/*
 * Copyright 2002-2017 the original author or authors.
 *
 * 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
 *
 *      https://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.springframework.format.support;

import java.util.Set;

import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.EmbeddedValueResolverAware;
import org.springframework.core.convert.support.ConversionServiceFactory;
import org.springframework.format.AnnotationFormatterFactory;
import org.springframework.format.Formatter;
import org.springframework.format.FormatterRegistrar;
import org.springframework.format.FormatterRegistry;
import org.springframework.format.Parser;
import org.springframework.format.Printer;
import org.springframework.lang.Nullable;
import org.springframework.util.StringValueResolver;

A factory providing convenient access to a FormattingConversionService configured with converters and formatters for common types such as numbers and datetimes. 
Additional converters and formatters can be registered declaratively through setConverters(Set<?>) and setFormatters(Set<?>). Another option is to register converters and formatters in code by implementing the FormatterRegistrar interface. You can then configure provide the set of registrars to use through setFormatterRegistrars(Set<FormatterRegistrar>). 
A good example for registering converters and formatters in code is JodaTimeFormatterRegistrar, which registers a number of date-related formatters and converters. For a more detailed list of cases see setFormatterRegistrars(Set<FormatterRegistrar>) 
Like all FactoryBean implementations, this class is suitable for use when configuring a Spring application context using Spring <beans> XML. When configuring the container with @Configuration classes, simply instantiate, configure and return the appropriate FormattingConversionService object from a @Bean method. 
Author:
Keith Donald, Juergen Hoeller, Rossen Stoyanchev, Chris Beams
Since:
3.0/**
 * A factory providing convenient access to a {@code FormattingConversionService}
 * configured with converters and formatters for common types such as numbers and
 * datetimes.
 *
 * <p>Additional converters and formatters can be registered declaratively through
 * {@link #setConverters(Set)} and {@link #setFormatters(Set)}. Another option
 * is to register converters and formatters in code by implementing the
 * {@link FormatterRegistrar} interface. You can then configure provide the set
 * of registrars to use through {@link #setFormatterRegistrars(Set)}.
 *
 * <p>A good example for registering converters and formatters in code is
 * {@code JodaTimeFormatterRegistrar}, which registers a number of
 * date-related formatters and converters. For a more detailed list of cases
 * see {@link #setFormatterRegistrars(Set)}
 *
 * <p>Like all {@code FactoryBean} implementations, this class is suitable for
 * use when configuring a Spring application context using Spring {@code <beans>}
 * XML. When configuring the container with
 * {@link org.springframework.context.annotation.Configuration @Configuration}
 * classes, simply instantiate, configure and return the appropriate
 * {@code FormattingConversionService} object from a
 * {@link org.springframework.context.annotation.Bean @Bean} method.
 *
 * @author Keith Donald
 * @author Juergen Hoeller
 * @author Rossen Stoyanchev
 * @author Chris Beams
 * @since 3.0
 */
public class FormattingConversionServiceFactoryBean
		implements FactoryBean<FormattingConversionService>, EmbeddedValueResolverAware, InitializingBean {

	@Nullable
	private Set<?> converters;

	@Nullable
	private Set<?> formatters;

	@Nullable
	private Set<FormatterRegistrar> formatterRegistrars;

	private boolean registerDefaultFormatters = true;

	@Nullable
	private StringValueResolver embeddedValueResolver;

	@Nullable
	private FormattingConversionService conversionService;


	
Configure the set of custom converter objects that should be added.
Params:
converters – instances of any of the following: Converter, ConverterFactory, GenericConverter/**
	 * Configure the set of custom converter objects that should be added.
	 * @param converters instances of any of the following:
	 * {@link org.springframework.core.convert.converter.Converter},
	 * {@link org.springframework.core.convert.converter.ConverterFactory},
	 * {@link org.springframework.core.convert.converter.GenericConverter}
	 */
	public void setConverters(Set<?> converters) {
		this.converters = converters;
	}

