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

   This file is part of the JUCE framework.
   Copyright (c) Raw Material Software Limited

   JUCE is an open source framework subject to commercial or open source
   licensing.

   By downloading, installing, or using the JUCE framework, or combining the
   JUCE framework with any other source code, object code, content or any other
   copyrightable work, you agree to the terms of the JUCE End User Licence
   Agreement, and all incorporated terms including the JUCE Privacy Policy and
   the JUCE Website Terms of Service, as applicable, which will bind you. If you
   do not agree to the terms of these agreements, we will not license the JUCE
   framework to you, and you must discontinue the installation or download
   process and cease use of the JUCE framework.

   JUCE End User Licence Agreement: https://juce.com/legal/juce-8-licence/
   JUCE Privacy Policy: https://juce.com/juce-privacy-policy
   JUCE Website Terms of Service: https://juce.com/juce-website-terms-of-service/

   Or:

   You may also use this code under the terms of the AGPLv3:
   https://www.gnu.org/licenses/agpl-3.0.en.html

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

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

namespace juce
{

// Using Random::getSystemRandom() can be a bit dangerous in multithreaded contexts!
class LockedRandom
{
public:
    int nextInt()
    {
        const ScopedLock lock (mutex);
        return random.nextInt();
    }

private:
    CriticalSection mutex;
    Random random;
};

static LockedRandom lockedRandom;

static File createTempFile (const File& parentDirectory, String name,
                            const String& suffix, int optionFlags)
{
    if ((optionFlags & TemporaryFile::useHiddenFile) != 0)
        name = "." + name;

    return parentDirectory.getNonexistentChildFile (name, suffix, (optionFlags & TemporaryFile::putNumbersInBrackets) != 0);
}

TemporaryFile::TemporaryFile (const String& suffix, const int optionFlags)
    : temporaryFile (createTempFile (File::getSpecialLocation (File::tempDirectory),
                                     "temp_" + String::toHexString (lockedRandom.nextInt()),
                                     suffix, optionFlags)),
      targetFile()
{
}

TemporaryFile::TemporaryFile (const File& target, const int optionFlags)
    : temporaryFile (createTempFile (target.getParentDirectory(),
                                     target.getFileNameWithoutExtension()
                                       + "_temp" + String::toHexString (lockedRandom.nextInt()),
                                     target.getFileExtension(), optionFlags)),
      targetFile (target)
{
    // If you use this constructor, you need to give it a valid target file!
    jassert (targetFile != File());
}

TemporaryFile::TemporaryFile (const File& target, const File& temporary)
    : temporaryFile (temporary), targetFile (target)
{
}

TemporaryFile::~TemporaryFile()
{
    if (! deleteTemporaryFile())
    {
        /* Failed to delete our temporary file! The most likely reason for this would be
           that you've not closed an output stream that was being used to write to file.

           If you find that something beyond your control is changing permissions on
           your temporary files and preventing them from being deleted, you may want to
           call TemporaryFile::deleteTemporaryFile() to detect those error cases and
           handle them appropriately.
        */
        jassertfalse;
    }
}

//==============================================================================
bool TemporaryFile::overwriteTargetFileWithTemporary() const
{
    // This method only works if you created this object with the constructor
    // that takes a target file!
    jassert (targetFile != File());

    if (temporaryFile.exists())
    {
        // Have a few attempts at overwriting the file before giving up..
        for (int i = 5; --i >= 0;)
        {
            if (temporaryFile.replaceFileIn (targetFile))
                return true;

            Thread::sleep (100);
        }
    }
    else
    {
        // There's no temporary file to use. If your write failed, you should
        // probably check, and not bother calling this method.
        jassertfalse;
    }

    return false;
}

bool TemporaryFile::deleteTemporaryFile() const
{
    // Have a few attempts at deleting the file before giving up..
    for (int i = 5; --i >= 0;)
    {
        if (temporaryFile.isDirectory() ? temporaryFile.deleteRecursively() : temporaryFile.deleteFile())
            return true;

        Thread::sleep (50);
    }

    return false;
}

} // namespace juce
