
3. 'ADD_ITEM': payload: { query: string, quantity: number }
4. 'UPDATE_QUANTITY': payload: { itemName: string, change?: number, exactQuantity?: number }
5. 'REMOVE_ITEM': payload: { itemName: string }
6. 'AUTO_BALANCE': payload: { mode: 'balance_exact'|'trim_overage'|'upgrade_premium' }
7. 'NAVIGATE_TAB': payload: { tab: 'define'|'review'|'refine_checkout' }
8. 'APPLY_COUPON': payload: { couponCode: string }
9. 'SELECT_PAYMENT': payload: { method: 'upi'|'card'|'cod'|'indianmart_pay', upiApp?: 'gpay'|'phonepe'|'paytm'|'cred' }
10. 'SELECT_DELIVERY': payload: { slot: string }
11. 'PLACE_ORDER': payload: {}
12. 'READ_SUMMARY': payload: {}
13. 'ASSISTANT_QUERY': payload: { text: string }

Output Requirement:
- Return valid JSON matching the schema.
- "spokenFeedback": A direct, friendly, informative spoken answer or confirmation in the target language (${language === 'hi' ? 'Hindi' : language === 'bn' ? 'Bengali' : 'English'}).
- "toastMessage": A concise confirmation tag with an emoji.`;

      const prompt = `User spoken speech in ${language}: "${transcript}"`;

      const response = await ai.models.generateContent({
        model: "gemini-3.7-flash",
        contents: prompt,
        config: {
          systemInstruction,
          responseMimeType: "application/json",
          responseSchema: {
            type: Type.OBJECT,
            properties: {
              spokenFeedback: { type: Type.STRING },
              toastMessage: { type: Type.STRING },
              actions: {
                type: Type.ARRAY,
                items: {
                  type: Type.OBJECT,
                  properties: {
                    type: { type: Type.STRING },
                    payload: {
                      type: Type.OBJECT,
                      properties: {
                        field: { type: Type.STRING },
                        value: { type: Type.STRING },
                        numericValue: { type: Type.NUMBER },
                        query: { type: Type.STRING },
                        quantity: { type: Type.NUMBER },
                        itemName: { type: Type.STRING },
                        change: { type: Type.NUMBER },
                        exactQuantity: { type: Type.NUMBER },
                        mode: { type: Type.STRING },
                        tab: { type: Type.STRING },
                        couponCode: { type: Type.STRING },
                        method: { type: Type.STRING },
                        upiApp: { type: Type.STRING },
                        slot: { type: Type.STRING },
                        text: { type: Type.STRING }
                      }
                    }
                  },
                  required: ["type"]
                }
              }
            },
            required: ["spokenFeedback", "toastMessage", "actions"]
          }
        }
      });

      const parsed = JSON.parse(response.text || "{}");
      return res.json({
        success: true,
        source: 'gemini_voice',
        actions: parsed.actions || [],
        spokenFeedback: parsed.spokenFeedback || (language === 'hi' ? "नमस्ते! मैं आपकी पार्टी शॉपिंग में मदद कर सकता हूँ।" : language === 'bn' ? "নমস্কার! আমি আপনার পার্টি শপিংয়ে সাহায্য করতে পারি।" : "Hello! I am here to help coordinate your party shopping."),
        toastMessage: parsed.toastMessage || (language === 'hi' ? "वॉयस प्रतिक्रिया" : language === 'bn' ? "ভয়েস প্রতিক্রিয়া" : "Voice response")
      });
    }

    // Rule-based parsing and Q&A fallback if Gemini API is offline
    const ruleResult = parseVoiceCommandRuleBased(transcript, activeTab, eventDefinition, items, currentTotal, language);
    return res.json({
      success: true,
      source: 'rule_voice',
      ...ruleResult
    });

  } catch (err: any) {
    console.error("Voice interpreter error:", err);
    // Fallback gracefully
    const ruleResult = parseVoiceCommandRuleBased(
      req.body.transcript || '',
      req.body.activeTab,
      req.body.eventDefinition,
      req.body.items,
      req.body.currentTotal,
      req.body.language || 'en'
    );
    return res.json({
      success: true,
      source: 'fallback_voice',
      ...ruleResult
    });
  }
});

function normalizeIndicNumerals(str: string): string {
  const indicDigits: Record<string, string> = {
    '०': '0', '१': '1', '२': '2', '३': '3', '४': '4', '५': '5', '६': '6', '७': '7', '८': '8', '९': '9',
    '০': '0', '১': '1', '২': '2', '৩': '3', '৪': '4', '৫': '5', '৬': '6', '৭': '7', '৮': '8', '৯': '9'
  };
  return str.replace(/[०-९০-৯]/g, d => indicDigits[d] || d);
}

// Conversational and Action Voice Parser with English, Hindi, Bengali support
function parseVoiceCommandRuleBased(
  transcript: string,
  activeTab: string,
  eventDefinition: any = {},
  items: any[] = [],
  currentTotal: number = 0,
  language: string = 'en'
) {
  const normalized = normalizeIndicNumerals(transcript);
  const lower = normalized.toLowerCase().trim();
  const actions: any[] = [];
  const guests = eventDefinition.guestCount || 20;
  const budget = eventDefinition.targetBudget || 10000;
  const city = eventDefinition.city || 'Bengaluru';
  
  let spokenFeedback = "";
  let toastMessage = "🎙️ Voice";

