/*
 * 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
 *
 *     https://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.avro.generic;

import static org.junit.jupiter.api.Assertions.*;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.Arrays;
import java.util.Collections;
import java.util.ConcurrentModificationException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import org.apache.avro.AvroTypeException;
import org.apache.avro.Schema;
import org.apache.avro.SchemaParser;
import org.apache.avro.UnresolvedUnionException;
import org.apache.avro.io.BinaryEncoder;
import org.apache.avro.io.DecoderFactory;
import org.apache.avro.io.Encoder;
import org.apache.avro.io.EncoderFactory;
import org.apache.avro.util.Utf8;
import org.junit.jupiter.api.Test;

public class TestGenericDatumWriter {
  @Test
  void unionUnresolvedExceptionExplicitWhichField() throws IOException {
    Schema s = schemaWithExplicitNullDefault();
    GenericRecord r = new GenericData.Record(s);
    r.put("f", 100);
    ByteArrayOutputStream bao = new ByteArrayOutputStream();
    try {
      new GenericDatumWriter<>(s).write(r, EncoderFactory.get().jsonEncoder(s, bao));
      fail();
    } catch (final UnresolvedUnionException uue) {
      assertEquals("Not in union [\"null\",\"string\"]: java.lang.Integer (field=f)", uue.getMessage());
    }
  }

  @Test
  void write() throws IOException {
    String json = "{\"type\": \"record\", \"name\": \"r\", \"fields\": [" + "{ \"name\": \"f1\", \"type\": \"long\" }"
        + "]}";
    Schema s = SchemaParser.parseSingle(json);
    GenericRecord r = new GenericData.Record(s);
    r.put("f1", 100L);
    ByteArrayOutputStream bao = new ByteArrayOutputStream();
    GenericDatumWriter<GenericRecord> w = new GenericDatumWriter<>(s);
    Encoder e = EncoderFactory.get().jsonEncoder(s, bao);
    w.write(r, e);
    e.flush();

    Object o = new GenericDatumReader<GenericRecord>(s).read(null,
        DecoderFactory.get().jsonDecoder(s, new ByteArrayInputStream(bao.toByteArray())));
    assertEquals(r, o);
  }

  @Test
  void arrayConcurrentModification() throws Exception {
    String json = "{\"type\": \"array\", \"items\": \"int\" }";
    Schema s = SchemaParser.parseSingle(json);
    final GenericArray<Integer> a = new GenericData.Array<>(1, s);
    ByteArrayOutputStream bao = new ByteArrayOutputStream();
    final GenericDatumWriter<GenericArray<Integer>> w = new GenericDatumWriter<>(s);

    CountDownLatch sizeWrittenSignal = new CountDownLatch(1);
    CountDownLatch eltAddedSignal = new CountDownLatch(1);

    final TestEncoder e = new TestEncoder(EncoderFactory.get().directBinaryEncoder(bao, null), sizeWrittenSignal,
        eltAddedSignal);

    // call write in another thread
    ExecutorService executor = Executors.newSingleThreadExecutor();
    Future<Void> result = executor.submit(() -> {
      w.write(a, e);
      return null;
    });
    sizeWrittenSignal.await();
    // size has been written so now add an element to the array
    a.add(7);
    // and signal for the element to be written
    eltAddedSignal.countDown();
    try {
      result.get();
      fail("Expected ConcurrentModificationException");
    } catch (ExecutionException ex) {
      assertTrue(ex.getCause() instanceof ConcurrentModificationException);
    }
  }

  @Test
  void mapConcurrentModification() throws Exception {
    String json = "{\"type\": \"map\", \"values\": \"int\" }";
    Schema s = SchemaParser.parseSingle(json);
    final Map<String, Integer> m = new HashMap<>();
    ByteArrayOutputStream bao = new ByteArrayOutputStream();
    final GenericDatumWriter<Map<String, Integer>> w = new GenericDatumWriter<>(s);

    CountDownLatch sizeWrittenSignal = new CountDownLatch(1);
    CountDownLatch eltAddedSignal = new CountDownLatch(1);

    final TestEncoder e = new TestEncoder(EncoderFactory.get().directBinaryEncoder(bao, null), sizeWrittenSignal,
        eltAddedSignal);

    // call write in another thread
    ExecutorService executor = Executors.newSingleThreadExecutor();
    Future<Void> result = executor.submit(() -> {
      w.write(m, e);
      return null;
    });
    sizeWrittenSignal.await();
    // size has been written so now add an entry to the map
    m.put("a", 7);
    // and signal for the entry to be written
    eltAddedSignal.countDown();
    try {
      result.get();
      fail("Expected ConcurrentModificationException");
    } catch (ExecutionException ex) {
      assertTrue(ex.getCause() instanceof ConcurrentModificationException);
    }
  }

