/*
 * Copyright 2010 Jon S Akhtar (Sylvanaar)
 *
 *   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.sylvanaar.idea.Lua.lang.formatter.processors;

import com.intellij.lang.ASTNode;
import com.intellij.psi.PsiElement;
import com.intellij.psi.PsiWhiteSpace;
import com.intellij.psi.formatter.FormatterUtil;
import com.intellij.psi.impl.source.tree.LeafElement;
import com.intellij.psi.impl.source.tree.LeafPsiElement;
import com.intellij.psi.tree.IElementType;
import com.intellij.psi.tree.TokenSet;
import com.sylvanaar.idea.Lua.lang.lexer.LuaTokenTypes;
import org.jetbrains.annotations.NotNull;


/**
 * @author ilyas
 */
public abstract class SpacingUtil {

  public static boolean isWhiteSpace(final ASTNode treePrev) {
    return treePrev != null && (treePrev.getPsi() instanceof PsiWhiteSpace || treePrev.getTextLength() == 0);
  }

  static boolean canStickChildrenTogether(final ASTNode child1, final ASTNode child2) {
    if (child1 == null || child2 == null || isWhiteSpace(child1) || isWhiteSpace(child2)) return true;
    return child1 instanceof LeafPsiElement || child2 instanceof LeafPsiElement;
  }

  static boolean shouldKeepSpace(@NotNull final PsiElement parent) {
    ASTNode node = parent.getNode();
    if (node == null) return true;
    final IElementType type = node.getElementType();

    return true;
  }

  static ASTNode getLeafNonSpaceBefore(final ASTNode element) {
    if (element == null) return null;
    ASTNode treePrev = element.getTreePrev();
    if (treePrev != null) {
      ASTNode candidate = getLastChildOf(treePrev);
      if (candidate != null && !isWhiteSpace(candidate) && candidate.getTextLength() > 0) {
        return candidate;
      } else {
        return getLeafNonSpaceBefore(candidate);
      }
    }
    final ASTNode treeParent = element.getTreeParent();

    if (treeParent == null || treeParent.getTreeParent() == null) {
      return null;
    } else {
      return getLeafNonSpaceBefore(treeParent);
    }
  }

  private static ASTNode getLastChildOf(ASTNode element) {
    if (element == null) {
      return null;
    }
    if (element instanceof LeafElement) {
      return element;
    } else {
      final ASTNode lastChild = element.getLastChildNode();
      if (lastChild == null) {
        return element;
      } else {
        return getLastChildOf(lastChild);
      }
    }
  }

  static ASTNode getPrevElementType(final ASTNode child) {
    return FormatterUtil.getLeafNonSpaceBefore(child);
  }

  static TokenSet COMMENT_BIT_SET = LuaTokenTypes.COMMENT_SET;
}