  // 1. Greetings & Introductions
  if (lower.includes('নমস্কার') || lower.includes('হ্যালো') || lower.includes('কেমন আছেন') || lower.includes('হাই') || lower.includes('কি করতে পারো') || lower.includes('সাহায্য') || lower.includes('नमस्ते') || lower.includes('हेलो') || lower.includes('hello') || lower.includes('hi') || lower.includes('hey')) {
    if (language === 'bn') {
      spokenFeedback = `নমস্কার! আমি আপনার IndianMart ভয়েস অ্যাসিস্ট্যান্ট। ${guests} জন অতিথির জন্য পার্টি শপিং, খাবারের সঠিক পরিমাণ হিসাব, স্ন্যাক্স বা মিষ্টির পরামর্শ, বা বাজেট নিয়ন্ত্রণে সাহায্য করতে পারি। আপনি কি জানতে চান?`;
      toastMessage = "👋 নমস্কার!";
    } else if (language === 'hi') {
      spokenFeedback = `नमस्ते! मैं आपका IndianMart वॉइस असिस्टेंट हूँ। ${guests} मेहमानों के लिए पार्टी प्लानिंग, खाने की मात्रा, स्नैक्स सुझाव या बजट में मदद कर सकता हूँ। बताएं मैं क्या करूँ?`;
      toastMessage = "👋 नमस्ते!";
    } else {
      spokenFeedback = `Namaste! I am your IndianMart Voice Assistant. I can help curate groceries, calculate food portions, or optimize your ₹${budget} budget for ${guests} guests in ${city}.`;
      toastMessage = "👋 Namaste!";
    }
    return { actions, spokenFeedback, toastMessage };
  }

  // 2. Questions about Food Portions & Quantities (কত খাবার / কত লাগবে / পরিমাণ / portion)
  if (lower.includes('কত খাবার') || lower.includes('কত লাগবে') || lower.includes('খাবারের পরিমাণ') || lower.includes('পরিমাণ') || lower.includes('কত মিষ্টি') || lower.includes('কত বিরিয়ানি') || lower.includes('কত সিঙ্গাড়া') || lower.includes('कितना खाना') || lower.includes('कितनी मात्रा') || lower.includes('portion') || lower.includes('how much food') || lower.includes('quantity')) {
    // If a new guest count was mentioned in the question, update it too
    const guestMatch = lower.match(/(\d+)\s*(guests?|people|persons?|জন|অতিথি|মানুষ|मेहमान|लोग)/i);
    let qGuests = guests;
    if (guestMatch) {
      const parsedNum = parseInt(guestMatch[1], 10);
      if (!isNaN(parsedNum) && parsedNum > 0) {
        qGuests = parsedNum;
        actions.push({ type: 'SET_EVENT_FIELD', payload: { field: 'guestCount', value: parsedNum, numericValue: parsedNum } });
      }
    }

    if (language === 'bn') {
      spokenFeedback = `${qGuests} জন অতিথির জন্য খাবারের হিসাব: মেইন কোর্সে প্রায় ${(qGuests * 0.18).toFixed(1)} কেজি বিরিয়ানি, স্ন্যাক্সে ${Math.ceil(qGuests * 2.5)}টি সিঙ্গাড়া ও কাটলেট, এবং মিষ্টিতে ${Math.ceil(qGuests * 1.8)}টি রসগোল্লা বা গোলাপ জাম লাগবে।`;
      toastMessage = `🍛 ${qGuests} জনের খাবার হিসাব`;
    } else if (language === 'hi') {
      spokenFeedback = `${qGuests} मेहमानों के लिए लगभग ${(qGuests * 0.18).toFixed(1)} किलो बिरयानी, ${Math.ceil(qGuests * 2.5)} पीस समोसे और कटलेट, तथा ${Math.ceil(qGuests * 1.8)} पीस गुलाब जामुन पर्याप्त रहेगा।`;
      toastMessage = `🍛 ${qGuests} लोगों की मात्रा`;
    } else {
      spokenFeedback = `For ${qGuests} guests, plan for approx ${(qGuests * 0.18).toFixed(1)} kg Biryani/Pulao, ${Math.ceil(qGuests * 2.5)} snack pieces (samosas/cutlets), and ${Math.ceil(qGuests * 1.8)} pieces of mithai/sweets.`;
      toastMessage = `🍛 Portions for ${qGuests}`;
    }
    return { actions, spokenFeedback, toastMessage };
  }

  // 3. Questions about Snacks & Food Suggestions (স্ন্যাক্স / নাস্তা / খাবার কি আছে / snacks)
  if (lower.includes('স্ন্যাক্স') || lower.includes('নাস্তা') || lower.includes('খাবার কি') || lower.includes('মেনু') || lower.includes('नाश्ता') || lower.includes('खाना') || lower.includes('snacks') || lower.includes('appetizer')) {
    if (language === 'bn') {
      spokenFeedback = `পার্টির সেরা স্ন্যাক্স হিসেবে হলদিরামের ককটেল সিঙ্গাড়া, পানির টিক্কা, পাপড়ি চাট কিট এবং কাজু বাদাম খুব দারুণ! আপনি চাইলে বলুন, আমি লিস্টে যোগ করে দেব।`;
      toastMessage = "🥟 স্ন্যাক্স মেনু পরামর্শ";
    } else if (language === 'hi') {
      spokenFeedback = `पार्टी के लिए हल्दीराम कॉकटेल समोसा, पनीर टिक्का सीख, पापड़ी चाट किट और रोस्टेड काजू-बादाम सबसे बेहतरीन हैं। क्या मैं इन्हें कार्ट में जोड़ दूँ?`;
      toastMessage = "🥟 स्नैक्स सुझाव";
    } else {
      spokenFeedback = `Top party snack recommendations include Haldiram Cocktail Samosas, Amul Paneer Tikka skewers, Papdi Chaat kits, and roasted cashews. Would you like to add these?`;
      toastMessage = "🥟 Snack Ideas";
    }
    return { actions, spokenFeedback, toastMessage };
  }