  @Test
  void allowWritingPrimitives() throws IOException {
    Schema doubleType = Schema.create(Schema.Type.DOUBLE);
    Schema.Field field = new Schema.Field("double", doubleType);
    List<Schema.Field> fields = Collections.singletonList(field);
    Schema schema = Schema.createRecord("test", "doc", "", false, fields);

    GenericRecord record = new GenericData.Record(schema);
    record.put("double", 456.4);
    record.put("double", 100000L);
    record.put("double", 444);

    ByteArrayOutputStream bao = new ByteArrayOutputStream();
    GenericDatumWriter<GenericRecord> writer = new GenericDatumWriter<>(schema);
    Encoder encoder = EncoderFactory.get().jsonEncoder(schema, bao);

    writer.write(record, encoder);
  }

  static class TestEncoder extends Encoder {

    Encoder e;
    CountDownLatch sizeWrittenSignal;
    CountDownLatch eltAddedSignal;

    TestEncoder(Encoder encoder, CountDownLatch sizeWrittenSignal, CountDownLatch eltAddedSignal) {
      this.e = encoder;
      this.sizeWrittenSignal = sizeWrittenSignal;
      this.eltAddedSignal = eltAddedSignal;
    }

    @Override
    public void writeArrayStart() throws IOException {
      e.writeArrayStart();
      sizeWrittenSignal.countDown();
      try {
        eltAddedSignal.await();
      } catch (InterruptedException e) {
        // ignore
      }
    }

    @Override
    public void writeMapStart() throws IOException {
      e.writeMapStart();
      sizeWrittenSignal.countDown();
      try {
        eltAddedSignal.await();
      } catch (InterruptedException e) {
        // ignore
      }
    }

    @Override
    public void flush() throws IOException {
      e.flush();
    }

    @Override
    public void writeNull() throws IOException {
      e.writeNull();
    }

    @Override
    public void writeBoolean(boolean b) throws IOException {
      e.writeBoolean(b);
    }

    @Override
    public void writeInt(int n) throws IOException {
      e.writeInt(n);
    }

    @Override
    public void writeLong(long n) throws IOException {
      e.writeLong(n);
    }

    @Override
    public void writeFloat(float f) throws IOException {
      e.writeFloat(f);
    }

    @Override
    public void writeDouble(double d) throws IOException {
      e.writeDouble(d);
    }

    @Override
    public void writeString(Utf8 utf8) throws IOException {
      e.writeString(utf8);
    }

    @Override
    public void writeBytes(ByteBuffer bytes) throws IOException {
      e.writeBytes(bytes);
    }

    @Override
    public void writeBytes(byte[] bytes, int start, int len) throws IOException {
      e.writeBytes(bytes, start, len);
    }

    @Override
    public void writeFixed(byte[] bytes, int start, int len) throws IOException {
      e.writeFixed(bytes, start, len);
    }

    @Override
    public void writeEnum(int en) throws IOException {
      e.writeEnum(en);
    }

    @Override
    public void setItemCount(long itemCount) throws IOException {
      e.setItemCount(itemCount);
    }

    @Override
    public void startItem() throws IOException {
      e.startItem();
    }

    @Override
    public void writeArrayEnd() throws IOException {
      e.writeArrayEnd();
    }

    @Override
    public void writeMapEnd() throws IOException {
      e.writeMapEnd();
    }

    @Override
    public void writeIndex(int unionIndex) throws IOException {
      e.writeIndex(unionIndex);
    }
  }

  @Test
  void writeDoesNotAllowStringForGenericEnum() throws IOException {
    assertThrows(AvroTypeException.class, () -> {
      final String json = "{\"type\": \"record\", \"name\": \"recordWithEnum\"," + "\"fields\": [ "
          + "{\"name\": \"field\", \"type\": " + "{\"type\": \"enum\", \"name\": \"enum\", \"symbols\": "
          + "[\"ONE\",\"TWO\",\"THREE\"] " + "}" + "}" + "]}";
      Schema schema = SchemaParser.parseSingle(json);
      GenericRecord record = new GenericData.Record(schema);
      record.put("field", "ONE");

