/*
 * Copyright 2015 Kevin Herron
 *
 * 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.
 */

package com.digitalpetri.opcua.stack.examples.client;

import java.security.KeyPair;
import java.security.cert.X509Certificate;
import java.util.Arrays;
import java.util.UUID;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.atomic.AtomicLong;

import com.digitalpetri.opcua.stack.client.UaTcpStackClient;
import com.digitalpetri.opcua.stack.client.config.UaTcpStackClientConfig;
import com.digitalpetri.opcua.stack.core.application.UaStackClient;
import com.digitalpetri.opcua.stack.core.types.builtin.DateTime;
import com.digitalpetri.opcua.stack.core.types.builtin.LocalizedText;
import com.digitalpetri.opcua.stack.core.types.builtin.NodeId;
import com.digitalpetri.opcua.stack.core.types.builtin.Variant;
import com.digitalpetri.opcua.stack.core.types.structured.EndpointDescription;
import com.digitalpetri.opcua.stack.core.types.structured.RequestHeader;
import com.digitalpetri.opcua.stack.core.types.structured.TestStackRequest;
import com.digitalpetri.opcua.stack.core.types.structured.TestStackResponse;

import static com.digitalpetri.opcua.stack.core.types.builtin.unsigned.Unsigned.uint;

public class ClientExample {

    private final AtomicLong requestHandle = new AtomicLong(1L);

    private final UaTcpStackClient client;

    public ClientExample(X509Certificate certificate, KeyPair keyPair) throws Exception {
        // Query endpoints and select highest security level.
        EndpointDescription[] endpoints = UaTcpStackClient.getEndpoints("opc.tcp://localhost:12685/example").get();

        EndpointDescription endpoint = Arrays.stream(endpoints)
                .sorted((e1, e2) -> e2.getSecurityLevel().intValue() - e1.getSecurityLevel().intValue())
                .findFirst()
                .orElseThrow(() -> new Exception("no endpoints returned"));

        UaTcpStackClientConfig config = UaTcpStackClientConfig.builder()
                .setApplicationName(LocalizedText.english("Stack Example Client"))
                .setApplicationUri(String.format("urn:example-client:%s", UUID.randomUUID()))
                .setCertificate(certificate)
                .setKeyPair(keyPair)
                .setEndpoint(endpoint)
                .build();

        client = new UaTcpStackClient(config);
    }

    public CompletableFuture<TestStackResponse> testStack(int input) {
        RequestHeader header = new RequestHeader(
                NodeId.NULL_VALUE,
                DateTime.now(),
                uint(requestHandle.getAndIncrement()),
                uint(0), null, uint(60), null);

        TestStackRequest request = new TestStackRequest(header, uint(0), 1, new Variant(input));

        return client.sendRequest(request);
    }

    public CompletableFuture<UaStackClient> disconnect() {
        return client.disconnect();
    }

}