/**
    *
    * Copyright (C) 2011 Cloud Conscious, LLC. <info@cloudconscious.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.jclouds.scriptbuilder.domain;
  
  import static com.google.common.base.Preconditions.checkNotNull;
  import static com.google.common.base.Preconditions.checkState;
  import static org.jclouds.scriptbuilder.domain.Statements.interpret;
  
  import java.util.Collections;
  import java.util.List;
  import java.util.Map;
  import java.util.Map.Entry;
  import java.util.regex.Pattern;
  
  import com.google.common.collect.ImmutableList;
  import com.google.common.collect.Iterables;
  import com.google.common.collect.Lists;
  import com.google.common.collect.Maps;
  
  /**
   * Creates a run script
   * 
   * @author Adrian Cole
   */
  public class AppendFile implements Statement {
     public static final String MARKER = "END_OF_FILE";
  
     final String path;
     final Iterable<String> lines;
     final String marker;
  
     public AppendFile(String path, Iterable<String> lines) {
        this(path, lines, MARKER);
     }
  
     public AppendFile(String path, Iterable<String> lines, String marker) {
        this.path = checkNotNull(path, "path");
        this.lines = checkNotNull(lines, "lines");
        this.marker = checkNotNull(marker, "marker");
        checkState(Iterables.size(lines) > 0, "you must pass something to execute");
     }
  
     public static String escapeVarTokens(String toEscape, OsFamily family) {
        Map<String, String> inputToEscape = Maps.newHashMap();
        for (ShellToken token : ImmutableList.of(ShellToken.VARL, ShellToken.VARR)) {
           if (!token.to(family).equals("")) {
              String tokenS = "{" + token.toString().toLowerCase() + "}";
              inputToEscape.put(tokenS, "{escvar}" + tokenS);
           }
        }
        for (Entry<String, String> entry : inputToEscape.entrySet()) {
           toEscape = toEscape.replace(entry.getKey(), entry.getValue());
        }
        return toEscape;
     }
  
     @Override
     public Iterable<String> functionDependencies(OsFamily family) {
        return Collections.emptyList();
     }
  
     @Override
     public String render(OsFamily family) {
        List<Statement> statements = Lists.newArrayList();
        if (family == OsFamily.UNIX) {
           StringBuilder builder = new StringBuilder();
           hereFile(path, builder);
           statements.add(interpret(builder.toString()));
        } else {
           for (String line : lines) {
              statements.add(appendToFile(line, path, family));
           }
        }
        return new StatementList(statements).render(family);
     }
  
     private void hereFile(String path, StringBuilder builder) {
        builder.append("cat >> ").append(path).append(" <<'").append(marker).append("'\n");
        for (String line : lines) {
           builder.append(line).append("\n");
        }
        builder.append(marker).append("\n");
     }
 
    private Statement appendToFile(String line, String path, OsFamily family) {
       String quote = "";
       if (!ShellToken.VQ.to(family).equals("")) {
          quote = "'";
       } else {
          line = escapeVarTokens(line, family);
       }
       return interpret(addSpaceToEnsureWeDontAccidentallyRedirectFd(String.format("echo %s%s%s>>%s{lf}", quote, line,
                quote, path)));
    }
 
    public static final Pattern REDIRECT_FD_PATTERN = Pattern.compile(".*[0-2]>>.*");
 
    static String addSpaceToEnsureWeDontAccidentallyRedirectFd(String line) {
       return REDIRECT_FD_PATTERN.matcher(line).matches() ? line.replace(">>", " >>") : line;
    }
 
 }