Membership

  count: u64,
  created_at: u64,
  is_following: bool,
  member_type: u8,
  updated_at: u64

  current_followers: u64,
  membership: sui::table::Table<address, Member>

  public fun assert_is_member(
      membership: &Membership,
      member_address: address
  ) {
      let is_member = is_member(
          membership,
          member_address
      );

      assert!(is_member, EIsNotMember);
  }

  public fun create(
      ctx: &mut TxContext
  ): Membership {
      let membership = Membership {
          current_followers: 0,
          membership: table::new(ctx)
      };

      membership
  }

  public fun get_count(
      membership: &Membership,
      member_address: address
  ): u64 {
      membership.membership[member_address].count
  }

  public fun get_created_at(
      membership: &Membership,
      member_address: address
  ): u64 {
      membership.membership[member_address].created_at
  }

  public fun get_member_length(
      membership: &Membership
  ): u64 {
      membership.current_followers
  }

  public fun get_type(
      membership: &Membership,
      member_address: address
  ): u8 {
      membership.membership[member_address].member_type
  }

  public fun get_updated_at(
      membership: &Membership,
      member_address: address
  ): u64 {
      membership.membership[member_address].updated_at
  }

  public fun is_member(
      membership: &Membership,
      member_address: address
  ): bool {
      membership.membership.contains(member_address) &&
      membership.membership[member_address].is_following
  }

  public fun object_join(
      membership: &mut Membership,
      obj_address: address,
      timestamp: u64
  ): (u8, u8, u64) {
      let count = join(
          membership,
          obj_address,
          OBJECT,
          timestamp
      );

      (MEMBER_ADD, OBJECT, count)
  }

  public fun object_leave(
      membership: &mut Membership,
      obj_address: address,
      timestamp: u64
  ): (u8, u8, u64) {
      let count = leave(
          membership,
          obj_address,
          timestamp
      );

      (MEMBER_REMOVE, OBJECT, count)
  }

  public fun wallet_join(
      membership: &mut Membership,
      user_address: address,
      timestamp: u64
  ): (u8, u8, u64) {
      let count = join(
          membership,
          user_address,
          WALLET,
          timestamp
      );

      (MEMBER_ADD, WALLET, count)
  }

  public fun wallet_leave(
      membership: &mut Membership,
      user_address: address,
      timestamp: u64
  ): (u8, u8, u64) {
      let count = leave(
          membership,
          user_address,
          timestamp
      );

      (MEMBER_REMOVE, WALLET, count)
  }