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

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

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

    // Calculer les tokens par jour (7 derniers jours)
    const dailyStats = [];
    const today = new Date();
    const dayNames = ["Dim", "Lun", "Mar", "Mer", "Jeu", "Ven", "Sam"];
    
    for (let i = 6; i >= 0; i--) {
      const date = new Date(today);
      date.setDate(date.getDate() - i);
      date.setHours(0, 0, 0, 0);
      
      const nextDate = new Date(date);
      nextDate.setDate(nextDate.getDate() + 1);
      
      const dayTransactions = transactions.filter(transaction => {
        const transactionDate = new Date(transaction.createdAt);
        return transactionDate >= date && transactionDate < nextDate;
      });
      
      const totalTokens = dayTransactions.reduce((sum, transaction) => {
        return sum + Math.abs(Number(transaction.rawAmount) || 0);
      }, 0);
      
      dailyStats.push({
        name: dayNames[date.getDay()],
        value: totalTokens
      });
    }

    // Calculer la répartition par modèle (vraies données)
    const modelStats = new Map<string, number>();
    
    transactions.forEach(transaction => {
      const model = transaction.model || "Inconnu";
      const tokens = Math.abs(Number(transaction.rawAmount) || 0);
      modelStats.set(model, (modelStats.get(model) || 0) + tokens);
    });

    // Convertir en array et trier par usage
    const modelData = Array.from(modelStats.entries())
      .map(([name, value]) => ({ name, value }))
      .sort((a, b) => b.value - a.value);

    return NextResponse.json({
      dailyTokens: dailyStats,
      modelDistribution: modelData
    });
  } catch (error) {
    console.error("Erreur lors du calcul des statistiques:", error);
    return NextResponse.json({ error: "Erreur serveur" }, { status: 500 });
  }
}