| // 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.docgen; | 
 |  | 
 | import com.google.common.collect.ImmutableMap; | 
 | import com.google.common.collect.ImmutableSet; | 
 | import java.util.HashMap; | 
 | import java.util.Locale; | 
 | import java.util.Map; | 
 | import java.util.regex.Matcher; | 
 |  | 
 | /** | 
 |  * Helper class used for expanding link references in rule and attribute documentation. | 
 |  * | 
 |  * <p>See {@link com.google.devtools.build.docgen.DocgenConsts.BLAZE_RULE_LINK} for the regex used | 
 |  * to match link references. | 
 |  */ | 
 | public class RuleLinkExpander { | 
 |   private static final String EXAMPLES_SUFFIX = "_examples"; | 
 |   private static final String ARGS_SUFFIX = "_args"; | 
 |   private static final String IMPLICIT_OUTPUTS_SUFFIX = "_implicit_outputs"; | 
 |   private static final String FUNCTIONS_PAGE = "functions"; | 
 |  | 
 |   private static final ImmutableSet<String> STATIC_PAGES = | 
 |       ImmutableSet.<String>of("common-definitions", "make-variables"); | 
 |   private static final ImmutableMap<String, String> FUNCTIONS = | 
 |       ImmutableMap.<String, String>builder() | 
 |           .put("load", FUNCTIONS_PAGE) | 
 |           .put("package", FUNCTIONS_PAGE) | 
 |           .put("package_group", FUNCTIONS_PAGE) | 
 |           .put("description", FUNCTIONS_PAGE) | 
 |           .put("distribs", FUNCTIONS_PAGE) | 
 |           .put("licenses", FUNCTIONS_PAGE) | 
 |           .put("exports_files", FUNCTIONS_PAGE) | 
 |           .put("glob", FUNCTIONS_PAGE) | 
 |           .put("select", FUNCTIONS_PAGE) | 
 |           .build(); | 
 |  | 
 |   private final String productName; | 
 |   private final Map<String, String> ruleIndex = new HashMap<>(); | 
 |   private final boolean singlePage; | 
 |  | 
 |   RuleLinkExpander(String productName, Map<String, String> ruleIndex, boolean singlePage) { | 
 |     this.productName = productName; | 
 |     this.ruleIndex.putAll(ruleIndex); | 
 |     this.ruleIndex.putAll(FUNCTIONS); | 
 |     this.singlePage = singlePage; | 
 |   } | 
 |  | 
 |   RuleLinkExpander(String productName, boolean singlePage) { | 
 |     this.productName = productName; | 
 |     this.ruleIndex.putAll(FUNCTIONS); | 
 |     this.singlePage = singlePage; | 
 |   } | 
 |  | 
 |   public void addIndex(Map<String, String> ruleIndex) { | 
 |     this.ruleIndex.putAll(ruleIndex); | 
 |   } | 
 |  | 
 |   private void appendRuleLink(Matcher matcher, StringBuffer sb, String ruleName, String ref) { | 
 |     String ruleFamily = ruleIndex.get(ruleName); | 
 |     String link = singlePage | 
 |         ?  "#" + ref | 
 |         : ruleFamily + ".html#" + ref; | 
 |     matcher.appendReplacement(sb, Matcher.quoteReplacement(link)); | 
 |   } | 
 |  | 
 |   /* | 
 |    * Match and replace all ${link rule.attribute} references. | 
 |    */ | 
 |   private String expandRuleLinks(String htmlDoc) throws IllegalArgumentException { | 
 |     Matcher matcher = DocgenConsts.BLAZE_RULE_LINK.matcher(htmlDoc); | 
 |     StringBuffer sb = new StringBuffer(htmlDoc.length()); | 
 |     while (matcher.find()) { | 
 |       // The first capture group matches the entire reference, e.g. "cc_binary.deps". | 
 |       String ref = matcher.group(1); | 
 |       // The second capture group only matches the rule name, e.g. "cc_binary" in "cc_binary.deps". | 
 |       String name = matcher.group(2); | 
 |  | 
 |       // The name in the reference is the name of a rule. Get the rule family for the rule and | 
 |       // replace the reference with a link with the form of rule-family.html#rule.attribute. For | 
 |       // example, ${link cc_library.deps} expands to c-cpp.html#cc_library.deps. | 
 |       if (ruleIndex.containsKey(name)) { | 
 |         appendRuleLink(matcher, sb, name, ref); | 
 |         continue; | 
 |       } | 
 |  | 
 |       // The name is referencing the examples, arguments, or implicit outputs of a rule (e.g. | 
 |       // "cc_library_args", "cc_library_examples", or "java_binary_implicit_outputs"). Strip the | 
 |       // suffix and then try matching the name to a rule family. | 
 |       if (name.endsWith(EXAMPLES_SUFFIX) | 
 |           || name.endsWith(ARGS_SUFFIX) | 
 |           || name.endsWith(IMPLICIT_OUTPUTS_SUFFIX)) { | 
 |         int endIndex; | 
 |         if (name.endsWith(EXAMPLES_SUFFIX)) { | 
 |           endIndex = name.indexOf(EXAMPLES_SUFFIX); | 
 |         } else if (name.endsWith(ARGS_SUFFIX)) { | 
 |           endIndex = name.indexOf(ARGS_SUFFIX); | 
 |         } else { | 
 |           endIndex = name.indexOf(IMPLICIT_OUTPUTS_SUFFIX); | 
 |         } | 
 |         String ruleName = name.substring(0, endIndex); | 
 |         if (ruleIndex.containsKey(ruleName)) { | 
 |           appendRuleLink(matcher, sb, ruleName, ref); | 
 |           continue; | 
