/*

 * 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

 * questions.

 */

package jdk.jfr.consumer;

import java.io.PrintWriter;

import java.io.StringWriter;

import java.time.Duration;

import java.time.Instant;

import java.util.List;

import java.util.Objects;

import jdk.jfr.Timespan;

import jdk.jfr.Timestamp;

import jdk.jfr.ValueDescriptor;

import jdk.jfr.internal.PrivateAccess;

/**

 * A complex data type that consists of one or more fields.

 * <p>

 * This class provides methods to select and query nested objects by passing a

 * dot {@code "."} delimited {@code String} object (for instance,

 * {@code "aaa.bbb"}). A method evaluates a nested object from left to right,

 * and if a part is {@code null}, it throws {@code NullPointerException}.

 *

 * @since 9

 */

public class RecordedObject {

    private final static class UnsignedValue {

        private final Object o;

        UnsignedValue(Object o) {

            this.o = o;

        }

        Object value() {

            return o;

        }

    }

    private final Object[] objects;

    private final List<ValueDescriptor> descriptors;

    private final TimeConverter timeConverter;

    // package private, not to be subclassed outside this package

    RecordedObject(List<ValueDescriptor> descriptors, Object[] objects, TimeConverter timeConverter) {

        this.descriptors = descriptors;

        this.objects = objects;

        this.timeConverter = timeConverter;

    }

    // package private

    final <T> T getTyped(String name, Class<T> clazz, T defaultValue) {

        // Unnecessary to check field presence twice, but this

        // will do for now.

        if (!hasField(name)) {

            return defaultValue;

        }

        T object = getValue(name);

        if (object == null || object.getClass().isAssignableFrom(clazz)) {

            return object;

        } else {

            return defaultValue;

        }

    }

    /**

     * Returns {@code true} if a field with the given name exists, {@code false}

     * otherwise.

     *

     * @param name name of the field to get, not {@code null}

     *

     * @return {@code true} if the field exists, {@code false} otherwise.

     *

     * @see #getFields()

     */

    public boolean hasField(String name) {

        Objects.requireNonNull(name);

        for (ValueDescriptor v : descriptors) {

            if (v.getName().equals(name)) {

                return true;

            }

        }

        int dotIndex = name.indexOf(".");

        if (dotIndex > 0) {

            String structName = name.substring(0, dotIndex);

            for (ValueDescriptor v : descriptors) {

                if (!v.getFields().isEmpty() && v.getName().equals(structName)) {

                    RecordedObject child = getValue(structName);

                    if (child != null) {

                        return child.hasField(name.substring(dotIndex + 1));

                    }

                }

            }

        }

        return false;

    }

    /**

     * Returns the value of the field with the given name.

     * <p>

     * The return type may be a primitive type or a subclass of

     * {@link RecordedObject}.

     * <p>

     * It's possible to index into a nested object by using {@code "."} (for

     * instance {@code "thread.group.parent.name}").

     * <p>

     * A field might change or be removed in a future JDK release. A best practice

     * for callers of this method is to validate the field before attempting access.

     * <p>

     * Example

     *

     * <pre>

     * <code>

     * if (event.hasField("intValue")) {

     *   int intValue = event.getValue("intValue");

     *   System.out.println("Int value: " + intValue);

     * }

     *

     * if (event.hasField("objectClass")) {

     *   RecordedClass clazz = event.getValue("objectClass");

     *   System.out.println("Class name: " + clazz.getName());

     * }

     *

     * if (event.hasField("sampledThread")) {

     *   RecordedThread sampledThread = event.getValue("sampledThread");

     *   System.out.println("Sampled thread: " + sampledThread.getName());

     * }

     * </code>

     * </pre>

     *

     * @param <T> the return type

     * @param  name of the field to get, not {@code null}

     * @throws IllegalArgumentException if no field called {@code name} exists

     *

     * @return the value, can be {@code null}

     *

     * @see #hasField(String)

