feat: enhance purchase intentions with chat integration and offer tracking

- Added MongoDB chat/message integration for seller responses
- Improved seller response validation and default messaging
- Integrated automatic chat creation/update when responding to intentions
- Added highest custom offer fields to listing queries and models
- Enhanced listing data with top offer information for buyers

components/marketplace/PurchaseModal.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import { useState } from "react";
+import { useEffect, useState } from "react";
 import {
   Dialog,
   DialogContent,
@@ -14,6 +14,7 @@ import { Label } from "@/components/ui/label";
 import { Separator } from "@/components/ui/separator";
 import { DollarSign, Coins, RefreshCw, Loader2 } from "lucide-react";
 import { useSession } from "@/lib/hooks/use-session";
+import { Input } from "@/components/ui/input";
 
 interface Listing {
   listing_id: number;
@@ -25,6 +26,8 @@ interface Listing {
   trade_item_id?: number | null;
   trade_item_name?: string | null;
   trade_item_quantity?: number | null;
+  highest_custom_offer_amount?: number | string | null;
+  highest_custom_offer_currency?: string | null;
 }
 
 interface PurchaseModalProps {
@@ -39,6 +42,21 @@ export function PurchaseModal({ open, onOpenChange, listing, onSuccess }: Purcha
   const [selectedMethod, setSelectedMethod] = useState<string | null>(null);
   const [loading, setLoading] = useState(false);
   const [error, setError] = useState<string | null>(null);
+  const [customOfferValue, setCustomOfferValue] = useState<string>("");
+
+  useEffect(() => {
+    if (!open) {
+      setSelectedMethod(null);
+      setCustomOfferValue("");
+      setError(null);
+    }
+  }, [open]);
+
+  useEffect(() => {
+    if (selectedMethod && !["pix", "tibia_coins", "gold_coins"].includes(selectedMethod)) {
+      setCustomOfferValue("");
+    }
+  }, [selectedMethod]);
 
   if (!listing) return null;
 
@@ -65,7 +83,7 @@ export function PurchaseModal({ open, onOpenChange, listing, onSuccess }: Purcha
       : listing.price_tibia_coins;
     if (!isNaN(price)) {
       availableMethods.push({
-        type: "tc",
+        type: "tibia_coins",
         label: "Tibia Coins",
         value: `${price.toLocaleString()} TC`,
         icon: Coins,
@@ -79,7 +97,7 @@ export function PurchaseModal({ open, onOpenChange, listing, onSuccess }: Purcha
       : listing.price_gold_coins;
     if (!isNaN(price)) {
       availableMethods.push({
-        type: "gp",
+        type: "gold_coins",
         label: "Gold Coins",
         value: `${price.toLocaleString()} GP`,
         icon: Coins,
@@ -96,6 +114,31 @@ export function PurchaseModal({ open, onOpenChange, listing, onSuccess }: Purcha
     });
   }
 
+  const formatOffer = (amount: number | string | null, currency: string | null) => {
+    if (amount === null || amount === undefined || !currency) {
+      return null;
+    }
+    const numeric = typeof amount === "string" ? Number(amount) : amount;
+    if (Number.isNaN(numeric)) {
+      return null;
+    }
+    switch (currency) {
+      case "pix":
+        return `R$ ${numeric.toFixed(2)}`;
+      case "tibia_coins":
+        return `${Math.round(numeric).toLocaleString()} TC`;
+      case "gold_coins":
+        return `${Math.round(numeric).toLocaleString()} GP`;
+      default:
+        return `${numeric}`;
+    }
+  };
+
+  const highestOfferLabel = formatOffer(
+    listing.highest_custom_offer_amount ?? null,
+    listing.highest_custom_offer_currency ?? null
+  );
+
   // Se houver apenas um método, selecionar automaticamente
   if (availableMethods.length === 1 && !selectedMethod) {
     setSelectedMethod(availableMethods[0].type);
@@ -107,18 +150,36 @@ export function PurchaseModal({ open, onOpenChange, listing, onSuccess }: Purcha
       return;
     }
 
