// Copyright (c) 2009 The Chromium Authors. All rights reserved.

// Use of this source code is governed by a BSD-style license that can be

// found in the LICENSE file.

package org.chromium.sdk.internal.protocolparser.dynamicimpl;

import java.lang.reflect.InvocationTargetException;

import java.lang.reflect.Method;

import org.chromium.sdk.internal.protocolparser.JsonProtocolModelParseException;

import org.chromium.sdk.internal.protocolparser.JsonProtocolParseException;

class EnumParser<T extends Enum<T>> extends QuickParser<T> {

  public static <T extends Enum<T>> EnumParser<T> create(Class<T> enumTypeClass,

      boolean isNullable) throws JsonProtocolModelParseException {

    return new EnumParser<T>(enumTypeClass, isNullable);

  }

  private final Method methodValueOf;

  private final boolean isNullable;

  private final Class<T> enumClass;

  private EnumParser(Class<T> enumClass, boolean isNullable)

      throws JsonProtocolModelParseException {

    this.enumClass = enumClass;

    this.isNullable = isNullable;

    try {

      this.methodValueOf = enumClass.getMethod("valueOf", String.class);

    } catch (NoSuchMethodException e) {

      throw new JsonProtocolModelParseException(

          "Failed to find valueOf method for parsing strings", e);

    }

  }

  @Override

  public T parseValueQuick(Object value) throws JsonProtocolParseException {

    if (isNullable && value == null) {

      return null;

    }

    if (value instanceof String == false) {

      throw new JsonProtocolParseException("String value expected");

    }

    String stringValue = (String) value;

    T result;

    try {

      result = enumClass.cast(methodValueOf.invoke(null, stringValue));

    } catch (IllegalArgumentException e) {

      throw new JsonProtocolParseException("Failed to parse enum constant " + stringValue, e);

    } catch (IllegalAccessException e) {

      throw new JsonProtocolParseException("Failed to call valueOf method", e);

    } catch (InvocationTargetException e) {

      throw new JsonProtocolParseException("Failed to call valueOf method", e);

    }

    if (result == null) {

      throw new JsonProtocolParseException("Failed to parse value " + value + " as enum");

    }

    return result;

  }

}