/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch 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
 *
 *    http://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.elasticsearch.cluster.metadata;

import com.carrotsearch.hppc.cursors.ObjectCursor;
import com.carrotsearch.hppc.cursors.ObjectObjectCursor;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Sets;
import org.elasticsearch.Version;
import org.elasticsearch.common.collect.ImmutableOpenMap;
import org.elasticsearch.common.collect.MapBuilder;
import org.elasticsearch.common.compress.CompressedString;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.settings.ImmutableSettings;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.settings.loader.SettingsLoader;
import org.elasticsearch.common.xcontent.*;
import org.elasticsearch.common.xcontent.ToXContent.DelegatingMapParams;

import java.io.IOException;
import java.util.Map;
import java.util.Set;

/**
 *
 */
public class IndexTemplateMetaData {

    private final String name;

    private final int order;

    private final String template;

    private final Settings settings;

    // the mapping source should always include the type as top level
    private final ImmutableOpenMap<String, CompressedString> mappings;

    private final ImmutableOpenMap<String, AliasMetaData> aliases;

    private final ImmutableOpenMap<String, IndexMetaData.Custom> customs;

    public IndexTemplateMetaData(String name, int order, String template, Settings settings, ImmutableOpenMap<String, CompressedString> mappings,
                                 ImmutableOpenMap<String, AliasMetaData> aliases, ImmutableOpenMap<String, IndexMetaData.Custom> customs) {
        this.name = name;
        this.order = order;
        this.template = template;
        this.settings = settings;
        this.mappings = mappings;
        this.aliases = aliases;
        this.customs = customs;
    }

    public String name() {
        return this.name;
    }

    public int order() {
        return this.order;
    }

    public int getOrder() {
        return order();
    }

    public String getName() {
        return this.name;
    }

    public String template() {
        return this.template;
    }

    public String getTemplate() {
        return this.template;
    }

    public Settings settings() {
        return this.settings;
    }

    public Settings getSettings() {
        return settings();
    }

    public ImmutableOpenMap<String, CompressedString> mappings() {
        return this.mappings;
    }

    public ImmutableOpenMap<String, CompressedString> getMappings() {
        return this.mappings;
    }

    public ImmutableOpenMap<String, AliasMetaData> aliases() {
        return this.aliases;
    }

    public ImmutableOpenMap<String, AliasMetaData> getAliases() {
        return this.aliases;
    }

    public ImmutableOpenMap<String, IndexMetaData.Custom> customs() {
        return this.customs;
    }

    public ImmutableOpenMap<String, IndexMetaData.Custom> getCustoms() {
        return this.customs;
    }

    @SuppressWarnings("unchecked")
    public <T extends IndexMetaData.Custom> T custom(String type) {
        return (T) customs.get(type);
    }

    public static Builder builder(String name) {
        return new Builder(name);
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        IndexTemplateMetaData that = (IndexTemplateMetaData) o;

        if (order != that.order) return false;
        if (!mappings.equals(that.mappings)) return false;
        if (!name.equals(that.name)) return false;
        if (!settings.equals(that.settings)) return false;
        if (!template.equals(that.template)) return false;

        return true;
    }

    @Override
    public int hashCode() {
        int result = name.hashCode();
        result = 31 * result + order;
        result = 31 * result + template.hashCode();
        result = 31 * result + settings.hashCode();
        result = 31 * result + mappings.hashCode();
        return result;
    }

    public static class Builder {

        private static final Set<String> VALID_FIELDS = Sets.newHashSet("template", "order", "mappings", "settings");
        static {
            VALID_FIELDS.addAll(IndexMetaData.customFactories.keySet());
        }

        private String name;

        private int order;

        private String template;

        private Settings settings = ImmutableSettings.Builder.EMPTY_SETTINGS;

        private final ImmutableOpenMap.Builder<String, CompressedString> mappings;

        private final ImmutableOpenMap.Builder<String, AliasMetaData> aliases;

        private final ImmutableOpenMap.Builder<String, IndexMetaData.Custom> customs;

        public Builder(String name) {
            this.name = name;
            mappings = ImmutableOpenMap.builder();
            aliases = ImmutableOpenMap.builder();
            customs = ImmutableOpenMap.builder();
        }

        public Builder(IndexTemplateMetaData indexTemplateMetaData) {
            this.name = indexTemplateMetaData.name();
            order(indexTemplateMetaData.order());
            template(indexTemplateMetaData.template());
            settings(indexTemplateMetaData.settings());

            mappings = ImmutableOpenMap.builder(indexTemplateMetaData.mappings());
            aliases = ImmutableOpenMap.builder(indexTemplateMetaData.aliases());
            customs = ImmutableOpenMap.builder(indexTemplateMetaData.customs());
        }

        public Builder order(int order) {
            this.order = order;
            return this;
        }

        public Builder template(String template) {
            this.template = template;
            return this;
        }

