/*
 * Copyright 2013 The 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
 *
 * 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 com.intellij.struts2.velocity;

import com.intellij.openapi.module.Module;
import com.intellij.openapi.module.ModuleUtilCore;
import com.intellij.psi.PsiFile;
import com.intellij.psi.search.FilenameIndex;
import com.intellij.psi.search.GlobalSearchScope;
import com.intellij.velocity.VtlGlobalMacroProvider;
import com.intellij.velocity.psi.VtlMacro;
import com.intellij.velocity.psi.files.VtlFile;
import org.jetbrains.annotations.NonNls;
import org.jetbrains.annotations.NotNull;

import java.util.Collection;
import java.util.Collections;

/**
 * Expose macros defined in {@code struts.vm}.
 *
 * @author Yann Cébron
 */
public class Struts2GlobalMacroProvider extends VtlGlobalMacroProvider {

  @NonNls
  private static final String STRUTS_MACROS_FILENAME = "struts.vm";

  @NotNull
  @Override
  public Collection<VtlMacro> getGlobalMacros(@NotNull final VtlFile vtlFile) {
    final Module module = ModuleUtilCore.findModuleForPsiElement(vtlFile);
    if (module == null) {
      return Collections.emptySet();
    }

    final PsiFile[] filesByName = FilenameIndex.getFilesByName(vtlFile.getProject(),
                                                               STRUTS_MACROS_FILENAME,
                                                               GlobalSearchScope.moduleRuntimeScope(module, false));
    if (filesByName.length == 1) {
      final PsiFile psiFile = filesByName[0];
      if (psiFile instanceof VtlFile) {
        return ((VtlFile) psiFile).getDefinedMacros();
      }
    }

    return Collections.emptySet();
  }

}