     *

     */

    final public <T> T getValue(String name) {

        @SuppressWarnings("unchecked")

        T t = (T) getValue(name, false);

        return t;

    }

    private Object getValue(String name, boolean allowUnsigned) {

        Objects.requireNonNull(name);

        int index = 0;

        for (ValueDescriptor v : descriptors) {

            if (name.equals(v.getName())) {

                Object object = objects[index];

                if (object == null) {

                    // error or missing

                    return null;

                }

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

                    if (allowUnsigned && PrivateAccess.getInstance().isUnsigned(v)) {

                        // Types that are meaningless to widen

                        if (object instanceof Character || object instanceof Long) {

                            return object;

                        }

                        return new UnsignedValue(object);

                    }

                    return object; // primitives and primitive arrays

                } else {

                    if (object instanceof RecordedObject) {

                        // known types from factory

                        return object;

                    }

                    // must be array type

                    Object[] array = (Object[]) object;

                    if (v.isArray()) {

                        // struct array

                        return structifyArray(v, array, 0);

                    }

                    // struct

                    return new RecordedObject(v.getFields(), (Object[]) object, timeConverter);

                }

            }

            index++;

        }

        int dotIndex = name.indexOf(".");

        if (dotIndex > 0) {

            String structName = name.substring(0, dotIndex);

            for (ValueDescriptor v : descriptors) {

                if (!v.getFields().isEmpty() && v.getName().equals(structName)) {

                    RecordedObject child = getValue(structName);

                    String subName = name.substring(dotIndex + 1);

                    if (child != null) {

                        return child.getValue(subName, allowUnsigned);

                    } else {

                        // Call getValueDescriptor to trigger IllegalArgumentException if the name is

                        // incorrect. Type can't be validate due to type erasure

                        getValueDescriptor(v.getFields(), subName, null);

                        throw new NullPointerException("Field value for \"" + structName + "\" was null. Can't access nested field \"" + subName + "\"");

                    }

                }

            }

        }

        throw new IllegalArgumentException("Could not find field with name " + name);

    }

    // Returns the leaf value descriptor matches both name or value, or throws an

    // IllegalArgumentException

    private ValueDescriptor getValueDescriptor(List<ValueDescriptor> descriptors, String name, String leafType) {

        int dotIndex = name.indexOf(".");

        if (dotIndex > 0) {

            String first = name.substring(0, dotIndex);

            String second = name.substring(dotIndex + 1);

            for (ValueDescriptor v : descriptors) {

                if (v.getName().equals(first)) {

                    List<ValueDescriptor> fields = v.getFields();

                    if (!fields.isEmpty()) {

                        return getValueDescriptor(v.getFields(), second, leafType);

                    }

                }

            }

            throw new IllegalArgumentException("Attempt to get unknown field \"" + first + "\"");

        }

        for (ValueDescriptor v : descriptors) {

            if (v.getName().equals(name)) {

                if (leafType != null && !v.getTypeName().equals(leafType)) {

                    throw new IllegalArgumentException("Attempt to get " + v.getTypeName() + " field \"" + name + "\" with illegal data type conversion " + leafType);

                }

                return v;

            }

        }

        throw new IllegalArgumentException("\"Attempt to get unknown field \"" + name + "\"");

    }

    // Gets a value, but checks that type and name is correct first

    // This is to prevent a call to getString on a thread field, that is

    // null to succeed.

    private <T> T getTypedValue(String name, String typeName) {

        Objects.requireNonNull(name);

        // Validate name and type first

        getValueDescriptor(descriptors, name, typeName);

        return getValue(name);

    }

    private Object[] structifyArray(ValueDescriptor v, Object[] array, int dimension) {

        if (array == null) {

            return null;

        }

        Object[] structArray = new Object[array.length];

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

            Object arrayElement = array[i];

            if (dimension == 0) {

                // No general way to handle structarrays

                // without invoking ObjectFactory for every instance (which may require id)

                if (isStackFrameType(v.getTypeName())) {

                    structArray[i] = new RecordedFrame(v.getFields(), (Object[]) arrayElement, timeConverter);

