package com.atlassian.plugins.rest.module;
   
   import com.google.common.base.Preconditions;
   import com.sun.jersey.api.core.DefaultResourceConfig;
   import org.apache.commons.lang.StringUtils;
   
   import java.util.Optional;
   import java.util.Set;
   import java.util.concurrent.atomic.AtomicReference;
  
  public class RestApiContext {
      public static final String SLASH = "/";
  
      public final static String LATEST = SLASH + "latest";
  
      public final static String ANY_PATH_PATTERN = "/*";
  
      private final String restContext;
      private final String apiPath;
      private final ApiVersion version;
      private final Set<String> packages;
  
      private final AtomicReference<DefaultResourceConfig> osgiResourceConfig = new AtomicReference<>();
  
      public RestApiContext(String restContext, String apiContext, ApiVersion version, Set<String> packages) {
          this.restContext = prependSlash(Preconditions.checkNotNull(restContext));
          this.apiPath = prependSlash(Preconditions.checkNotNull(apiContext));
          this.version = Preconditions.checkNotNull(version);
          this.packages = Preconditions.checkNotNull(packages);
      }
  
      /**
       * @return the REST context, always starts with "/".
       */
      public String getRestContext() {
          return restContext;
      }
  
      /**
       * @return the API path, always starts with "/"
       */
      public String getApiPath() {
          return apiPath;
      }
  
      /**
       * @return the API version
       */
      public ApiVersion getVersion() {
          return version;
      }
  
      /**
       * @return String representing /restContext/apiPath/version, always starts with "/"
       */
      public String getPathToVersion() {
          // if you say that you want to go versionless then you get the latest version
          // (this is a point of indirection where we could potentially choose a version other than latest)
          return getPathToVersion(version);
      }
  
      /**
       * @return String representing /restContext/apiPath/"latest", always starts with "/"
       */
      public String getPathToLatest() {
          return getPathToVersion(LATEST);
      }
  
      /**
       * @param version ApiVersion such as "1.2.3" or "none"
       * @return String representing /restContext/apiPath/version, always starts with "/"
       */
      public String getPathToVersion(String version) {
          return restContext + getContextlessPathToVersion(version);
      }
  
      /**
       * @param version ApiVersion such as "1.2.3" or "none"
       * @return String representing /restContext/apiPath/version, always starts with "/"
       */
      private String getPathToVersion(ApiVersion version) {
          return restContext + getContextlessPathToVersion(version);
      }
  
      /**
       * @return String representing /apiPath/version, always starts with "/"
       */
      public String getContextlessPathToVersion() {
          return getContextlessPathToVersion(version);
      }
  
      /**
       * @param version ApiVersion such as "1.2.3" or "none"
       * @return String representing /apiPath/version, always starts with "/"
       */
      private String getContextlessPathToVersion(String version) {
          return ApiVersion.isNone(version)
                  ? apiPath
                  : apiPath + prependSlash(version);
     }
 
     /**
      * Handles the version="none" case more efficiently than the overload that takes a String.
      *
      * @param version ApiVersion such as "1.2.3" or "none"
      * @return String representing /apiPath/version, always starts with "/"
      */
     private String getContextlessPathToVersion(ApiVersion version) {
         return version.isNone()
                 ? apiPath
                 : apiPath + prependSlash(version.toString());
     }
 
     private String prependSlash(String path) {
         return StringUtils.startsWith(path, SLASH) ? path : SLASH + path;
     }
 
     public Set<String> getPackages() {
         return packages;
     }
 
     public void setConfig(DefaultResourceConfig config) {
         osgiResourceConfig.set(config);
     }
 
     public Optional<DefaultResourceConfig> getConfig() {
         return osgiResourceConfig.get() != null
                 ? Optional.of(osgiResourceConfig.get())
                 : Optional.empty();
     }
 
     public void disabled() {
         osgiResourceConfig.set(null);
     }
 }