/*

 * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

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 */

package jdk.jfr.consumer;

import java.io.IOException;

import java.util.ArrayList;

import java.util.List;

import java.util.Objects;

import jdk.jfr.EventType;

import jdk.jfr.ValueDescriptor;

import jdk.jfr.internal.MetadataDescriptor;

import jdk.jfr.internal.PrivateAccess;

import jdk.jfr.internal.Type;

import jdk.jfr.internal.consumer.RecordingInput;

/**

 * Class that create parsers suitable for reading events and constant pools

 */

final class ParserFactory {

    private final LongMap<Parser> parsers = new LongMap<>();

    private final TimeConverter timeConverter;

    private final LongMap<Type> types = new LongMap<>();

    private final LongMap<ConstantMap> constantPools;

    public ParserFactory(MetadataDescriptor metadata, TimeConverter timeConverter) throws IOException {

        this.constantPools = new LongMap<>();

        this.timeConverter = timeConverter;

        for (Type t : metadata.getTypes()) {

            types.put(t.getId(), t);

        }

        for (Type t : types) {

            if (!t.getFields().isEmpty()) { // Avoid primitives

                CompositeParser cp = createCompositeParser(t);

                if (t.isSimpleType()) { // Reduce to nested parser

                   parsers.put(t.getId(), cp.parsers[0]);

                }

            }

        }

        // Override event types with event parsers

        for (EventType t : metadata.getEventTypes()) {

            parsers.put(t.getId(), createEventParser(t));

        }

    }

    public LongMap<Parser> getParsers() {

        return parsers;

    }

    public LongMap<ConstantMap> getConstantPools() {

        return constantPools;

    }

    public LongMap<Type> getTypeMap() {

        return types;

    }

    private EventParser createEventParser(EventType eventType) throws IOException {

        List<Parser> parsers = new ArrayList<Parser>();

        for (ValueDescriptor f : eventType.getFields()) {

            parsers.add(createParser(f));

        }

        return new EventParser(timeConverter, eventType, parsers.toArray(new Parser[0]));

    }

    private Parser createParser(ValueDescriptor v) throws IOException {

        boolean constantPool = PrivateAccess.getInstance().isConstantPool(v);

        if (v.isArray()) {

            Type valueType = PrivateAccess.getInstance().getType(v);

            ValueDescriptor element = PrivateAccess.getInstance().newValueDescriptor(v.getName(), valueType, v.getAnnotationElements(), 0, constantPool, null);

            return new ArrayParser(createParser(element));

        }

        long id = v.getTypeId();

        Type type = types.get(id);

        if (type == null) {

            throw new IOException("Type '" + v.getTypeName() + "' is not defined");

        }

        if (constantPool) {

            ConstantMap pool = constantPools.get(id);

            if (pool == null) {

                pool = new ConstantMap(ObjectFactory.create(type, timeConverter), type.getName());

                constantPools.put(id, pool);

            }

            return new ConstantMapValueParser(pool);

        }

        Parser parser = parsers.get(id);

        if (parser == null) {

            if (!v.getFields().isEmpty()) {

                return createCompositeParser(type);

            } else {

                return registerParserType(type, createPrimitiveParser(type));

            }

        }

        return parser;

    }

    private Parser createPrimitiveParser(Type type) throws IOException {

        switch (type.getName()) {

        case "int":

            return new IntegerParser();

        case "long":

            return new LongParser();

        case "float":

            return new FloatParser();

        case "double":

            return new DoubleParser();

        case "char":

            return new CharacterParser();

        case "boolean":

            return new BooleanParser();

        case "short":

            return new ShortParser();

        case "byte":

            return new ByteParser();

        case "java.lang.String":

            ConstantMap pool = new ConstantMap(ObjectFactory.create(type, timeConverter), type.getName());

            constantPools.put(type.getId(), pool);

            return new StringParser(pool);

        default:

            throw new IOException("Unknown primitive type " + type.getName());

