// Copyright 2014 The Bazel Authors. All rights reserved.
//
// 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.google.devtools.build.lib.util;

import com.google.common.collect.ImmutableList;
import com.google.devtools.build.lib.vfs.PathFragment;
import com.google.devtools.common.options.Converter;
import com.google.devtools.common.options.Converters;
import com.google.devtools.common.options.OptionsParser.UnparsedOptionValueDescription;
import com.google.devtools.common.options.OptionsParsingException;
import com.google.devtools.common.options.OptionsProvider;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * Blaze-specific option utilities.
 */
public final class OptionsUtils {

  /**
   * Returns a string representation of the non-hidden specified options; option values are
   * shell-escaped.
   */
  public static String asShellEscapedString(Iterable<UnparsedOptionValueDescription> optionsList) {
    StringBuilder result = new StringBuilder();
    for (UnparsedOptionValueDescription option : optionsList) {
      if (option.isHidden()) {
        continue;
      }
      if (result.length() != 0) {
        result.append(' ');
      }
      String value = option.getUnparsedValue();
      if (option.isBooleanOption()) {
        boolean isEnabled = false;
        try {
          isEnabled = new Converters.BooleanConverter().convert(value);
        } catch (OptionsParsingException e) {
          throw new RuntimeException("Unexpected parsing exception", e);
        }
        result.append(isEnabled ? "--" : "--no").append(option.getName());
      } else {
        result.append("--").append(option.getName());
        if (value != null) { // Can be null for Void options.
          result.append("=").append(ShellEscaper.escapeString(value));
        }
      }
    }
    return result.toString();
  }

  /**
   * Returns a string representation of the non-hidden explicitly or implicitly
   * specified options; option values are shell-escaped.
   */
  public static String asShellEscapedString(OptionsProvider options) {
    return asShellEscapedString(options.asListOfUnparsedOptions());
  }

  /**
   * Return a representation of the non-hidden specified options, as a list of string. No escaping
   * is done.
   */
  public static List<String> asArgumentList(Iterable<UnparsedOptionValueDescription> optionsList) {
    ImmutableList.Builder<String> builder = ImmutableList.builder();
    for (UnparsedOptionValueDescription option : optionsList) {
      if (option.isHidden()) {
        continue;
      }
      String value = option.getUnparsedValue();
      if (option.isBooleanOption()) {
        boolean isEnabled = false;
        try {
          isEnabled = new Converters.BooleanConverter().convert(value);
        } catch (OptionsParsingException e) {
          throw new RuntimeException("Unexpected parsing exception", e);
        }
        builder.add((isEnabled ? "--" : "--no") + option.getName());
      } else {
        String optionString = "--" + option.getName();
        if (value != null) { // Can be null for Void options.
          optionString += "=" + value;
        }
        builder.add(optionString);
      }
    }
    return builder.build();
  }

  /**
   * Return a representation of the non-hidden specified options, as a list of string. No escaping
   * is done.
   */
  public static List<String> asArgumentList(OptionsProvider options) {
    return asArgumentList(options.asListOfUnparsedOptions());
  }

  /**
   * Returns a string representation of the non-hidden explicitly or implicitly
   * specified options, filtering out any sensitive options; option values are
   * shell-escaped.
   */
  public static String asFilteredShellEscapedString(OptionsProvider options,
      Iterable<UnparsedOptionValueDescription> optionsList) {
    return asShellEscapedString(optionsList);
  }

  /**
   * Returns a string representation of the non-hidden explicitly or implicitly
   * specified options, filtering out any sensitive options; option values are
   * shell-escaped.
   */
  public static String asFilteredShellEscapedString(OptionsProvider options) {
    return asFilteredShellEscapedString(options, options.asListOfUnparsedOptions());
  }

  /**
   * Converter from String to PathFragment.
   */
  public static class PathFragmentConverter
      implements Converter<PathFragment> {

    @Override
    public PathFragment convert(String input) {
      return PathFragment.create(input);
    }

    @Override
    public String getTypeDescription() {
      return "a path";
    }
  }

  /**
   * Converts from a colon-separated list of strings into a list of PathFragment instances.
   */
  public static class PathFragmentListConverter
      implements Converter<List<PathFragment>> {

    @Override
    public List<PathFragment> convert(String input) {
      List<PathFragment> list = new ArrayList<>();
      for (String piece : input.split(":")) {
        if (!piece.isEmpty()) {
          list.add(PathFragment.create(piece));
        }
      }
      return Collections.unmodifiableList(list);
    }

    @Override
    public String getTypeDescription() {
      return "a colon-separated list of paths";
    }
  }
}