  // 4. Questions about Sweets & Desserts (মিষ্টি / ডেজার্ট / मिठाई / sweets)
  if (lower.includes('মিষ্টি') || lower.includes('গোলাপ জাম') || lower.includes('রসমঞ্জরী') || lower.includes('मिठाई') || lower.includes('गुलाब जामुन') || lower.includes('sweet') || lower.includes('dessert') || lower.includes('mithai')) {
    if (language === 'bn') {
      spokenFeedback = `মিষ্টির জন্য বিকানেরওয়ালা প্রিমিয়াম গুলাব জামুন টিন, বিকাজি কাজু বরফি এবং কেশর পেস্তা কুলফি সেরা! প্রতি অতিথির জন্য প্রায় ২টি করে মিষ্টি রাখুন।`;
      toastMessage = "🍯 মিষ্টির পরামর্শ";
    } else if (language === 'hi') {
      spokenFeedback = `मिठाई में बीकानेरवाला गुलाब जामुन टिन, काजू कतली और केसर पिस्ता कुल्फी सबसे लोकप्रिय हैं। प्रति मेहमान 2 पीस का हिसाब रखें।`;
      toastMessage = "🍯 मिठाई सुझाव";
    } else {
      spokenFeedback = `For dessert, Bikanervala Gulab Jamun family tins, Kaju Katli, and Kesar Pista Kulfi are host favorites. Plan for ~2 pieces per guest.`;
      toastMessage = "🍯 Sweets Guide";
    }
    return { actions, spokenFeedback, toastMessage };
  }

  // 5. Questions about Drinks & Mocktails (ড্রিংকস / পানীয় / शरबत / drinks)
  if (lower.includes('ড্রিংকস') || lower.includes('পানীয়') || lower.includes('শরবত') || lower.includes('ড্রिंक्स') || lower.includes('drinks') || lower.includes('beverage') || lower.includes('mocktail')) {
    if (language === 'bn') {
      spokenFeedback = `পার্টিতে পেপার বোট আমপানা, রুহ আফজা গোলাপ শরবত এবং কিনলে ক্লাব সোডা দিয়ে রিফ্রেশিং মকটেল পরিবেশন করতে পারেন। প্রতি অতিথির জন্য ২৫০ মিলি হিসাব রাখুন।`;
      toastMessage = "🥤 পানীয় পরামর্শ";
    } else if (language === 'hi') {
      spokenFeedback = `ड्रिंक्स में पेपर बोट आमरस, रूह अफ़ज़ा शरबत और क्लब सोडा मिंट मॉकटेल्स सबसे ताज़गी भरे हैं। प्रति व्यक्ति 250ml का अनुमान रखें।`;
      toastMessage = "🥤 ड्रिंक्स सुझाव";
    } else {
      spokenFeedback = `Great beverage options include Paper Boat coolers, Rooh Afza gulab sharbat, and Kinley Club Soda mocktail mixes. Plan for ~250ml per person.`;
      toastMessage = "🥤 Drink Ideas";
    }
    return { actions, spokenFeedback, toastMessage };
  }

  // 6. Navigation Commands (চেকআউট / রিভিউ / ইভেন্ট / checkout / review)
  if (lower.includes('checkout') || lower.includes('finalize') || lower.includes('step 3') || lower.includes('proceed to checkout') || lower.includes('চেকআউট') || lower.includes('चेकआउट') || (lower.includes('next step') && activeTab === 'review')) {
    actions.push({ type: 'NAVIGATE_TAB', payload: { tab: 'refine_checkout' } });
    spokenFeedback = language === 'bn' ? "স্মার্ট সেভ এবং চেকআউটে নিয়ে যাচ্ছি।" : language === 'hi' ? "चेकआउट और अंतिम बचत पृष्ठ पर जा रहे हैं।" : "Navigating to smart save and checkout.";
    toastMessage = language === 'bn' ? "👉 চেকআউট" : language === 'hi' ? "👉 चेकआउट" : "👉 Checkout";
    return { actions, spokenFeedback, toastMessage };
  } else if (lower.includes('review') || lower.includes('step 2') || lower.includes('shopping list') || lower.includes('curate') || lower.includes('তালিকা') || lower.includes('লিস্ট') || lower.includes('लिस्ट') || (lower.includes('next step') && activeTab === 'define')) {
    actions.push({ type: 'NAVIGATE_TAB', payload: { tab: 'review' } });
    spokenFeedback = language === 'bn' ? "আপনার কিউরেট করা শপিং লিস্ট দেখাচ্ছি।" : language === 'hi' ? "आपकी शॉपिंग लिस्ट पर जा रहे हैं।" : "Navigating to your curated shopping list.";
    toastMessage = language === 'bn' ? "👉 শপিং লিস্ট" : language === 'hi' ? "👉 शॉपिंग लिस्ट" : "👉 Review List";
    return { actions, spokenFeedback, toastMessage };
  } else if (lower.includes('define') || lower.includes('step 1') || lower.includes('event details') || lower.includes('go back') || lower.includes('ফিরে যান') || lower.includes('वापस')) {
    actions.push({ type: 'NAVIGATE_TAB', payload: { tab: 'define' } });
    spokenFeedback = language === 'bn' ? "ইভেন্টের বিবরণে ফিরে যাচ্ছি।" : language === 'hi' ? "इवेंट विवरण पर वापस जा रहे हैं।" : "Navigating to event definition.";
    toastMessage = language === 'bn' ? "👉 ইভেন্ট বিবরণ" : language === 'hi' ? "👉 इवेंट विवरण" : "👉 Define Event";
    return { actions, spokenFeedback, toastMessage };
  }

