/*
 * 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.jackrabbit.oak.spi.state;

import static java.util.Objects.requireNonNull;
import static org.apache.jackrabbit.JcrConstants.JCR_LASTMODIFIED;
import static org.apache.jackrabbit.oak.api.Type.LONG;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;
import static org.junit.Assume.assumeTrue;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Calendar;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;

import org.apache.jackrabbit.oak.NodeStoreFixtures;
import org.apache.jackrabbit.oak.OakBaseTest;
import org.apache.jackrabbit.oak.api.CommitFailedException;
import org.apache.jackrabbit.oak.api.PropertyState;
import org.apache.jackrabbit.oak.commons.collections.IterableUtils;
import org.apache.jackrabbit.oak.commons.collections.SetUtils;
import org.apache.jackrabbit.oak.fixture.NodeStoreFixture;
import org.apache.jackrabbit.oak.plugins.commit.ConflictHook;
import org.apache.jackrabbit.oak.plugins.commit.ConflictValidatorProvider;
import org.apache.jackrabbit.oak.plugins.commit.JcrConflictHandler;
import org.apache.jackrabbit.oak.plugins.memory.MultiStringPropertyState;
import org.apache.jackrabbit.oak.spi.commit.CommitHook;
import org.apache.jackrabbit.oak.spi.commit.CommitInfo;
import org.apache.jackrabbit.oak.spi.commit.CompositeHook;
import org.apache.jackrabbit.oak.spi.commit.EditorHook;
import org.apache.jackrabbit.oak.spi.commit.EmptyHook;
import org.apache.jackrabbit.oak.spi.commit.Observable;
import org.apache.jackrabbit.oak.spi.commit.Observer;
import org.jetbrains.annotations.NotNull;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;


public class NodeStoreTest extends OakBaseTest {
    private NodeState root;

    public NodeStoreTest(NodeStoreFixture fixture) {
        super(fixture);
    }

    @Before
    public void setUp() throws Exception {
        NodeBuilder builder = store.getRoot().builder();
        NodeBuilder test = builder.child("test");
        test.setProperty("a", 1);
        test.setProperty("b", 2);
        test.setProperty("c", 3);
        test.child("x");
        test.child("y");
        test.child("z");
        root = store.merge(builder, EmptyHook.INSTANCE, CommitInfo.EMPTY);
    }

    @After
    public void tearDown() {
        fixture.dispose(store);
    }

    @Test
    public void getRoot() {
        assertEquals(root, store.getRoot());
        assertEquals(root.getChildNode("test"), store.getRoot().getChildNode("test"));
        assertEquals(root.getChildNode("test").getChildNode("x"),
                store.getRoot().getChildNode("test").getChildNode("x"));
        assertEquals(root.getChildNode("test").getChildNode("any"),
                store.getRoot().getChildNode("test").getChildNode("any"));
        assertEquals(root.getChildNode("test").getProperty("a"),
                store.getRoot().getChildNode("test").getProperty("a"));
        assertEquals(root.getChildNode("test").getProperty("any"),
                store.getRoot().getChildNode("test").getProperty("any"));
    }

    @Test
    public void addExistingNode() throws CommitFailedException {
        // FIXME OAK-1550 Incorrect handling of addExistingNode conflict in NodeStore
        assumeTrue(fixture != NodeStoreFixtures.DOCUMENT_MEM);
        assumeTrue(fixture != NodeStoreFixtures.DOCUMENT_NS);
        assumeTrue(fixture != NodeStoreFixtures.DOCUMENT_RDB);

        CommitHook hook = new CompositeHook(
                new ConflictHook(JcrConflictHandler.createJcrConflictHandler()),
                new EditorHook(new ConflictValidatorProvider())
        );

        NodeBuilder b1 = store.getRoot().builder();
        NodeBuilder b2 = store.getRoot().builder();

