/*
 * Copyright 2017-2020 original 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 io.micronaut.core.value;

import edu.umd.cs.findbugs.annotations.NonNull;
import io.micronaut.core.convert.ArgumentConversionContext;
import io.micronaut.core.convert.ConversionService;
import io.micronaut.core.util.StringUtils;

import java.util.Collection;
import java.util.Collections;
import java.util.Map;
import java.util.Optional;
import java.util.stream.Collectors;

A PropertyResolver that resolves values from a backing map. 
Author:
Graeme Rocher
Since:
1.0/**
 * A {@link PropertyResolver} that resolves values from a backing map.
 *
 * @author Graeme Rocher
 * @since 1.0
 */
public class MapPropertyResolver implements PropertyResolver {
    private final Map<String, Object> map;
    private final ConversionService<?> conversionService;

    
Params:
map – The map to resolves the properties from/**
     * @param map The map to resolves the properties from
     */
    public MapPropertyResolver(Map<String, Object> map) {
        this.map = map;
        this.conversionService = ConversionService.SHARED;
    }

    
Params:
map –               The map to resolves the properties from
conversionService – The conversion service/**
     * @param map               The map to resolves the properties from
     * @param conversionService The conversion service
     */
    public MapPropertyResolver(Map<String, Object> map, ConversionService conversionService) {
        this.map = map;
        this.conversionService = conversionService;
    }

    @Override
    public boolean containsProperty(String name) {
        return map.containsKey(name);
    }

    @Override
    public boolean containsProperties(String name) {
        return map.keySet().stream().anyMatch(k -> k.startsWith(name));
    }

    @Override
    public <T> Optional<T> getProperty(String name, ArgumentConversionContext<T> conversionContext) {
        Object value = map.get(name);
        return conversionService.convert(value, conversionContext);
    }

    @NonNull
    @Override
    public Collection<String> getPropertyEntries(@NonNull String name) {
        if (StringUtils.isNotEmpty(name)) {
            String prefix = name + ".";
            return map.keySet().stream().filter(k -> k.startsWith(prefix))
                    .map(k -> {
                        String withoutPrefix = k.substring(prefix.length());
                        int i = withoutPrefix.indexOf('.');
                        if (i > -1) {
                            return withoutPrefix.substring(0, i);
                        }
                        return withoutPrefix;
                    })
                    // to list to retain order from linked hash map
                    .collect(Collectors.toList());
        }
        return Collections.emptySet();
    }
}