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/*
 * Copyright © 2017-2019 Cask Data, Inc.
 *
 * 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 io.cdap.wrangler.parser;

import io.cdap.wrangler.api.CompileException;
import io.cdap.wrangler.api.CompileStatus;
import io.cdap.wrangler.api.Compiler;
import io.cdap.wrangler.api.RecipeSymbol;
import org.antlr.v4.runtime.CharStream;
import org.antlr.v4.runtime.CharStreams;
import org.antlr.v4.runtime.CommonTokenStream;
import org.antlr.v4.runtime.tree.ParseTree;
import org.antlr.v4.tool.GrammarParserInterpreter;
import org.apache.twill.filesystem.Location;

import java.io.IOException;
import java.nio.file.Path;

/**
 * Class description here.
 */
public final class RecipeCompiler implements Compiler {
  public RecipeCompiler() {
  }

  @Override
  public CompileStatus compile(String recipe) throws CompileException {
    return compile(CharStreams.fromString(recipe));
  }

  @Override
  public CompileStatus compile(Location location) throws CompileException {
    try {
      return compile(CharStreams.fromStream(location.getInputStream()));
    } catch (IOException e) {
      throw new CompileException(e.getMessage(), e);
    } catch (Exception e) {
      throw new CompileException(e.getMessage(), e);
    }
  }

  @Override
  public CompileStatus compile(Path path) throws CompileException {
    try {
      return compile(CharStreams.fromPath(path));
    } catch (IOException e) {
      throw new CompileException(e.getMessage(), e);
    } catch (Exception e) {
      throw new CompileException(e.getMessage(), e);
    }
  }

  private CompileStatus compile(CharStream stream) throws CompileException {
    try {
      SyntaxErrorListener errorListener = new SyntaxErrorListener();
      DirectivesLexer lexer = new DirectivesLexer(stream);
      lexer.removeErrorListeners();
      lexer.addErrorListener(errorListener);

      DirectivesParser parser = new DirectivesParser(new CommonTokenStream(lexer));
      parser.removeErrorListeners();
      parser.addErrorListener(errorListener);
      parser.setErrorHandler(new GrammarParserInterpreter.BailButConsumeErrorStrategy());
      parser.setBuildParseTree(true);
      ParseTree tree = parser.statements();

      if (errorListener.hasErrors()) {
        return new CompileStatus(true, errorListener.iterator());
      }

      RecipeVisitor visitor = new RecipeVisitor();
      visitor.visit(tree);
      RecipeSymbol symbol = visitor.getCompiledUnit();
      return new CompileStatus(symbol);
    } catch (StringIndexOutOfBoundsException e) {
      throw new CompileException("Issue in compiling directives");
    }
  }
}