/*
 * The MIT License
 *
 * Copyright 2013 Oleg Nenashev, Synopsys Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

package com.synopsys.arc.jenkins.plugins.rolestrategy;

import com.synopsys.arc.jenkins.plugins.rolestrategy.macros.StubMacro;
import edu.umd.cs.findbugs.annotations.CheckForNull;
import hudson.ExtensionList;
import hudson.ExtensionPoint;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * Extension for macro roles (automatic membership handling).
 *
 * @author Oleg Nenashev
 * @since 2.1.0
 */
public abstract class RoleMacroExtension implements ExtensionPoint, IMacroExtension {

  private static final Map<String, RoleMacroExtension> NAME_CACHE = new ConcurrentHashMap<>();

  private static final Map<String, Macro> MACRO_CACHE = new ConcurrentHashMap<>();

  private static void updateRegistry() {
    NAME_CACHE.clear();
    for (RoleMacroExtension ext : all()) {
      NAME_CACHE.put(ext.getName(), ext);
    }
  }

  /**
   * Parse Macro and return it.
   *
   * @param unparsedMacroString String to parse
   * @return parsed Macro
   */
  @CheckForNull
  public static Macro getMacro(String unparsedMacroString) {
    if (MACRO_CACHE.containsKey(unparsedMacroString)) {
      return MACRO_CACHE.get(unparsedMacroString);
    }
    try {
      Macro m = Macro.parse(unparsedMacroString);
      MACRO_CACHE.put(unparsedMacroString, m);
      return m;
    } catch (MacroException ex) {
      MACRO_CACHE.put(unparsedMacroString, null);
      return null;
    }
  }

  /**
   * Get Macro with the given name.
   *
   * @param macroName Name of Macro
   * @return RoleMacroExtension
   */
  public static RoleMacroExtension getMacroExtension(String macroName) {
    // TODO: the method is not thread-safe
    if (NAME_CACHE.isEmpty()) {
      updateRegistry();
    }
    RoleMacroExtension ext = NAME_CACHE.get(macroName);
    return ext != null ? ext : StubMacro.Instance;
  }

  /**
   * Get list of all registered {@link RoleMacroExtension}s.
   *
   * @return List of {@link RoleMacroExtension}s.
   */
  public static ExtensionList<RoleMacroExtension> all() {
    return ExtensionList.lookup(RoleMacroExtension.class);
  }
}
