/*
 * Copyright 2012-2020 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.boot.context.config;

import java.util.Collections;
import java.util.List;

import org.apache.commons.logging.Log;

import org.springframework.boot.BootstrapContext;
import org.springframework.boot.BootstrapRegistry;
import org.springframework.boot.ConfigurableBootstrapContext;
import org.springframework.boot.context.properties.bind.Binder;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.core.env.Environment;
import org.springframework.core.io.ResourceLoader;

Strategy interface used to resolve locations into one or more resources. Implementations should be added as a spring.factories entries. The following constructor parameter types are supported: 

Log - if the resolver needs deferred logging
Binder - if the resolver needs to obtain values from the initial Environment
ResourceLoader - if the resolver needs a resource loader
ConfigurableBootstrapContext - A bootstrap context that can be used to store objects that may be expensive to create, or need to be shared (BootstrapContext or BootstrapRegistry may also be used).

 Resolvers may implement Ordered or use the @Order annotation. The first resolver that supports the given location will be used. 
Author:
Phillip Webb, Madhura Bhave
Type parameters:
<R> – the location type
Since:
2.4.0/**
 * Strategy interface used to resolve {@link ConfigDataLocation locations} into one or
 * more {@link ConfigDataResource resources}. Implementations should be added as a
 * {@code spring.factories} entries. The following constructor parameter types are
 * supported:
 * <ul>
 * <li>{@link Log} - if the resolver needs deferred logging</li>
 * <li>{@link Binder} - if the resolver needs to obtain values from the initial
 * {@link Environment}</li>
 * <li>{@link ResourceLoader} - if the resolver needs a resource loader</li>
 * <li>{@link ConfigurableBootstrapContext} - A bootstrap context that can be used to
 * store objects that may be expensive to create, or need to be shared
 * ({@link BootstrapContext} or {@link BootstrapRegistry} may also be used).</li>
 * </ul>
 * <p>
 * Resolvers may implement {@link Ordered} or use the {@link Order @Order} annotation. The
 * first resolver that supports the given location will be used.
 *
 * @param <R> the location type
 * @author Phillip Webb
 * @author Madhura Bhave
 * @since 2.4.0
 */
public interface ConfigDataLocationResolver<R extends ConfigDataResource> {

	
Returns if the specified location address can be resolved by this resolver.
Params:
context – the location resolver context
location – the location to check.
Returns:
if the location is supported by this resolver/**
	 * Returns if the specified location address can be resolved by this resolver.
	 * @param context the location resolver context
	 * @param location the location to check.
	 * @return if the location is supported by this resolver
	 */
	boolean isResolvable(ConfigDataLocationResolverContext context, ConfigDataLocation location);

	
Resolve a ConfigDataLocation into one or more ConfigDataResource instances. 
Params:
context – the location resolver context
location – the location that should be resolved
Throws:
ConfigDataLocationNotFoundException – on a non-optional location that cannot
be found
ConfigDataResourceNotFoundException – if a resolved resource cannot be found
Returns:
a list of resources in ascending priority order./**
	 * Resolve a {@link ConfigDataLocation} into one or more {@link ConfigDataResource}
	 * instances.
	 * @param context the location resolver context
	 * @param location the location that should be resolved
	 * @return a list of {@link ConfigDataResource resources} in ascending priority order.
	 * @throws ConfigDataLocationNotFoundException on a non-optional location that cannot
	 * be found
	 * @throws ConfigDataResourceNotFoundException if a resolved resource cannot be found
	 */
	List<R> resolve(ConfigDataLocationResolverContext context, ConfigDataLocation location)
			throws ConfigDataLocationNotFoundException, ConfigDataResourceNotFoundException;

	
Resolve a ConfigDataLocation into one or more ConfigDataResource instances based on available profiles. This method is called once profiles have been deduced from the contributed values. By default this method returns an empty list. 
Params:
context – the location resolver context
location – the location that should be resolved
profiles – profile information
Throws:
ConfigDataLocationNotFoundException – on a non-optional location that cannot
be found
Returns:
a list of resolved locations in ascending priority order./**
	 * Resolve a {@link ConfigDataLocation} into one or more {@link ConfigDataResource}
	 * instances based on available profiles. This method is called once profiles have
	 * been deduced from the contributed values. By default this method returns an empty
	 * list.
	 * @param context the location resolver context
	 * @param location the location that should be resolved
	 * @param profiles profile information
	 * @return a list of resolved locations in ascending priority order.
	 * @throws ConfigDataLocationNotFoundException on a non-optional location that cannot
	 * be found
	 */
	default List<R> resolveProfileSpecific(ConfigDataLocationResolverContext context, ConfigDataLocation location,
			Profiles profiles) throws ConfigDataLocationNotFoundException {
		return Collections.emptyList();
	}

}