import { NextRequest, NextResponse } from "next/server";
import { getServerSession } from "next-auth/next";
import { authOptions } from "@/app/api/auth/[...nextauth]/route";
import { prisma } from "@/lib/prisma";

/**
 * Handles the creation of a default calendar for an authenticated user.
 *
 * This function checks if the user already has a default calendar named "Calendrier principal".
 * If such a calendar exists, it returns the existing calendar.
 * Otherwise, it creates a new default calendar for the user.
 *
 * @param req - The incoming request object.
 * @returns A JSON response containing the existing or newly created calendar, or an error message.
 *
 * @throws Will return a 401 status if the user is not authenticated.
 * @throws Will return a 500 status if there is a server error during the calendar creation process.
 */
export async function POST(req: NextRequest) {
  const session = await getServerSession(authOptions);

  if (!session?.user?.username) {
    return NextResponse.json({ error: "Non authentifié" }, { status: 401 });
  }

  try {
    // Vérifier si l'utilisateur a déjà un calendrier par défaut
    const existingCalendar = await prisma.calendar.findFirst({
      where: {
        userId: session.user.username,
        name: "Calendrier principal",
      },
    });

    if (existingCalendar) {
      return NextResponse.json(existingCalendar);
    }

    // Créer un calendrier par défaut
    const calendar = await prisma.calendar.create({
      data: {
        name: "Calendrier principal",
        color: "#0082c9",
        description: "Calendrier principal",
        userId: session.user.username,
      },
    });

    return NextResponse.json(calendar, { status: 201 });
  } catch (error) {
    console.error(
      "Erreur lors de la création du calendrier par défaut:",
      error
    );
    return NextResponse.json({ error: "Erreur serveur" }, { status: 500 });
  }
}