// Copyright © Aptos Foundation
// SPDX-License-Identifier: Apache-2.0

import { Serializer, Deserializer, Serializable } from "../../bcs";
import { AnyPublicKey, AnySignature } from "../../core/crypto";
import { Ed25519PublicKey, Ed25519Signature } from "../../core/crypto/ed25519";
import { MultiEd25519PublicKey, MultiEd25519Signature } from "../../core/crypto/multiEd25519";
import { MultiKey, MultiKeySignature } from "../../core/crypto/multiKey";
import { AccountAuthenticatorVariant, HexInput, MoveFunctionId } from "../../types";
import { AASigningDataVariant, AbstractAuthenticationDataVariant } from "../../types/abstraction";
import { AccountAddress, Hex } from "../../core";
import { getFunctionParts, isValidFunctionInfo } from "../../utils/helpers";

/**
 * Represents an account authenticator that can handle multiple authentication variants.
 * This class serves as a base for different types of account authenticators, allowing for serialization
 * and deserialization of various authenticator types.
 *
 * @extends Serializable
 * @group Implementation
 * @category Transactions
 */
export abstract class AccountAuthenticator extends Serializable {
  abstract serialize(serializer: Serializer): void;

  /**
   * Deserializes an AccountAuthenticator from the provided deserializer.
   * This function helps in reconstructing the AccountAuthenticator object based on the variant index.
   *
   * @param deserializer - The deserializer instance used to read the serialized data.
   * @group Implementation
   * @category Transactions
   */
  static deserialize(deserializer: Deserializer): AccountAuthenticator {
    const index = deserializer.deserializeUleb128AsU32();
    switch (index) {
      case AccountAuthenticatorVariant.Ed25519:
        return AccountAuthenticatorEd25519.load(deserializer);
      case AccountAuthenticatorVariant.MultiEd25519:
        return AccountAuthenticatorMultiEd25519.load(deserializer);
      case AccountAuthenticatorVariant.SingleKey:
        return AccountAuthenticatorSingleKey.load(deserializer);
      case AccountAuthenticatorVariant.MultiKey:
        return AccountAuthenticatorMultiKey.load(deserializer);
      case AccountAuthenticatorVariant.NoAccountAuthenticator:
        return AccountAuthenticatorNoAccountAuthenticator.load(deserializer);
      case AccountAuthenticatorVariant.Abstraction:
        return AccountAuthenticatorAbstraction.load(deserializer);
      default:
        throw new Error(`Unknown variant index for AccountAuthenticator: ${index}`);
    }
  }

  /**
   * Determines if the current instance is an Ed25519 account authenticator.
   *
   * @returns {boolean} True if the instance is of type AccountAuthenticatorEd25519, otherwise false.
   * @group Implementation
   * @category Transactions
   */
  isEd25519(): this is AccountAuthenticatorEd25519 {
    return this instanceof AccountAuthenticatorEd25519;
  }

  /**
   * Determines if the current instance is of type AccountAuthenticatorMultiEd25519.
   *
   * @returns {boolean} True if the instance is a multi-signature Ed25519 account authenticator, otherwise false.
   * @group Implementation
   * @category Transactions
   */
  isMultiEd25519(): this is AccountAuthenticatorMultiEd25519 {
    return this instanceof AccountAuthenticatorMultiEd25519;
  }

  /**
   * Determines if the current instance is of the type AccountAuthenticatorSingleKey.
   *
   * @returns {boolean} True if the instance is an AccountAuthenticatorSingleKey, otherwise false.
   * @group Implementation
   * @category Transactions
   */
  isSingleKey(): this is AccountAuthenticatorSingleKey {
    return this instanceof AccountAuthenticatorSingleKey;
  }

  /**
   * Determine if the current instance is of type AccountAuthenticatorMultiKey.
   *
   * @returns {boolean} Returns true if the instance is an AccountAuthenticatorMultiKey, otherwise false.
   * @group Implementation
   * @category Transactions
   */
  isMultiKey(): this is AccountAuthenticatorMultiKey {
    return this instanceof AccountAuthenticatorMultiKey;
  }
}

