/*
 * 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
 *
 *     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.apache.brooklyn.rest.domain;

import java.io.Serializable;
import java.net.URI;
import java.util.Arrays;
import java.util.List;
import java.util.Map;

import javax.annotation.Nullable;

import org.apache.brooklyn.config.ConfigKey;
import org.apache.brooklyn.util.collections.Jsonya;
import org.codehaus.jackson.annotate.JsonProperty;
import org.codehaus.jackson.map.annotate.JsonSerialize;
import org.codehaus.jackson.map.annotate.JsonSerialize.Inclusion;

import com.google.common.base.Function;
import com.google.common.collect.FluentIterable;
import com.google.common.collect.ImmutableMap;

public abstract class ConfigSummary implements HasName, Serializable {

    private static final long serialVersionUID = -2831796487073496730L;
    
    private final String name;
    private final String type;
    @JsonSerialize(include = Inclusion.NON_NULL)
    private final Object defaultValue;
    @JsonSerialize(include = Inclusion.NON_NULL)
    private final String description;
    @JsonSerialize
    private final boolean reconfigurable;
    @JsonSerialize(include = Inclusion.NON_NULL)
    private final String label;
    @JsonSerialize(include = Inclusion.NON_NULL)
    private final Double priority;
    @JsonSerialize(include = Inclusion.NON_NULL)
    private final List<Map<String, String>> possibleValues;

    protected ConfigSummary(
            @JsonProperty("name") String name,
            @JsonProperty("type") String type,
            @JsonProperty("description") String description,
            @JsonProperty("defaultValue") Object defaultValue,
            @JsonProperty("reconfigurable") boolean reconfigurable,
            @JsonProperty("label") String label,
            @JsonProperty("priority") Double priority,
            @JsonProperty("possibleValues") List<Map<String, String>> possibleValues) {
        this.name = name;
        this.type = type;
        this.description = description;
        this.defaultValue = defaultValue;
        this.reconfigurable = reconfigurable;
        this.label = label;
        this.priority = priority;
        this.possibleValues = possibleValues;
    }

    protected ConfigSummary(ConfigKey<?> config) {
        this(config, null, null);
    }

    @SuppressWarnings("rawtypes")
    protected ConfigSummary(ConfigKey<?> config, String label, Double priority) {
        this.name = config.getName();
        this.description = config.getDescription();
        this.reconfigurable = config.isReconfigurable();

        /* Use String, to guarantee it is serializable; otherwise get:
         *   No serializer found for class org.apache.brooklyn.policy.autoscaling.AutoScalerPolicy$3 and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationConfig.Feature.FAIL_ON_EMPTY_BEANS) ) (through reference chain: java.util.ArrayList[9]->org.apache.brooklyn.rest.domain.PolicyConfigSummary["defaultValue"])
         *   at org.codehaus.jackson.map.ser.impl.UnknownSerializer.failForEmpty(UnknownSerializer.java:52)
         */
        this.label = label;
        this.priority = priority;
        if (config.getType().isEnum()) {
            this.type = Enum.class.getName();
            this.defaultValue = (config.getDefaultValue() == null) ? null : ((Enum) config.getDefaultValue()).name();
            this.possibleValues = FluentIterable
                    .from(Arrays.asList((Enum[])(config.getType().getEnumConstants())))
                    .transform(new Function<Enum, Map<String, String>>() {
                        @Nullable
                        @Override
                        public Map<String, String> apply(@Nullable Enum input) {
                            return ImmutableMap.of(
                                    "value", input != null ? input.name() : null,
                                   "description", input != null ? input.toString() : null);
                        }})
                    .toList();
        } else {
            this.type = config.getTypeName();
            this.defaultValue = Jsonya.convertToJsonPrimitive(config.getDefaultValue());
            this.possibleValues = null;
        }
    }

    @Override
    public String getName() {
        return name;
    }

    public String getType() {
        return type;
    }

    public String getDescription() {
        return description;
    }

    public boolean isReconfigurable() {
        return reconfigurable;
    }

    public Object getDefaultValue() {
        // note constructor has converted to string, so this is safe for clients to use
        return defaultValue;
    }

    public String getLabel() {
        return label;
    }

    public Double getPriority() {
        return priority;
    }

    public List<Map<String, String>> getPossibleValues() {
        return possibleValues;
    }

    public abstract Map<String, URI> getLinks();

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

        ConfigSummary that = (ConfigSummary) o;

        if (name != null ? !name.equals(that.name) : that.name != null)
            return false;

        return true;
    }

    @Override
    public int hashCode() {
        int result = name != null ? name.hashCode() : 0;
        return result;
    }

    @Override
    public abstract String toString();
}