import { PrismaClient } from '@prisma/client';
import { AuthenticationError, ForbiddenError } from 'apollo-server-express';
import { PubSub, withFilter } from 'graphql-subscriptions';

const prisma = new PrismaClient();
const pubsub = new PubSub();

export const MESSAGE_ADDED = 'MESSAGE_ADDED';

export const messageResolvers = {
  Query: {
    messages: async (_: any, { roomId }: { roomId: string }, context: any) => {
      if (!context.userId) {
        throw new AuthenticationError('You must be logged in to view messages');
      }

      // Check if user is a member of the room
      const room = await prisma.room.findUnique({
        where: { id: roomId },
        include: { members: true },
      });

      if (!room) {
        throw new ForbiddenError('Room not found');
      }

      const isMember = room.members.some(
        (member: { id: string }) => member.id === context.userId
      );
      if (!isMember) {
        throw new ForbiddenError('You are not a member of this room');
      }

      return prisma.message.findMany({
        where: { roomId },
        orderBy: { createdAt: 'asc' },
      });
    },
  },
  Mutation: {
    sendMessage: async (
      _: any,
      { content, roomId }: { content: string; roomId: string },
      context: any
    ) => {
      if (!context.userId) {
        throw new AuthenticationError(
          'You must be logged in to send a message'
        );
      }

      // Check if user is a member of the room
      const room = await prisma.room.findUnique({
        where: { id: roomId },
        include: { members: true },
      });

      if (!room) {
        throw new ForbiddenError('Room not found');
      }

      const isMember = room.members.some(
        (member: { id: string }) => member.id === context.userId
      );
      if (!isMember) {
        throw new ForbiddenError('You are not a member of this room');
      }

      const message = await prisma.message.create({
        data: {
          content,
          user: {
            connect: { id: context.userId },
          },
          room: {
            connect: { id: roomId },
          },
        },
        include: {
          user: true,
          room: true,
        },
      });

      pubsub.publish(MESSAGE_ADDED, { messageAdded: message, roomId });

      return message;
    },
  },
  Subscription: {
    messageAdded: {
      subscribe: withFilter(
        () => pubsub.asyncIterator([MESSAGE_ADDED]),
        (payload, variables) => {
          return payload.roomId === variables.roomId;
        }
      ),
    },
  },
  Message: {
    user: async (parent: any) => {
      return prisma.user.findUnique({
        where: { id: parent.userId },
      });
    },
    room: async (parent: any) => {
      return prisma.room.findUnique({
        where: { id: parent.roomId },
      });
    },
  },
};