co.easimart.EasimartObjectCurrentCoder Maven / Gradle / Ivy

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package co.easimart;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.Date;
import java.util.Iterator;

/**
 * Handles encoding/decoding EasimartObjects to/from /2 format JSON. /2 format json is only used for
 * persisting current EasimartObject(currentInstallation, currentUser) to disk when LDS is not enabled.
 */
/** package */ class EasimartObjectCurrentCoder extends EasimartObjectCoder {

  /*
  /2 format JSON Keys
  */
  private static final String KEY_OBJECT_ID = "objectId";
  private static final String KEY_CLASS_NAME = "classname";
  private static final String KEY_CREATED_AT = "createdAt";
  private static final String KEY_UPDATED_AT = "updatedAt";
  private static final String KEY_DATA = "data";

  /*
  Old serialized JSON keys
   */
  private static final String KEY_OLD_OBJECT_ID = "id";
  private static final String KEY_OLD_CREATED_AT = "created_at";
  private static final String KEY_OLD_UPDATED_AT = "updated_at";
  private static final String KEY_OLD_POINTERS = "pointers";

  private static final EasimartObjectCurrentCoder INSTANCE =
      new EasimartObjectCurrentCoder();

  public static EasimartObjectCurrentCoder get() {
    return INSTANCE;
  }

  /* package */ EasimartObjectCurrentCoder() {
    // do nothing
  }

  /**
   * Converts a {@code EasimartObject} to /2/ JSON representation suitable for saving to disk.
   *
   *    * {
   *   data: {
   *     // data fields, including objectId, createdAt, updatedAt
   *   },
   *   classname: class name for the object,
   *   operations: { } // operations per field
   * }
   * 
   *
   * All keys are included, regardless of whether they are dirty.
   *
   * @see #decode(EasimartObject.State.Init, JSONObject, EasimartDecoder)
   */
  @Override
  public  JSONObject encode(
      T state, EasimartOperationSet operations, EasimartEncoder encoder) {
    if (operations != null) {
      throw new IllegalArgumentException("Parameter EasimartOperationSet is not null");
    }

    // Public data goes in dataJSON; special fields go in objectJSON.
    JSONObject objectJSON = new JSONObject();
    JSONObject dataJSON = new JSONObject();

    try {
      // Serialize the data
      for (String key : state.keySet()) {
        Object object = state.get(key);
        dataJSON.put(key, encoder.encode(object));

        // TODO(grantland): Use cached value from hashedObjects, but only if we're not dirty.
      }

      if (state.createdAt() > 0) {
        dataJSON.put(KEY_CREATED_AT,
            EasimartDateFormat.getInstance().format(new Date(state.createdAt())));
      }
      if (state.updatedAt() > 0) {
        dataJSON.put(KEY_UPDATED_AT,
            EasimartDateFormat.getInstance().format(new Date(state.updatedAt())));
      }
      if (state.objectId() != null) {
        dataJSON.put(KEY_OBJECT_ID, state.objectId());
      }

      objectJSON.put(KEY_DATA, dataJSON);
      objectJSON.put(KEY_CLASS_NAME, state.className());
    } catch (JSONException e) {
      throw new RuntimeException("could not serialize object to JSON");
    }

    return objectJSON;
  }

  /**
   * Decodes from /2/ JSON.
   *
   * This is only used to read EasimartObjects stored on disk in JSON.
   *
   * @see #encode(EasimartObject.State, EasimartOperationSet, EasimartEncoder)
   */
  @Override
  public > T decode(
      T builder, JSONObject json, EasimartDecoder decoder) {
    try {
      // The handlers for id, created_at, updated_at, and pointers are for
      // backward compatibility with old serialized users.
      if (json.has(KEY_OLD_OBJECT_ID)) {
        String newObjectId = json.getString(KEY_OLD_OBJECT_ID);
        builder.objectId(newObjectId);
      }
      if (json.has(KEY_OLD_CREATED_AT)) {
        String createdAtString =
            json.getString(KEY_OLD_CREATED_AT);
        if (createdAtString != null) {
          builder.createdAt(EasimartImpreciseDateFormat.getInstance().parse(createdAtString));
        }
      }
      if (json.has(KEY_OLD_UPDATED_AT)) {
        String updatedAtString =
            json.getString(KEY_OLD_UPDATED_AT);
        if (updatedAtString != null) {
          builder.updatedAt(EasimartImpreciseDateFormat.getInstance().parse(updatedAtString));
        }
      }
      if (json.has(KEY_OLD_POINTERS)) {
        JSONObject newPointers =
            json.getJSONObject(KEY_OLD_POINTERS);
        Iterator keys = newPointers.keys();
        while (keys.hasNext()) {
          String key = (String) keys.next();
          JSONArray pointerArray = newPointers.getJSONArray(key);
          builder.put(key, EasimartObject.createWithoutData(pointerArray.optString(0),
                  pointerArray.optString(1)));
        }
      }

      JSONObject data = json.optJSONObject(KEY_DATA);
      if (data != null) {
        Iterator keys = data.keys();
        while (keys.hasNext()) {
          String key = (String) keys.next();

          if (key.equals(KEY_OBJECT_ID)) {
            String newObjectId = data.getString(key);
            builder.objectId(newObjectId);
            continue;
          }
          if (key.equals(KEY_CREATED_AT)) {
            builder.createdAt(EasimartDateFormat.getInstance().parse(data.getString(key)));
            continue;
          }
          if (key.equals(KEY_UPDATED_AT)) {
            builder.updatedAt(EasimartDateFormat.getInstance().parse(data.getString(key)));
            continue;
          }

          Object value = data.get(key);
          Object decodedObject = decoder.decode(value);
          builder.put(key, decodedObject);
        }
      }

      return builder;
    } catch (JSONException e) {
      throw new RuntimeException(e);
    }
  }
}