/*
 * Jalview - A Sequence Alignment Editor and Viewer ($$Version-Rel$$)
 * Copyright (C) $$Year-Rel$$ The Jalview Authors
 *
 * This file is part of Jalview.
 *
 * Jalview is free software: you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation, either version 3
 * of the License, or (at your option) any later version.
 *
 * Jalview 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 General Public License
 * along with Jalview.  If not, see <http://www.gnu.org/licenses/>.
 * The Jalview Authors are detailed in the 'AUTHORS' file.
 */
package jalview.util.dialogrunner;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

/**
 * daft gymnastics to allow Dialogs to extend from a Swing class and use this
 * class to implement chained Response run() definition and execution.
 * 
 * There is probably a better way of doing this.
 * 
 * @author jprocter
 *
 * @param <T>
 *          the actual dialog that will be shown - which will also initiate the
 *          response chain.
 */
public class DialogRunner<T extends DialogRunnerI> implements DialogRunnerI
{

  private Map<Response, List<RunResponse>> callbacks = new java.util.HashMap<>();

  public T dialog;

  public DialogRunner(T ourDialog)
  {
    dialog = ourDialog;
  }

  /**
   * clear all 'was ran' flags so responses can be called again, and firstRun will
   * trigger response execution
   */
  public void resetResponses()
  {
    for (List<RunResponse> lr : callbacks.values())
    {
      for (RunResponse response : lr)
      {
        response.reset();
      }
    }
    responses.clear();
    if (defaultResponse != null)
    {
      defaultResponse.reset();
    }
    firstRunWasCalled = false;
  }

  @Override
  public T response(RunResponse action)
  {
    return addResponse(false, action);
  }

  /**
   * insert a response at the beginning of the chain for the action. Useful to add
   * pre-action validations local to the Dialog class
   * 
   * @param action
   * @return
   */
  public T firstResponse(RunResponse action)
  {
    return addResponse(true, action);
  }

  protected T addResponse(boolean prePend, RunResponse action)
  {
    List<RunResponse> laction = callbacks.get(action.ourTrigger);
    if (laction == null)
    {
      laction = new ArrayList<>();
      callbacks.put(action.ourTrigger, laction);
    }
    if (prePend)
    {
      laction.add(0,action);
    } else {
      laction.add(action);
    }
    return dialog;
  }

  /**
   * 
   * @param action
   * @return true if action is a registered callback
   */
  public boolean isRegistered(RunResponse action)
  {
    List<RunResponse> resp = callbacks.get(action.ourTrigger);
    if (resp != null)
    {
      for (RunResponse r : resp)
      {
        if (r == action)
        {
          return true;
        }
      }
    }
    return false;
  }
  /**
   * handle a response
   * 
   * @param responseCode
   */
  public void run(int responseCode)
  {
    run(new Response(responseCode));
  }

  public void run(String responseString)
  {
    run(new Response(responseString));
  }

  public void run(Object responseObj)
  {
    run(new Response(responseObj));
  }

  /**
   * start of response handling.
   * 
   * @param responseCode
   */
  public void firstRun(int responseCode)
  {
    doFirstRun(new Response(responseCode));
  }

  public void firstRun(String responseString)
  {
    doFirstRun(new Response(responseString));
  }

  public void firstRun(Object responseObj)
  {
    if (responseObj != null && !responseObj.equals(responseObj))
    {
      // NaN is an object in Chrome - catch this weirdness
      // this so we don't cause issues later
      return;
    }
    doFirstRun(new Response(responseObj));
  }


  boolean firstRunWasCalled = false;

  private void doFirstRun(Response response)
  {
    if (firstRunWasCalled)
    {
      return;
    }
    firstRunWasCalled = true;
    run(response);
  }

  private void run(Response response)
  {
    if (response.objresp != null
            && !response.objresp.equals(response.objresp))
    {
      // NaN is an object in Chrome - catch this weirdness
      // this so we don't cause issues later
      return;
    }
    responses.add(response);
    
    List<RunResponse> laction = response.isNull() ? null : callbacks.get(response);

    if (laction == null)
    {
      if (defaultResponse != null)
      {
        defaultResponse.ourTrigger = response;
        defaultResponse.wasRun = true;
        defaultResponse.run();
      }
      else
      {
        System.err.println("Doing nothing for " + response);
      }
      return;
    }
    boolean wasRun = false;
    int num = 0;
    for (RunResponse action : laction)
    {
      num++;
      // find next action to execute
      if (!action.wasRun)
      {
        System.err
                .println("Executing action (" + num + ") for " + response);
        wasRun = true;
        action.wasRun = true;
        action.run();
        if (action.returned != null)
        {
          run(action.returned);
        }
        break;
      }
    }
    if (!wasRun)
    {
      System.err.println("Did nothing for " + response);
    }
  }

  List<Response> responses = new ArrayList<>();

  RunResponse defaultResponse = null;

  /**
   * Convenience wrapper for setting default response to a runnable
   * 
   * @param runnable
   */
  public void setDefaultResponse(Runnable runnable)
  {
    defaultResponse = new RunResponse(runnable)
    {
      @Override
      public void run()
      {
        runnable.run();
      }
    };
  }

  /**
   * Default responses are called once, with ourTrigger set to the unHandled
   * response received
   * 
   * @param runnable
   */
  public void setDefaultResponse(RunResponse runnable)
  {
    defaultResponse = runnable;
  }
}