Add filterAddress() method to Motoko backend (#54)

* Progress

* Add 'filteredAddresses' state

* Pass caller to core

* Filter addresses from 'getNfts()'

* Add access control to 'filterAddress()'

* Filter addresses from public history

* Refactor 'filterAddress(Text)' -> 'setAddressFiltered(Text, Bool)'

* Implement filtered=false functionality

canisters/backend/Core.mo

@@ -91,7 +91,7 @@ module {
  };
 
  public func getNfts(caller : Principal) : [Types.Nft.Nft] {
- let nfts = Iter.mapFilter<Types.PublicEvent, Types.Nft.Nft>(
+ let nfts = Iter.filterMap<Types.PublicEvent, Types.Nft.Nft>(
  state.getPublicHistory(),
  func(e : Types.PublicEvent) : ?Types.Nft.Nft {
  switch (e) {
@@ -105,6 +105,17 @@ module {
  Iter.toArray(nfts);
  };
 
+ public func setAddressFiltered(caller : Principal, address : Types.Address.Address, filtered : Bool) : async Bool {
+ assert caller == installer;
+ let log = logger.Begin(caller, #setAddressFiltered(address, filtered));
+ if (filtered) {
+ state.filteredAddresses.put(address);
+ } else {
+ state.filteredAddresses.remove(address);
+ };
+ log.okWith(true);
+ };
+
  public func getPublicHistory(caller : Principal) : [Types.PublicEvent] {
  Iter.toArray(state.getPublicHistory());
  };

canisters/backend/History.mo

@@ -15,6 +15,7 @@ module {
  #connectEthWallet : (Types.EthWallet, Types.SignedPrincipal);
  #isNftOwned : Types.Nft.Nft;
  #addNfts : [Types.Nft.Nft];
+ #setAddressFiltered : (Types.Address.Address, Bool);
  };
 
  public type Response = {

canisters/backend/Main.mo

@@ -49,6 +49,11 @@ shared ({ caller = installer }) actor class Main() {
  core.getNfts(caller);
  };
 
+ /// Hide or show all NFTs with the given smart contract or wallet address.
+ public shared ({ caller }) func setAddressFiltered(address : Types.Address.Address, filtered : Bool) : async Bool {
+ await core.setAddressFiltered(caller, address, filtered);
+ };
+
  /// Retrieve the full log for this canister.
  public query ({ caller }) func getHistory() : async ?[History.Event] {
  core.getHistory(caller);

canisters/backend/State.mo

@@ -5,6 +5,7 @@ import Principal "mo:base/Principal";
 import Int "mo:base/Int";
 import Seq "mo:sequence/Sequence";
 import Stream "mo:sequence/Stream";
+import Iter_ "lib/IterMore";
 import Relate "lib/Relate";
 import System "lib/System";
 
@@ -38,8 +39,8 @@ module {
  //
  principals : Relate.Stable.Map<Principal, CreateSuccess>;
  ethWallets : Relate.Stable.Map<EthWallet, CreateSuccess>;
-
  ethNfts : Relate.Stable.Map<NftId, Nft>;
+ filteredAddresses : Relate.Stable.Map<Address.Address, ()>;
 
  //
  // Relations
@@ -57,6 +58,7 @@ module {
  principals = Relate.Stable.emptyMap();
  ethWallets = Relate.Stable.emptyMap();
  ethNfts = Relate.Stable.emptyMap();
+ filteredAddresses = Relate.Stable.emptyMap();
 
  walletSignsPrincipal = Relate.Stable.emptyTernRel();
  walletOwnsNft = Relate.Stable.emptyTernRel();
@@ -80,6 +82,8 @@ module {
 
  public let ethNfts = Relate.OO.Map<NftId, Nft>(state.ethNfts, NftId.hash, NftId.equal);
 
+ public let filteredAddresses = Relate.OO.UnRel<Address.Address>(state.filteredAddresses, Address.hash, Address.equal);
+
  public let walletSignsPrincipal = Relate.OO.TernRel<EthWallet, Principal, SignatureCheckSuccess>(
  state.walletSignsPrincipal,
  (Address.hash, Principal.hash),
@@ -142,7 +146,19 @@ module {
  };
 
  public func getPublicHistory() : Iter.Iter<Types.PublicEvent> {
- Seq.iter(state.publicHistory.events, #bwd);
+ Iter_.filterMap<Types.PublicEvent, Types.PublicEvent>(
+ Seq.iter(state.publicHistory.events, #bwd),
+ func(e : Types.PublicEvent) : ?Types.PublicEvent {
+ switch (e) {
+ case (#addNft(e)) {
+ if (
+ not filteredAddresses.has(e.nft.contract) and not filteredAddresses.has(e.nft.owner)
+ ) ? #addNft(e) else null;
+ };
+ case (e) ?e;
+ };
+ },
+ );
  };
 
  };

canisters/backend/lib/IterMore.mo

@@ -70,7 +70,7 @@ module {
  };
  };
 
- public func mapFilter<X, Y>(xs : Iter<X>, f : X -> ?Y) : Iter<Y> {
+ public func filterMap<X, Y>(xs : Iter<X>, f : X -> ?Y) : Iter<Y> {
  object {
  public func next() : ?Y {
  loop {