/*
    * Copyright 2020-2022 Foreseeti AB <https://foreseeti.com>
    *
    * 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.mal_lang.langspec.builders.step;
  
  import java.util.List;
  import java.util.Map;
  import org.mal_lang.langspec.Asset;
  import org.mal_lang.langspec.builders.AssetBuilder;
  import org.mal_lang.langspec.builders.VariableBuilder;
  
  /**
   * A builder for creating {@link org.mal_lang.langspec.step.StepVariable} objects.
   *
   * @since 1.0.0
   */
  public final class StepVariableBuilder extends StepReferenceBuilder {
    /**
     * Constructs a new {@code StepVariableBuilder} object.
     *
     * @param name the name of the variable
     * @throws java.lang.NullPointerException if {@code name} is {@code null}
     * @throws java.lang.IllegalArgumentException if {@code name} is not a valid identifier
     * @since 1.0.0
     */
    public StepVariableBuilder(String name) {
      super(name);
    }
  
    private static AssetBuilder getAssetBuilder(String assetName, List<AssetBuilder> assetBuilders) {
      for (var assetBuilder : assetBuilders) {
        if (assetBuilder.getName().equals(assetName)) {
          return assetBuilder;
        }
      }
      throw new IllegalStateException();
    }
  
    private static VariableBuilder getVariableBuilder(
        String assetName, String variableName, List<AssetBuilder> assetBuilders) {
      var assetBuilder = StepVariableBuilder.getAssetBuilder(assetName, assetBuilders);
      for (var variableBuilder : assetBuilder.getVariables()) {
        if (variableBuilder.getName().equals(variableName)) {
          return variableBuilder;
        }
      }
      var superAsset = assetBuilder.getSuperAsset();
      if (superAsset != null) {
        return StepVariableBuilder.getVariableBuilder(superAsset, variableName, assetBuilders);
      }
      throw new IllegalStateException();
    }
  
    @Override
    public Asset getTarget(
        Asset sourceAsset, Map<String, Asset> assets, List<AssetBuilder> assetBuilders) {
      if (!sourceAsset.hasVariable(this.getName())) {
        throw new IllegalArgumentException(
            String.format("Variable %s.%s not found", sourceAsset.getName(), this.getName()));
      }
      return StepVariableBuilder.getVariableBuilder(
              sourceAsset.getName(), this.getName(), assetBuilders)
          .getStepExpression()
          .getTarget(sourceAsset, assets, assetBuilders);
    }
  }