        // make sure we make it past DocumentRootBuilder.UPDATE_LIMIT
        // in order to see the conflict handling of the stores involved
        // rather the in memory one from AbstractRebaseDiff
        for (int k = 0; k < 1002; k++) {
            b1.setChildNode("n" + k);
            b2.setChildNode("m" + k);
        }

        b1.setChildNode("conflict");
        b2.setChildNode("conflict");

        store.merge(b1, hook, CommitInfo.EMPTY);
        store.merge(b2, hook, CommitInfo.EMPTY);
    }

    @Test(expected = IllegalArgumentException.class)
    public void mergeNodeRoot() throws CommitFailedException {
        NodeBuilder x = store.getRoot().builder().getChildNode("x");
        store.merge(x, EmptyHook.INSTANCE, CommitInfo.EMPTY);
    }

    @Test
    public void addExistingNodeJCRLastModified() throws CommitFailedException {
        CommitHook hook = new CompositeHook(
            new ConflictHook(JcrConflictHandler.createJcrConflictHandler()),
            new EditorHook(new ConflictValidatorProvider())
        );

        NodeBuilder b1 = store.getRoot().builder();
        NodeBuilder b2 = store.getRoot().builder();

        Calendar calendar = Calendar.getInstance();
        b1.setChildNode("addExistingNodeJCRLastModified").setProperty(JCR_LASTMODIFIED, calendar);
        calendar.add(Calendar.MINUTE, 1);
        b2.setChildNode("addExistingNodeJCRLastModified").setProperty(JCR_LASTMODIFIED, calendar);

        b1.setChildNode("conflict");
        b2.setChildNode("conflict");

        store.merge(b1, hook, CommitInfo.EMPTY);
        store.merge(b2, hook, CommitInfo.EMPTY);
    }

    @Test
    public void addChangeChangedJCRLastModified() throws CommitFailedException {
        CommitHook hook = new CompositeHook(
            new ConflictHook(JcrConflictHandler.createJcrConflictHandler()),
            new EditorHook(new ConflictValidatorProvider())
        );

        NodeBuilder b = store.getRoot().builder();
        Calendar calendar = Calendar.getInstance();
        b.setChildNode("addExistingNodeJCRLastModified").setProperty(JCR_LASTMODIFIED, calendar);
        store.merge(b, hook, CommitInfo.EMPTY);

        NodeBuilder b1 = store.getRoot().builder();
        NodeBuilder b2 = store.getRoot().builder();

        calendar.add(Calendar.MINUTE, 1);
        b1.setChildNode("addExistingNodeJCRLastModified").setProperty(JCR_LASTMODIFIED, calendar);
        calendar.add(Calendar.MINUTE, 1);
        b2.setChildNode("addExistingNodeJCRLastModified").setProperty(JCR_LASTMODIFIED, calendar);

        b1.setChildNode("conflict");
        b2.setChildNode("conflict");

        store.merge(b1, hook, CommitInfo.EMPTY);
        store.merge(b2, hook, CommitInfo.EMPTY);
    }

    @Test
    public void simpleMerge() throws CommitFailedException {
        NodeBuilder rootBuilder = store.getRoot().builder();
        NodeBuilder testBuilder = rootBuilder.child("test");
        NodeBuilder newNodeBuilder = testBuilder.child("newNode");

        testBuilder.getChildNode("x").remove();

        newNodeBuilder.setProperty("n", 42);

        // Assert changes are present in the builder
        NodeState testState = rootBuilder.getNodeState().getChildNode("test");
        assertTrue(testState.getChildNode("newNode").exists());
        assertFalse(testState.getChildNode("x").exists());
        assertEquals(42, (long) testState.getChildNode("newNode").getProperty("n").getValue(LONG));

        // Assert changes are not yet present in the trunk
        testState = store.getRoot().getChildNode("test");
        assertFalse(testState.getChildNode("newNode").exists());
        assertTrue(testState.getChildNode("x").exists());

        store.merge(rootBuilder, EmptyHook.INSTANCE, CommitInfo.EMPTY);