        public String template() {
            return template;
        }

        public Builder settings(Settings.Builder settings) {
            this.settings = settings.build();
            return this;
        }

        public Builder settings(Settings settings) {
            this.settings = settings;
            return this;
        }

        public Builder removeMapping(String mappingType) {
            mappings.remove(mappingType);
            return this;
        }

        public Builder putMapping(String mappingType, CompressedString mappingSource) throws IOException {
            mappings.put(mappingType, mappingSource);
            return this;
        }

        public Builder putMapping(String mappingType, String mappingSource) throws IOException {
            mappings.put(mappingType, new CompressedString(mappingSource));
            return this;
        }

        public Builder putAlias(AliasMetaData aliasMetaData) {
            aliases.put(aliasMetaData.alias(), aliasMetaData);
            return this;
        }

        public Builder putAlias(AliasMetaData.Builder aliasMetaData) {
            aliases.put(aliasMetaData.alias(), aliasMetaData.build());
            return this;
        }

        public Builder putCustom(String type, IndexMetaData.Custom customIndexMetaData) {
            this.customs.put(type, customIndexMetaData);
            return this;
        }

        public Builder removeCustom(String type) {
            this.customs.remove(type);
            return this;
        }

        public IndexMetaData.Custom getCustom(String type) {
            return this.customs.get(type);
        }

        public IndexTemplateMetaData build() {
            return new IndexTemplateMetaData(name, order, template, settings, mappings.build(), aliases.build(), customs.build());
        }

        @SuppressWarnings("unchecked")
        public static void toXContent(IndexTemplateMetaData indexTemplateMetaData, XContentBuilder builder, ToXContent.Params params) throws IOException {
            builder.startObject(indexTemplateMetaData.name(), XContentBuilder.FieldCaseConversion.NONE);

            builder.field("order", indexTemplateMetaData.order());
            builder.field("template", indexTemplateMetaData.template());

            builder.startObject("settings");
            // backward compatibility: flat_settings was ignored before 1.3 and always true
            final Map<String, String> overrideParams = ImmutableMap.of(ImmutableSettings.FLAT_SETTINGS_KEY, params.param(ImmutableSettings.FLAT_SETTINGS_KEY, Boolean.TRUE.toString()));
            indexTemplateMetaData.settings().toXContent(builder, new DelegatingMapParams(overrideParams, params));
            builder.endObject();

            if (params.paramAsBoolean("reduce_mappings", false)) {
                builder.startObject("mappings");
                for (ObjectObjectCursor<String, CompressedString> cursor : indexTemplateMetaData.mappings()) {
                    byte[] mappingSource = cursor.value.uncompressed();
                    XContentParser parser = XContentFactory.xContent(mappingSource).createParser(mappingSource);
                    Map<String, Object> mapping = parser.map();
                    if (mapping.size() == 1 && mapping.containsKey(cursor.key)) {
                        // the type name is the root value, reduce it
                        mapping = (Map<String, Object>) mapping.get(cursor.key);
                    }
                    builder.field(cursor.key);
                    builder.map(mapping);
                }
                builder.endObject();
            } else {
                builder.startArray("mappings");
                for (ObjectObjectCursor<String, CompressedString> cursor : indexTemplateMetaData.mappings()) {
                    byte[] data = cursor.value.uncompressed();
                    XContentParser parser = XContentFactory.xContent(data).createParser(data);
                    Map<String, Object> mapping = parser.mapOrderedAndClose();
                    builder.map(mapping);
                }
                builder.endArray();
            }

            for (ObjectObjectCursor<String, IndexMetaData.Custom> cursor : indexTemplateMetaData.customs()) {
                builder.startObject(cursor.key, XContentBuilder.FieldCaseConversion.NONE);
                IndexMetaData.lookupFactorySafe(cursor.key).toXContent(cursor.value, builder, params);
                builder.endObject();
            }

            builder.startObject("aliases");
            for (ObjectCursor<AliasMetaData> cursor : indexTemplateMetaData.aliases().values()) {
                AliasMetaData.Builder.toXContent(cursor.value, builder, params);
            }
            builder.endObject();

            builder.endObject();
        }

        public static IndexTemplateMetaData fromXContent(XContentParser parser, String templateName) throws IOException {
            Builder builder = new Builder(templateName);

