import { FindOptionsOrder, FindOptionsWhere, IsNull, MoreThanOrEqual, Not } from 'typeorm'
import { Community as DbCommunity } from '../entity'
import { urlSchema, uuidv4Schema } from 'shared'

/**
 * Retrieves the home community, i.e., a community that is not foreign.
 * @returns A promise that resolves to the home community, or null if no home community was found
 */
export async function getHomeCommunity(): Promise<DbCommunity | null> {
  // TODO: Put in Cache, it is needed nearly always
  // TODO: return only DbCommunity or throw to reduce unnecessary checks, because there should be always a home community
  return await DbCommunity.findOne({
    where: { foreign: false },
  })
}

export async function getCommunityByUuid(communityUuid: string): Promise<DbCommunity | null> {
  return await DbCommunity.findOne({
    where: [{ communityUuid }],
  })
}

export function findWithCommunityIdentifier(communityIdentifier: string): FindOptionsWhere<DbCommunity> {
  const where: FindOptionsWhere<DbCommunity> = {}
  // pre filter identifier type to reduce db query complexity
  if (urlSchema.safeParse(communityIdentifier).success) {
    where.url = communityIdentifier
  } else if (uuidv4Schema.safeParse(communityIdentifier).success) {
    where.communityUuid = communityIdentifier
  } else {
    where.name = communityIdentifier
  }
  return where
}

export async function getCommunityWithFederatedCommunityByIdentifier(
  communityIdentifier: string,
): Promise<DbCommunity | null> {
  return await DbCommunity.findOne({
    where: { ...findWithCommunityIdentifier(communityIdentifier) },
    relations: ['federatedCommunities'],
  })
}

// returns all reachable communities 
// home community and all federated communities which have been verified within the last authenticationTimeoutMs
export async function getReachableCommunities(
  authenticationTimeoutMs: number,
  order?: FindOptionsOrder<DbCommunity>
): Promise<DbCommunity[]> {
  return await DbCommunity.find({
    where: [ 
      { 
        authenticatedAt: Not(IsNull()), 
        federatedCommunities: { 
          verifiedAt: MoreThanOrEqual(new Date(Date.now() - authenticationTimeoutMs)) 
        } 
      },
      { foreign: false },
    ],
    order,
  })
}