        // Assert changes are present in the trunk
        testState = store.getRoot().getChildNode("test");
        assertTrue(testState.getChildNode("newNode").exists());
        assertFalse(testState.getChildNode("x").exists());
        assertEquals(42, (long) testState.getChildNode("newNode").getProperty("n").getValue(LONG));
    }

    @Test
    public void afterCommitHook() throws CommitFailedException, InterruptedException {
        assumeTrue(store instanceof Observable);

        final AtomicReference<NodeState> observedRoot =
                new AtomicReference<NodeState>(null);
        final CountDownLatch latch = new CountDownLatch(2);

        ((Observable) store).addObserver(new Observer() {
            @Override
            public void contentChanged(
                    @NotNull NodeState root, @NotNull CommitInfo info) {
                if (root.getChildNode("test").hasChildNode("newNode")) {
                    observedRoot.set(requireNonNull(root));
                    latch.countDown();
                }
            }
        });

        NodeState root = store.getRoot();
        NodeBuilder rootBuilder= root.builder();
        NodeBuilder testBuilder = rootBuilder.child("test");
        NodeBuilder newNodeBuilder = testBuilder.child("newNode");

        newNodeBuilder.setProperty("n", 42);
        testBuilder.getChildNode("a").remove();

        store.merge(rootBuilder, EmptyHook.INSTANCE, CommitInfo.EMPTY);
        NodeState newRoot = store.getRoot(); // triggers the observer
        latch.await(2, TimeUnit.SECONDS);

        NodeState after = observedRoot.get();
        assertNotNull(after);
        assertTrue(after.getChildNode("test").getChildNode("newNode").exists());
        assertFalse(after.getChildNode("test").getChildNode("a").exists());
        assertEquals(42, (long) after.getChildNode("test").getChildNode("newNode").getProperty("n").getValue(LONG));
        assertEquals(newRoot, after);
    }

    @Test
    public void beforeCommitHook() throws CommitFailedException {
        NodeState root = store.getRoot();
        NodeBuilder rootBuilder = root.builder();
        NodeBuilder testBuilder = rootBuilder.child("test");
        NodeBuilder newNodeBuilder = testBuilder.child("newNode");

        newNodeBuilder.setProperty("n", 42);

        testBuilder.getChildNode("a").remove();

        store.merge(rootBuilder, new CommitHook() {
            @NotNull
            @Override
            public NodeState processCommit(
                    NodeState before, NodeState after, CommitInfo info) {
                NodeBuilder rootBuilder = after.builder();
                NodeBuilder testBuilder = rootBuilder.child("test");
                testBuilder.child("fromHook");
                return rootBuilder.getNodeState();
            }
        }, CommitInfo.EMPTY);

        NodeState test = store.getRoot().getChildNode("test");
        assertTrue(test.getChildNode("newNode").exists());
        assertTrue(test.getChildNode("fromHook").exists());
        assertFalse(test.getChildNode("a").exists());
        assertEquals(42, (long) test.getChildNode("newNode").getProperty("n").getValue(LONG));
        assertEquals(test, store.getRoot().getChildNode("test"));
    }

    @Test
    public void manyChildNodes() throws CommitFailedException {
        NodeBuilder root = store.getRoot().builder();
        NodeBuilder parent = root.child("parent");
        for (int i = 0; i <= 100; i++) {
            parent.child("child-" + i);
        }
        store.merge(root, EmptyHook.INSTANCE, CommitInfo.EMPTY);

        NodeState base = store.getRoot();
        root = base.builder();
        parent = root.child("parent");
        parent.child("child-new");
        store.merge(root, EmptyHook.INSTANCE, CommitInfo.EMPTY);