	
Configure the set of custom formatter objects that should be added.
Params:
formatters – instances of Formatter or AnnotationFormatterFactory/**
	 * Configure the set of custom formatter objects that should be added.
	 * @param formatters instances of {@link Formatter} or {@link AnnotationFormatterFactory}
	 */
	public void setFormatters(Set<?> formatters) {
		this.formatters = formatters;
	}

	
Configure the set of FormatterRegistrars to invoke to register Converters and Formatters in addition to those added declaratively via setConverters(Set<?>) and setFormatters(Set<?>). 
FormatterRegistrars are useful when registering multiple related
converters and formatters for a formatting category, such as Date
formatting. All types related needed to support the formatting
category can be registered from one place.
FormatterRegistrars can also be used to register Formatters
indexed under a specific field type different from its own <T>,
or when registering a Formatter from a Printer/Parser pair.
See Also:
FormatterRegistry.addFormatterForFieldType(Class<?>, Formatter<?>)
FormatterRegistry.addFormatterForFieldType(Class<?>, Printer<?>, Parser<?>)/**
	 * <p>Configure the set of FormatterRegistrars to invoke to register
	 * Converters and Formatters in addition to those added declaratively
	 * via {@link #setConverters(Set)} and {@link #setFormatters(Set)}.
	 * <p>FormatterRegistrars are useful when registering multiple related
	 * converters and formatters for a formatting category, such as Date
	 * formatting. All types related needed to support the formatting
	 * category can be registered from one place.
	 * <p>FormatterRegistrars can also be used to register Formatters
	 * indexed under a specific field type different from its own &lt;T&gt;,
	 * or when registering a Formatter from a Printer/Parser pair.
	 * @see FormatterRegistry#addFormatterForFieldType(Class, Formatter)
	 * @see FormatterRegistry#addFormatterForFieldType(Class, Printer, Parser)
	 */
	public void setFormatterRegistrars(Set<FormatterRegistrar> formatterRegistrars) {
		this.formatterRegistrars = formatterRegistrars;
	}

	
Indicate whether default formatters should be registered or not.
By default, built-in formatters are registered. This flag can be used
to turn that off and rely on explicitly registered formatters only.
See Also:
setFormatters(Set)
setFormatterRegistrars(Set<FormatterRegistrar>)/**
	 * Indicate whether default formatters should be registered or not.
	 * <p>By default, built-in formatters are registered. This flag can be used
	 * to turn that off and rely on explicitly registered formatters only.
	 * @see #setFormatters(Set)
	 * @see #setFormatterRegistrars(Set)
	 */
	public void setRegisterDefaultFormatters(boolean registerDefaultFormatters) {
		this.registerDefaultFormatters = registerDefaultFormatters;
	}

	@Override
	public void setEmbeddedValueResolver(StringValueResolver embeddedValueResolver) {
		this.embeddedValueResolver = embeddedValueResolver;
	}


	@Override
	public void afterPropertiesSet() {
		this.conversionService = new DefaultFormattingConversionService(this.embeddedValueResolver, this.registerDefaultFormatters);
		ConversionServiceFactory.registerConverters(this.converters, this.conversionService);
		registerFormatters(this.conversionService);
	}

	private void registerFormatters(FormattingConversionService conversionService) {
		if (this.formatters != null) {
			for (Object formatter : this.formatters) {
				if (formatter instanceof Formatter<?>) {
					conversionService.addFormatter((Formatter<?>) formatter);
				}
				else if (formatter instanceof AnnotationFormatterFactory<?>) {
					conversionService.addFormatterForFieldAnnotation((AnnotationFormatterFactory<?>) formatter);
				}
				else {
					throw new IllegalArgumentException(
							"Custom formatters must be implementations of Formatter or AnnotationFormatterFactory");
				}
			}
		}
		if (this.formatterRegistrars != null) {
			for (FormatterRegistrar registrar : this.formatterRegistrars) {
				registrar.registerFormatters(conversionService);
			}
		}
	}


	@Override
	@Nullable
	public FormattingConversionService getObject() {
		return this.conversionService;
	}

	@Override
	public Class<? extends FormattingConversionService> getObjectType() {
		return FormattingConversionService.class;
	}

	@Override
	public boolean isSingleton() {
		return true;
	}

}