/*
  ==============================================================================

   This file is part of the JUCE library.
   Copyright (c) 2017 - ROLI Ltd.

   JUCE is an open source library subject to commercial or open-source
   licensing.

   The code included in this file is provided under the terms of the ISC license
   http://www.isc.org/downloads/software-support-policy/isc-license. Permission
   To use, copy, modify, and/or distribute this software for any purpose with or
   without fee is hereby granted provided that the above copyright notice and
   this permission notice appear in all copies.

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

  ==============================================================================
*/

namespace juce
{

//==============================================================================
/**
    A universally unique 128-bit identifier.

    This class generates very random unique numbers. It's vanishingly unlikely
    that two identical UUIDs would ever be created by chance. The values are
    formatted to meet the RFC 4122 version 4 standard.

    The class includes methods for saving the ID as a string or as raw binary data.

    @tags{Core}
*/
class JUCE_API  Uuid
{
public:
    //==============================================================================
    /** Creates a new unique ID, compliant with RFC 4122 version 4. */
    Uuid();

    /** Destructor. */
    ~Uuid() noexcept;

    /** Creates a copy of another UUID. */
    Uuid (const Uuid&) noexcept;

    /** Copies another UUID. */
    Uuid& operator= (const Uuid&) noexcept;

    //==============================================================================
    /** Returns true if the ID is zero. */
    bool isNull() const noexcept;

    /** Returns a null Uuid object. */
    static Uuid null() noexcept;

    bool operator== (const Uuid&) const noexcept;
    bool operator!= (const Uuid&) const noexcept;
    bool operator<  (const Uuid&) const noexcept;
    bool operator>  (const Uuid&) const noexcept;
    bool operator<= (const Uuid&) const noexcept;
    bool operator>= (const Uuid&) const noexcept;

    //==============================================================================
    /** Returns a stringified version of this UUID.

        A Uuid object can later be reconstructed from this string using operator= or
        the constructor that takes a string parameter.

        @returns a 32 character hex string.
    */
    String toString() const;

    /** Returns a stringified version of this UUID, separating it into sections with dashes.
        @returns a string in the format: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
    */
    String toDashedString() const;

    /** Creates an ID from an encoded string version.
        @see toString
    */
    Uuid (const String& uuidString);

    /** Copies from a stringified UUID.
        The string passed in should be one that was created with the toString() method.
    */
    Uuid& operator= (const String& uuidString);


    //==============================================================================
    /** Returns the time-low section of the UUID. */
    uint32 getTimeLow() const noexcept;
    /** Returns the time-mid section of the UUID. */
    uint16 getTimeMid() const noexcept;
    /** Returns the time-high-and-version section of the UUID. */
    uint16 getTimeHighAndVersion() const noexcept;
    /** Returns the clock-seq-and-reserved section of the UUID. */
    uint8  getClockSeqAndReserved() const noexcept;
    /** Returns the clock-seq-low section of the UUID. */
    uint8  getClockSeqLow() const noexcept;
    /** Returns the node section of the UUID. */
    uint64 getNode() const noexcept;

    /** Returns a hash of the UUID. */
    uint64 hash() const noexcept;

    //==============================================================================
    /** Returns a pointer to the internal binary representation of the ID.

        This is an array of 16 bytes. To reconstruct a Uuid from its data, use
        the constructor or operator= method that takes an array of uint8s.
    */
    const uint8* getRawData() const noexcept                { return uuid; }

    /** Creates a UUID from a 16-byte array.
        @see getRawData
    */
    Uuid (const uint8* rawData) noexcept;

    /** Sets this UUID from 16-bytes of raw data. */
    Uuid& operator= (const uint8* rawData) noexcept;


private:
    //==============================================================================
    uint8 uuid[16];
    String getHexRegion (int, int) const;
    int compare (Uuid) const noexcept;

    JUCE_LEAK_DETECTOR (Uuid)
};

} // namespace juce

#if ! DOXYGEN
namespace std
{
    template <> struct hash<juce::Uuid>
    {
        size_t operator() (const juce::Uuid& u) const noexcept   { return (size_t) u.hash(); }
    };
}
#endif
