/*
 * Copyright Hyperledger Besu Contributors.
 *
 * 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.services;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;

import org.hyperledger.besu.ethereum.api.jsonrpc.internal.methods.JsonRpcMethod;
import org.hyperledger.besu.ethereum.api.jsonrpc.internal.methods.PluginJsonRpcMethod;
import org.hyperledger.besu.plugin.services.RpcEndpointService;
import org.hyperledger.besu.plugin.services.rpc.PluginRpcRequest;

import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.function.Function;
import java.util.stream.Collectors;

/** The RPC endpoint service implementation. */
public class RpcEndpointServiceImpl implements RpcEndpointService {
  private final Map<String, Function<PluginRpcRequest, ?>> rpcMethods = new HashMap<>();

  @Override
  public <T> void registerRPCEndpoint(
      final String namespace,
      final String functionName,
      final Function<PluginRpcRequest, T> function) {
    checkArgument(namespace.matches("\\p{Alnum}+"), "Namespace must be only alpha numeric");
    checkArgument(functionName.matches("\\p{Alnum}+"), "Function Name must be only alpha numeric");
    checkNotNull(function);

    rpcMethods.put(namespace + "_" + functionName, function);
  }

  /**
   * Gets plugin methods.
   *
   * @param namespaces the namespaces collection
   * @return the Json Rpc Methods from plugins
   */
  public Map<String, ? extends JsonRpcMethod> getPluginMethods(
      final Collection<String> namespaces) {
    return rpcMethods.entrySet().stream()
        .filter(
            entry ->
                namespaces.stream()
                    .anyMatch(
                        namespace ->
                            entry.getKey().toUpperCase().startsWith(namespace.toUpperCase())))
        .map(entry -> new PluginJsonRpcMethod(entry.getKey(), entry.getValue()))
        .collect(Collectors.toMap(PluginJsonRpcMethod::getName, e -> e));
  }

  /**
   * Checks if RPC methods belongs to a namespace
   *
   * @param namespace the namespace to check against
   * @return true if any of the RPC method starts with given namespace, false otherwise.
   */
  public boolean hasNamespace(final String namespace) {
    return rpcMethods.keySet().stream()
        .anyMatch(key -> key.toUpperCase().startsWith(namespace.toUpperCase()));
  }
}
