/*
    * 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
    *
    * http://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.basepom.mojo.propertyhelper.fields;
  
  import static com.google.common.base.Preconditions.checkState;
  import static java.lang.String.format;
  
  import org.basepom.mojo.propertyhelper.Field;
  import org.basepom.mojo.propertyhelper.FieldContext;
  import org.basepom.mojo.propertyhelper.ValueProvider;
  import org.basepom.mojo.propertyhelper.definitions.MacroDefinition;
  import org.basepom.mojo.propertyhelper.macros.MacroType;
  
  import java.util.Optional;
  import java.util.StringJoiner;
  
  import com.google.common.annotations.VisibleForTesting;
  import org.apache.maven.plugin.MojoExecutionException;
  
  public final class MacroField extends Field<String, MacroDefinition> {
  
      private final ValueProvider valueProvider;
      private final FieldContext context;
  
      @VisibleForTesting
      public static MacroField forTesting(MacroDefinition dateDefinition, ValueProvider valueProvider, FieldContext fieldContext) {
          return new MacroField(dateDefinition, valueProvider, fieldContext);
      }
  
      public MacroField(final MacroDefinition macroDefinition, final ValueProvider valueProvider, final FieldContext context) {
          super(macroDefinition, context);
  
          this.valueProvider = valueProvider;
          this.context = context;
      }
  
      @Override
      public String getFieldName() {
          return fieldDefinition.getId();
      }
  
      @Override
      public String getValue() throws MojoExecutionException {
          final Optional<String> type = fieldDefinition.getMacroType();
          final MacroType macroType;
  
          try {
              if (type.isPresent()) {
                  macroType = context.getMacros().get(type.get());
                  checkState(macroType != null, "Could not locate macro '%s'", type.get());
              } else {
                  final Optional<String> macroClassName = fieldDefinition.getMacroClass();
                  checkState(macroClassName.isPresent(), "No definition for macro '%s' found!", fieldDefinition.getId());
                  final Class<? extends MacroType> macroClass = (Class<? extends MacroType>) Class.forName(macroClassName.get());
                  macroType = macroClass.getDeclaredConstructor().newInstance();
              }
  
              return formatResult(macroType.getValue(fieldDefinition, valueProvider, context).orElse(null));
  
          } catch (ReflectiveOperationException e) {
              throw new MojoExecutionException(format("Could not instantiate '%s'", fieldDefinition), e);
          }
      }
  
      @Override
      public String toString() {
          return new StringJoiner(", ", MacroField.class.getSimpleName() + "[", "]")
              .add("valueProvider=" + valueProvider)
              .add("context=" + context)
              .toString();
      }
  }