  // 7. Generate Plan (প্ল্যান তৈরি / योजना बनाएं / generate plan)
  if (lower.includes('generate plan') || lower.includes('create plan') || lower.includes('create list') || lower.includes('generate shopping list') || lower.includes('প্ল্যান তৈরি') || lower.includes('তৈরি করুন') || lower.includes('योजना बनाएं')) {
    actions.push({ type: 'GENERATE_PLAN', payload: {} });
    spokenFeedback = language === 'bn' ? "আপনার IndianMart পার্টি প্ল্যান এবং শপিং লিস্ট তৈরি করা হচ্ছে।" : language === 'hi' ? "आपकी IndianMart पार्टी योजना तैयार की जा रही है।" : "Generating your customized IndianMart party plan now.";
    toastMessage = language === 'bn' ? "✨ প্ল্যান তৈরি হচ্ছে" : language === 'hi' ? "✨ पार्टी योजना तैयार" : "✨ Generating Plan";
    return { actions, spokenFeedback, toastMessage };
  }

  // 8. Order Placement (অর্ডার করুন / অর্ডার দিন / ऑर्डर दें / place order)
  if (lower.includes('place order') || lower.includes('confirm order') || lower.includes('complete order') || lower.includes('buy now') || lower.includes('অর্ডার') || lower.includes('কনফার্ম') || lower.includes('ऑर्डर दें') || lower.includes('खरीदें')) {
    actions.push({ type: 'PLACE_ORDER', payload: {} });
    spokenFeedback = language === 'bn' ? "IndianMart এক্সপ্রেস ডেলিভারিতে আপনার অর্ডার নিশ্চিত করা হচ্ছে!" : language === 'hi' ? "IndianMart एक्सप्रेस डिलीवरी पर आपका ऑर्डर दिया जा रहा है!" : "Placing your party order on IndianMart express delivery!";
    toastMessage = language === 'bn' ? "🎉 অর্ডার সফল!" : language === 'hi' ? "🎉 অর্ডার सफल!" : "🎉 Order Placed!";
    return { actions, spokenFeedback, toastMessage };
  }

  // 9. Budget Status (বাজেট কত / মোট খরচ / कुल कितना / total)
  if (lower.includes('total') || lower.includes('budget') || lower.includes('মোট কত') || lower.includes('খরচ কত') || lower.includes('বাজেট') || lower.includes('कुल') || lower.includes('बजट')) {
    actions.push({ type: 'READ_SUMMARY', payload: {} });
    spokenFeedback = language === 'bn'
      ? `আপনার বর্তমান মোট খরচ ₹${currentTotal} এবং টার্গেট বাজেট ₹${budget}।`
      : language === 'hi'
      ? `आपका वर्तमान कुल ₹${currentTotal} है और लक्ष्य बजट ₹${budget} है।`
      : `Your current total is ₹${currentTotal} against your target budget of ₹${budget}.`;
    toastMessage = `💰 Total: ₹${currentTotal}`;
    return { actions, spokenFeedback, toastMessage };
  }

  // 10. Auto Balance (বাজেট ব্যালেন্স / संतुलित / auto balance)
  if (lower.includes('auto balance') || lower.includes('balance budget') || lower.includes('fit to budget') || lower.includes('ব্যালেন্স') || lower.includes('সমান') || lower.includes('संतुलित')) {
    actions.push({ type: 'AUTO_BALANCE', payload: { mode: 'balance_exact' } });
    spokenFeedback = language === 'bn' ? "আপনার শপিং লিস্ট টার্গেট বাজেটের সাথে ব্যালেন্স করা হচ্ছে।" : language === 'hi' ? "आपकी शॉपिंग लिस्ट को बजट के अनुसार संतुलित किया जा रहा है।" : "Auto-balancing your shopping list to match your target budget.";
    toastMessage = language === 'bn' ? "⚡ বাজেট ব্যালেন্স" : language === 'hi' ? "⚡ बजट संतुलित" : "⚡ Auto-Balanced";
    return { actions, spokenFeedback, toastMessage };
  }

  // 11. Guest Count Extraction (e.g., "২৫ জন অতিথি", "30 guests", "25 मेहमान")
  const guestMatch = lower.match(/(\d+)\s*(guests?|people|persons?|জন|অতিথি|মানুষ|मेहमान|लोग)/i) || lower.match(/(?:guests?|অতিথি|জন|मेहমান)\s*(?:to|is)?\s*(\d+)/i);
  if (guestMatch) {
    const num = parseInt(guestMatch[1] || guestMatch[2], 10);
    if (!isNaN(num) && num > 0) {
      actions.push({ type: 'SET_EVENT_FIELD', payload: { field: 'guestCount', value: num, numericValue: num } });
      spokenFeedback = language === 'bn' ? `অতিথির সংখ্যা ${num} জন নির্ধারণ করা হয়েছে।` : language === 'hi' ? `मेहमानों की संख्या ${num} सेट की गई।` : `Updated guest count to ${num} people.`;
      toastMessage = `👥 Guests: ${num}`;
      return { actions, spokenFeedback, toastMessage };
    }
  }

  // 12. Budget Amount Extraction (e.g., "বাজেট ১৫০০০", "budget 12000", "बजट 10000")
  const budgetMatch = lower.match(/(?:budget|বাজেট|টাকা|बजट|रुपये)\s*(?:to|is)?\s*(?:₹|rs\.?|rupees|টাকা|रुपये)?\s*(\d+)/i) || lower.match(/(\d+)\s*(?:rupees|budget|inr|টাকা|বাজেট|रुपये)/i);
  if (budgetMatch) {
    const num = parseInt(budgetMatch[1] || budgetMatch[2], 10);
    if (!isNaN(num) && num > 0) {
      actions.push({ type: 'SET_EVENT_FIELD', payload: { field: 'targetBudget', value: num, numericValue: num } });
      spokenFeedback = language === 'bn' ? `আপনার টার্গেট বাজেট ₹${num} নির্ধারণ করা হয়েছে।` : language === 'hi' ? `आपका लक्ष्य बजट ₹${num} निर्धारित किया गया।` : `Updated your target budget to ₹${num}.`;
      toastMessage = `💰 Budget: ₹${num}`;
      return { actions, spokenFeedback, toastMessage };
    }
  }