        Diff diff = new Diff();
        store.getRoot().compareAgainstBaseState(base, diff);

        assertEquals(0, diff.removed.size());
        assertEquals(1, diff.added.size());
        assertEquals("child-new", diff.added.get(0));

        base = store.getRoot();
        root = base.builder();
        parent = root.getChildNode("parent");
        parent.getChildNode("child-new").moveTo(parent, "child-moved");
        store.merge(root, EmptyHook.INSTANCE, CommitInfo.EMPTY);

        diff = new Diff();
        store.getRoot().compareAgainstBaseState(base, diff);

        assertEquals(1, diff.removed.size());
        assertEquals("child-new", diff.removed.get(0));
        assertEquals(1, diff.added.size());
        assertEquals("child-moved", diff.added.get(0));

        base = store.getRoot();
        root = base.builder();
        parent = root.child("parent");
        parent.child("child-moved").setProperty("foo", "value");
        parent.child("child-moved").setProperty(
                new MultiStringPropertyState("bar", Arrays.asList("value")));
        store.merge(root, EmptyHook.INSTANCE, CommitInfo.EMPTY);

        diff = new Diff();
        store.getRoot().compareAgainstBaseState(base, diff);

        assertEquals(0, diff.removed.size());
        assertEquals(0, diff.added.size());
        assertEquals(2, diff.addedProperties.size());
        assertTrue(diff.addedProperties.contains("foo"));
        assertTrue(diff.addedProperties.contains("bar"));

        base = store.getRoot();
        root = base.builder();
        parent = root.child("parent");
        parent.setProperty("foo", "value");
        parent.setProperty(new MultiStringPropertyState(
                "bar", Arrays.asList("value")));
        store.merge(root, EmptyHook.INSTANCE, CommitInfo.EMPTY);

        diff = new Diff();
        store.getRoot().compareAgainstBaseState(base, diff);

        assertEquals(0, diff.removed.size());
        assertEquals(0, diff.added.size());
        assertEquals(2, diff.addedProperties.size());
        assertTrue(diff.addedProperties.contains("foo"));
        assertTrue(diff.addedProperties.contains("bar"));

        base = store.getRoot();
        root = base.builder();
        parent = root.child("parent");
        parent.getChildNode("child-moved").remove();
        store.merge(root, EmptyHook.INSTANCE, CommitInfo.EMPTY);

        diff = new Diff();
        store.getRoot().compareAgainstBaseState(base, diff);

        assertEquals(1, diff.removed.size());
        assertEquals(0, diff.added.size());
        assertEquals("child-moved", diff.removed.get(0));
    }

    @Test
    public void move() {
        NodeBuilder test = store.getRoot().builder().getChildNode("test");
        NodeBuilder x = test.getChildNode("x");
        NodeBuilder y = test.getChildNode("y");
        assertTrue(x.moveTo(y, "xx"));
        assertFalse(x.exists());
        assertTrue(y.exists());
        assertFalse(test.hasChildNode("x"));
        assertTrue(y.hasChildNode("xx"));
    }

    @Test
    public void moveNonExisting() {
        NodeBuilder test = store.getRoot().builder().getChildNode("test");
        NodeBuilder any = test.getChildNode("any");
        NodeBuilder y = test.getChildNode("y");
        assertFalse(any.moveTo(y, "xx"));
        assertFalse(any.exists());
        assertTrue(y.exists());
        assertFalse(y.hasChildNode("xx"));
    }

    @Test
    public void moveToExisting() {
        NodeBuilder test = store.getRoot().builder().getChildNode("test");
        NodeBuilder x = test.getChildNode("x");
        assertFalse(x.moveTo(test, "y"));
        assertTrue(x.exists());
        assertTrue(test.hasChildNode("x"));
        assertTrue(test.hasChildNode("y"));
    }

    @Test
    public void rename() {
        NodeBuilder test = store.getRoot().builder().getChildNode("test");
        NodeBuilder x = test.getChildNode("x");
        assertTrue(x.moveTo(test, "xx"));
        assertFalse(x.exists());
        assertFalse(test.hasChildNode("x"));
        assertTrue(test.hasChildNode("xx"));
    }