      ByteArrayOutputStream bao = new ByteArrayOutputStream();
      GenericDatumWriter<GenericRecord> writer = new GenericDatumWriter<>(schema);
      Encoder encoder = EncoderFactory.get().jsonEncoder(schema, bao);

      writer.write(record, encoder);
    });
  }

  private enum AnEnum {
    ONE, TWO, THREE
  }

  @Test
  void writeDoesNotAllowJavaEnumForGenericEnum() throws IOException {
    assertThrows(AvroTypeException.class, () -> {
      final String json = "{\"type\": \"record\", \"name\": \"recordWithEnum\"," + "\"fields\": [ "
          + "{\"name\": \"field\", \"type\": " + "{\"type\": \"enum\", \"name\": \"enum\", \"symbols\": "
          + "[\"ONE\",\"TWO\",\"THREE\"] " + "}" + "}" + "]}";
      Schema schema = SchemaParser.parseSingle(json);
      GenericRecord record = new GenericData.Record(schema);
      record.put("field", AnEnum.ONE);

      ByteArrayOutputStream bao = new ByteArrayOutputStream();
      GenericDatumWriter<GenericRecord> writer = new GenericDatumWriter<>(schema);
      Encoder encoder = EncoderFactory.get().jsonEncoder(schema, bao);

      writer.write(record, encoder);
    });
  }

  @Test
  void writeFieldWithDefaultWithExplicitNullDefaultInSchema() throws Exception {
    Schema schema = schemaWithExplicitNullDefault();
    GenericRecord record = createRecordWithDefaultField(schema);
    writeObject(record);
  }

  @Test
  void writeFieldWithDefaultWithoutExplicitNullDefaultInSchema() throws Exception {
    Schema schema = schemaWithoutExplicitNullDefault();
    GenericRecord record = createRecordWithDefaultField(schema);
    writeObject(record);
  }

  @Test
  void nestedNPEErrorClarity() throws Exception {
    GenericData.Record topLevelRecord = buildComplexRecord();
    @SuppressWarnings("unchecked")
    Map<String, GenericData.Record> map = (Map<String, GenericData.Record>) ((List<GenericData.Record>) ((GenericData.Record) topLevelRecord
        .get("unionField")).get("arrayField")).get(0).get("mapField");
    map.get("a").put("strField", null);
    try {
      writeObject(topLevelRecord);
      fail("expected to throw");
    } catch (NullPointerException expected) {
      assertTrue(
          expected.getMessage()
              .contains("RecordWithRequiredFields.unionField[UnionRecord].arrayField[0].mapField[\"a\"].strField"),
          "unexpected message " + expected.getMessage());
    }
  }

  @Test
  void nPEForMapKeyErrorClarity() throws Exception {
    GenericData.Record topLevelRecord = buildComplexRecord();
    @SuppressWarnings("unchecked")
    Map<String, GenericData.Record> map = (Map<String, GenericData.Record>) ((List<GenericData.Record>) ((GenericData.Record) topLevelRecord
        .get("unionField")).get("arrayField")).get(0).get("mapField");
    map.put(null, map.get("a")); // value is valid, but key is null
    try {
      writeObject(topLevelRecord);
      fail("expected to throw");
    } catch (NullPointerException expected) {
      assertTrue(
          expected.getMessage()
              .contains("null key in map at RecordWithRequiredFields.unionField[UnionRecord].arrayField[0].mapField"),
          "unexpected message " + expected.getMessage());
    }
  }

  @Test
  void shortPathNPEErrorClarity() throws Exception {
    try {
      writeObject(Schema.create(Schema.Type.STRING), null);
      fail("expected to throw");
    } catch (NullPointerException expected) {
      assertTrue(expected.getMessage().contains("null value for (non-nullable) string"),
          "unexpected message " + expected.getMessage());
    }
  }

  @Test
  void nestedCCEErrorClarity() throws Exception {
    GenericData.Record topLevelRecord = buildComplexRecord();
    @SuppressWarnings("unchecked")
    Map<String, GenericData.Record> map = (Map<String, GenericData.Record>) ((List<GenericData.Record>) ((GenericData.Record) topLevelRecord
        .get("unionField")).get("arrayField")).get(0).get("mapField");
    map.get("a").put("strField", 42); // not a string
    try {
      writeObject(topLevelRecord);
      fail("expected to throw");
    } catch (ClassCastException expected) {
      assertTrue(
          expected.getMessage()
              .contains("RecordWithRequiredFields.unionField[UnionRecord].arrayField[0].mapField[\"a\"].strField"),
          "unexpected message " + expected.getMessage());
    }
  }

  @Test
  void shortPathCCEErrorClarity() throws Exception {
    try {
      writeObject(Schema.create(Schema.Type.STRING), 42);
      fail("expected to throw");
    } catch (ClassCastException expected) {
      assertTrue(
          expected.getMessage().contains("value 42 (a java.lang.Integer) cannot be cast to expected type string"),
          "unexpected message " + expected.getMessage());
    }
  }