  // 13. Add Item Extraction (e.g., "২ প্যাকেট সিঙ্গাড়া যোগ করুন", "add samosas", "समोसे जोड़ें")
  if (lower.includes('যোগ') || lower.includes('जोड़ें') || lower.includes('add') || lower.includes('include') || lower.includes('put') || lower.includes('দাও')) {
    let cleanItem = lower
      .replace(/^(?:please\s+|can\s+you\s+)?(?:add|include|put|যোগ করুন|যোগ|जोड़ें|ডাল|লাগবে)/i, '')
      .replace(/(?:যোগ করুন|যোগ|जोड़ें|add|দাও|দিন|দিয়ে দাও|চাই|লাগবে)$/i, '')
      .trim();

    let qty = 1;
    const qtyMatch = cleanItem.match(/^(\d+)\s*(?:packs?|packets?|pieces?|packs?\s+of\s+|প্যাকেট|পিস|টি|पैकेट|पीस)?\s*/i);
    if (qtyMatch) {
      qty = parseInt(qtyMatch[1], 10) || 1;
      cleanItem = cleanItem.replace(qtyMatch[0], '').trim();
    }

    if (cleanItem && cleanItem.length >= 2 && !cleanItem.includes('budget') && !cleanItem.includes('guest') && !cleanItem.includes('বাজেট') && !cleanItem.includes('অতিথি') && !cleanItem.includes('জন')) {
      actions.push({ type: 'ADD_ITEM', payload: { query: cleanItem, quantity: qty } });
      spokenFeedback = language === 'bn'
        ? `ক্যাটালগ থেকে ${qty > 1 ? qty + 'টি ' : ''}${cleanItem} শপিং লিস্টে যোগ করা হয়েছে।`
        : language === 'hi'
        ? `कैटलॉग से ${qty > 1 ? qty + ' ' : ''}${cleanItem} शॉपिंग लिस्ट में जोड़ दिया गया है।`
        : `Added ${qty > 1 ? qty + ' of ' : ''}${cleanItem} to your shopping list.`;
      toastMessage = `➕ ${cleanItem}`;
      return { actions, spokenFeedback, toastMessage };
    }
  }

  // 14. Remove Item Extraction (e.g., "সিঙ্গাড়া মুছে দিন", "remove samosas", "समोसा हटाएं")
  const removeMatch = lower.match(/(?:remove|delete|drop|মুছে দিন|বাদ দিন|হটাও|हटाएं)\s+([a-z0-9\s'-\u0900-\u097F\u0980-\u09FF]+)/i) || lower.match(/([a-z0-9\s'-\u0900-\u097F\u0980-\u09FF]+)\s+(?:মুছে দিন|বাদ দিন|हटाएं|हटाओ)/i);
  if (removeMatch && !lower.includes('budget') && !lower.includes('guest')) {
    const itemName = removeMatch[1].trim();
    actions.push({ type: 'REMOVE_ITEM', payload: { itemName } });
    spokenFeedback = language === 'bn' ? `আপনার শপিং লিস্ট থেকে ${itemName} বাদ দেওয়া হয়েছে।` : language === 'hi' ? `आपकी लिस्ट से ${itemName} को हटा दिया गया है।` : `Removed ${itemName} from your list.`;
    toastMessage = `🗑️ Removed ${itemName}`;
    return { actions, spokenFeedback, toastMessage };
  }

  // 15. General Conversational Fallback
  if (language === 'bn') {
    spokenFeedback = `আমি আপনার কথা বুঝতে পেরেছি: "${transcript}"। আপনি আমাকে অতিথি সংখ্যা পরিবর্তন, খাবারের পরিমাণ হিসাব, বাজেট সমন্বয়, বা যেকোনো আইটেম যোগ করার জন্য বলতে পারেন।`;
    toastMessage = `🎙️ "${transcript.slice(0, 18)}..."`;
  } else if (language === 'hi') {
    spokenFeedback = `मैंने सुना: "${transcript}"। आप मुझसे खाने की मात्रा, बजट, स्नैक्स सुझाव या लिस्ट में आइटम जोड़ने के बारे में पूछ सकते हैं।`;
    toastMessage = `🎙️ "${transcript.slice(0, 18)}..."`;
  } else {
    spokenFeedback = `I understood: "${transcript}". You can ask me for portion calculations, food recommendations, budget advice, or to add items to your list.`;
    toastMessage = `🎙️ "${transcript.slice(0, 18)}..."`;
  }

  return { actions, spokenFeedback, toastMessage };
}

function generateAssistantFallbackReply(msg: string, eventContext: any = {}, cartContext: any = {}): string {
  const lower = msg.toLowerCase();
  const guests = eventContext.guestCount || 20;
  const budget = eventContext.targetBudget || 10000;
  const city = eventContext.city || 'Bengaluru';