        }

    }

    private Parser registerParserType(Type t, Parser parser) {

        Parser p = parsers.get(t.getId());

        // check if parser exists (known type)

        if (p != null) {

            return p;

        }

        parsers.put(t.getId(), parser);

        return parser;

    }

    private CompositeParser createCompositeParser(Type type) throws IOException {

        List<ValueDescriptor> vds = type.getFields();

        Parser[] parsers = new Parser[vds.size()];

        CompositeParser composite = new CompositeParser(parsers);

        // need to pre-register so recursive types can be handled

        registerParserType(type, composite);

        int index = 0;

        for (ValueDescriptor vd : vds) {

            parsers[index++] = createParser(vd);

        }

        return composite;

    }

    private static final class BooleanParser extends Parser {

        @Override

        public Object parse(RecordingInput input) throws IOException {

            return input.readBoolean() ? Boolean.TRUE : Boolean.FALSE;

        }

    }

    private static final class ByteParser extends Parser {

        @Override

        public Object parse(RecordingInput input) throws IOException {

            return Byte.valueOf(input.readByte());

        }

    }

    private static final class LongParser extends Parser {

        @Override

        public Object parse(RecordingInput input) throws IOException {

            return Long.valueOf(input.readLong());

        }

    }

    private static final class IntegerParser extends Parser {

        @Override

        public Object parse(RecordingInput input) throws IOException {

            return Integer.valueOf(input.readInt());

        }

    }

    private static final class ShortParser extends Parser {

        @Override

        public Object parse(RecordingInput input) throws IOException {

            return Short.valueOf(input.readShort());

        }

    }

    private static final class CharacterParser extends Parser {

        @Override

        public Object parse(RecordingInput input) throws IOException {

            return Character.valueOf(input.readChar());

        }

    }

    private static final class FloatParser extends Parser {

        @Override

        public Object parse(RecordingInput input) throws IOException {

            return Float.valueOf(input.readFloat());

        }

    }

    private static final class DoubleParser extends Parser {

        @Override

        public Object parse(RecordingInput input) throws IOException {

            return Double.valueOf(input.readDouble());

        }

    }

    private static final class StringParser extends Parser {

        private final ConstantMap stringConstantMap;

        private String last;

        StringParser(ConstantMap stringConstantMap) {

            this.stringConstantMap = stringConstantMap;

        }

        @Override

        public Object parse(RecordingInput input) throws IOException {

            String s = parseEncodedString(input);

            if (!Objects.equals(s, last)) {

                last = s;

            }

            return last;

        }

        private String parseEncodedString(RecordingInput input) throws IOException {

            byte encoding = input.readByte();

            if (encoding == RecordingInput.STRING_ENCODING_CONSTANT_POOL) {

                long id = input.readLong();

                return (String) stringConstantMap.get(id);

            } else {

                return input.readEncodedString(encoding);

            }

        }

    }

    private final static class ArrayParser extends Parser {

        private final Parser elementParser;

        public ArrayParser(Parser elementParser) {

            this.elementParser = elementParser;

        }

        @Override

        public Object parse(RecordingInput input) throws IOException {

            final int size = input.readInt();

            final Object[] array = new Object[size];

            for (int i = 0; i < size; i++) {

                array[i] = elementParser.parse(input);

            }

            return array;

        }

    }

    private final static class CompositeParser extends Parser {

        private final Parser[] parsers;

        public CompositeParser(Parser[] valueParsers) {

            this.parsers = valueParsers;

        }

        @Override

        public Object parse(RecordingInput input) throws IOException {

            final Object[] values = new Object[parsers.length];

            for (int i = 0; i < values.length; i++) {

                values[i] = parsers[i].parse(input);

            }

            return values;

        }

    }

    private static final class ConstantMapValueParser extends Parser {

        private final ConstantMap pool;

        ConstantMapValueParser(ConstantMap pool) {

            this.pool = pool;

        }

        @Override

        public Object parse(RecordingInput input) throws IOException {

            return pool.get(input.readLong());

        }

    }

}