// Copyright 2015 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.rules.apple;

import static com.google.devtools.build.lib.packages.Attribute.attr;
import static com.google.devtools.build.lib.packages.BuildType.LABEL;
import static com.google.devtools.build.lib.packages.BuildType.LABEL_LIST;

import com.google.devtools.build.lib.analysis.BaseRuleClasses;
import com.google.devtools.build.lib.analysis.RuleDefinition;
import com.google.devtools.build.lib.analysis.RuleDefinitionEnvironment;
import com.google.devtools.build.lib.packages.RuleClass;

/**
 * Rule definition for {@code xcode_config} rule.
 */
public class XcodeConfigRule implements RuleDefinition {

  public static final String XCODE_CONFIG_ATTR_NAME = ":xcode_config";
  static final String DEFAULT_ATTR_NAME = "default";
  static final String VERSIONS_ATTR_NAME = "versions";

  @Override
  public RuleClass build(RuleClass.Builder builder, RuleDefinitionEnvironment env) {
    return builder
        .requiresConfigurationFragments(AppleConfiguration.class)
        .exemptFromConstraintChecking(
            "this rule refines configuration variables and does not build actual content")
        /* <!-- #BLAZE_RULE(xcode_config).ATTRIBUTE(version) -->
        The default official version of xcode to use.
        The version specified by the provided <code>xcode_version</code> target is to be used if
        no <code>xcode_version</code> build flag is specified. This is required if any
        <code>versions</code> are set.
        <!-- #END_BLAZE_RULE.ATTRIBUTE --> */
        .add(attr(DEFAULT_ATTR_NAME, LABEL)
            .allowedRuleClasses("xcode_version")
            .allowedFileTypes()
            .nonconfigurable("this rule determines configuration"))
        /* <!-- #BLAZE_RULE(xcode_config).ATTRIBUTE(version) -->
        Accepted <code>xcode_version<code> targets that may be used.
        If the value of the <code>xcode_version</code> build flag matches one of the aliases
        or version number of any of the given <code>xcode_version</code> targets, the matching
        target will be used.
        <!-- #END_BLAZE_RULE.ATTRIBUTE --> */
        .add(attr(VERSIONS_ATTR_NAME, LABEL_LIST)
            .allowedRuleClasses("xcode_version")
            .allowedFileTypes()
            .nonconfigurable("this rule determines configuration"))
        .build();
  }

  @Override
  public Metadata getMetadata() {
    return RuleDefinition.Metadata.builder()
        .name("xcode_config")
        .ancestors(BaseRuleClasses.BaseRule.class)
        .factoryClass(XcodeConfig.class)
        .build();
  }
}

/*<!-- #BLAZE_RULE (NAME = xcode_config, TYPE = OTHER, FAMILY = Workspace)[GENERIC_RULE] -->

<p>A single target of this rule can be referenced by the <code>--xcode_version_config</code> build
flag to translate the <code>--xcode_version</code> flag into an accepted official xcode version.
This allows selection of a an official xcode version from a number of registered aliases.</p>

<!-- #END_BLAZE_RULE -->*/