  if (lower.includes('portion') || lower.includes('how much') || lower.includes('quantity') || lower.includes('biryani')) {
    return `### 🍛 Quantity Guidelines for ${guests} Guests\n\nHere is the IndianMart rule of thumb for Indian catering:\n\n- **Main Course (Biryani/Pulao):** ~150g–180g cooked per person = **${(guests * 0.18).toFixed(1)} kg** total.\n- **Appetizers & Samosas:** 2 to 3 pieces per guest = **${Math.ceil(guests * 2.5)} pieces**.\n- **Mithai / Sweets:** 1.5 to 2 pieces per guest = **${Math.ceil(guests * 1.8)} pieces** (approx ${(guests * 0.05).toFixed(1)} kg).\n- **Beverages / Coolers:** 250ml per person = **${Math.ceil(guests * 0.3)} Liters**.\n- **Areca Palm Tableware:** 1 full dinner set per guest + 20% backup buffer = **${Math.ceil(guests * 1.2)} sets**.\n\nWould you like me to add any specific items to your shopping list?`;
  }

  if (lower.includes('jain') || lower.includes('vegetarian') || lower.includes('dietary')) {
    return `### 🌱 Jain & Pure Veg Friendly Options\n\nFor a 100% Jain-friendly gathering in ${city}:\n\n- **Snacks:** Haldiram's Jain Samosas (made with raw banana instead of potato), roasted Makhana, Khandvi, and Dhokla.\n- **Mains:** Paneer Makhani (No onion, no garlic cashew gravy) + Tata Sampann Jeera Rice.\n- **Beverages:** Paper Boat Aamras & Rooh Afza Gulab Sharbat.\n- **Mithai:** Kesar Pista Kulfi and Bikanervala Kaju Katli.\n\nAll items are labeled with Green Dot & Jain verification on IndianMart!`;
  }

  if (lower.includes('budget') || lower.includes('save') || lower.includes('reduce') || lower.includes('cheap')) {
    return `### 💡 Smart Budget Tips (Target: ₹${budget})\n\n1. **Value Pack Swaps:** Choose 1kg family tins of Gulab Jamun instead of individual sweet boxes (saves ~25%).\n2. **Concentrated Syrups:** Using Rooh Afza or Real mocktail cordials with club soda costs ~₹8/glass vs ₹35/can for ready-to-drink cans.\n3. **Combo Tableware:** 10-inch Areca Palm multi-compartment thalis reduce separate katori bowl expenses by 40%!\n\nYou can also click the **Auto-Balance** button on the Review List to instantly align your list to ₹${budget}.`;
  }

  if (lower.includes('delivery') || lower.includes('time') || lower.includes('slot') || lower.includes('shipping')) {
    return `### 🚚 IndianMart Delivery in ${city}\n\n- **30-Min Express Instant Delivery:** Available 24/7 across ${city} for chilled mocktails, ice, samosas, and fresh sweets.\n- **Party Slot (5 PM - 7 PM):** Scheduled delivery right before your evening gathering.\n- **Free Shipping:** Automatic free delivery on all party orders over ₹999!`;
  }

  return `Namaste! I am your **IndianMart Assistant**. I'm here to help you curate, portion, and optimize everything for your **${eventContext.occasionTitle || 'Party'}** for **${guests} guests** in ${city}.\n\nFeel free to ask me about:\n- Exact food & beverage portion calculations\n- Jain, vegan, or kid-friendly snack ideas\n- How to fit your ₹${budget} budget\n- Ambiance, lighting, and eco-friendly tableware recommendations`;
}

// Smart local rule-based fallback generator
function generateSmartCatalogPlan(params: any) {
  const {
    occasion = 'diwali_festive',
    occasionTitle = 'Festive Indian Gathering',
    themeDescription = 'Celebratory gathering with authentic Indian snacks, sweets, and decor',
    guestCount = 20,
    targetBudget = 12000,
    dietary = 'pure_veg',
    ecoFriendly = true
  } = params;

  // Scale multipliers based on guest count
  const guestFactor = Math.max(0.5, guestCount / 20);