/**
 * Represents an Ed25519 transaction authenticator for multi-signer transactions.
 * This class encapsulates the account's Ed25519 public key and signature.
 *
 * @param public_key - The Ed25519 public key associated with the account.
 * @param signature - The Ed25519 signature for the account.
 * @group Implementation
 * @category Transactions
 */
export class AccountAuthenticatorEd25519 extends AccountAuthenticator {
  public readonly public_key: Ed25519PublicKey;

  public readonly signature: Ed25519Signature;

  /**
   * Creates an instance of the class with the specified public keys and signatures.
   *
   * @param public_key The public key used for verification.
   * @param signature The signatures corresponding to the public keys.
   * @group Implementation
   * @category Transactions
   */
  constructor(public_key: Ed25519PublicKey, signature: Ed25519Signature) {
    super();
    this.public_key = public_key;
    this.signature = signature;
  }

  /**
   * Serializes the account authenticator data into the provided serializer.
   * This function captures the multi-key variant, public keys, and signatures for serialization.
   *
   * @param serializer - The serializer instance used to perform the serialization.
   * @group Implementation
   * @category Transactions
   */
  serialize(serializer: Serializer): void {
    serializer.serializeU32AsUleb128(AccountAuthenticatorVariant.Ed25519);
    this.public_key.serialize(serializer);
    this.signature.serialize(serializer);
  }

  /**
   * Loads an instance of AccountAuthenticatorMultiKey from the provided deserializer.
   * This function helps in reconstructing the authenticator object using the deserialized public keys and signatures.
   *
   * @param deserializer - The deserializer used to extract the necessary data for loading the authenticator.
   * @group Implementation
   * @category Transactions
   */
  static load(deserializer: Deserializer): AccountAuthenticatorEd25519 {
    const public_key = Ed25519PublicKey.deserialize(deserializer);
    const signature = Ed25519Signature.deserialize(deserializer);
    return new AccountAuthenticatorEd25519(public_key, signature);
  }
}

/**
 * Represents a transaction authenticator for Multi Ed25519, designed for multi-signer transactions.
 *
 * @param public_key - The MultiEd25519 public key of the account.
 * @param signature - The MultiEd25519 signature of the account.
 * @group Implementation
 * @category Transactions
 */
export class AccountAuthenticatorMultiEd25519 extends AccountAuthenticator {
  public readonly public_key: MultiEd25519PublicKey;

  public readonly signature: MultiEd25519Signature;

  constructor(public_key: MultiEd25519PublicKey, signature: MultiEd25519Signature) {
    super();
    this.public_key = public_key;
    this.signature = signature;
  }

  serialize(serializer: Serializer): void {
    serializer.serializeU32AsUleb128(AccountAuthenticatorVariant.MultiEd25519);
    this.public_key.serialize(serializer);
    this.signature.serialize(serializer);
  }

  static load(deserializer: Deserializer): AccountAuthenticatorMultiEd25519 {
    const public_key = MultiEd25519PublicKey.deserialize(deserializer);
    const signature = MultiEd25519Signature.deserialize(deserializer);
    return new AccountAuthenticatorMultiEd25519(public_key, signature);
  }
}

/**
 * Represents an account authenticator that utilizes a single key for signing.
 * This class is designed to handle authentication using a public key and its corresponding signature.
 *
 * @param public_key - The public key used for authentication.
 * @param signature - The signature associated with the public key.
 * @group Implementation
 * @category Transactions
 */
export class AccountAuthenticatorSingleKey extends AccountAuthenticator {
  public readonly public_key: AnyPublicKey;

  public readonly signature: AnySignature;

  constructor(public_key: AnyPublicKey, signature: AnySignature) {
    super();
    this.public_key = public_key;
    this.signature = signature;
  }

  serialize(serializer: Serializer): void {
    serializer.serializeU32AsUleb128(AccountAuthenticatorVariant.SingleKey);
    this.public_key.serialize(serializer);
    this.signature.serialize(serializer);
  }

  static load(deserializer: Deserializer): AccountAuthenticatorSingleKey {
    const public_key = AnyPublicKey.deserialize(deserializer);
    const signature = AnySignature.deserialize(deserializer);
    return new AccountAuthenticatorSingleKey(public_key, signature);
  }
}

