/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * 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 com.android.inputmethod.compat;

import android.content.Intent;
import android.text.TextUtils;
import android.util.Log;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;

public class CompatUtils {
    private static final String TAG = CompatUtils.class.getSimpleName();
    private static final String EXTRA_INPUT_METHOD_ID = "input_method_id";
    // TODO: Can these be constants instead of literal String constants?
    private static final String INPUT_METHOD_SUBTYPE_SETTINGS =
            "android.settings.INPUT_METHOD_SUBTYPE_SETTINGS";

    public static Intent getInputLanguageSelectionIntent(String inputMethodId,
            int flagsForSubtypeSettings) {
        // Refer to android.provider.Settings.ACTION_INPUT_METHOD_SUBTYPE_SETTINGS
        final String action = INPUT_METHOD_SUBTYPE_SETTINGS;
        final Intent intent = new Intent(action);
        if (!TextUtils.isEmpty(inputMethodId)) {
            intent.putExtra(EXTRA_INPUT_METHOD_ID, inputMethodId);
        }
        if (flagsForSubtypeSettings > 0) {
            intent.setFlags(flagsForSubtypeSettings);
        }
        return intent;
    }

    public static Class<?> getClass(String className) {
        try {
            return Class.forName(className);
        } catch (ClassNotFoundException e) {
            return null;
        }
    }

    public static Method getMethod(Class<?> targetClass, String name,
            Class<?>... parameterTypes) {
        if (targetClass == null || TextUtils.isEmpty(name)) return null;
        try {
            return targetClass.getMethod(name, parameterTypes);
        } catch (SecurityException e) {
            // ignore
        } catch (NoSuchMethodException e) {
            // ignore
        }
        return null;
    }

    public static Field getField(Class<?> targetClass, String name) {
        if (targetClass == null || TextUtils.isEmpty(name)) return null;
        try {
            return targetClass.getField(name);
        } catch (SecurityException e) {
            // ignore
        } catch (NoSuchFieldException e) {
            // ignore
        }
        return null;
    }

    public static Constructor<?> getConstructor(Class<?> targetClass, Class<?> ... types) {
        if (targetClass == null || types == null) return null;
        try {
            return targetClass.getConstructor(types);
        } catch (SecurityException e) {
            // ignore
        } catch (NoSuchMethodException e) {
            // ignore
        }
        return null;
    }

    public static Object newInstance(Constructor<?> constructor, Object ... args) {
        if (constructor == null) return null;
        try {
            return constructor.newInstance(args);
        } catch (Exception e) {
            Log.e(TAG, "Exception in newInstance: " + e.getClass().getSimpleName());
        }
        return null;
    }

    public static Object invoke(
            Object receiver, Object defaultValue, Method method, Object... args) {
        if (method == null) return defaultValue;
        try {
            return method.invoke(receiver, args);
        } catch (Exception e) {
            Log.e(TAG, "Exception in invoke: " + e.getClass().getSimpleName());
        }
        return defaultValue;
    }

    public static Object getFieldValue(Object receiver, Object defaultValue, Field field) {
        if (field == null) return defaultValue;
        try {
            return field.get(receiver);
        } catch (Exception e) {
            Log.e(TAG, "Exception in getFieldValue: " + e.getClass().getSimpleName());
        }
        return defaultValue;
    }

    public static void setFieldValue(Object receiver, Field field, Object value) {
        if (field == null) return;
        try {
            field.set(receiver, value);
        } catch (Exception e) {
            Log.e(TAG, "Exception in setFieldValue: " + e.getClass().getSimpleName());
        }
    }
}