/*
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.qpid.server.util;

import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

public class MapValueConverter
{

    public static String getStringAttribute(String name, Map<String,Object> attributes, String defaultVal)
    {
        final Object value = attributes.get(name);
        return toString(value, defaultVal);
    }

    public static String toString(final Object value)
    {
        return toString(value, null);
    }

    public static String toString(final Object value, String defaultVal)
    {
        if (value == null)
        {
            return defaultVal;
        }
        else if (value instanceof String)
        {
            return (String)value;
        }
        return String.valueOf(value);
    }

    public static String getStringAttribute(String name, Map<String, Object> attributes)
    {
        assertMandatoryAttribute(name, attributes);
        return getStringAttribute(name, attributes, null);
    }

    private static void assertMandatoryAttribute(String name, Map<String, Object> attributes)
    {
        if (!attributes.containsKey(name))
        {
            throw new IllegalArgumentException("Value for attribute " + name + " is not found");
        }
    }

    public static Map<String,Object> getMapAttribute(String name, Map<String,Object> attributes, Map<String,Object> defaultVal)
    {
        final Object value = attributes.get(name);
        if(value == null)
        {
            return defaultVal;
        }
        else if(value instanceof Map)
        {
            @SuppressWarnings("unchecked")
            Map<String,Object> retVal = (Map<String,Object>) value;
            return retVal;
        }
        else
        {
            throw new IllegalArgumentException("Value for attribute " + name + " is not of required type Map");
        }
    }


    @SuppressWarnings({ "unchecked", "rawtypes" })
    public static <E extends Enum> E getEnumAttribute(Class<E> clazz, String name, Map<String,Object> attributes, E defaultVal)
    {
        Object obj = attributes.get(name);
        if(obj == null)
        {
            return defaultVal;
        }
        else if(clazz.isInstance(obj))
        {
            return (E) obj;
        }
        else if(obj instanceof String)
        {
            return (E) Enum.valueOf(clazz, (String)obj);
        }
        else
        {
            throw new IllegalArgumentException("Value for attribute " + name + " is not of required type " + clazz.getSimpleName());
        }
    }

    public static <E extends Enum<?>> E getEnumAttribute(Class<E> clazz, String name, Map<String,Object> attributes)
    {
        assertMandatoryAttribute(name, attributes);
        return getEnumAttribute(clazz, name, attributes, null);
    }

    public static Boolean getBooleanAttribute(String name, Map<String,Object> attributes, Boolean defaultValue)
    {
        Object obj = attributes.get(name);
        return toBoolean(name, obj, defaultValue);
    }

    public static Boolean toBoolean(String name, Object obj)
    {
        return toBoolean(name, obj, null);
    }

    public static Boolean toBoolean(String name, Object obj, Boolean defaultValue)
    {
        if(obj == null)
        {
            return defaultValue;
        }
        else if(obj instanceof Boolean)
        {
            return (Boolean) obj;
        }
        else if(obj instanceof String)
        {
            return Boolean.parseBoolean((String) obj);
        }
        else
        {
            throw new IllegalArgumentException("Value for attribute " + name + " is not of required type Boolean");
        }
    }


    public static boolean getBooleanAttribute(String name, Map<String, Object> attributes)
    {
        assertMandatoryAttribute(name, attributes);
        return getBooleanAttribute(name, attributes, null);
    }

    public static Integer getIntegerAttribute(String name, Map<String,Object> attributes, Integer defaultValue)
    {
        Object obj = attributes.get(name);
        return toInteger(name, obj, defaultValue);
    }

    public static Integer toInteger(String name, Object obj)
    {
        return toInteger(name, obj, null);
    }

    public static Integer toInteger(String name, Object obj, Integer defaultValue)
    {
        if(obj == null)
        {
            return defaultValue;
        }
        else if(obj instanceof Number)
        {
            return ((Number) obj).intValue();
        }
        else if(obj instanceof String)
        {
            return Integer.valueOf((String) obj);
        }
        else
        {
            throw new IllegalArgumentException("Value for attribute " + name + " is not of required type Integer");
        }
    }

