/*
 * Copyright ConsenSys AG.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 *
 * SPDX-License-Identifier: Apache-2.0
 */
package org.hyperledger.besu.ethereum.api.jsonrpc.internal.methods;

import org.hyperledger.besu.crypto.Hash;
import org.hyperledger.besu.ethereum.api.jsonrpc.RpcMethod;
import org.hyperledger.besu.ethereum.api.jsonrpc.internal.JsonRpcRequestContext;
import org.hyperledger.besu.ethereum.api.jsonrpc.internal.exception.InvalidJsonRpcParameters;
import org.hyperledger.besu.ethereum.api.jsonrpc.internal.parameters.JsonRpcParameter.JsonRpcParameterException;
import org.hyperledger.besu.ethereum.api.jsonrpc.internal.response.JsonRpcErrorResponse;
import org.hyperledger.besu.ethereum.api.jsonrpc.internal.response.JsonRpcResponse;
import org.hyperledger.besu.ethereum.api.jsonrpc.internal.response.JsonRpcSuccessResponse;
import org.hyperledger.besu.ethereum.api.jsonrpc.internal.response.RpcErrorType;

import org.apache.tuweni.bytes.Bytes;

public class Web3Sha3 implements JsonRpcMethod {

  public Web3Sha3() {}

  @Override
  public String getName() {
    return RpcMethod.WEB3_SHA3.getMethodName();
  }

  @Override
  public JsonRpcResponse response(final JsonRpcRequestContext requestContext) {
    if (requestContext.getRequest().getParamLength() != 1) {
      // Do we want custom messages for each different type of invalid params?
      return new JsonRpcErrorResponse(
          requestContext.getRequest().getId(), RpcErrorType.INVALID_PARAM_COUNT);
    }

    final String data;
    try {
      data = requestContext.getRequiredParameter(0, String.class);
    } catch (JsonRpcParameterException e) {
      throw new InvalidJsonRpcParameters(
          "Invalid data parameter (index 0)", RpcErrorType.INVALID_DATA_PARAMS, e);
    }

    if (!data.isEmpty() && !data.startsWith("0x")) {
      return new JsonRpcErrorResponse(
          requestContext.getRequest().getId(), RpcErrorType.INVALID_DATA_PARAMS);
    }

    try {
      final Bytes byteData = Bytes.fromHexString(data);
      return new JsonRpcSuccessResponse(
          requestContext.getRequest().getId(), Hash.keccak256(byteData).toString());
    } catch (final IllegalArgumentException err) {
      return new JsonRpcErrorResponse(
          requestContext.getRequest().getId(), RpcErrorType.INVALID_DATA_PARAMS);
    }
  }
}