    @Test
    public void renameNonExisting() {
        NodeBuilder test = store.getRoot().builder().getChildNode("test");
        NodeBuilder any = test.getChildNode("any");
        assertFalse(any.moveTo(test, "xx"));
        assertFalse(any.exists());
        assertFalse(test.hasChildNode("xx"));
    }

    @Test
    public void renameToExisting() {
        NodeBuilder test = store.getRoot().builder().getChildNode("test");
        NodeBuilder x = test.getChildNode("x");
        assertFalse(x.moveTo(test, "y"));
        assertTrue(x.exists());
        assertTrue(test.hasChildNode("x"));
        assertTrue(test.hasChildNode("y"));
    }

    @Test
    public void moveToSelf() {
        NodeBuilder test = store.getRoot().builder().getChildNode("test");
        NodeBuilder x = test.getChildNode("x");
        assertFalse(x.moveTo(test, "x"));
        assertTrue(x.exists());
        assertTrue(test.hasChildNode("x"));
    }

    @Test
    public void moveToSelfNonExisting() {
        NodeBuilder test = store.getRoot().builder().getChildNode("test");
        NodeBuilder any = test.getChildNode("any");
        assertFalse(any.moveTo(test, "any"));
        assertFalse(any.exists());
        assertFalse(test.hasChildNode("any"));
    }

    @Test
    public void moveToDescendant() {
        NodeBuilder test = store.getRoot().builder().getChildNode("test");
        NodeBuilder x = test.getChildNode("x");
        if (fixture == NodeStoreFixtures.SEGMENT_TAR || fixture == NodeStoreFixtures.MEMORY_NS 
                || fixture == NodeStoreFixtures.COMPOSITE_MEM || fixture == NodeStoreFixtures.COMPOSITE_SEGMENT
                || fixture == NodeStoreFixtures.COW_DOCUMENT || fixture == NodeStoreFixtures.SEGMENT_AWS
                || fixture == NodeStoreFixtures.SEGMENT_AZURE_V8 || fixture == NodeStoreFixtures.SEGMENT_AZURE) {
            assertTrue(x.moveTo(x, "xx"));
            assertFalse(x.exists());
            assertFalse(test.hasChildNode("x"));
        } else {
            assertFalse(x.moveTo(x, "xx"));
            assertTrue(x.exists());
            assertTrue(test.hasChildNode("x"));
        }
    }

    @Test
    public void oak965() throws CommitFailedException {
        NodeStore store1 = init(fixture.createNodeStore());
        NodeStore store2 = init(fixture.createNodeStore());
        try {
            NodeState tree1 = store1.getRoot();
            NodeState tree2 = store2.getRoot();
            tree1.equals(tree2);
        } finally {
            fixture.dispose(store1);
            fixture.dispose(store2);
        }
    }

    private static NodeStore init(NodeStore store) throws CommitFailedException {
        NodeBuilder builder = store.getRoot().builder();
        builder.setChildNode("root");
        store.merge(builder, EmptyHook.INSTANCE, CommitInfo.EMPTY);
        return store;
    }

    @Test
    public void merge() throws CommitFailedException {
        NodeState base = store.getRoot();
        NodeBuilder builder1 = base.builder();

        NodeBuilder builder2 = base.builder();

        builder1.setChildNode("node1");
        builder2.setChildNode("node2");

        store.merge(builder1, EmptyHook.INSTANCE, CommitInfo.EMPTY);
        assertTrue(store.getRoot().hasChildNode("node1"));
        assertFalse(store.getRoot().hasChildNode("node2"));

        store.merge(builder2, EmptyHook.INSTANCE, CommitInfo.EMPTY);
        assertTrue(store.getRoot().hasChildNode("node1"));
        assertTrue(store.getRoot().hasChildNode("node2"));
    }