    public static Integer getIntegerAttribute(String name, Map<String,Object> attributes)
    {
        assertMandatoryAttribute(name, attributes);
        return getIntegerAttribute(name, attributes, null);
    }

    public static Long getLongAttribute(String name, Map<String,Object> attributes, Long defaultValue)
    {
        Object obj = attributes.get(name);
        return toLong(name, obj, defaultValue);
    }

    public static Long toLong(String name, Object obj)
    {
        return toLong(name, obj, null);
    }

    public static Long toLong(String name, Object obj, Long defaultValue)
    {
        if(obj == null)
        {
            return defaultValue;
        }
        else if(obj instanceof Number)
        {
            return ((Number) obj).longValue();
        }
        else if(obj instanceof String)
        {
            return Long.valueOf((String) obj);
        }
        else
        {
            throw new IllegalArgumentException("Value for attribute " + name + " is not of required type Long");
        }
    }

    public static <T> Set<T> getSetAttribute(String name, Map<String,Object> attributes)
    {
        assertMandatoryAttribute(name, attributes);
        return getSetAttribute(name, attributes, Collections.<T>emptySet());
    }

    @SuppressWarnings("unchecked")
    public static <T> Set<T> getSetAttribute(String name, Map<String,Object> attributes, Set<T> defaultValue)
    {
        Object obj = attributes.get(name);
        if(obj == null)
        {
            return defaultValue;
        }
        else if(obj instanceof Set)
        {
            return (Set<T>) obj;
        }
        else
        {
            throw new IllegalArgumentException("Value for attribute " + name + " is not of required type Set");
        }
    }

    @SuppressWarnings("unchecked")
    public static <T extends Enum<T>> Set<T> getEnumSetAttribute(String name, Map<String, Object> attributes, Class<T> clazz)
    {
        Object obj = attributes.get(name);
        Object[] items = null;
        if (obj == null)
        {
            return null;
        }
        else if (obj instanceof Collection)
        {
            Collection<?> data = (Collection<?>) obj;
            items = data.toArray(new Object[data.size()]);
        }
        else if (obj instanceof String[])
        {
            items = (String[]) obj;
        }
        else if (obj instanceof Object[])
        {
            items = (Object[]) obj;
        }
        else
        {
            throw new IllegalArgumentException("Value for attribute " + name + "[" + obj
                    + "] cannot be converted into set of enum of " + clazz);
        }
        Set<T> set = new HashSet<T>();
        for (int i = 0; i < items.length; i++)
        {
            T item = null;
            Object value = items[i];
            if (value instanceof String)
            {
                item = (T) Enum.valueOf(clazz, (String) value);
            }
            else if (clazz.isInstance(value))
            {
                item = (T) value;
            }
            else
            {
                throw new IllegalArgumentException("Cannot convert " + value + " from [" + obj + "] into enum of " + clazz
                        + " for attribute " + name);
            }
            set.add(item);
        }
        return set;
    }

    public static Map<String, Object> convert(Map<String, Object> configurationAttributes, Map<String, Class<?>> attributeTypes)
    {
        Map<String, Object> attributes = new HashMap<String, Object>();
        for (Map.Entry<String, Class<?>> attributeEntry : attributeTypes.entrySet())
        {
            String attributeName = attributeEntry.getKey();
            if (configurationAttributes.containsKey(attributeName))
            {
                Class<?> classObject = attributeEntry.getValue();
                Object rawValue = configurationAttributes.get(attributeName);
                Object value = null;
                if (classObject == Long.class || classObject == long.class)
                {
                    value = toLong(attributeName, rawValue);
                }
                else if (classObject == Integer.class || classObject == int.class)
                {
                    value = toInteger(attributeName, rawValue);
                }
                else if (classObject == Boolean.class || classObject == boolean.class)
                {
                    value = toBoolean(attributeName, rawValue);
                }
                else if (classObject == String.class)
                {
                    value = toString(rawValue);
                }
                else
                {
                    throw new IllegalArgumentException("Cannot convert '" + rawValue + "' into " + classObject);
                }
                attributes.put(attributeName, value);
            }
        }
        return attributes;
    }
}