 |         } | 
 |       } | 
 |  | 
 |       // The name is not the name of a rule but is the name of a static page, such as | 
 |       // common-definitions. Generate a link to that page. | 
 |       if (STATIC_PAGES.contains(name)) { | 
 |         String link = singlePage | 
 |             ? "#" + name | 
 |             : name + ".html"; | 
 |         // For referencing headings on a static page, use the following syntax: | 
 |         // ${link static_page_name#heading_name}, example: ${link make-variables#gendir} | 
 |         String pageHeading = matcher.group(4); | 
 |         if (pageHeading != null) { | 
 |           throw new IllegalArgumentException( | 
 |               "Invalid link syntax for BE page: " + matcher.group() | 
 |               + "\nUse ${link static-page#heading} syntax instead."); | 
 |         } | 
 |         matcher.appendReplacement(sb, Matcher.quoteReplacement(link)); | 
 |         continue; | 
 |       } | 
 |  | 
 |       // If the reference does not match any rule or static page, throw an exception. | 
 |       throw new IllegalArgumentException( | 
 |           "Rule family " + name + " in link tag does not match any rule or BE page: " | 
 |           + matcher.group()); | 
 |     } | 
 |     matcher.appendTail(sb); | 
 |     return sb.toString(); | 
 |   } | 
 |  | 
 |   /* | 
 |    * Match and replace all ${link rule#heading} references. | 
 |    */ | 
 |   private String expandRuleHeadingLinks(String htmlDoc) throws IllegalArgumentException { | 
 |     Matcher matcher = DocgenConsts.BLAZE_RULE_HEADING_LINK.matcher(htmlDoc); | 
 |     StringBuffer sb = new StringBuffer(htmlDoc.length()); | 
 |     while (matcher.find()) { | 
 |       // The second capture group only matches the rule name, e.g. "cc_library" in | 
 |       // "cc_library#some_heading" | 
 |       String name = matcher.group(2); | 
 |       // The third capture group only matches the heading, e.g. "some_heading" in | 
 |       // "cc_library#some_heading" | 
 |       String heading = matcher.group(3); | 
 |  | 
 |       // The name in the reference is the name of a rule. Get the rule family for the rule and | 
 |       // replace the reference with the link in the form of rule-family.html#heading. Examples of | 
 |       // this include custom <a name="heading"> tags in the description or examples for the rule. | 
 |       if (ruleIndex.containsKey(name)) { | 
 |         String ruleFamily = ruleIndex.get(name); | 
 |         String link = singlePage | 
 |             ? "#" + heading | 
 |             : ruleFamily + ".html#" + heading; | 
 |         matcher.appendReplacement(sb, Matcher.quoteReplacement(link)); | 
 |         continue; | 
 |       } | 
 |  | 
 |       // The name is of a static page, such as common.definitions. Generate a link to that page, and | 
 |       // append the page heading. For example, ${link common-definitions#label-expansion} expands to | 
 |       // common-definitions.html#label-expansion. | 
 |       if (STATIC_PAGES.contains(name)) { | 
 |         String link = singlePage | 
 |             ? "#" + heading | 
 |             : name + ".html#" + heading; | 
 |         matcher.appendReplacement(sb, Matcher.quoteReplacement(link)); | 
 |         continue; | 
 |       } | 
 |  | 
 |       // Links to the user manual are handled specially. Meh. | 
 |       if ("user-manual".equals(name)) { | 
 |         String link = productName.toLowerCase(Locale.US) + "-" + name + ".html#" + heading; | 
 |         matcher.appendReplacement(sb, Matcher.quoteReplacement(link)); | 
 |         continue; | 
 |       } | 
 |  | 
 |       // If the reference does not match any rule or static page, throw an exception. | 
 |       throw new IllegalArgumentException( | 
 |           "Rule family " + name + " in link tag does not match any rule or BE page: " | 
 |           + matcher.group()); | 
 |     } | 
 |     matcher.appendTail(sb); | 
 |     return sb.toString(); | 
 |   } | 
 |  | 
 |   /** | 
 |    * Expands all rule references in the input HTML documentation. | 
 |    * | 
 |    * @param htmlDoc The input HTML documentation with ${link foo.bar} references. | 
 |    * @return The HTML documentation with all link references expanded. | 
 |    */ | 
 |   public String expand(String htmlDoc) throws IllegalArgumentException { | 
 |     String expanded = expandRuleLinks(htmlDoc); | 
 |     return expandRuleHeadingLinks(expanded); | 
 |   } | 
 |  | 
 |   /** | 
 |    * Expands the rule reference. | 
 |    * | 
 |    * <p>This method is used to expand references in the BE velocity templates. | 
 |    * | 
 |    * @param ref The rule reference to expand. | 
 |    * @return The expanded rule reference. | 
 |    */ | 
 |   public String expandRef(String ref) throws IllegalArgumentException { | 
 |     return expand("${link " + ref + "}"); | 
 |   } | 
 | } |