FIX implant must not have owner to be sold

src/handlers/implants.ts

 import { type Request, type Response } from 'express';
-import { implantsTable } from '@/db/schema';
+import { implantsTable, purchasesTable, usersTable} from '@/db/schema';
 import { db } from "@/db";
 import { eq } from 'drizzle-orm';
 import { implantSchema, updateImplantSchema } from '@/validators/implantsValidator';
+import { error } from 'console';
 
 export default class implant{
     static implantRequestValidation (req: Request){
@@ -101,7 +102,7 @@ export default class implant{
     }
 
     static async implantCreate(req: Request, res: Response){
-        const implant_package = implant.implantRequestUnzip(req);setInterval
+        const implant_package = implant.implantRequestUnzip(req);
         if (!implant_package.success)
         {
             return res.status(400).json("Invalid Request");
@@ -122,4 +123,54 @@ export default class implant{
             return res.status(500).json({ error: "User Creation Error"});
         }
     }
+
+    static async implantBuy (req: Request, res: Response): Promise<any>{
+        try{
+            const { buyer_id, product_id } = req.body;
+
+            const user = await db.select().from(usersTable).where(eq(usersTable.id, buyer_id));
+            const cyberPart = await db.select().from(implantsTable).where(eq(implantsTable.id, product_id));
+
+            if (!user || !cyberPart)
+                return res.status(404).json({ error: "User or implant not found" });
+
+            const bought = await db.select().from(purchasesTable).where(eq(purchasesTable.implant_id, product_id))
+            if (bought)
+                return res.status(404).json({ error: "Implant was already bought" });
+
+            var userMoney = parseFloat(user.money);
+            const implantPrice = parseFloat(cyberPart.price);
+            var userCyberPsychosis = parseInt(user.cyberpsychosis, 10);
+            const userCyberLimit = parseInt(user.cyberLimit, 10);
+            const implantCyberCost = parseInt(cyberPart.cyberCost, 10)
+
+            if (userMoney < implantPrice)
+                return res.status(404).json({ error: "Insufficient money" });
+
+            userMoney -= implantPrice;
+            userCyberPsychosis += implantCyberCost;
+
+            if (userCyberPsychosis >= userCyberLimit)
+                return res.status(404).json({ error: "Impossible to use implant, risk of cyberpsychosis is too high" });
+            
+            const updated_user = await db.update(usersTable)
+            .set({
+                money: userMoney.toString(),
+                cyberpsychosis: userCyberPsychosis.toString()
+            }).where(eq(usersTable.id, buyer_id)).returning();
+            
+            const purchase = await db.insert(purchasesTable)
+            .values({   
+                user_id: buyer_id,
+                implant_id: product_id,
+            }).returning();
+            
+            return res.status(200)
+            .json({ message: "Implant bought successfully", 
+                purchase, user: updated_user });
+        } catch (error) {
+            console.error(error);
+            return res.status(500).json({ error: "Erro ao realizar a compra" });
+        }
+    }
 }