import com.gmail.nossr50.util.blockmeta.*;
import com.google.common.io.Files;
import org.bukkit.Bukkit;
import org.bukkit.World;
import org.junit.*;
import org.junit.runner.RunWith;
import org.mockito.Mockito;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

import java.io.*;
import java.util.UUID;

import static org.mockito.Mockito.mock;

/**
 * Could be a lot better.  But some tests are better than none!  Tests the major things, still kinda unit-testy.  Verifies that the serialization isn't completely broken.
 */
@RunWith(PowerMockRunner.class)
@PrepareForTest(Bukkit.class)
public class ChunkStoreTest {
    private static File tempDir;
    @BeforeClass
    public static void setUpClass() {
        tempDir = Files.createTempDir();
    }

    @AfterClass
    public static void tearDownClass() {
        recursiveDelete(tempDir);
    }

    private World mockWorld;
    @Before
    public void setUpMock(){
        UUID worldUUID = UUID.randomUUID();
        mockWorld = mock(World.class);
        Mockito.when(mockWorld.getUID()).thenReturn(worldUUID);
        Mockito.when(mockWorld.getMaxHeight()).thenReturn(256);
        Mockito.when(mockWorld.getWorldFolder()).thenReturn(tempDir);
        PowerMockito.mockStatic(Bukkit.class);
        Mockito.when(Bukkit.getWorld(worldUUID)).thenReturn(mockWorld);
    }

    @Test
    public void testSetValue() {
        BitSetChunkStore original = new BitSetChunkStore(mockWorld, 0, 0);
        original.setTrue(0, 0, 0);
        Assert.assertTrue(original.isTrue(0, 0, 0));
        original.setFalse(0, 0, 0);
        Assert.assertFalse(original.isTrue(0, 0, 0));
    }

    @Test
    public void testIsEmpty() {
        BitSetChunkStore original = new BitSetChunkStore(mockWorld, 0, 0);
        Assert.assertTrue(original.isEmpty());
        original.setTrue(0, 0, 0);
        original.setFalse(0, 0, 0);
        Assert.assertTrue(original.isEmpty());
    }

    @Test
    public void testRoundTrip() throws IOException {
        BitSetChunkStore original = new BitSetChunkStore(mockWorld, 1, 2);
        original.setTrue(14, 89, 12);
        original.setTrue(14, 90, 12);
        original.setTrue(13, 89, 12);
        byte[] serializedBytes = serializeChunkstore(original);
        ChunkStore deserialized = BitSetChunkStore.Serialization.readChunkStore(new DataInputStream(new ByteArrayInputStream(serializedBytes)));
        assertEqual(original, deserialized);
    }

    @Test
    public void testChunkCoords() throws IOException {
        for (int x = -96; x < 0; x++) {
                int cx = x >> 4;
                int ix = Math.abs(x) % 16;
                System.out.print(cx + ":" + ix + "  ");
        }
    }

    @Test
    public void testUpgrade() throws IOException {
        LegacyChunkStore original = new LegacyChunkStore(mockWorld, 12, 32);
        original.setTrue(14, 89, 12);
        original.setTrue(14, 90, 12);
        original.setTrue(13, 89, 12);
        byte[] serializedBytes = serializeChunkstore(original);
        ChunkStore deserialized = BitSetChunkStore.Serialization.readChunkStore(new DataInputStream(new ByteArrayInputStream(serializedBytes)));
        assertEqual(original, deserialized);
    }

    @Test
    public void testSimpleRegionRoundtrip() throws IOException {
        LegacyChunkStore original = new LegacyChunkStore(mockWorld, 12, 12);
        original.setTrue(14, 89, 12);
        original.setTrue(14, 90, 12);
        original.setTrue(13, 89, 12);
        File file = new File(tempDir, "SimpleRegionRoundTrip.region");
        McMMOSimpleRegionFile region = new McMMOSimpleRegionFile(file, 0, 0);
        try (DataOutputStream outputStream = region.getOutputStream(12, 12)){
            outputStream.write(serializeChunkstore(original));
        }
        region.close();
        region = new McMMOSimpleRegionFile(file, 0, 0);
        try (DataInputStream is = region.getInputStream(original.getChunkX(), original.getChunkZ()))
        {
            Assert.assertNotNull(is);
            ChunkStore deserialized = BitSetChunkStore.Serialization.readChunkStore(is);
            assertEqual(original, deserialized);
        }
        region.close();
        file.delete();
    }

    @Test
    public void testSimpleRegionRejectsOutOfBounds() {
        File file = new File(tempDir, "SimpleRegionRoundTrip.region");
        McMMOSimpleRegionFile region = new McMMOSimpleRegionFile(file, 0, 0);
        assertThrows(() -> region.getOutputStream(-1, 0), IndexOutOfBoundsException.class);
        assertThrows(() -> region.getOutputStream(0, -1), IndexOutOfBoundsException.class);
        assertThrows(() -> region.getOutputStream(32, 0), IndexOutOfBoundsException.class);
        assertThrows(() -> region.getOutputStream(0, 32), IndexOutOfBoundsException.class);
        region.close();
    }