+    const hasCustomOffer = customOfferValue.trim().length > 0;
+    if (hasCustomOffer) {
+      const offerNumber = Number(customOfferValue);
+      if (Number.isNaN(offerNumber) || offerNumber <= 0) {
+        setError("Informe um valor válido para a oferta personalizada.");
+        return;
+      }
+    }
+
     setLoading(true);
     setError(null);
 
     try {
+      const payload: Record<string, unknown> = {
+        payment_method: selectedMethod,
+      };
+
+      if (hasCustomOffer && ["pix", "tibia_coins", "gold_coins"].includes(selectedMethod)) {
+        const offerNumber = Number(customOfferValue);
+        payload.custom_offer_amount =
+          selectedMethod === "pix" ? Number(offerNumber.toFixed(2)) : Math.floor(offerNumber);
+        payload.custom_offer_currency = selectedMethod;
+      }
+
       const response = await fetch(`/api/listings/${listing.listing_id}/purchase`, {
         method: "POST",
         headers: {
           "Content-Type": "application/json",
         },
-        body: JSON.stringify({
-          payment_method: selectedMethod,
-        }),
+        body: JSON.stringify(payload),
       });
 
       const data = await response.json();
@@ -132,6 +193,7 @@ export function PurchaseModal({ open, onOpenChange, listing, onSuccess }: Purcha
         onSuccess();
       }
       onOpenChange(false);
+      setCustomOfferValue("");
     } catch (err) {
       setError(err instanceof Error ? err.message : "Erro ao processar compra");
     } finally {
@@ -143,9 +205,9 @@ export function PurchaseModal({ open, onOpenChange, listing, onSuccess }: Purcha
     switch (type) {
       case "pix":
         return "bg-green-500 hover:bg-green-600 text-white";
-      case "tc":
+      case "tibia_coins":
         return "bg-blue-500 hover:bg-blue-600 text-white";
-      case "gp":
+      case "gold_coins":
         return "bg-yellow-500 hover:bg-yellow-600 text-white";
       case "trade":
         return "bg-purple-500 hover:bg-purple-600 text-white";
@@ -173,6 +235,24 @@ export function PurchaseModal({ open, onOpenChange, listing, onSuccess }: Purcha
             </p>
           </div>
 
+          <div className="space-y-2">
+            <p className="text-sm font-medium">Valores anunciados pelo vendedor</p>
+            <div className="flex flex-wrap gap-2">
+              {availableMethods.map((method) => (
+                <Badge key={`original-${method.type}`} variant="secondary" className="gap-1">
+                  {method.label}: {method.value}
+                </Badge>
+              ))}
+            </div>
+          </div>
+
+          {highestOfferLabel && (
+            <div className="rounded-lg border border-primary/30 bg-primary/5 px-3 py-2 text-sm">
+              Maior oferta registrada:{" "}
+              <span className="font-semibold">{highestOfferLabel}</span>
+            </div>
+          )}
+
           <Separator />
 
           {/* Seleção de método de pagamento */}
@@ -224,6 +304,27 @@ export function PurchaseModal({ open, onOpenChange, listing, onSuccess }: Purcha
             </p>
           )}
 
+          {selectedMethod &&
+            ["pix", "tibia_coins", "gold_coins"].includes(selectedMethod) && (
+              <div className="space-y-2">
+                <Label className="text-sm font-medium">
+                  Propor valor personalizado ({selectedMethod === "pix" ? "R$" : "quantidade"})
+                </Label>
+                <Input
+                  type="number"
+                  min="0"
+                  step={selectedMethod === "pix" ? "0.01" : "1"}
+                  value={customOfferValue}
+                  onChange={(event) => setCustomOfferValue(event.target.value)}
+                  placeholder={selectedMethod === "pix" ? "Ex.: 199.90" : "Ex.: 1200"}
+                />
+                <p className="text-xs text-muted-foreground">
+                  Esse valor será enviado ao vendedor como sua proposta. Ele pode aceitar, negar ou
+                  responder.
+                </p>
+              </div>
+            )}
+
           {error && (
             <div className="bg-destructive/10 text-destructive p-3 rounded-lg text-sm">
               {error}