// Copyright 2014 Google Inc. 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.pkgcache;

import com.google.devtools.build.lib.cmdline.ResolvedTargets;
import com.google.devtools.build.lib.cmdline.TargetParsingException;
import com.google.devtools.build.lib.packages.Package;
import com.google.devtools.build.lib.packages.Target;
import com.google.devtools.build.lib.syntax.Label;
import com.google.devtools.build.lib.util.StringUtilities;

/**
 * Common utility methods for target pattern resolution.
 */
public final class TargetPatternResolverUtil {
  private TargetPatternResolverUtil() {
    // Utility class.
  }

  // Parse 'label' as a Label, mapping Label.SyntaxException into
  // TargetParsingException.
  public static Label label(String label) throws TargetParsingException {
    try {
      return Label.parseAbsolute(label);
    } catch (Label.SyntaxException e) {
      throw invalidTarget(label, e.getMessage());
    }
  }

  /**
   * Returns a new exception indicating that a command-line target is invalid.
   */
  private static TargetParsingException invalidTarget(String packageName,
                                                      String additionalMessage) {
    return new TargetParsingException("invalid target format: '" +
        StringUtilities.sanitizeControlChars(packageName) + "'; " +
        StringUtilities.sanitizeControlChars(additionalMessage));
  }

  public static String getParsingErrorMessage(String message, String originalPattern) {
    if (originalPattern == null) {
      return message;
    } else {
      return String.format("while parsing '%s': %s", originalPattern, message);
    }
  }

  public static ResolvedTargets<Target> resolvePackageTargets(Package pkg,
                                                              FilteringPolicy policy) {
    ResolvedTargets.Builder<Target> builder = ResolvedTargets.builder();
    for (Target target : pkg.getTargets()) {
      if (policy.shouldRetain(target, false)) {
        builder.add(target);
      }
    }
    return builder.build();
  }
}