  const baseItems = [
    {
      id: 'snack-1',
      name: 'Haldiram\'s Cocktail Samosas (Party Pack)',
      brand: 'Haldiram\'s',
      category: 'food_snacks',
      unitPrice: 280,
      quantity: Math.max(1, Math.round(2 * guestFactor)),
      unitSize: 'Pack of 20 pcs (600g)',
      portionsPerUnit: 'Serves 6-8',
      isEssential: true,
      tags: ['Bestseller', 'Pure Veg', 'Quick Fry'],
      alternative: {
        name: 'Bikaji Mini Samosa Namkeen',
        unitPrice: 160,
        savingAmount: 120,
        reason: 'Economical dry snack alternative'
      }
    },
    {
      id: 'snack-2',
      name: 'Haldiram\'s Pani Puri & Papdi Chaat Magic Kit',
      brand: 'Haldiram\'s',
      category: 'food_snacks',
      unitPrice: 220,
      quantity: Math.max(1, Math.round(2 * guestFactor)),
      unitSize: '50 Puris + Chutney & Boondi kit',
      portionsPerUnit: 'Serves 10',
      isEssential: true,
      tags: ['Crowd Favorite', 'Pure Veg', 'Instant Chaat'],
      alternative: {
        name: 'Haldiram\'s Bhel Puri Combo Box',
        unitPrice: 150,
        savingAmount: 70,
        reason: 'Faster assembly dry chaat mix'
      }
    },
    {
      id: 'snack-3',
      name: dietary === 'veg_and_nonveg' ? 'IndianMart Kitchen Chicken Tikka & Paneer Platter' : 'Amul Marinated Paneer Tikka Skewers',
      brand: 'Amul / IndianMart',
      category: 'food_snacks',
      unitPrice: dietary === 'veg_and_nonveg' ? 390 : 340,
      quantity: Math.max(1, Math.round(2.5 * guestFactor)),
      unitSize: '500g pack (12 skewers)',
      portionsPerUnit: 'Serves 4-6',
      isEssential: true,
      tags: ['High Protein', 'Chef Special'],
    },
    {
      id: 'snack-4',
      name: 'Tata Sampann Salted Cashews & California Almonds Combo',
      brand: 'Tata Sampann',
      category: 'food_snacks',
      unitPrice: 480,
      quantity: Math.max(1, Math.round(1.5 * guestFactor)),
      unitSize: '500g Jar Combo',
      portionsPerUnit: 'Nibbles for 15-20',
      isEssential: true,
      tags: ['Premium Dry Fruits', 'Jain Friendly'],
    },
    {
      id: 'main-1',
      name: 'IndianMart Kitchen Dum Biryani Handi Party Tray (with Raita & Salan)',
      brand: 'IndianMart Kitchen',
      category: 'main_course',
      unitPrice: 850,
      quantity: Math.max(1, Math.round(2 * guestFactor)),
      unitSize: '1.5kg Party Tray',
      portionsPerUnit: 'Serves 6-8',
      isEssential: true,
      tags: ['Party Hero Dish', 'Authentic Dum'],
    },
    {
      id: 'main-2',
      name: 'MTR Dal Makhani & Paneer Butter Masala Catering Combo',
      brand: 'MTR',
      category: 'main_course',
      unitPrice: 420,
      quantity: Math.max(1, Math.round(2 * guestFactor)),
      unitSize: 'Pack of 3 x 300g Pouches',
      portionsPerUnit: 'Serves 6-8',
      isEssential: true,
      tags: ['Ready in 5 Mins', 'Rich Gravy'],
    },
    {
      id: 'main-3',
      name: 'Harvest Gold Tandoori Butter Naan & Kulchas',
      brand: 'Harvest Gold',
      category: 'main_course',
      unitPrice: 150,
      quantity: Math.max(2, Math.round(3.5 * guestFactor)),
      unitSize: 'Pack of 6 pieces',
      portionsPerUnit: 'Serves 3-4',
      isEssential: true,
      tags: ['Soft & Fluffy'],
    },
    {
      id: 'bev-1',
      name: 'Hamdard Rooh Afza Herbal Sharbat Bottle',
      brand: 'Hamdard',
      category: 'beverages',
      unitPrice: 185,
      quantity: Math.max(1, Math.round(1 * guestFactor)),
      unitSize: '750ml Glass Bottle',
      portionsPerUnit: 'Makes 25-30 glasses',
      isEssential: true,
      tags: ['Classic Indian Chiller', 'Crowd Pleaser'],
    },
    {
      id: 'bev-2',
      name: 'Thums Up & Limca Carbonated Cans Party Pack',
      brand: 'Coca-Cola / Thums Up',
      category: 'beverages',
      unitPrice: 360,
      quantity: Math.max(1, Math.round(2 * guestFactor)),
      unitSize: 'Pack of 6 x 300ml Cans',
      portionsPerUnit: '12 Servings',
      isEssential: true,
      tags: ['Party Chiller', 'Chilled Delivery'],
    },
    {
      id: 'sweet-1',
      name: 'Haldiram\'s Desi Ghee Gulab Jamun Tin',
      brand: 'Haldiram\'s',
      category: 'sweets_desserts',
      unitPrice: 260,
      quantity: Math.max(1, Math.round(2 * guestFactor)),
      unitSize: '1kg Tin (16-18 pcs)',
      portionsPerUnit: 'Serves 8-10',
      isEssential: true,
      tags: ['Celebration Must-Have', 'Desi Ghee'],
    },
    {
      id: 'sweet-2',
      name: 'Bikanervala Premium Silver Foil Kaju Katli Gift Box',
      brand: 'Bikanervala',
      category: 'sweets_desserts',
      unitPrice: 580,
      quantity: Math.max(1, Math.round(1 * guestFactor)),
      unitSize: '500g Box',
      portionsPerUnit: '24 Pieces',
      isEssential: true,
      tags: ['Mithai Luxury', 'Jain Friendly'],
    },
    {
      id: 'decor-1',
      name: 'Vibrant Artificial Marigold Garland Strands Set',
      brand: 'IndianMart Decor',
      category: 'decor_lighting',
      unitPrice: 350,
      quantity: 2,
      unitSize: 'Set of 5 Strands (5ft each)',
      portionsPerUnit: 'Doorway & Photo backdrop',
      isEssential: true,
      tags: ['Reusable', 'Festive Vibe'],
    },
    {
      id: 'decor-2',
      name: 'Warm White Copper Wire LED Fairy Rice Lights',
      brand: 'BrightGlow',
      category: 'decor_lighting',
      unitPrice: 240,
      quantity: 2,
      unitSize: '10m String Lights',
      portionsPerUnit: 'Living room & balcony',
      isEssential: true,
      tags: ['Warm Golden Glow'],
    },
    {
      id: 'table-1',
      name: ecoFriendly ? 'EcoVeda Areca Palm Leaf 10" Dinner Plates' : 'Premium Heavy Paper Dinner Plates',
      brand: 'EcoVeda',
      category: 'tableware_essentials',
      unitPrice: ecoFriendly ? 290 : 180,
      quantity: Math.max(1, Math.round(1.5 * guestFactor)),
      unitSize: 'Pack of 25 Sturdy Plates',
      portionsPerUnit: 'Covers guest meals + extras',
      isEssential: true,
      tags: [ecoFriendly ? '100% Compostable' : 'Recyclable', 'Leak Proof'],
    },
    {
      id: 'table-2',
      name: 'Birchwood Biodegradable Cutlery (Forks & Spoons)',
      brand: 'EcoVeda',
      category: 'tableware_essentials',
      unitPrice: 190,
      quantity: Math.max(1, Math.round(1.5 * guestFactor)),
      unitSize: 'Pack of 50 Pcs',
      portionsPerUnit: '50 Uses',
      isEssential: true,
      tags: ['Plastic Free', 'Smooth Finish'],
    },
    {
      id: 'table-3',
      name: 'Origami 3-Ply Luxury Table Napkins & Wet Wipes Combo',
      brand: 'Origami',
      category: 'tableware_essentials',
      unitPrice: 180,
      quantity: Math.max(1, Math.round(1.5 * guestFactor)),
      unitSize: '100 Napkins + 30 Wipes',
      portionsPerUnit: 'Full party cleanup',
      isEssential: true,
      tags: ['Host Essential'],
    },
    {
      id: 'game-1',
      name: 'Classic Indian Tambola / Housie Board & Tickets Set',
      brand: 'FunTime',
      category: 'games_favors',
      unitPrice: 220,
      quantity: 1,
      unitSize: 'Complete Set with 100 Tickets',
      portionsPerUnit: 'Up to 50 players',
      isEssential: false,
      tags: ['Crowd Energizer', 'All Ages'],
    }
  ];

