// @flow
const { db } = require('shared/db');
import intersection from 'lodash.intersection';
import { uploadImage } from '../utils/file-storage';
import getRandomDefaultPhoto from '../utils/get-random-default-photo';
import type { DBCommunity } from 'shared/types';

export const getCommunityById = (id: string): Promise<DBCommunity> => {
  return db
    .table('communities')
    .get(id)
    .run()
    .then(result => {
      if (result && result.deletedAt) return null;
      return result;
    });
};

// prettier-ignore
export const getCommunities = (communityIds: Array<string>): Promise<Array<DBCommunity>> => {
  return db
    .table('communities')
    .getAll(...communityIds)
    .filter(community => db.not(community.hasFields('deletedAt')))
    .run();
};

// prettier-ignore
export const getCommunitiesBySlug = (slugs: Array<string>): Promise<Array<DBCommunity>> => {
  return db
    .table('communities')
    .getAll(...slugs, { index: 'slug' })
    .filter(community => db.not(community.hasFields('deletedAt')))
    .run();
};

export const getCommunityBySlug = (slug: string): Promise<?DBCommunity> => {
  return db
    .table('communities')
    .getAll(slug, { index: 'slug' })
    .filter(community => db.not(community.hasFields('deletedAt')))
    .run()
    .then(results => {
      if (!results || results.length === 0) return null;
      return results[0];
    });
};

// prettier-ignore
export const getCommunitiesByUser = (userId: string): Promise<Array<DBCommunity>> => {
  return (
    db
      .table('usersCommunities')
      // get all the user's communities
      .getAll([userId, true], { index: 'userIdAndIsMember' })
      // get the community objects for each community
      .eqJoin('communityId', db.table('communities'))
      // get rid of unnecessary info from the usersCommunities object on the left
      .without({ left: ['id', 'communityId', 'userId', 'createdAt'] })
      // zip the tables
      .zip()
      // ensure we don't return any deleted communities
      .filter(community => db.not(community.hasFields('deletedAt')))
      .run()
  );
};

// prettier-ignore
export const getVisibleCommunitiesByUser = async (evaluatingUserId: string, currentUserId: string) => {
  const evaluatingUserMemberships = await db
    .table('usersCommunities')
    // get all the user's communities
    .getAll([evaluatingUserId, true], { index: 'userIdAndIsMember' })
    // get the community objects for each community
    .eqJoin('communityId', db.table('communities'))
    // get rid of unnecessary info from the usersCommunities object on the left
    .without({ left: ['id', 'communityId', 'userId', 'createdAt'] })
    // zip the tables
    .zip()
    // ensure we don't return any deleted communities
    .filter(community => db.not(community.hasFields('deletedAt')))
    .run()

  const currentUserMemberships = await db
    .table('usersCommunities')
    // get all the user's communities
    .getAll([currentUserId, true], { index: 'userIdAndIsMember' })
    // get the community objects for each community
    .eqJoin('communityId', db.table('communities'))
    // get rid of unnecessary info from the usersCommunities object on the left
    .without({ left: ['id', 'communityId', 'userId', 'createdAt'] })
    // zip the tables
    .zip()
    // ensure we don't return any deleted communities
    .filter(community => db.not(community.hasFields('deletedAt')))
    .run()

  const evaluatingUserCommunityIds = evaluatingUserMemberships.map(community => community.id)
  const currentUserCommunityIds = currentUserMemberships.map(community => community.id)
  const publicCommunityIds = evaluatingUserMemberships
    .filter(community => !community.isPrivate)
    .map(community => community.id)

  const overlappingMemberships = intersection(evaluatingUserCommunityIds, currentUserCommunityIds)
  const allVisibleCommunityIds = [...publicCommunityIds, ...overlappingMemberships]
  const distinctCommunityIds = allVisibleCommunityIds.filter((x, i, a) => a.indexOf(x) === i)

  return await db
    .table('communities')
    .getAll(...distinctCommunityIds)
    .run()
}

export const getPublicCommunitiesByUser = async (userId: string) => {
  return await db
    .table('usersCommunities')
    // get all the user's communities
    .getAll([userId, true], { index: 'userIdAndIsMember' })
    // get the community objects for each community
    .eqJoin('communityId', db.table('communities'))
    // only return public community ids
    .filter(row => row('right')('isPrivate').eq(false))
    // get rid of unnecessary info from the usersCommunities object on the left
    .without({ left: ['id', 'communityId', 'userId', 'createdAt'] })
    // zip the tables
    .zip()
    // ensure we don't return any deleted communities
    .filter(community => db.not(community.hasFields('deletedAt')))
    .run();
};

export const getCommunitiesChannelCounts = (communityIds: Array<string>) => {
  return db
    .table('channels')
    .getAll(...communityIds, { index: 'communityId' })
    .filter(channel => db.not(channel.hasFields('deletedAt')))
    .group('communityId')
    .count()
    .run();
};

export const getCommunitiesMemberCounts = (communityIds: Array<string>) => {
  return db
    .table('usersCommunities')
    .getAll(...communityIds.map(id => [id, true]), {
      index: 'communityIdAndIsMember',
    })
    .group('communityId')
    .count()
    .run();
};

export type EditCommunityInput = {
  input: {
    name: string,
    slug: string,
    description: string,
    website: string,
    file: Object,
    coverFile: Object,
    coverPhoto: string,
    communityId: string,
    watercoolerId?: boolean,
  },
};