/**
 * Represents an account authenticator that supports multiple keys and signatures for multi-signature scenarios.
 *
 * @param public_keys - The public keys used for authentication.
 * @param signatures - The signatures corresponding to the public keys.
 * @group Implementation
 * @category Transactions
 */
export class AccountAuthenticatorMultiKey extends AccountAuthenticator {
  public readonly public_keys: MultiKey;

  public readonly signatures: MultiKeySignature;

  constructor(public_keys: MultiKey, signatures: MultiKeySignature) {
    super();
    this.public_keys = public_keys;
    this.signatures = signatures;
  }

  serialize(serializer: Serializer): void {
    serializer.serializeU32AsUleb128(AccountAuthenticatorVariant.MultiKey);
    this.public_keys.serialize(serializer);
    this.signatures.serialize(serializer);
  }

  static load(deserializer: Deserializer): AccountAuthenticatorMultiKey {
    const public_keys = MultiKey.deserialize(deserializer);
    const signatures = MultiKeySignature.deserialize(deserializer);
    return new AccountAuthenticatorMultiKey(public_keys, signatures);
  }
}

/**
 * AccountAuthenticatorNoAccountAuthenticator for no account authenticator
 * It represents the absence of a public key for transaction simulation.
 * It allows skipping the public/auth key check during the simulation.
 */
export class AccountAuthenticatorNoAccountAuthenticator extends AccountAuthenticator {
  serialize(serializer: Serializer): void {
    serializer.serializeU32AsUleb128(AccountAuthenticatorVariant.NoAccountAuthenticator);
  }

  static load(deserializer: Deserializer): AccountAuthenticatorNoAccountAuthenticator {
    return new AccountAuthenticatorNoAccountAuthenticator();
  }
}

/**
 * Represents an account authenticator that supports abstract authentication.
 *
 * @param functionInfo - The function info of the authentication function.
 * @param signingMessageDigest - The digest of the signing message.
 * @param abstractionSignature - The signature of the authentication function.
 * @param accountIdentity - optional. The account identity for DAA.
 * @group Implementation
 * @category Transactions
 */
export class AccountAuthenticatorAbstraction extends AccountAuthenticator {
  public readonly functionInfo: string;

  public readonly signingMessageDigest: Hex;

  public readonly abstractionSignature: Uint8Array;

  /**
   * DAA, which is extended of the AA module, requires an account identity
   */
  public readonly accountIdentity?: Uint8Array;

  constructor(
    functionInfo: string,
    signingMessageDigest: HexInput,
    abstractionSignature: Uint8Array,
    accountIdentity?: Uint8Array,
  ) {
    super();
    if (!isValidFunctionInfo(functionInfo)) {
      throw new Error(`Invalid function info ${functionInfo} passed into AccountAuthenticatorAbstraction`);
    }
    this.functionInfo = functionInfo;
    this.abstractionSignature = abstractionSignature;
    this.signingMessageDigest = Hex.fromHexInput(Hex.fromHexInput(signingMessageDigest).toUint8Array());
    this.accountIdentity = accountIdentity;
  }

