/*
    * Copyright (c) 2001-2017, Zoltan Farkas All Rights Reserved.
    *
    * This library is free software; you can redistribute it and/or
    * modify it under the terms of the GNU Lesser General Public
    * License as published by the Free Software Foundation; either
    * version 2.1 of the License, or (at your option) any later version.
    *
    * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
   *
   * Additionally licensed with:
   *
   * 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 org.spf4j.base;
  
  import com.google.common.escape.Escaper;
  import com.google.common.html.HtmlEscapers;
  import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  import gnu.trove.map.hash.THashMap;
  import java.io.IOException;
  import java.io.Writer;
  import java.util.Map;
  import javax.annotation.concurrent.Immutable;
  import org.spf4j.base.avro.Converters;
  import org.spf4j.base.avro.Method;
  
  /**
   * @author zoly
   */
  @Immutable
  // using racy single check idiom makes findbugs think the Method obejct is mutable...
  @SuppressFBWarnings("JCIP_FIELD_ISNT_FINAL_IN_IMMUTABLE_CLASS")
  public final class Methods  {
  
    public static final Method ROOT = Converters.ROOT;
  
    private static final Map<String, Map<String, Method>> INSTANCE_REPO = new THashMap<>(1024);
  
  
    private Methods() { }
  
    public static void writeHtml(final Method m, final Writer w) throws IOException {
      Escaper htmlEscaper = HtmlEscapers.htmlEscaper();
      w.append(htmlEscaper.escape(m.getName())).append(htmlEscaper.escape("@")).
              append(htmlEscaper.escape(m.getDeclaringClass()));
    }
  
    public static Method getMethod(final StackTraceElement elem) {
      return getMethod(elem.getClassName(), elem.getMethodName());
    }
  
    /*
       * this function is to allow reuse of Method instances.
       * not thread safe, use with care, see description for suppressed findbugs bug for more detail.
     */
    @SuppressFBWarnings("PMB_POSSIBLE_MEMORY")
    public static synchronized Method getMethod(final String className, final String methodName) {
      Map<String, Method> mtom = INSTANCE_REPO.get(className);
      Method result;
      if (mtom == null) {
        mtom = new THashMap<>(5);
        result = new Method(className, methodName);
        mtom.put(methodName, result);
        INSTANCE_REPO.put(className, mtom);
      } else {
        result = mtom.get(methodName);
        if (result == null) {
          result = new Method(className, methodName);
          mtom.put(methodName, result);
        }
      }
      return result;
    }
  
    public static void writeTo(final Method m, final Appendable w) throws IOException {
      w.append(m.getName()).append('@').append(m.getDeclaringClass());
    }
  
    public static void writeTo(final Method m, final StringBuilder w) {
      w.append(m.getName()).append('@').append(m.getDeclaringClass());
    }
 
   public static CharSequence toCharSequence(final Method m) {
     StringBuilder sb = new StringBuilder(32);
     writeTo(m, sb);
     return sb;
   }
 
   public static String toString(final Method m) {
     return toCharSequence(m).toString();
   }
 
   public static Method from(final CharSequence cs) {
     return from(cs, 0, cs.length());
   }
 
   public static Method from(final CharSequence cs, final int start, final int end) {
     int idx = CharSequences.indexOf(cs, start, end, '@');
     if (idx < 0) {
       throw new IllegalArgumentException("Invalid method representation: " + cs);
     }
     return getMethod(cs.subSequence(idx + 1, end).toString(), cs.subSequence(start, idx).toString());
   }
 
 }