  @Test
  void nestedATEErrorClarity() throws Exception {
    GenericData.Record topLevelRecord = buildComplexRecord();
    @SuppressWarnings("unchecked")
    Map<String, GenericData.Record> map = (Map<String, GenericData.Record>) ((List<GenericData.Record>) ((GenericData.Record) topLevelRecord
        .get("unionField")).get("arrayField")).get(0).get("mapField");
    map.get("a").put("enumField", 42); // not an enum
    try {
      writeObject(topLevelRecord);
      fail("expected to throw");
    } catch (AvroTypeException expected) {
      assertTrue(
          expected.getMessage()
              .contains("RecordWithRequiredFields.unionField[UnionRecord].arrayField[0].mapField[\"a\"].enumField"),
          "unexpected message " + expected.getMessage());
      assertTrue(expected.getMessage().contains("42 (a java.lang.Integer) is not a MapRecordEnum"),
          "unexpected message " + expected.getMessage());
    }
  }

  private GenericData.Record buildComplexRecord() throws IOException {

    Schema schema = new SchemaParser()
        .parse(new File("target/test-classes/share/test/schemas/RecordWithRequiredFields.avsc")).mainSchema();

    GenericData.Record topLevelRecord = new GenericData.Record(schema);
    GenericData.Record unionRecord = new GenericData.Record(schema.getField("unionField").schema().getTypes().get(1));
    Schema arraySchema = unionRecord.getSchema().getField("arrayField").schema();
    GenericData.Record arrayRecord1 = new GenericData.Record(arraySchema.getElementType());
    GenericData.Record arrayRecord2 = new GenericData.Record(arraySchema.getElementType());
    GenericData.Array<GenericData.Record> array = new GenericData.Array<>(arraySchema,
        Arrays.asList(arrayRecord1, arrayRecord2));
    Schema mapRecordSchema = arraySchema.getElementType().getField("mapField").schema().getValueType();
    GenericData.Record mapRecordA = new GenericData.Record(mapRecordSchema);
    Schema mapRecordEnumSchema = mapRecordSchema.getField("enumField").schema();

    mapRecordA.put("enumField", new GenericData.EnumSymbol(mapRecordEnumSchema, "B"));
    mapRecordA.put("strField", "4");

    arrayRecord1.put("strField", "2");
    HashMap<String, GenericData.Record> map1 = new HashMap<>();
    map1.put("a", mapRecordA);
    arrayRecord1.put("mapField", map1);

    arrayRecord2.put("strField", "2");
    HashMap<String, GenericData.Record> map2 = new HashMap<>();
    map2.put("a", mapRecordA);
    arrayRecord2.put("mapField", map2);

    unionRecord.put(unionRecord.getSchema().getField("strField").pos(), "1");
    unionRecord.put(unionRecord.getSchema().getField("arrayField").pos(), array); // BOOM

    topLevelRecord.put(topLevelRecord.getSchema().getField("strField").pos(), "0");
    topLevelRecord.put(topLevelRecord.getSchema().getField("unionField").pos(), unionRecord);

    return topLevelRecord;
  }

  private Schema schemaWithExplicitNullDefault() {
    String schema = "{\"type\":\"record\",\"name\":\"my_record\",\"namespace\":\"mytest.namespace\",\"doc\":\"doc\","
        + "\"fields\":[{\"name\":\"f\",\"type\":[\"null\",\"string\"],\"doc\":\"field doc doc\", "
        + "\"default\":null}]}";
    return SchemaParser.parseSingle(schema);
  }

  private Schema schemaWithoutExplicitNullDefault() {
    String schema = "{\"type\":\"record\",\"name\":\"my_record\",\"namespace\":\"mytest.namespace\",\"doc\":\"doc\","
        + "\"fields\":[{\"name\":\"f\",\"type\":[\"null\",\"string\"],\"doc\":\"field doc doc\"}]}";
    return SchemaParser.parseSingle(schema);
  }

  private void writeObject(GenericRecord datum) throws Exception {
    writeObject(datum.getSchema(), datum);
  }

  private void writeObject(Schema schema, Object datum) throws Exception {
    BinaryEncoder encoder = EncoderFactory.get().binaryEncoder(new ByteArrayOutputStream(), null);
    GenericDatumWriter<Object> writer = new GenericDatumWriter<>(schema);
    writer.write(datum, encoder);
    encoder.flush();
  }

  private GenericRecord createRecordWithDefaultField(Schema schema) {
    GenericRecord record = new GenericData.Record(schema);
    record.put("f", schema.getField("f").defaultVal());
    return record;
  }
}
