import { z } from "zod";
import { requireAdmin } from "@/lib/middleware/admin";
import {
  getAllUsers,
  getUserById,
  updateUser,
  deleteUserById,
} from "@/lib/db/queries";
import { ChatSDKError } from "@/lib/errors";

const updateUserSchema = z.object({
  id: z.string().uuid(),
  role: z.enum(["guest", "regular", "admin"]).optional(),
  isActive: z.boolean().optional(),
  email: z.string().email().optional(),
  monthlyImageLimit: z.number().int().min(0).nullable().optional(),
});

export async function GET(request: Request) {
  try {
    await requireAdmin();

    const { searchParams } = new URL(request.url);
    const page = Number.parseInt(searchParams.get("page") || "1", 10);
    const limit = Number.parseInt(searchParams.get("limit") || "10", 10);
    const search = searchParams.get("search") || "";

    const offset = (page - 1) * limit;

    const { users, total } = await getAllUsers({ limit, offset, search });
    
    return Response.json({ 
      users, 
      total,
      page,
      limit,
      totalPages: Math.ceil(total / limit)
    });
  } catch (error) {
    if (error instanceof ChatSDKError) {
      return error.toResponse();
    }
    return new ChatSDKError("offline:admin").toResponse();
  }
}

export async function PATCH(request: Request) {
  try {
    await requireAdmin();

    const body = await request.json();
    const { id, role, isActive, email, monthlyImageLimit } = updateUserSchema.parse(body);

    const result = await updateUser({ id, role, isActive, email, monthlyImageLimit });

    if (result.length === 0) {
      return new ChatSDKError("bad_request:api", "User not found").toResponse();
    }

    return Response.json({ user: result[0] });
  } catch (error) {
    if (error instanceof ChatSDKError) {
      return error.toResponse();
    }
    if (error instanceof z.ZodError) {
      return new ChatSDKError("bad_request:api", error.message).toResponse();
    }
    return new ChatSDKError("offline:admin").toResponse();
  }
}

export async function DELETE(request: Request) {
  try {
    await requireAdmin();

    const { searchParams } = new URL(request.url);
    const id = searchParams.get("id");

    if (!id) {
      return new ChatSDKError("bad_request:api", "User ID is required").toResponse();
    }

    await deleteUserById({ id });

    return Response.json({ success: true });
  } catch (error) {
    if (error instanceof ChatSDKError) {
      return error.toResponse();
    }
    return new ChatSDKError("offline:admin").toResponse();
  }
}