/*
 * Copyright (c) 2016, Matias Fontanini
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following disclaimer
 *   in the documentation and/or other materials provided with the
 *   distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#ifndef CPPKAFKA_BUFFER_H
#define CPPKAFKA_BUFFER_H

#include <cstddef>
#include <algorithm>

namespace cppkafka {

/**
 * \brief Represents a view of a buffer.
 * 
 * This is only a view, hence you should convert the contents of a buffer into
 * some other container if you want to store it somewhere. 
 *
 * If you're using this to produce a message, you *need* to guarantee that the
 * pointer that this buffer points to will still until the call to Producer::produce
 * returns.
 */
class Buffer {
public:
    using DataType = unsigned char;

    /**
     * Constructs an empty buffer
     */
    Buffer();

    /**
     * Constructs a buffer from a pointer and a size
     *
     * \param data A pointer to some type of size 1
     * \param size The size of the buffer
     */
    template <typename T>
    Buffer(const T* data, size_t size) 
    : data_(reinterpret_cast<const DataType*>(data)), size_(size) {
        static_assert(sizeof(T) == 1, "Buffer must point to elements of 1 byte");
    }

    /**
     * \brief Construct a buffer from a const string ref
     *
     * Note that you *can't use temporaries* here as they would be destructed after
     * the constructor finishes.
     */
    Buffer(const std::string& data); 

    // Don't allow construction from temporaries
    Buffer(std::string&&) = delete;

    Buffer(const Buffer&) = delete;
    Buffer(Buffer&&) = default;
    Buffer& operator=(const Buffer&) = delete;
    Buffer& operator=(Buffer&&) = default;

    /**
     * Getter for the data pointer
     */
    const DataType* get_data() const;

    /**
     * Getter for the size of the buffer
     */
    size_t get_size() const;

    /**
     * Converts the contents of the buffer into a string
     */
    std::string as_string() const;
private:
    const DataType* data_;
    size_t size_;
};

} // cppkafka

#endif // CPPKAFKA_BUFFER_H