                } else {

                    structArray[i] = new RecordedObject(v.getFields(), (Object[]) arrayElement, timeConverter);

                }

            } else {

                structArray[i] = structifyArray(v, (Object[]) arrayElement, dimension - 1);

            }

        }

        return structArray;

    }

    private boolean isStackFrameType(String typeName) {

        if (ObjectFactory.STACK_FRAME_VERSION_1.equals(typeName)) {

            return true;

        }

        if (ObjectFactory.STACK_FRAME_VERSION_2.equals(typeName)) {

            return true;

        }

        return false;

    }

    /**

     * Returns an immutable list of the fields for this object.

     *

     * @return the fields, not {@code null}

     */

    public List<ValueDescriptor> getFields() {

        return descriptors;

    }

    /**

     * Returns the value of a field of type {@code boolean}.

     * <p>

     * It's possible to index into a nested object using {@code "."} (for example,

     * {@code "aaa.bbb"}).

     * <p>

     * A field might change or be removed in a future JDK release. A best practice

     * for callers of this method is to validate the field before attempting access.

     *

     * @param name name of the field to get, not {@code null}

     *

     * @return the value of the field, {@code true} or {@code false}

     *

     * @throws IllegalArgumentException if the field doesn't exist, or the field is

     *         not of type {@code boolean}

     *

     * @see #hasField(String)

     * @see #getValue(String)

     */

    public final boolean getBoolean(String name) {

        Object o = getValue(name);

        if (o instanceof Boolean) {

            return ((Boolean) o).booleanValue();

        }

        throw newIllegalArgumentException(name, "boolean");

    }

    /**

     * Returns the value of a field of type {@code byte}.

     * <p>

     * It's possible to index into a nested object using {@code "."} (for example,

     * {@code "foo.bar"}).

     * <p>

     * A field might change or be removed in a future JDK release. A best practice

     * for callers of this method is to validate the field before attempting access.

     *

     * @param name of the field to get, not {@code null}

     *

     * @return the value of the field

     *

     * @throws IllegalArgumentException if the field doesn't exist, or the field is

     *         not of type {@code byte}

     *

     * @see #hasField(String)

     * @see #getValue(String)

     */

    public final byte getByte(String name) {

        Object o = getValue(name);

        if (o instanceof Byte) {

            return ((Byte) o).byteValue();

        }

        throw newIllegalArgumentException(name, "byte");

    }

    /**

     * Returns the value of a field of type {@code char}.

     * <p>

     * It's possible to index into a nested object using {@code "."} (for example,

     * {@code "aaa.bbb"}).

     * <p>

     * A field might change or be removed in a future JDK release. A best practice

     * for callers of this method is to validate the field before attempting access.

     *

     * @param name of the field to get, not {@code null}

     *

     * @return the value of the field as a {@code char}

     *

     * @throws IllegalArgumentException if the field doesn't exist, or the field is

     *         not of type {@code char}

     *

     * @see #hasField(String)

     * @see #getValue(String)

     */

    public final char getChar(String name) {

        Object o = getValue(name);

        if (o instanceof Character) {

            return ((Character) o).charValue();

        }

        throw newIllegalArgumentException(name, "char");

    }

    /**

     * Returns the value of a field of type {@code short} or of another primitive

     * type convertible to type {@code short} by a widening conversion.

     * <p>

     * This method can be used on the following types: {@code short} and {@code byte}.

     * <p>

     * If the field has the {@code @Unsigned} annotation and is of a narrower type

     * than {@code short}, then the value is returned as an unsigned.

     * <p>

     * It's possible to index into a nested object using {@code "."} (for example,

     * {@code "aaa.bbb"}).

     * <p>

     * A field might change or be removed in a future JDK release. A best practice

     * for callers of this method is to validate the field before attempting access.

