/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements. See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You 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.apache.commons.text.lookup;
  
  import java.util.HashMap;
  import java.util.Map;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.function.BiFunction;
  
  import org.apache.commons.lang3.StringUtils;
  import org.junit.jupiter.api.Assertions;
  import org.junit.jupiter.api.Test;
  
  /**
   * Tests {@link FunctionStringLookup}.
   */
  class BiFunctionStringLookupTest {
  
      private static final String SEPARATOR = ".";
  
      @SuppressWarnings("unchecked")
      private final BiFunction<String, Map<String, Object>, Object> nestedMapBiFunction = (k, m) -> {
          final String keyCandidate = StringUtils.substringBefore(k, SEPARATOR);
          if (keyCandidate.isEmpty()) {
              return m.get(k);
          }
          final Object value = m.get(keyCandidate);
          if (value instanceof Map) {
              return this.nestedMapBiFunction.apply(StringUtils.substringAfter(k, SEPARATOR),
                  (Map<String, Object>) value);
          }
          return value;
      };
  
      @Test
      void testBiFunctionForNestedMap() {
          // Build map
          final String subSubKey = "subsubkeyMap";
          final String subSubValue = "subsubvalue";
          final Map<String, String> subSubMap = new HashMap<>();
          subSubMap.put(subSubKey, subSubValue);
          //
          final String subKey = "subkey";
          final String subKeyMap = "subkeyMap";
          final String subValue = "subvalue";
          final Map<String, Object> rootSubMap = new HashMap<>();
          rootSubMap.put(subKey, subValue);
          rootSubMap.put(subKeyMap, subSubMap);
          //
          final String rootKey = "keyMap";
          final String rootKey2 = "key2";
          final String rootValue2 = "value2";
          final Map<String, Object> rootMap = new HashMap<>();
          rootMap.put(rootKey, rootSubMap);
          rootMap.put(rootKey2, rootValue2);
          // Use map
          final BiStringLookup<Map<String, Object>> stringLookup = StringLookupFactory.INSTANCE
              .biFunctionStringLookup(nestedMapBiFunction);
          Assertions.assertEquals(rootValue2, stringLookup.lookup(rootKey2, rootMap));
          Assertions.assertEquals(subValue, stringLookup.lookup(rootKey + SEPARATOR + subKey, rootMap));
          Assertions.assertEquals(subSubValue,
              stringLookup.lookup(rootKey + SEPARATOR + subKeyMap + SEPARATOR + subSubKey, rootMap));
      }
  
      @Test
      void testConcurrentHashMapNull() {
          Assertions.assertNull(BiFunctionStringLookup.on(new ConcurrentHashMap<>()).apply(null));
      }
  
      @Test
      void testHashMapNull() {
          Assertions.assertNull(BiFunctionStringLookup.on(new HashMap<>()).apply(null));
      }
  
      @Test
      void testNullBiFunction() {
          Assertions.assertNull(BiFunctionStringLookup.on((BiFunction<String, Object, Object>) null).apply(null));
      }
  
      @Test
      void testOne() {
          final String key = "key";
          final String value = "value";
          final Map<String, String> map = new HashMap<>();
         map.put(key, value);
         Assertions.assertEquals(value, FunctionStringLookup.on(map).apply(key));
     }
 
     @Test
     void testToString() {
         // does not blow up and gives some kind of string.
         Assertions.assertFalse(BiFunctionStringLookup.on(new HashMap<>()).toString().isEmpty());
     }
 
 }