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

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

export const ROOM_ADDED = 'ROOM_ADDED';
export const ROOM_UPDATED = 'ROOM_UPDATED';

export const roomResolvers = {
  Query: {
    rooms: async () => {
      return prisma.room.findMany({
        where: { isPrivate: false },
      });
    },
    room: async (_: any, { id }: { id: string }) => {
      return prisma.room.findUnique({
        where: { id },
      });
    },
  },
  Mutation: {
    createRoom: async (
      _: any,
      {
        name,
        description,
        isPrivate = false,
      }: { name: string; description?: string; isPrivate?: boolean },
      context: any
    ) => {
      if (!context.userId) {
        throw new AuthenticationError('You must be logged in to create a room');
      }

      const room = await prisma.room.create({
        data: {
          name,
          description,
          isPrivate,
          owner: {
            connect: { id: context.userId },
          },
          members: {
            connect: { id: context.userId },
          },
        },
      });

      pubsub.publish(ROOM_ADDED, { roomAdded: room });

      return room;
    },
    joinRoom: async (_: any, { roomId }: { roomId: string }, context: any) => {
      if (!context.userId) {
        throw new AuthenticationError('You must be logged in to join a room');
      }

      const room = await prisma.room.findUnique({
        where: { id: roomId },
        include: { members: true },
      });

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

      if (room.isPrivate) {
        // In a real application, you would check if the user has been invited
        throw new ForbiddenError(
          'You cannot join a private room without an invitation'
        );
      }

      // Check if user is already a member
      const isMember = room.members.some(
        (member: { id: string }) => member.id === context.userId
      );
      if (isMember) {
        return room;
      }

      const updatedRoom = await prisma.room.update({
        where: { id: roomId },
        data: {
          members: {
            connect: { id: context.userId },
          },
        },
        include: { members: true },
      });

      // Publish room updated event
      pubsub.publish(ROOM_UPDATED, { roomUpdated: updatedRoom });

      return updatedRoom;
    },
    leaveRoom: async (_: any, { roomId }: { roomId: string }, context: any) => {
      if (!context.userId) {
        throw new AuthenticationError('You must be logged in to leave a room');
      }

      const room = await prisma.room.findUnique({
        where: { id: roomId },
        include: { members: true },
      });

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

      // Check if user is a member
      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');
      }

      // If user is the owner, they cannot leave
      if (room.ownerId === context.userId) {
        throw new ForbiddenError('You cannot leave a room you own');
      }

      const updatedRoom = await prisma.room.update({
        where: { id: roomId },
        data: {
          members: {
            disconnect: { id: context.userId },
          },
        },
        include: { members: true },
      });

      // Publish room updated event
      pubsub.publish(ROOM_UPDATED, { roomUpdated: updatedRoom });

      return true;
    },
  },
  Subscription: {
    roomAdded: {
      subscribe: () => pubsub.asyncIterator([ROOM_ADDED]),
    },
    roomUpdated: {
      subscribe: () => pubsub.asyncIterator([ROOM_UPDATED]),
    },
  },
  Room: {
    messages: async (parent: any) => {
      return prisma.message.findMany({
        where: { roomId: parent.id },
        orderBy: { createdAt: 'asc' },
      });
    },
    members: async (parent: any) => {
      return prisma.user.findMany({
        where: {
          rooms: {
            some: {
              id: parent.id,
            },
          },
        },
      });
    },
    owner: async (parent: any) => {
      return prisma.user.findUnique({
        where: { id: parent.ownerId },
      });
    },
  },
};