001/*
002 * SPDX-License-Identifier: Apache-2.0
003 *
004 * Copyright 2025-2026 The Enola <https://enola.dev> Authors
005 *
006 * Licensed under the Apache License, Version 2.0 (the "License");
007 * you may not use this file except in compliance with the License.
008 * You may obtain a copy of the License at
009 *
010 *     https://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package dev.enola.common.template;
019
020import com.google.common.collect.ImmutableList;
021
022import dev.enola.common.io.resource.ReadableResource;
023
024import java.io.IOException;
025import java.util.Optional;
026
027/** Chain ⛓️ of {@link TemplateProvider}s. */
028public class TemplateProviderChain implements TemplateProvider {
029
030    private final Iterable<TemplateProvider> providers;
031
032    public TemplateProviderChain(Iterable<TemplateProvider> providers) {
033        this.providers = ImmutableList.copyOf(providers);
034    }
035
036    public TemplateProviderChain(TemplateProvider... providers) {
037        this.providers = ImmutableList.copyOf(providers);
038    }
039
040    @Override
041    public Optional<Template> optional(ReadableResource source) throws IOException {
042        for (var provider : providers) {
043            Optional<Template> optional = provider.optional(source);
044            if (optional.isPresent()) {
045                return optional;
046            }
047        }
048        return Optional.empty();
049    }
050}