/*
 * Copyright 2011-2016 UnboundID Corp.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License (GPLv2 only)
 * or the terms of the GNU Lesser General Public License (LGPLv2.1 only)
 * as published by the Free Software Foundation.
 *
 * This program 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 this program; if not, see <http://www.gnu.org/licenses>.
 */

package com.unboundid.scim.marshal.json;

import com.unboundid.scim.data.BaseResource;
import com.unboundid.scim.data.BulkConfig;
import com.unboundid.scim.data.ResourceFactory;
import com.unboundid.scim.marshal.Unmarshaller;
import com.unboundid.scim.schema.ResourceDescriptor;
import com.unboundid.scim.sdk.BulkContentHandler;
import com.unboundid.scim.sdk.Debug;
import com.unboundid.scim.sdk.InvalidResourceException;
import com.unboundid.scim.sdk.Resources;
import com.unboundid.scim.sdk.SCIMException;
import com.unboundid.scim.sdk.ServerErrorException;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.json.JSONTokener;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

import static com.unboundid.scim.marshal.json.JsonParser.makeCaseInsensitive;
import static com.unboundid.scim.sdk.SCIMConstants.*;



/**
 * This class provides a SCIM object un-marshaller implementation to read SCIM
 * objects from their JSON representation.
 */
public class JsonUnmarshaller implements Unmarshaller
{
  /**
   * {@inheritDoc}
   */
  public <R extends BaseResource> R unmarshal(
      final InputStream inputStream,
      final ResourceDescriptor resourceDescriptor,
      final ResourceFactory<R> resourceFactory) throws InvalidResourceException
  {
    try
    {
      final JSONObject jsonObject =
            makeCaseInsensitive(new JSONObject(new JSONTokener(inputStream)));

      final JsonParser parser = new JsonParser();
      return parser.unmarshal(jsonObject, resourceDescriptor, resourceFactory,
                              null);
    }
    catch(JSONException e)
    {
      throw new InvalidResourceException("Error while reading JSON: " +
          e.getMessage(), e);
    }
  }

  /**
   * {@inheritDoc}
   */
  public <R extends BaseResource> Resources<R> unmarshalResources(
      final InputStream inputStream,
      final ResourceDescriptor resourceDescriptor,
      final ResourceFactory<R> resourceFactory) throws InvalidResourceException
  {
    try
    {
      final JsonParser parser = new JsonParser();
      final JSONObject jsonObject =
              makeCaseInsensitive(new JSONObject(new JSONTokener(inputStream)));

      int totalResults = 0;
      if(jsonObject.has("totalresults"))
      {
        totalResults = jsonObject.getInt("totalresults");
      }

      int startIndex = 1;
      if(jsonObject.has("startindex"))
      {
        startIndex = jsonObject.getInt("startindex");
      }

      final JSONArray schemas = jsonObject.optJSONArray("schemas");

      List<R> resources = Collections.emptyList();
      if(jsonObject.has("resources"))
      {
        JSONArray resourcesArray = jsonObject.getJSONArray("resources");
        resources = new ArrayList<R>(resourcesArray.length());
        for(int i = 0; i < resourcesArray.length(); i++)
        {
          JSONObject subObject = makeCaseInsensitive(
                  resourcesArray.getJSONObject(i));

          R resource = parser.unmarshal(subObject,
                                        resourceDescriptor,
                                        resourceFactory,
                                        schemas);
          resources.add(resource);
        }
      }

      return new Resources<R>(resources, totalResults, startIndex);
    }
    catch(JSONException e)
    {
      throw new InvalidResourceException("Error while reading JSON: " +
          e.getMessage(), e);
    }
  }


  /**
   * {@inheritDoc}
   */
  public SCIMException unmarshalError(final InputStream inputStream)
      throws InvalidResourceException
  {
    try
    {
      final JSONObject jsonObject =
          makeCaseInsensitive(new JSONObject(new JSONTokener(inputStream)));

      if(jsonObject.has("errors"))
      {
        JSONArray errors = jsonObject.getJSONArray("errors");
        if(errors.length() >= 1)
        {
          JSONObject error = errors.getJSONObject(0);
          int code = error.optInt("code");
          String description = error.optString("description");
          return SCIMException.createException(code, description);
        }
      }
      return null;
    }
    catch (JSONException e)
    {
      throw new InvalidResourceException("Error while reading JSON: " +
          e.getMessage(), e);
    }
  }



  /**
   * {@inheritDoc}
   */
  public void bulkUnmarshal(final InputStream inputStream,
                            final BulkConfig bulkConfig,
                            final BulkContentHandler handler)
      throws SCIMException
  {
    final JsonBulkParser bulkUnmarshaller =
        new JsonBulkParser(inputStream, bulkConfig, handler);
    bulkUnmarshaller.unmarshal();
  }



  /**
   * {@inheritDoc}
   */
  public void bulkUnmarshal(final File file,
                            final BulkConfig bulkConfig,
                            final BulkContentHandler handler)
      throws SCIMException
  {
    // First pass: ensure the number of operations is less than the max,
    // and save the failOnErrrors value.
    final AtomicInteger failOnErrorsValue = new AtomicInteger(-1);
    final BulkContentHandler preProcessHandler = new BulkContentHandler()
    {
      @Override
      public void handleFailOnErrors(final int failOnErrors)
      {
        failOnErrorsValue.set(failOnErrors);
      }
    };
    try
    {
      final FileInputStream fileInputStream = new FileInputStream(file);
      try
      {
        final BufferedInputStream bufferedInputStream =
            new BufferedInputStream(fileInputStream);
        try
        {
          final JsonBulkParser jsonBulkParser =
              new JsonBulkParser(bufferedInputStream, bulkConfig,
                                 preProcessHandler);
          jsonBulkParser.setSkipOperations(true);
          jsonBulkParser.unmarshal();
        }
        finally
        {
          bufferedInputStream.close();
        }
      }
      finally
      {
        fileInputStream.close();
      }
    }
    catch (IOException e)
    {
      Debug.debugException(e);
      throw new ServerErrorException(
          "Error pre-processing bulk request: " + e.getMessage());
    }

    int failOnErrors = failOnErrorsValue.get();
    if (failOnErrors != -1)
    {
      handler.handleFailOnErrors(failOnErrors);
    }

    // Second pass: Parse fully.
    try
    {
      final FileInputStream fileInputStream = new FileInputStream(file);
      try
      {
        final BufferedInputStream bufferedInputStream =
            new BufferedInputStream(fileInputStream);
        try
        {
          final JsonBulkParser jsonBulkParser =
              new JsonBulkParser(bufferedInputStream, bulkConfig, handler);
          jsonBulkParser.unmarshal();
        }
        finally
        {
          bufferedInputStream.close();
        }
      }
      finally
      {
        fileInputStream.close();
      }
    }
    catch (IOException e)
    {
      Debug.debugException(e);
      throw new ServerErrorException(
          "Error parsing bulk request: " + e.getMessage());
    }
  }
}