            String currentFieldName = skipTemplateName(parser);
            XContentParser.Token token;
            while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
                if (token == XContentParser.Token.FIELD_NAME) {
                    currentFieldName = parser.currentName();
                } else if (token == XContentParser.Token.START_OBJECT) {
                    if ("settings".equals(currentFieldName)) {
                        ImmutableSettings.Builder templateSettingsBuilder = ImmutableSettings.settingsBuilder();
                        templateSettingsBuilder.put(SettingsLoader.Helper.loadNestedFromMap(parser.mapOrdered())).normalizePrefix(IndexMetaData.INDEX_SETTING_PREFIX);
                        builder.settings(templateSettingsBuilder.build());
                    } else if ("mappings".equals(currentFieldName)) {
                        while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
                            if (token == XContentParser.Token.FIELD_NAME) {
                                currentFieldName = parser.currentName();
                            } else if (token == XContentParser.Token.START_OBJECT) {
                                String mappingType = currentFieldName;
                                Map<String, Object> mappingSource = MapBuilder.<String, Object>newMapBuilder().put(mappingType, parser.mapOrdered()).map();
                                builder.putMapping(mappingType, XContentFactory.jsonBuilder().map(mappingSource).string());
                            }
                        }
                    } else if ("aliases".equals(currentFieldName)) {
                        while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
                            builder.putAlias(AliasMetaData.Builder.fromXContent(parser));
                        }
                    } else {
                        // check if its a custom index metadata
                        IndexMetaData.Custom.Factory<IndexMetaData.Custom> factory = IndexMetaData.lookupFactory(currentFieldName);
                        if (factory == null) {
                            //TODO warn
                            parser.skipChildren();
                        } else {
                            builder.putCustom(factory.type(), factory.fromXContent(parser));
                        }
                    }
                } else if (token == XContentParser.Token.START_ARRAY) {
                    if ("mappings".equals(currentFieldName)) {
                        while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
                            Map<String, Object> mapping = parser.mapOrdered();
                            if (mapping.size() == 1) {
                                String mappingType = mapping.keySet().iterator().next();
                                String mappingSource = XContentFactory.jsonBuilder().map(mapping).string();

                                if (mappingSource == null) {
                                    // crap, no mapping source, warn?
                                } else {
                                    builder.putMapping(mappingType, mappingSource);
                                }
                            }
                        }
                    }
                } else if (token.isValue()) {
                    if ("template".equals(currentFieldName)) {
                        builder.template(parser.text());
                    } else if ("order".equals(currentFieldName)) {
                        builder.order(parser.intValue());
                    }
                }
            }
            return builder.build();
        }

        private static String skipTemplateName(XContentParser parser) throws IOException {
            XContentParser.Token token = parser.nextToken();
            if (token != null && token == XContentParser.Token.START_OBJECT) {
                token = parser.nextToken();
                if (token == XContentParser.Token.FIELD_NAME) {
                    String currentFieldName = parser.currentName();
                    if (VALID_FIELDS.contains(currentFieldName)) {
                        return currentFieldName;
                    } else {
                        // we just hit the template name, which should be ignored and we move on
                        parser.nextToken();
                    }
                }
            }

            return null;
        }

        public static IndexTemplateMetaData readFrom(StreamInput in) throws IOException {
            Builder builder = new Builder(in.readString());
            builder.order(in.readInt());
            builder.template(in.readString());
            builder.settings(ImmutableSettings.readSettingsFromStream(in));
            int mappingsSize = in.readVInt();
            for (int i = 0; i < mappingsSize; i++) {
                builder.putMapping(in.readString(), CompressedString.readCompressedString(in));
            }
            if (in.getVersion().onOrAfter(Version.V_1_1_0)) {
                int aliasesSize = in.readVInt();
                for (int i = 0; i < aliasesSize; i++) {
                    AliasMetaData aliasMd = AliasMetaData.Builder.readFrom(in);
                    builder.putAlias(aliasMd);
                }
            }
            int customSize = in.readVInt();
            for (int i = 0; i < customSize; i++) {
                String type = in.readString();
                IndexMetaData.Custom customIndexMetaData = IndexMetaData.lookupFactorySafe(type).readFrom(in);
                builder.putCustom(type, customIndexMetaData);
            }
            return builder.build();
        }

        public static void writeTo(IndexTemplateMetaData indexTemplateMetaData, StreamOutput out) throws IOException {
            out.writeString(indexTemplateMetaData.name());
            out.writeInt(indexTemplateMetaData.order());
            out.writeString(indexTemplateMetaData.template());
            ImmutableSettings.writeSettingsToStream(indexTemplateMetaData.settings(), out);
            out.writeVInt(indexTemplateMetaData.mappings().size());
            for (ObjectObjectCursor<String, CompressedString> cursor : indexTemplateMetaData.mappings()) {
                out.writeString(cursor.key);
                cursor.value.writeTo(out);
            }
            if (out.getVersion().onOrAfter(Version.V_1_1_0)) {
                out.writeVInt(indexTemplateMetaData.aliases().size());
                for (ObjectCursor<AliasMetaData> cursor : indexTemplateMetaData.aliases().values()) {
                    AliasMetaData.Builder.writeTo(cursor.value, out);
                }
            }
            out.writeVInt(indexTemplateMetaData.customs().size());
            for (ObjectObjectCursor<String, IndexMetaData.Custom> cursor : indexTemplateMetaData.customs()) {
                out.writeString(cursor.key);
                IndexMetaData.lookupFactorySafe(cursor.key).writeTo(cursor.value, out);
            }
        }
    }

}