    @Test
    public void testChunkStoreRejectsOutOfBounds() {
        ChunkStore chunkStore = new BitSetChunkStore(mockWorld, 0, 0);
        assertThrows(() -> chunkStore.setTrue(-1, 0, 0), IndexOutOfBoundsException.class);
        assertThrows(() -> chunkStore.setTrue(0, -1, 0), IndexOutOfBoundsException.class);
        assertThrows(() -> chunkStore.setTrue(0, 0, -1), IndexOutOfBoundsException.class);
        assertThrows(() -> chunkStore.setTrue(16, 0, 0), IndexOutOfBoundsException.class);
        assertThrows(() -> chunkStore.setTrue(0, mockWorld.getMaxHeight(), 0), IndexOutOfBoundsException.class);
        assertThrows(() -> chunkStore.setTrue(0, 0, 16), IndexOutOfBoundsException.class);
    }

    @Test
    public void testRegressionChunkMirrorBug() {
        ChunkManager chunkManager = new HashChunkManager();
        chunkManager.setTrue(15,0,15, mockWorld);
        chunkManager.setFalse(-15, 0, -15, mockWorld);
        Assert.assertTrue(chunkManager.isTrue(15, 0, 15, mockWorld));
    }

    private interface Delegate {
        void run();
    }

    private void assertThrows(Delegate delegate, Class<?> clazz) {
        try {
            delegate.run();
            Assert.fail(); // We didn't throw
        }
        catch (Throwable t) {
            Assert.assertTrue(t.getClass().equals(clazz));
        }
    }

    private void assertEqual(ChunkStore expected, ChunkStore actual)
    {
        Assert.assertEquals(expected.getChunkX(), actual.getChunkX());
        Assert.assertEquals(expected.getChunkZ(), actual.getChunkZ());
        Assert.assertEquals(expected.getWorldId(), actual.getWorldId());
        for (int y = 0; y < 256; y++)
            for (int x = 0; x < 16; x++)
                for (int z = 0; z < 16; z++)
                    Assert.assertTrue(expected.isTrue(x, y, z) == actual.isTrue(x, y, z));
    }

    private static void recursiveDelete(File directoryToBeDeleted) {
        if (directoryToBeDeleted.isDirectory()) {
            for (File file : directoryToBeDeleted.listFiles()) {
                recursiveDelete(file);
            }
        }
        directoryToBeDeleted.delete();
    }

    private static byte[] serializeChunkstore(ChunkStore chunkStore) throws IOException {
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        if (chunkStore instanceof BitSetChunkStore)
            BitSetChunkStore.Serialization.writeChunkStore(new DataOutputStream(byteArrayOutputStream), chunkStore);
        else
            new UnitTestObjectOutputStream(byteArrayOutputStream).writeObject(chunkStore); // Serializes the class as if it were the old PrimitiveChunkStore
        return byteArrayOutputStream.toByteArray();
    }


    public static class LegacyChunkStore implements ChunkStore, Serializable {
        private static final long serialVersionUID = -1L;
        transient private boolean dirty = false;
        public boolean[][][] store;
        private static final int CURRENT_VERSION = 7;
        private static final int MAGIC_NUMBER = 0xEA5EDEBB;
        private int cx;
        private int cz;
        private UUID worldUid;

        public LegacyChunkStore(World world, int cx, int cz) {
            this.cx = cx;
            this.cz = cz;
            this.worldUid = world.getUID();
            this.store = new boolean[16][16][world.getMaxHeight()];
        }

        @Override
        public boolean isDirty() {
            return dirty;
        }

        @Override
        public void setDirty(boolean dirty) {
            this.dirty = dirty;
        }

        @Override
        public int getChunkX() {
            return cx;
        }

        @Override
        public int getChunkZ() {
            return cz;
        }

        @Override
        public UUID getWorldId() {
            return worldUid;
        }

        @Override
        public boolean isTrue(int x, int y, int z) {
            return store[x][z][y];
        }

        @Override
        public void setTrue(int x, int y, int z) {
            if (y >= store[0][0].length || y < 0)
                return;
            store[x][z][y] = true;
            dirty = true;
        }

        @Override
        public void setFalse(int x, int y, int z) {
            if (y >= store[0][0].length || y < 0)
                return;
            store[x][z][y] = false;
            dirty = true;
        }

        @Override
        public void set(int x, int y, int z, boolean value) {
            if (y >= store[0][0].length || y < 0)
                return;
            store[x][z][y] = value;
            dirty = true;
        }

        @Override
        public boolean isEmpty() {
            for (int x = 0; x < 16; x++) {
                for (int z = 0; z < 16; z++) {
                    for (int y = 0; y < store[0][0].length; y++) {
                        if (store[x][z][y]) {
                            return false;
                        }
                    }
                }
            }
            return true;
        }

        private void writeObject(ObjectOutputStream out) throws IOException {
            out.writeInt(MAGIC_NUMBER);
            out.writeInt(CURRENT_VERSION);

            out.writeLong(worldUid.getLeastSignificantBits());
            out.writeLong(worldUid.getMostSignificantBits());
            out.writeInt(cx);
            out.writeInt(cz);
            out.writeObject(store);

            dirty = false;
        }

        private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
            throw new UnsupportedOperationException();
        }
    }

    private static class UnitTestObjectOutputStream extends ObjectOutputStream {
        public UnitTestObjectOutputStream(OutputStream outputStream) throws IOException {
            super(outputStream);
        }

        @Override
        public void writeUTF(String str) throws IOException {
            // Pretend to be the old class
            if (str.equals(LegacyChunkStore.class.getName()))
                str = "com.gmail.nossr50.util.blockmeta.chunkmeta.PrimitiveChunkStore";
            super.writeUTF(str);
        }
    }
}