/*
 * 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 createObject 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.tamaya.validation.spi;

import org.apache.tamaya.Configuration;
import org.apache.tamaya.validation.ConfigModel;
import org.apache.tamaya.validation.ModelTarget;
import org.apache.tamaya.validation.Validation;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.Objects;

/**
 * Default configuration Model for a configuration section.
 */
public class SectionModel extends GroupModel {

    /**
     * Creates a new builder.
     * @param owner owner, not null.
     * @param name the section name.
     * @return a new builder instance.
     */
    public static Builder builder(String owner, String name){
        return new Builder(owner, name);
    }

    /**
     * Creates a section validation for the given section.
     * @param owner owner, not null.
     * @param name the fully qualified section name
     * @param required flag, if the section is required to be present.
     * @return the ConfigModel instance
     */
    public static ConfigModel of(String owner, String name, boolean required){
        return new Builder(owner, name).setRequired(required).build();
    }

    /**
     * Creates a section validation for the given section.
     * @param owner owner, not null.
     * @param name the fully qualified section name
     * @param required flag, if the section is required to be present.
     * @param configModels additional configModels
     * @return a new builder, never null.
     */
    public static ConfigModel of(String owner, String name, boolean required, ConfigModel... configModels){
        return new Builder(owner, name).setRequired(required).addValidations(configModels).build();
    }

    /**
     * Internal constructor.
     * @param builder the builder, not null.
     */
    protected SectionModel(Builder builder) {
        super(builder.owner, builder.name, builder.childConfigModels);
    }

    @Override
    public ModelTarget getType(){
        return ModelTarget.Section;
    }

    @Override
    public Collection<Validation> validate(Configuration config) {
        Map<String,String> map = config.getProperties();
        String lookupKey = getName() + '.';
        boolean present = false;
        for(String key:map.keySet()){
            if(key.startsWith("_")){
                continue;
            }
            if(key.startsWith(lookupKey)){
                present = true;
                break;
            }
        }
        List<Validation> result = new ArrayList<>(1);
        if(isRequired() && !present) {
            result.add(Validation.createMissing(this));
        }
        result.addAll(super.validate(config));
        return result;
    }

    @Override
    public String toString() {
        StringBuilder b = new StringBuilder();
        b.append(getType()).append(": ").append(getName());
        if(isRequired()) {
            b.append(", required: " ).append(isRequired());
        }
        for(ConfigModel val:getValidations()){
             b.append(", ").append(val.toString());
        }
        return b.toString();
    }

    /**
     * Builder for setting up a AreaConfigModel instance.
     */
    public static class Builder{
        /** The section owner. */
        private String owner;
        /** The section name. */
        private String name;
        /** The optional description. */
        private String description;
        /** The required flag. */
        private boolean required;
        /** The (optional) custom validations.*/
        private final List<ConfigModel> childConfigModels = new ArrayList<>();

        /**
         * Creates a new Builder.
         * @param owner owner, not null.
         * @param sectionName the section name, not null.
         */
        public Builder(String owner, String sectionName){
            this.owner = Objects.requireNonNull(owner);
            this.name = Objects.requireNonNull(sectionName);
        }

        /**
         * Add configModels.
         * @param configModels the configModels, not null.
         * @return the Builder for chaining.
         */
        public Builder addValidations(ConfigModel... configModels){
            this.childConfigModels.addAll(Arrays.asList(configModels));
            return this;
        }

        /**
         * Add configModels.
         * @param configModels the configModels, not null.
         * @return the Builder for chaining.
         */
        public Builder addValidations(Collection<ConfigModel> configModels){
            this.childConfigModels.addAll(configModels);
            return this;
        }

        /**
         * Sets the required flag.
         * @param required zhe flag.
         * @return the Builder for chaining.
         */
        public Builder setRequired(boolean required){
            this.required = required;
            return this;
        }

        /**
         * Set the )optional) description.
         * @param description the description.
         * @return the Builder for chaining.
         */
        public Builder setDescription(String description){
            this.description = description;
            return this;
        }

        /**
         * Set the section name
         * @param name the section name, not null.
         * @return the Builder for chaining.
         */
        public Builder setName(String name){
            this.name = Objects.requireNonNull(name);
            return this;
        }

        /**
         * Build a new ConfigModel instance.
         * @return the new ConfigModel instance, not null.
         */
        public ConfigModel build(){
            return new SectionModel(this);
        }
    }
}