/*

 * 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.internal;

import static jdk.jfr.internal.MetadataDescriptor.ATTRIBUTE_CONSTANT_POOL;

import static jdk.jfr.internal.MetadataDescriptor.ATTRIBUTE_DIMENSION;

import static jdk.jfr.internal.MetadataDescriptor.ATTRIBUTE_ID;

import static jdk.jfr.internal.MetadataDescriptor.ATTRIBUTE_NAME;

import static jdk.jfr.internal.MetadataDescriptor.ATTRIBUTE_SIMPLE_TYPE;

import static jdk.jfr.internal.MetadataDescriptor.ATTRIBUTE_SUPER_TYPE;

import static jdk.jfr.internal.MetadataDescriptor.ATTRIBUTE_TYPE_ID;

import static jdk.jfr.internal.MetadataDescriptor.ELEMENT_ANNOTATION;

import static jdk.jfr.internal.MetadataDescriptor.ELEMENT_FIELD;

import static jdk.jfr.internal.MetadataDescriptor.ELEMENT_SETTING;

import static jdk.jfr.internal.MetadataDescriptor.ELEMENT_TYPE;

import java.io.DataInput;

import java.io.IOException;

import java.util.ArrayList;

import java.util.Collections;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import jdk.jfr.AnnotationElement;

import jdk.jfr.SettingDescriptor;

import jdk.jfr.ValueDescriptor;

import jdk.jfr.internal.MetadataDescriptor.Element;

/**

 * Parses metadata.

 *

 */

final class MetadataReader {

    private final DataInput input;

    private final List<String> pool;

    private final MetadataDescriptor descriptor;

    private final Map<Long, Type> types = new HashMap<>();

    public MetadataReader(DataInput input) throws IOException {

        this.input = input;

        int size = input.readInt();

        this.pool = new ArrayList<>(size);

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

            this.pool.add(input.readUTF());

        }

        descriptor = new MetadataDescriptor();

        Element root = createElement();

        Element metadata = root.elements("metadata").get(0);

        declareTypes(metadata);

        defineTypes(metadata);

        annotateTypes(metadata);

        buildEvenTypes();

        Element time = root.elements("region").get(0);

        descriptor.gmtOffset = time.attribute(MetadataDescriptor.ATTRIBUTE_GMT_OFFSET, 1);

        descriptor.locale = time.attribute(MetadataDescriptor.ATTRIBUTE_LOCALE, "");

        descriptor.root = root;

        if (LogTag.JFR_SYSTEM_PARSER.shouldLog(LogLevel.TRACE.level)) {

             List<Type> ts = new ArrayList<>(types.values());

             Collections.sort(ts, (x,y) -> x.getName().compareTo(y.getName()));

             for (Type t : ts) {

                 t.log("Found", LogTag.JFR_SYSTEM_PARSER, LogLevel.TRACE);

             }

        }

    }

    private String readString() throws IOException {

        return pool.get(readInt());

    }

    private int readInt() throws IOException {

        return input.readInt();

    }

    private Element createElement() throws IOException {

        String name = readString();

        Element e = new Element(name);

        int attributeCount = readInt();

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

            e.addAttribute(readString(), readString());

        }

        int childrenCount = readInt();

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

            e.add(createElement());

        }

        return e;

    }

    private void annotateTypes(Element metadata) throws IOException {

        for (Element typeElement : metadata.elements(ELEMENT_TYPE)) {

            Type type = getType(ATTRIBUTE_ID, typeElement);

            ArrayList<AnnotationElement> aes = new ArrayList<>();

            for (Element annotationElement : typeElement.elements(ELEMENT_ANNOTATION)) {

                aes.add(makeAnnotation(annotationElement));

            }

            aes.trimToSize();

            type.setAnnotations(aes);

            int index = 0;

            if (type instanceof PlatformEventType) {

                List<SettingDescriptor> settings = ((PlatformEventType) type).getAllSettings();

                for (Element settingElement : typeElement.elements(ELEMENT_SETTING)) {

                    ArrayList<AnnotationElement> annotations = new ArrayList<>();

                    for (Element annotationElement : settingElement.elements(ELEMENT_ANNOTATION)) {

                        annotations.add(makeAnnotation(annotationElement));

                    }

                    annotations.trimToSize();

                    PrivateAccess.getInstance().setAnnotations(settings.get(index), annotations);

                    index++;

                }

            }

            index = 0;

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

            for (Element fieldElement : typeElement.elements(ELEMENT_FIELD)) {

                ArrayList<AnnotationElement> annotations = new ArrayList<>();

                for (Element annotationElement : fieldElement.elements(ELEMENT_ANNOTATION)) {

                    annotations.add(makeAnnotation(annotationElement));

                }

                annotations.trimToSize();

