/**
 * #-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=#
 *   This file is part of the LDP4j Project:
 *     http://www.ldp4j.org/
 *
 *   Center for Open Middleware
 *     http://www.centeropenmiddleware.com/
 * #-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=#
 *   Copyright (C) 2014 Center for Open Middleware.
 * #-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=#
 *   Licensed 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.
 * #-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=#
 *   Artifact    : org.ldp4j.framework:ldp4j-application-api:0.2.0
 *   Bundle      : ldp4j-application-api-0.2.0.jar
 * #-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=#
 */
package org.ldp4j.application.data;

import java.io.Serializable;
import java.net.URI;
import java.util.HashMap;
import java.util.Map;

import javax.xml.namespace.QName;

import org.ldp4j.application.vocabulary.Term;

import com.google.common.collect.ImmutableMap;

public final class NamingScheme {

  public enum NameType {
    TERM(Term.class),
    URI(URI.class),
    QNAME(QName.class),
    STRING(String.class),
    NUMBER(Number.class),
    SERIALIZABLE(Serializable.class),
    ;

    private final Class<?> clazz;

    private NameType(Class<?> clazz) {
      this.clazz = clazz;
    }

    private static NameType valueOf(Object t) {
      for(NameType candidate:values()) {
        if(candidate.clazz.isInstance(t)) {
          return candidate;
        }
      }
      throw new IllegalArgumentException("Invalid name type '"+t.getClass().getCanonicalName()+"'");
    }

    @Override
    public String toString() {
      return clazz.getCanonicalName();
    }

  }

  private enum NamingStrategy {
    LOCAL,
    GLOBAL,
    ;
  }

  private interface NameFactory {

    <T extends Serializable> Name<T> create(T id);

  }

  private static final class GlobalNameFactory implements NameFactory {

    @Override
    public <T extends Serializable> Name<T> create(T id) {
      return ImmutableName.newGlobalName(id);
    }

  }

  private static final class LocalNameFactory implements NameFactory {

    @Override
    public <T extends Serializable> Name<T> create(T id) {
      return ImmutableName.newLocalName(id);
    }

  }

  public static final class NamingSchemeBuilder {

    private Map<NameType, NamingStrategy> configuration=new HashMap<NameType, NamingStrategy>();

    private void addMappings(NamingStrategy strategy, NameType type, NameType... rest) {
      this.configuration.put(type, strategy);
      for(NameType r:rest) {
        this.configuration.put(r, strategy);
      }
    }

    public NamingSchemeBuilder withLocal(NameType type, NameType... rest) {
      addMappings(NamingStrategy.LOCAL, type, rest);
      return this;
    }

    public NamingSchemeBuilder withGlobal(NameType type, NameType... rest) {
      addMappings(NamingStrategy.GLOBAL, type, rest);
      return this;
    }

    public NamingScheme build() {
      return new NamingScheme(this.configuration);
    }

  }

  private static final Map<NamingStrategy,NameFactory> FACTORIES=
    ImmutableMap.<NamingStrategy, NameFactory>
      builder().
        put(NamingStrategy.GLOBAL, new GlobalNameFactory()).
        put(NamingStrategy.LOCAL, new LocalNameFactory()).
        build();

  private final Map<NameType, NamingStrategy> configuration;

  private NamingScheme(Map<NameType,NamingStrategy> configuration) {
    this.configuration = configuration;
  }

  private NameFactory getFactory(NameType type) {
    NamingStrategy namingStrategy = configuration.get(type);
    if(namingStrategy==null) {
      namingStrategy=NamingStrategy.GLOBAL;
    }
    return FACTORIES.get(namingStrategy);
  }


  private static void append(StringBuilder builder, String part) {
    if (part != null && !part.isEmpty()) {
      if (builder.length() > 0) {
        builder.append('.');
      }
      builder.append(part);
    }
  }

  private static String assemble(String name, String... names) {
    StringBuilder builder=new StringBuilder();
    append(builder,name);
    if(names!=null) {
      for(String s:names) {
        append(builder,s);
      }
    }
    return builder.toString();
  }

  private <T extends Serializable> Name<T> createName(T id) {
    return getFactory(NameType.valueOf(id)).create(id);
  }

  public Name<URI> name(URI id) {
    return createName(id);
  }

  public Name<QName> name(QName id) {
    return createName(id);
  }

  public Name<Term> name(Term id) {
    return createName(id);
  }

  /**
   * Concatenates elements to form a dotted name, discarding null values
   * and empty strings.
   *
   * @param name
   *            the first element of the name
   * @param names
   *            the remaining elements of the name
   * @return {@code name} and {@code names} concatenated by periods
   */
  public Name<String> name(String name, String... names) {
    return createName(assemble(name, names));
  }

  /**
   * Concatenates a canonical class name and elements to form a dotted name, discarding any null values or empty strings
   * any null values or empty strings.
   *
   * @param clazz
   *            the first element of the name
   * @param names
   *            the remaining elements of the name
   * @return {@code clazz} and {@code names} concatenated by periods
   */
  public Name<String> name(Class<?> clazz, String... names) {
    return name(clazz.getCanonicalName(), names);
  }

  public <T extends Number> Name<T> name(T id) {
    return createName(id);
  }

  public <T extends Serializable> Name<T> name(T id) {
    return createName(id);
  }

  public static NamingSchemeBuilder builder() {
    return new NamingSchemeBuilder();
  }

  public static NamingScheme getDefault() {
    return builder().build();
  }
}