/*

  * #%L

  * JavaHg

  * %%

  * Copyright (C) 2011 aragost Trifork ag

  * %%

  * Permission is hereby granted, free of charge, to any person obtaining a copy

  * of this software and associated documentation files (the "Software"), to deal

  * in the Software without restriction, including without limitation the rights

  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

  * copies of the Software, and to permit persons to whom the Software is

  * furnished to do so, subject to the following conditions:

  * 

  * The above copyright notice and this permission notice shall be included in

  * all copies or substantial portions of the Software.

  * 

  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

  * THE SOFTWARE.

  * #L%

  */

 package com.aragost.javahg.internals;

 import java.io.BufferedReader;

 import java.io.IOException;

 import java.io.InputStream;

 import java.io.StringReader;

 import java.util.regex.Matcher;

 import java.util.regex.Pattern;

 import com.aragost.javahg.commands.ManifestMergeOracle;

 import com.aragost.javahg.commands.UpdateResult;

 import com.google.common.io.ByteStreams;

 /**

  * A helper class to parse output from update and merge commands.

  */

 public class UpdateMergeHelper {

     private static final Pattern MANIFEST_MERGE_PATTERN = Pattern.compile("remote changed (.*) which local deleted\n"

             + "use \\(c\\)hanged version or leave \\(d\\)eleted\\? ");

     private InputStream stdout;

     private ManifestMergeOracle oracle;

     private AbstractCommand command;

     public UpdateMergeHelper(InputStream stdout, ManifestMergeOracle oracle, AbstractCommand command) {

         this.stdout = stdout;

         this.oracle = oracle;

         this.command = command;

     }

     public void merge() throws IOException {

         processManifestMergeConflictPrompting();

     }

     public UpdateResult update() throws IOException {

         String output = processManifestMergeConflictPrompting();

         BufferedReader reader = new BufferedReader(new StringReader(output));

         String line;

         UpdateResult result = null;

         while ((line = reader.readLine()) != null) {

             if (line.startsWith("merging ")) {

                 // Just ignore

             } else if (line.equals("use 'hg resolve' to retry unresolved file merges")) {

                 // Ignore

             } else {

                 result = UpdateResult.fromLine(line);

             }

         }

         if (result == null) {

             throw new IllegalStateException("No 'update' line found in output");

         }

         return result;

     }

     private String processManifestMergeConflictPrompting() throws IOException {

         if (this.oracle != null) {

             this.oracle.getMissingAnswers().clear();

         }

         String output = null;

         while (true) {

             output = new String(ByteStreams.toByteArray(this.stdout));

             Matcher matcher = MANIFEST_MERGE_PATTERN.matcher(output);

             if (matcher.matches()) {

                 if (oracle == null) {

                     throw new RuntimeException("Manifest merge conflict, but no oracle");

                 }

                 String filename = output.substring(matcher.start(1), matcher.end(1));

                 String answer = oracle.ask(filename);

                 this.command.sendLine(answer);

                 this.command.reopenOutputChannelStream();

             } else {

                 break;

             }

         }

         return output;

     }

 }