import { NextRequest, NextResponse } from "next/server";
import { prisma } from "@/lib/prisma";
import { requireAuth } from "@/lib/auth";

// GET /api/groups/[id] — group details + member list
export async function GET(
  request: NextRequest,
  { params }: { params: Promise<{ id: string }> }
) {
  try {
    const auth = await requireAuth(request);
    if (!auth) {
      return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
    }

    const { id } = await params;

    const group = await prisma.group.findUnique({
      where: { id },
      include: {
        owner: {
          select: { id: true, name: true, isPremium: true, isPro: true },
        },
        members: {
          include: {
            user: {
              select: { id: true, name: true, isPremium: true, isPro: true },
            },
          },
          orderBy: { joinedAt: "asc" },
        },
        _count: {
          select: { members: true, threads: true },
        },
      },
    });

    if (!group) {
      return NextResponse.json({ error: "Group not found" }, { status: 404 });
    }

    // Verify user is a member of this group
    const isMember = group.members.some((m) => m.userId === auth.userId);
    if (!isMember) {
      return NextResponse.json(
        { error: "You are not a member of this group" },
        { status: 403 }
      );
    }

    return NextResponse.json({ group });
  } catch (error) {
    console.error("GET /api/groups/[id] error:", error);
    return NextResponse.json(
      { error: "Internal server error" },
      { status: 500 }
    );
  }
}