/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.hcatalog.hbase.snapshot;

import java.io.IOException;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import org.apache.commons.lang.builder.ToStringBuilder;
import org.apache.commons.lang.builder.ToStringStyle;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.coprocessor.CoprocessorHost;
import org.apache.hcatalog.hbase.SkeletonHBaseTest;
import org.junit.Assert;
import org.junit.Test;

public class TestRevisionManagerEndpoint extends SkeletonHBaseTest {

    static {
        // test case specific mini cluster settings
        testConf = new Configuration(false);
        testConf.setStrings(CoprocessorHost.REGION_COPROCESSOR_CONF_KEY,
            "org.apache.hcatalog.hbase.snapshot.RevisionManagerEndpoint",
            "org.apache.hadoop.hbase.coprocessor.GenericEndpoint");
        testConf.set(RMConstants.REVISION_MGR_ENDPOINT_IMPL_CLASS, MockRM.class.getName());
    }

    /**
     * Mock implementation to test the protocol/serialization
     */
    public static class MockRM implements RevisionManager {

        private static class Invocation {
            Invocation(String methodName, Object ret, Object... args) {
                this.methodName = methodName;
                this.args = args;
                this.ret = ret;
            }

            String methodName;
            Object[] args;
            Object ret;

            private static boolean equals(Object obj1, Object obj2) {
                if (obj1 == obj2) return true;
                if (obj1 == null || obj2 == null) return false;
                if (obj1 instanceof Transaction || obj1 instanceof TableSnapshot) {
                    return obj1.toString().equals(obj2.toString());
                }
                return obj1.equals(obj2);
            }

            @Override
            public boolean equals(Object obj) {
                Invocation other = (Invocation) obj;
                if (this == other) return true;
                if (other == null) return false;
                if (this.args != other.args) {
                    if (this.args == null || other.args == null) return false;
                    if (this.args.length != other.args.length) return false;
                    for (int i = 0; i < args.length; i++) {
                        if (!equals(this.args[i], other.args[i])) return false;
                    }
                }
                return equals(this.ret, other.ret);
            }

            @Override
            public String toString() {
                return new ToStringBuilder(this, ToStringStyle.SHORT_PREFIX_STYLE).
                    append("method", this.methodName).
                    append("args", this.args).
                    append("returns", this.ret).
                    toString();
            }
        }

        final static String DEFAULT_INSTANCE = "default";
        final static Map<String, MockRM> INSTANCES = new ConcurrentHashMap<String, MockRM>();
        Invocation lastCall;
        boolean isOpen = false;

        private <T extends Object> T recordCall(T result, Object... args) {
            StackTraceElement[] stackTrace = Thread.currentThread().getStackTrace();
            lastCall = new Invocation(stackTrace[2].getMethodName(), result, args);
            return result;
        }

        @Override
        public void initialize(Configuration conf) {
            if (!INSTANCES.containsKey(DEFAULT_INSTANCE))
                INSTANCES.put(DEFAULT_INSTANCE, this);
        }

        @Override
        public void open() throws IOException {
            isOpen = true;
        }

        @Override
        public void close() throws IOException {
            isOpen = false;
        }

        @Override
        public void createTable(String table, List<String> columnFamilies) throws IOException {
        }

        @Override
        public void dropTable(String table) throws IOException {
        }

        @Override
        public Transaction beginWriteTransaction(String table,
                                                 List<String> families) throws IOException {
            return recordCall(null, table, families);
        }

        @Override
        public Transaction beginWriteTransaction(String table,
                                                 List<String> families, long keepAlive) throws IOException {
            return recordCall(null, table, families, keepAlive);
        }

        @Override
        public void commitWriteTransaction(Transaction transaction)
            throws IOException {
        }

        @Override
        public void abortWriteTransaction(Transaction transaction)
            throws IOException {
        }

        @Override
        public List<FamilyRevision> getAbortedWriteTransactions(String table,
                                                                String columnFamily) throws IOException {
            return null;
        }

        @Override
        public TableSnapshot createSnapshot(String tableName)
            throws IOException {
            return null;
        }

        @Override
        public TableSnapshot createSnapshot(String tableName, long revision)
            throws IOException {
            TableSnapshot ret = new TableSnapshot(tableName, new HashMap<String, Long>(), revision);
            return recordCall(ret, tableName, revision);
        }

        @Override
        public void keepAlive(Transaction transaction) throws IOException {
            recordCall(null, transaction);
        }
    }

    @Test
    public void testRevisionManagerProtocol() throws Throwable {

        Configuration conf = getHbaseConf();
        RevisionManager rm = RevisionManagerFactory.getOpenedRevisionManager(
            RevisionManagerEndpointClient.class.getName(), conf);

        MockRM mockImpl = MockRM.INSTANCES.get(MockRM.DEFAULT_INSTANCE);
        Assert.assertNotNull(mockImpl);
        Assert.assertTrue(mockImpl.isOpen);

        Transaction t = new Transaction("t1", Arrays.asList("f1", "f2"), 0, 0);
        MockRM.Invocation call = new MockRM.Invocation("keepAlive", null, t);
        rm.keepAlive(t);
        Assert.assertEquals(call.methodName, call, mockImpl.lastCall);

        t = new Transaction("t2", Arrays.asList("f21", "f22"), 0, 0);
        call = new MockRM.Invocation("beginWriteTransaction", null, t.getTableName(), t.getColumnFamilies());
        call.ret = rm.beginWriteTransaction(t.getTableName(), t.getColumnFamilies());
        Assert.assertEquals(call.methodName, call, mockImpl.lastCall);

        call = new MockRM.Invocation("createSnapshot", null, "t3", 1L);
        call.ret = rm.createSnapshot("t3", 1);
        Assert.assertEquals(call.methodName, call, mockImpl.lastCall);

    }

}