                PrivateAccess.getInstance().setAnnotations(fields.get(index), annotations);

                index++;

            }

        }

    }

    private AnnotationElement makeAnnotation(Element annotationElement) throws IOException {

        Type annotationType = getType(ATTRIBUTE_TYPE_ID, annotationElement);

        List<Object> values = new ArrayList<>();

        for (ValueDescriptor v : annotationType.getFields()) {

            if (v.isArray()) {

                List<Object> list = new ArrayList<>();

                int index = 0;

                while (true) {

                    String text = annotationElement.attribute(v.getName() + "-" + index);

                    if (text == null) {

                        break;

                    }

                    list.add(objectify(v.getTypeName(), text));

                    index++;

                }

                Object object = Utils.makePrimitiveArray(v.getTypeName(), list);

                if (object == null) {

                    throw new IOException("Unsupported type " + list + " in array");

                }

                values.add(object);

            } else {

                String text = annotationElement.attribute(v.getName());

                values.add(objectify(v.getTypeName(), text));

            }

        }

        return PrivateAccess.getInstance().newAnnotation(annotationType, values, false);

    }

    private Object objectify(String typeName, String text) throws IOException {

        try {

            switch (typeName) {

            case "int":

                return Integer.valueOf(text);

            case "long":

                return Long.valueOf(text);

            case "double":

                return Double.valueOf(text);

            case "float":

                return Float.valueOf(text);

            case "short":

                return Short.valueOf(text);

            case "char":

                if (text.length() != 1) {

                    throw new IOException("Unexpected size of char");

                }

                return text.charAt(0);

            case "byte":

                return Byte.valueOf(text);

            case "boolean":

                return Boolean.valueOf(text);

            case "java.lang.String":

                return text;

            }

        } catch (IllegalArgumentException iae) {

            throw new IOException("Could not parse text representation of " + typeName);

        }

        throw new IOException("Unsupported type for annotation " + typeName);

    }

    private Type getType(String attribute, Element element) {

        long id = element.longValue(attribute);

        Type type = types.get(id);

        if (type == null) {

            String name = element.attribute("type");

            throw new IllegalStateException("Type '" + id + "' is not defined for " + name);

        }

        return type;

    }

    private void buildEvenTypes() {

        for (Type type : descriptor.types) {

            if (type instanceof PlatformEventType) {

                descriptor.eventTypes.add(PrivateAccess.getInstance().newEventType((PlatformEventType) type));

            }

        }

    }

    private void defineTypes(Element metadata) {

        for (Element typeElement : metadata.elements(ELEMENT_TYPE)) {

            long id = typeElement.attribute(ATTRIBUTE_ID, -1);

            Type t = types.get(id);

            for (Element fieldElement : typeElement.elements(ELEMENT_SETTING)) {

                String name = fieldElement.attribute(ATTRIBUTE_NAME);

                String defaultValue = fieldElement.attribute(ATTRIBUTE_NAME);

                Type settingType = getType(ATTRIBUTE_TYPE_ID, fieldElement);

                PlatformEventType eventType = (PlatformEventType) t;

                eventType.add(PrivateAccess.getInstance().newSettingDescriptor(settingType, name, defaultValue, new ArrayList<>(2)));

            }

            for (Element fieldElement : typeElement.elements(ELEMENT_FIELD)) {

                String name = fieldElement.attribute(ATTRIBUTE_NAME);

                Type fieldType = getType(ATTRIBUTE_TYPE_ID, fieldElement);

                long dimension = fieldElement.attribute(ATTRIBUTE_DIMENSION, 0);

                boolean constantPool = fieldElement.attribute(ATTRIBUTE_CONSTANT_POOL) != null;

                // Add annotation later, because they may refer to undefined

                // types at this stage

                t.add(PrivateAccess.getInstance().newValueDescriptor(name, fieldType, new ArrayList<>(), (int) dimension, constantPool, null));

            }

            t.trimFields();

        }

    }

    private void declareTypes(Element metadata) {

        for (Element typeElement : metadata.elements(ELEMENT_TYPE)) {

            String typeName = typeElement.attribute(ATTRIBUTE_NAME);

            String superType = typeElement.attribute(ATTRIBUTE_SUPER_TYPE);

            boolean simpleType = typeElement.attribute(ATTRIBUTE_SIMPLE_TYPE) != null;

            long id = typeElement.attribute(ATTRIBUTE_ID, -1);

            Type t;

            if (Type.SUPER_TYPE_EVENT.equals(superType)) {

                t = new PlatformEventType(typeName, id, false, false);

            } else {

                t = new Type(typeName, superType, id, false, simpleType);

            }

            types.put(id, t);

            descriptor.types.add(t);

        }

    }

    public MetadataDescriptor getDescriptor() {

        return descriptor;

    }

}