    @Test
    public void compareAgainstBaseState0() throws CommitFailedException {
        compareAgainstBaseState(0);
    }

    @Test
    public void compareAgainstBaseState20() throws CommitFailedException {
        compareAgainstBaseState(20);
    }

    @Test
    public void compareAgainstBaseState100() throws CommitFailedException {
        compareAgainstBaseState(100);
    }

    @Test // OAK-1320
    public void rebaseWithFailedMerge() throws CommitFailedException {
        NodeBuilder rootBuilder = store.getRoot().builder();
        rootBuilder.child("foo");

        // commit something in between to force rebase
        NodeBuilder b = store.getRoot().builder();
        b.child("bar");
        store.merge(b, EmptyHook.INSTANCE, CommitInfo.EMPTY);

        try {
            store.merge(rootBuilder, new CommitHook() {
                @NotNull
                @Override
                public NodeState processCommit(
                        NodeState before, NodeState after, CommitInfo info)
                        throws CommitFailedException {
                    throw new CommitFailedException("", 0, "commit rejected");
                }
            }, CommitInfo.EMPTY);
            fail("must throw CommitFailedException");
        } catch (CommitFailedException e) {
            // expected
        }
        // merge again
        NodeState root = store.merge(
                rootBuilder, EmptyHook.INSTANCE, CommitInfo.EMPTY);
        assertTrue(root.hasChildNode("bar"));
    }

    @Test
    public void checkpoints() throws Exception {
        assumeTrue(fixture != NodeStoreFixtures.SEGMENT_TAR);
        int numCps = 3;
        Map<String, String> info = new HashMap<>();
        Set<String> cps = new HashSet<>();
        for (int i = 0; i < numCps; i++) {
            info.put("key", "" + i);
            cps.add(store.checkpoint(TimeUnit.HOURS.toMillis(1), info));
        }
        assertEquals(numCps, cps.size());
        assertEquals(cps, SetUtils.toSet(store.checkpoints()));
        Set<String> keys = new HashSet<>();
        for (String cp : cps) {
            info = store.checkpointInfo(cp);
            assertTrue(info.containsKey("key"));
            keys.add(info.get("key"));
        }
        assertEquals(Set.of("0", "1", "2"), keys);
        while (!cps.isEmpty()) {
            String cp = cps.iterator().next();
            cps.remove(cp);
            store.release(cp);
            assertEquals(cps.size(), IterableUtils.size(store.checkpoints()));
        }
    }

    private void compareAgainstBaseState(int childNodeCount) throws CommitFailedException {
        NodeState before = store.getRoot();
        NodeBuilder builder = before.builder();
        for (int k = 0; k < childNodeCount; k++) {
            builder.child("c" + k);
        }

        builder.child("foo").child(":bar").child("quz").setProperty("p", "v");
        store.merge(builder, EmptyHook.INSTANCE, CommitInfo.EMPTY);

        NodeState after = store.getRoot();
        Diff diff = new Diff();
        after.compareAgainstBaseState(before, diff);

        assertEquals(0, diff.removed.size());
        assertEquals(childNodeCount + 1, diff.added.size());
        assertEquals(0, diff.addedProperties.size());
    }

    private static class Diff extends DefaultNodeStateDiff {
        final List<String> addedProperties = new ArrayList<String>();
        final List<String> added = new ArrayList<String>();
        final List<String> removed = new ArrayList<String>();

        @Override
        public boolean childNodeAdded(String name, NodeState after) {
            added.add(name);
            return true;
        }

        @Override
        public boolean childNodeDeleted(String name, NodeState before) {
            removed.add(name);
            return true;
        }

        @Override
        public boolean childNodeChanged(
                String name, NodeState before, NodeState after) {
            return after.compareAgainstBaseState(before, this);
        }

        @Override
        public boolean propertyAdded(PropertyState after) {
            addedProperties.add(after.getName());
            return true;
        }
    }

}