     *

     * @param name of the field to get, not {@code null}

     *

     * @return the value of the field converted to type {@code short}

     *

     * @throws IllegalArgumentException if the field doesn't exist, or the field

     *         value can't be converted to the type {@code short} by a widening

     *         conversion

     *

     * @see #hasField(String)

     * @set #getValue(String)

     */

    public final short getShort(String name) {

        Object o = getValue(name, true);

        if (o instanceof Short) {

            return ((Short) o).shortValue();

        }

        if (o instanceof Byte) {

            return ((Byte) o).byteValue();

        }

        if (o instanceof UnsignedValue) {

            Object u = ((UnsignedValue) o).value();

            if (u instanceof Short) {

                return ((Short) u).shortValue();

            }

            if (u instanceof Byte) {

                return (short) Byte.toUnsignedInt(((Byte) u));

            }

        }

        throw newIllegalArgumentException(name, "short");

    }

    /**

     * Returns the value of a field of type {@code int} or of another primitive type

     * that is convertible to type {@code int} by a widening conversion.

     * <p>

     * This method can be used on fields of the following types: {@code int},

     * {@code short}, {@code char}, and {@code byte}.

     * <p>

     * If the field has the {@code @Unsigned} annotation and is of a narrower type

     * than {@code int}, then the value will be returned as an unsigned.

     * <p>

     * It's possible to index into a nested object using {@code "."} (for example,

     * {@code "aaa.bbb"}).

     * <p>

     * A field might change or be removed in a future JDK release. A best practice

     * for callers of this method is to validate the field before attempting access.

     *

     * @param name of the field to get, not {@code null}

     *

     * @return the value of the field converted to type {@code int}

     *

     * @throws IllegalArgumentException if the field doesn't exist, or the field

     *         value can't be converted to the type {@code int} by a widening

     *         conversion

     *

     * @see #hasField(String)

     * @set #getValue(String)

     */

    public final int getInt(String name) {

        Object o = getValue(name, true);

        if (o instanceof Integer) {

            return ((Integer) o).intValue();

        }

        if (o instanceof Short) {

            return ((Short) o).intValue();

        }

        if (o instanceof Character) {

            return ((Character) o).charValue();

        }

        if (o instanceof Byte) {

            return ((Byte) o).intValue();

        }

        if (o instanceof UnsignedValue) {

            Object u = ((UnsignedValue) o).value();

            if (u instanceof Integer) {

                return ((Integer) u).intValue();

            }

            if (u instanceof Short) {

                return Short.toUnsignedInt(((Short) u));

            }

            if (u instanceof Byte) {

                return Byte.toUnsignedInt(((Byte) u));

            }

        }

        throw newIllegalArgumentException(name, "int");

    }

    /**

     * Returns the value of a field of type {@code float} or of another primitive

     * type convertible to type {@code float} by a widening conversion.

     * <p>

     * This method can be used on fields of the following types: {@code float},

     * {@code long}, {@code int}, {@code short}, {@code char}, and {@code byte}.

     * <p>

     * It's possible to index into a nested object using {@code "."} (for example,

     * {@code "aaa.bbb"}).

     * <p>

     * A field might change or be removed in a future JDK release. A best practice

     * for callers of this method is to validate the field before attempting access.

     *

     * @param name of the field to get, not {@code null}

     *

     * @return the value of the field converted to type {@code float}

     *

     * @throws IllegalArgumentException if the field doesn't exist, or the field

     *         value can't be converted to the type {@code float} by a widening

     *         conversion

     *

     * @see #hasField(String)

     * @set #getValue(String)

     */

    public final float getFloat(String name) {

        Object o = getValue(name);

        if (o instanceof Float) {

            return ((Float) o).floatValue();

        }

        if (o instanceof Long) {

            return ((Long) o).floatValue();

        }

        if (o instanceof Integer) {

            return ((Integer) o).floatValue();

        }

        if (o instanceof Short) {