type SessionAttributes = {
  email: string
  isAdmin: boolean
  provider: string
  termsOfServiceSigned: boolean
  unsignedClientContracts: string[]
  unsignedOwnerContracts: string[]
  wishlistToken: null | string
  incompleteSignup: boolean
}

type SessionOptions = {
  serialized?: boolean
  fields?: 'attributes' | 'id' | 'type'
  optionalAttributes?: boolean
}

type SessionFieldsCondition<Options extends SessionOptions> =
  Options['fields'] extends keyof SessionFields<Options['optionalAttributes']>
    ? Options['fields']
    : keyof SessionFields<Options['optionalAttributes']>

type SessionAttributesCondition<AttributeOptions> =
  AttributeOptions extends true ? Partial<SessionAttributes> : SessionAttributes

type SessionFields<AttributeOptions> = {
  attributes: SessionAttributesCondition<AttributeOptions>
  id: string
  type: string
}

type SessionCondition<Options extends SessionOptions> =
  Options['serialized'] extends true
    ? 'id'
    : keyof SessionFields<Options['optionalAttributes']>

type SessionFieldsPick<Options extends SessionOptions> = Pick<
  SessionFields<Options['optionalAttributes']>,
  SessionFieldsCondition<Options>
>

type SessionSerialize<Options extends SessionOptions> = Pick<
  SessionFieldsPick<Options>,
  SessionCondition<Options>
> &
  SessionAttributesCondition<Options['optionalAttributes']>

export type Session<
  Options extends SessionOptions = {
    serialized: false
    optionalAttributes: false
  },
> = Options['serialized'] extends true
  ? SessionSerialize<Options>
  : SessionFieldsPick<Options>