/*
 * 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.
 */

#ifndef _HDFS_LIBHDFS3_COMMON_XMLCONFIG_H_
#define _HDFS_LIBHDFS3_COMMON_XMLCONFIG_H_

#include <stdint.h>
#include <string>
#include <sstream>
#include <map>

namespace Yarn {

/**
 * A configure file parser.
 */
class Config {
public:
    /**
     * Construct a empty Config instance.
     */
    Config() {
    }

    /**
     * Construct a Config with given configure file.
     * @param path The path of configure file.
     * @throw YarnBadConfigFormat
     */
    Config(const char * path);

    /**
     * Parse the configure file.
     * @throw YarnBadConfigFormat
     */
    void update(const char * path);

    /**
     * Get a string with given configure key.
     * @param key The key of the configure item.
     * @return The value of configure item.
     * @throw YarnConfigNotFound
     */
    const char * getString(const char * key) const;

    /**
     * Get a string with given configure key.
     * Return the default value def if key is not found.
     * @param key The key of the configure item.
     * @param def The defalut value.
     * @return The value of configure item.
     */
    const char * getString(const char * key, const char * def) const;

    /**
     * Get a string with given configure key.
     * @param key The key of the configure item.
     * @return The value of configure item.
     * @throw YarnConfigNotFound
     */
    const char * getString(const std::string & key) const;

    /**
     * Get a string with given configure key.
     * Return the default value def if key is not found.
     * @param key The key of the configure item.
     * @param def The defalut value.
     * @return The value of configure item.
     */
    const char * getString(const std::string & key,
                           const std::string & def) const;

    /**
     * Get a 64 bit integer with given configure key.
     * @param key The key of the configure item.
     * @return The value of configure item.
     * @throw YarnConfigNotFound
     */
    int64_t getInt64(const char * key) const;

    /**
     * Get a 64 bit integer with given configure key.
     * Return the default value def if key is not found.
     * @param key The key of the configure item.
     * @param def The defalut value.
     * @return The value of configure item.
     */
    int64_t getInt64(const char * key, int64_t def) const;

    /**
     * Get a 32 bit integer with given configure key.
     * @param key The key of the configure item.
     * @return The value of configure item.
     * @throw YarnConfigNotFound
     */
    int32_t getInt32(const char * key) const;

    /**
     * Get a 32 bit integer with given configure key.
     * Return the default value def if key is not found.
     * @param key The key of the configure item.
     * @param def The defalut value.
     * @return The value of configure item.
     */
    int32_t getInt32(const char * key, int32_t def) const;

    /**
     * Get a double with given configure key.
     * @param key The key of the configure item.
     * @return The value of configure item.
     * @throw YarnConfigNotFound
     */
    double getDouble(const char * key) const;

    /**
     * Get a double with given configure key.
     * Return the default value def if key is not found.
     * @param key The key of the configure item.
     * @param def The defalut value.
     * @return The value of configure item.
     */
    double getDouble(const char * key, double def) const;

    /**
     * Get a boolean with given configure key.
     * @param key The key of the configure item.
     * @return The value of configure item.
     * @throw YarnConfigNotFound
     */
    bool getBool(const char * key) const;

    /**
     * Get a boolean with given configure key.
     * Return the default value def if key is not found.
     * @param key The key of the configure item.
     * @param def The default value.
     * @return The value of configure item.
     */
    bool getBool(const char * key, bool def) const;

    /**
     * Set a configure item
     * @param key The key will set.
     * @param value The value will be set to.
     */
    template<typename T>
    void set(const char * key, T const & value) {
        std::stringstream ss;
        ss << value;
        kv[key] = ss.str();
    }

    /**
     * Get the hash value of this object
     *
     * @return The hash value
     */
    size_t hash_value() const;

private:
    std::string path;
    std::map<std::string, std::string> kv;
};

}

#endif /* _HDFS_LIBHDFS3_COMMON_XMLCONFIG_H_ */