import { NextResponse } from "next/server";
import { getDatabase } from "@/lib/db/mongodb";

export async function POST() {
  try {
    const db = await getDatabase();

    // Récupérer tous les utilisateurs existants
    const users = await db.collection("users").find({}).toArray();
    const userIds = new Set(users.map(user => user._id.toString()));

    // Récupérer toutes les balances
    const balances = await db.collection("balances").find({}).toArray();

    // Identifier les balances fantômes
    const phantomBalances = balances.filter(balance => 
      !userIds.has(balance.user.toString())
    );

    // Calculer les statistiques avant nettoyage
    const totalBalances = balances.length;
    const phantomCount = phantomBalances.length;
    const phantomCredits = phantomBalances.reduce(
      (sum, balance) => sum + (balance.tokenCredits || 0), 
      0
    );

    console.log(`🗑️ SUPPRESSION: ${phantomCount} balances fantômes détectées`);
    console.log(`💰 CRÉDITS FANTÔMES: ${phantomCredits}`);

    // SUPPRESSION DÉFINITIVE des balances fantômes
    const deleteResult = await db.collection("balances").deleteMany({
      user: { $nin: Array.from(userIds) }
    });

    console.log(`✅ SUPPRIMÉES: ${deleteResult.deletedCount} balances`);

    return NextResponse.json({
      success: true,
      statistics: {
        totalBalances,
        phantomCount,
        phantomCredits,
        cleanedCount: deleteResult.deletedCount
      },
      message: `${deleteResult.deletedCount} balances fantômes supprimées définitivement`
    });

  } catch (error) {
    console.error("Erreur lors du nettoyage des balances:", error);
    return NextResponse.json({ error: "Erreur serveur" }, { status: 500 });
  }
}

// Endpoint pour analyser sans nettoyer
export async function GET() {
  try {
    const db = await getDatabase();

    const users = await db.collection("users").find({}).toArray();
    const userIds = new Set(users.map(user => user._id.toString()));

    const balances = await db.collection("balances").find({}).toArray();

    const phantomBalances = balances.filter(balance => 
      !userIds.has(balance.user.toString())
    );

    const phantomCredits = phantomBalances.reduce(
      (sum, balance) => sum + (balance.tokenCredits || 0), 
      0
    );

    // Analyser les doublons aussi
    const userCounts = new Map<string, number>();
    balances.forEach(balance => {
      const userId = balance.user.toString();
      userCounts.set(userId, (userCounts.get(userId) || 0) + 1);
    });

    const duplicates = Array.from(userCounts.entries())
      .filter(([, count]) => count > 1)
      .map(([userId, count]) => ({
        userId,
        count,
        isPhantom: !userIds.has(userId)
      }));

    return NextResponse.json({
      analysis: {
        totalBalances: balances.length,
        totalUsers: users.length,
        phantomBalances: phantomBalances.length,
        phantomCredits,
        duplicateUsers: duplicates.length,
        duplicates: duplicates.slice(0, 10) // Premiers 10 exemples
      }
    });

  } catch (error) {
    console.error("Erreur lors de l'analyse des balances:", error);
    return NextResponse.json({ error: "Erreur serveur" }, { status: 500 });
  }
}