module arch.node.engines.decryption_behaviour;

import prelude open;
import arch.node.types.messages open;
import arch.system.identity.identity open;
import arch.node.types.engine open;
import arch.node.engines.decryption_config open;
import arch.node.engines.decryption_environment open;
import arch.node.engines.decryption_messages open;
import arch.node.types.identities open;
import arch.node.types.anoma as Anoma open;

type ReplyTo :=
  mkReplyTo@{
    whoAsked : Option EngineID;
    mailbox : Option MailboxID;
  };

type DecryptionActionArgument := | DecryptionActionArgumentReplyTo ReplyTo;

DecryptionActionArguments : Type := List DecryptionActionArgument;

DecryptionAction : Type :=
  Action
    DecryptionCfg
    DecryptionLocalState
    DecryptionMailboxState
    DecryptionTimerHandle
    DecryptionActionArguments
    Anoma.Msg
    Anoma.Cfg
    Anoma.Env;

DecryptionActionInput : Type :=
  ActionInput
    DecryptionCfg
    DecryptionLocalState
    DecryptionMailboxState
    DecryptionTimerHandle
    DecryptionActionArguments
    Anoma.Msg;

DecryptionActionEffect : Type :=
  ActionEffect
    DecryptionLocalState
    DecryptionMailboxState
    DecryptionTimerHandle
    Anoma.Msg
    Anoma.Cfg
    Anoma.Env;

DecryptionActionExec : Type :=
  ActionExec
    DecryptionCfg
    DecryptionLocalState
    DecryptionMailboxState
    DecryptionTimerHandle
    DecryptionActionArguments
    Anoma.Msg
    Anoma.Cfg
    Anoma.Env;

decryptAction (input : DecryptionActionInput) : Option DecryptionActionEffect :=
  let
    env := ActionInput.env input;
    cfg := ActionInput.cfg input;
    tt := ActionInput.trigger input;
  in case getEngineMsgFromTimestampedTrigger tt of
       | some emsg :=
         case EngineMsg.msg emsg of {
           | Anoma.PreMsg.MsgDecryption (DecryptionMsg.Request request) :=
             let
               decryptedData :=
                 Decryptor.decrypt
                   (DecryptionCfg.decryptor (EngineCfg.cfg cfg))
                   (DecryptionCfg.backend (EngineCfg.cfg cfg))
                   (RequestDecryption.data request);
               responseMsg :=
                 case decryptedData of
                   | none :=
                     ReplyDecryption.mkReplyDecryption@{
                       data := emptyByteString;
                       err := some "Decryption Failed";
                     }
                   | some plaintext :=
                     ReplyDecryption.mkReplyDecryption@{
                       data := plaintext;
                       err := none;
                     };
             in some
               ActionEffect.mk@{
                 env := env;
                 msgs :=
                   [
                     EngineMsg.mk@{
                       sender := getEngineIDFromEngineCfg cfg;
                       target := EngineMsg.sender emsg;
                       mailbox := some 0;
                       msg :=
                         Anoma.PreMsg.MsgDecryption
                           (DecryptionMsg.Reply responseMsg);
                     };
                   ];
                 timers := [];
                 engines := [];
               }
           | _ := none
         }
       | _ := none;

decryptActionLabel : DecryptionActionExec := ActionExec.Seq [decryptAction];

DecryptionGuard : Type :=
  Guard
    DecryptionCfg
    DecryptionLocalState
    DecryptionMailboxState
    DecryptionTimerHandle
    DecryptionActionArguments
    Anoma.Msg
    Anoma.Cfg
    Anoma.Env;

DecryptionGuardOutput : Type :=
  GuardOutput
    DecryptionCfg
    DecryptionLocalState
    DecryptionMailboxState
    DecryptionTimerHandle
    DecryptionActionArguments
    Anoma.Msg
    Anoma.Cfg
    Anoma.Env;

DecryptionGuardEval : Type :=
  GuardEval
    DecryptionCfg
    DecryptionLocalState
    DecryptionMailboxState
    DecryptionTimerHandle
    DecryptionActionArguments
    Anoma.Msg
    Anoma.Cfg
    Anoma.Env;

decryptGuard
  (tt : TimestampedTrigger DecryptionTimerHandle Anoma.Msg)
  (cfg : EngineCfg DecryptionCfg)
  (env : DecryptionEnv)
  : Option DecryptionGuardOutput :=
  case getEngineMsgFromTimestampedTrigger tt of
    | some EngineMsg.mk@{
             msg := Anoma.PreMsg.MsgDecryption (DecryptionMsg.Request _);
           } :=
      some
        GuardOutput.mk@{
          action := decryptActionLabel;
          args := [];
        }
    | _ := none;

DecryptionBehaviour : Type :=
  EngineBehaviour
    DecryptionCfg
    DecryptionLocalState
    DecryptionMailboxState
    DecryptionTimerHandle
    DecryptionActionArguments
    Anoma.Msg
    Anoma.Cfg
    Anoma.Env;

decryptionBehaviour : DecryptionBehaviour :=
  EngineBehaviour.mk@{
    guards := GuardEval.First [decryptGuard];
  };