  serialize(serializer: Serializer): void {
    serializer.serializeU32AsUleb128(AccountAuthenticatorVariant.Abstraction);
    const { moduleAddress, moduleName, functionName } = getFunctionParts(this.functionInfo as MoveFunctionId);
    AccountAddress.fromString(moduleAddress).serialize(serializer);
    serializer.serializeStr(moduleName);
    serializer.serializeStr(functionName);
    if (this.accountIdentity) {
      serializer.serializeU32AsUleb128(AbstractAuthenticationDataVariant.DerivableV1);
    } else {
      serializer.serializeU32AsUleb128(AbstractAuthenticationDataVariant.V1);
    }
    serializer.serializeBytes(this.signingMessageDigest.toUint8Array());
    if (this.accountIdentity) {
      serializer.serializeBytes(this.abstractionSignature);
    } else {
      serializer.serializeFixedBytes(this.abstractionSignature);
    }

    if (this.accountIdentity) {
      serializer.serializeBytes(this.accountIdentity);
    }
  }

  static load(deserializer: Deserializer): AccountAuthenticatorAbstraction {
    // deserialize the function info
    const moduleAddress = AccountAddress.deserialize(deserializer);
    const moduleName = deserializer.deserializeStr();
    const functionName = deserializer.deserializeStr();
    // deserialize the variant
    const variant = deserializer.deserializeUleb128AsU32();
    // deserialize the signing message digest
    const signingMessageDigest = deserializer.deserializeBytes();

    if (variant === AbstractAuthenticationDataVariant.V1) {
      const abstractionSignature = deserializer.deserializeFixedBytes(deserializer.remaining());
      return new AccountAuthenticatorAbstraction(
        `${moduleAddress}::${moduleName}::${functionName}`,
        signingMessageDigest,
        abstractionSignature,
      );
    }
    if (variant === AbstractAuthenticationDataVariant.DerivableV1) {
      const abstractionSignature = deserializer.deserializeBytes();
      const abstractPublicKey = deserializer.deserializeBytes();
      return new AccountAuthenticatorAbstraction(
        `${moduleAddress}::${moduleName}::${functionName}`,
        signingMessageDigest,
        abstractionSignature,
        abstractPublicKey,
      );
    }
    throw new Error(`Unknown variant index for AccountAuthenticatorAbstraction: ${variant}`);
  }
}

/**
 * Represents an account abstraction message that contains the original signing message and the function info.
 *
 * @param originalSigningMessage - The original signing message.
 * @param functionInfo - The function info of the authentication function.
 * @group Implementation
 * @category Transactions
 */
export class AccountAbstractionMessage extends Serializable {
  public readonly originalSigningMessage: Hex;

  public readonly functionInfo: string;

  constructor(originalSigningMessage: HexInput, functionInfo: string) {
    super();
    this.originalSigningMessage = Hex.fromHexInput(Hex.fromHexInput(originalSigningMessage).toUint8Array());
    this.functionInfo = functionInfo;
  }

  serialize(serializer: Serializer): void {
    serializer.serializeU32AsUleb128(AASigningDataVariant.V1);
    serializer.serializeBytes(this.originalSigningMessage.toUint8Array());
    const { moduleAddress, moduleName, functionName } = getFunctionParts(this.functionInfo as MoveFunctionId);
    AccountAddress.fromString(moduleAddress).serialize(serializer);
    serializer.serializeStr(moduleName);
    serializer.serializeStr(functionName);
  }

  static deserialize(deserializer: Deserializer): AccountAbstractionMessage {
    const variant = deserializer.deserializeUleb128AsU32();
    if (variant !== AASigningDataVariant.V1) {
      throw new Error(`Unknown variant index for AccountAbstractionMessage: ${variant}`);
    }
    const originalSigningMessage = deserializer.deserializeBytes();
    const functionInfoModuleAddress = AccountAddress.deserialize(deserializer);
    const functionInfoModuleName = deserializer.deserializeStr();
    const functionInfoFunctionName = deserializer.deserializeStr();
    const functionInfo = `${functionInfoModuleAddress}::${functionInfoModuleName}::${functionInfoFunctionName}`;
    return new AccountAbstractionMessage(originalSigningMessage, functionInfo);
  }
}