  const totalCost = baseItems.reduce((sum, item) => sum + (item.unitPrice * item.quantity), 0);
  const diff = totalCost - targetBudget;

  let status: 'within_budget' | 'over_budget' | 'under_budget' = 'within_budget';
  if (diff > targetBudget * 0.1) status = 'over_budget';
  else if (diff < -targetBudget * 0.15) status = 'under_budget';

  return {
    eventName: occasionTitle || 'Curated IndianMart Party Plan',
    eventSummary: `Tailored for ${guestCount} guests in ${themeDescription}. Portions and tableware carefully calculated with Indian hospitality standards.`,
    budgetAnalysis: {
      status,
      totalCost,
      difference: Math.abs(diff),
      tip: status === 'over_budget' 
        ? `Currently ₹${diff} over target. Click "Auto-Balance to Budget" to trim non-essentials or switch to value packs.` 
        : status === 'under_budget' 
        ? `You have ₹${Math.abs(diff)} surplus budget! You can add gourmet mocktails or premium dry fruit return gift potlis.` 
        : `Spot on! Total is within ₹${Math.abs(diff)} of your target budget.`
    },
    items: baseItems,
    hostChecklist: [
      'Pre-chill all Thums Up, Rooh Afza syrups, and canned beverages 4 hours before guest arrival.',
      'Air-fry or bake Haldiram cocktail samosas 20 mins prior to the first doorbell.',
      'Arrange areca palm plates, wooden cutlery, and napkins in an accessible buffet flow.',
      'Set up the Tambola board and write out prize vouchers (e.g. First Line, Full House).',
      'Warm the gulab jamun in a serving bowl with fresh cardamom garnish right before dinner.',
      'Place biodegradable waste bins with clear signage near beverage and dining zones.'
    ],
    timelineGuide: [
      { time: "T-3 Hours", activity: "Receive IndianMart Express delivery, verify perishables & chill drinks in freezer/fridge." },
      { time: "T-1 Hour", activity: "Hang marigold garlands, turn on warm fairy lights & light fragrant dhoop/agarbatti." },
      { time: "00:00 (Start)", activity: "Welcome guests with chilled Rooh Afza sharbat & warm spiced cocktail samosas." },
      { time: "+1.5 Hours", activity: "Start the Tambola / Housie game or Bollywood karaoke round with finger snacks." },
      { time: "+2.5 Hours", activity: "Open the main Dum Biryani, Dal Makhani & hot Naan buffet." },
      { time: "+3.5 Hours", activity: "Serve warm Gulab Jamuns & Kesar Pista Kulfi, distribute return gifts." }
    ]
  };
}

function optimizeItemsRuleBased(items: any[], targetBudget: number, mode: string) {
  let currentTotal = items.reduce((acc, it) => acc + (it.unitPrice * it.quantity), 0);
  const adjustments: any[] = [];

  if (currentTotal > targetBudget) {
    // Need to trim or adjust
    for (const item of items) {
      if (!item.isEssential && item.quantity > 0) {
        const reduction = Math.min(item.quantity, Math.ceil((currentTotal - targetBudget) / item.unitPrice));
        if (reduction > 0) {
          const newQty = Math.max(0, item.quantity - reduction);
          adjustments.push({
            itemId: item.id,
            itemName: item.name,
            recommendedQuantity: newQty,
            reason: `Non-essential item adjusted to save ₹${(item.quantity - newQty) * item.unitPrice}`
          });
          currentTotal -= (item.quantity - newQty) * item.unitPrice;
          if (currentTotal <= targetBudget) break;
        }
      }
    }
  }

  return {
    optimizationSummary: `Balanced items according to ${mode} mode to align with your ₹${targetBudget} goal.`,
    newTotalEstimate: currentTotal,
    adjustments
  };
}

// Vite middleware & Static serving
async function startServer() {
  if (process.env.NODE_ENV !== "production") {
    const { createServer: createViteServer } = await import("vite");
    const vite = await createViteServer({
      server: { middlewareMode: true },
      appType: "spa",
    });
    app.use(vite.middlewares);
  } else {
    const distPath = path.join(process.cwd(), "dist");
    app.use(express.static(distPath));
    app.get("*", (req: Request, res: Response) => {
      res.sendFile(path.join(distPath, "index.html"));
    });
  }

  app.listen(PORT, () => {
    console.log(`IndianMart Party Planner server running on port ${PORT}`);
  });
}

if (!process.env.VERCEL && process.env.NODE_ENV !== "test") {
  startServer();
}

export { app };
export default app;