// prettier-ignore
export const editCommunity = async ({ input }: EditCommunityInput, userId: string): Promise<DBCommunity> => {
  const { name, slug, description, website, watercoolerId, file, coverPhoto, coverFile, communityId } = input

  let community = await db.table('communities').get(communityId).run()

  // if the input comes in with a coverPhoto of length 0 (empty string), it means
  // the user was trying to delete or reset their cover photo from the front end.
  // in this case we can just set a new default. Otherwise, just keep their
  // original cover photo
  let updatedCoverPhoto = community.coverPhoto
  if (input.coverPhoto.length === 0) {
    ({ coverPhoto: updatedCoverPhoto } = getRandomDefaultPhoto())
  }

  return db
    .table('communities')
    .get(communityId)
    .update({
      ...community,
      name,
      slug,
      description,
      website,
      watercoolerId: watercoolerId || community.watercoolerId,
      coverPhoto: coverFile 
        ? await uploadImage(coverFile, 'communities', community.id) 
        : updatedCoverPhoto,
      profilePhoto: file 
        ? await uploadImage(file, 'communities', community.id) 
        : community.profilePhoto,
      modifiedAt: new Date()
    }, { returnChanges: 'always' })
    .run()
    .then(result => {
      if (result.replaced === 1) {
        community = result.changes[0].new_val;
      }

      // an update was triggered from the client, but no data was changed
      if (result.unchanged === 1) {
        community = result.changes[0].old_val;
      }

      return community
    })
};

export const toggleCommunityRedirect = async (communityId: string) => {
  const community = await db.table('communities').get(communityId);
  if (!community) return null;

  return db
    .table('communities')
    .get(communityId)
    .update(
      {
        redirect: !community.redirect,
      },
      {
        returnChanges: true,
      }
    )
    .then(result => {
      if (!Array.isArray(result.changes) || result.changes.length === 0)
        return getCommunityById(communityId);
      return result.changes[0].new_val;
    });
};

export const toggleCommunityNoindex = async (communityId: string) => {
  const community = await db.table('communities').get(communityId);
  if (!community) return null;

  return db
    .table('communities')
    .get(communityId)
    .update(
      {
        noindex: !community.noindex,
      },
      {
        returnChanges: true,
      }
    )
    .then(result => {
      if (!Array.isArray(result.changes) || result.changes.length === 0)
        return getCommunityById(communityId);
      return result.changes[0].new_val;
    });
};

// prettier-ignore
export const deleteCommunity = (communityId: string, userId: string): Promise<DBCommunity> => {
  return db
    .table('communities')
    .get(communityId)
    .update(
      {
        deletedBy: userId,
        deletedAt: new Date(),
        slug: db.uuid(),
      },
      {
        returnChanges: 'always',
        nonAtomic: true,
      }
    )
    .run()
};

// prettier-ignore
export const userIsMemberOfAnyChannelInCommunity = (communityId: string, userId: string): Promise<Boolean> => {
  return db('spectrum')
    .table('channels')
    .getAll(communityId, { index: 'communityId' })
    .eqJoin('id', db.table('usersChannels'), { index: 'channelId' })
    .zip()
    .filter({ userId })
    .pluck('isMember')
    .run()
    .then(channels => channels.some(channel => channel.isMember));
};

export const getRecentCommunities = (): Array<DBCommunity> => {
  return db
    .table('communities')
    .orderBy({ index: db.desc('createdAt') })
    .filter(community => db.not(community.hasFields('deletedAt')))
    .limit(100)
    .run();
};

export const getThreadCount = (communityId: string) => {
  return db
    .table('threads')
    .getAll(communityId, { index: 'communityId' })
    .filter(thread => db.not(thread.hasFields('deletedAt')))
    .count()
    .run();
};

export const setMemberCount = (
  communityId: string,
  value: number
): Promise<DBCommunity> => {
  return db
    .table('communities')
    .get(communityId)
    .update(
      {
        memberCount: value,
      },
      { returnChanges: true }
    )
    .run()
    .then(result => result.changes[0].new_val || result.changes[0].old_val);
};

export const decrementMemberCount = (
  communityId: string
): Promise<DBCommunity> => {
  return db
    .table('communities')
    .get(communityId)
    .update(
      {
        memberCount: db
          .row('memberCount')
          .default(1)
          .sub(1),
      },
      { returnChanges: true }
    )
    .run()
    .then(result => result.changes[0].new_val || result.changes[0].old_val);
};