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

   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-9-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
{

namespace PropertyFileConstants
{
    constexpr static const int magicNumber            = (int) ByteOrder::makeInt ('P', 'R', 'O', 'P');
    constexpr static const int magicNumberCompressed  = (int) ByteOrder::makeInt ('C', 'P', 'R', 'P');

    constexpr static const char* const fileTag        = "PROPERTIES";
    constexpr static const char* const valueTag       = "VALUE";
    constexpr static const char* const nameAttribute  = "name";
    constexpr static const char* const valueAttribute = "val";
}

//==============================================================================
PropertiesFile::Options::Options()
    : commonToAllUsers (false),
      ignoreCaseOfKeyNames (false),
      doNotSave (false),
      millisecondsBeforeSaving (3000),
      storageFormat (PropertiesFile::storeAsXML),
      processLock (nullptr)
{
}

File PropertiesFile::Options::getDefaultFile() const
{
    // mustn't have illegal characters in this name
    jassert (applicationName == File::createLegalFileName (applicationName));

   #if JUCE_MAC || JUCE_IOS
    File dir (commonToAllUsers ?  "/Library/"
                               : "~/Library/");

    if (osxLibrarySubFolder != "Preferences"
        && ! osxLibrarySubFolder.startsWith ("Application Support")
        && ! osxLibrarySubFolder.startsWith ("Containers"))
    {
        /* The PropertiesFile class always used to put its settings files in "Library/Preferences", but Apple
           have changed their advice, and now stipulate that settings should go in "Library/Application Support",
           or Library/Containers/[app_bundle_id] for a sandboxed app.

           Because older apps would be broken by a silent change in this class's behaviour, you must now
           explicitly set the osxLibrarySubFolder value to indicate which path you want to use.

           In newer apps, you should always set this to "Application Support"
           or "Application Support/YourSubFolderName".

           If your app needs to load settings files that were created by older versions of juce and
           you want to maintain backwards-compatibility, then you can set this to "Preferences".
           But, for better Apple-compliance, the recommended approach would be to write some code that
           finds your old settings files in ~/Library/Preferences, moves them to ~/Library/Application Support,
           and then uses the new path.
        */
        jassertfalse;

        dir = dir.getChildFile ("Application Support");
    }
    else
    {
        dir = dir.getChildFile (osxLibrarySubFolder);
    }

    if (folderName.isNotEmpty())
        dir = dir.getChildFile (folderName);

   #elif JUCE_LINUX || JUCE_BSD || JUCE_ANDROID
    auto dir = File (commonToAllUsers ? "/var" : "~")
                      .getChildFile (folderName.isNotEmpty() ? folderName
                                                             : ("." + applicationName));

   #elif JUCE_WINDOWS
    auto dir = File::getSpecialLocation (commonToAllUsers ? File::commonApplicationDataDirectory
                                                          : File::userApplicationDataDirectory);

    if (dir == File())
        return {};

    dir = dir.getChildFile (folderName.isNotEmpty() ? folderName
                                                    : applicationName);
   #endif

    return (filenameSuffix.startsWithChar (L'.')
               ? dir.getChildFile (applicationName).withFileExtension (filenameSuffix)
               : dir.getChildFile (applicationName + "." + filenameSuffix));
}


//==============================================================================
PropertiesFile::PropertiesFile (const File& f, const Options& o)
    : PropertySet (o.ignoreCaseOfKeyNames),
      file (f), options (o)
{
    reload();
}

PropertiesFile::PropertiesFile (const Options& o)
    : PropertySet (o.ignoreCaseOfKeyNames),
      file (o.getDefaultFile()), options (o)
{
    reload();
}

bool PropertiesFile::reload()
{
    ProcessScopedLock pl (createProcessLock());

    if (pl != nullptr && ! pl->isLocked())
        return false; // locking failure

    loadedOk = (! file.exists()) || loadAsBinary() || loadAsXml();
    return loadedOk;
}

PropertiesFile::~PropertiesFile()
{
    saveIfNeeded();
}

InterProcessLock::ScopedLockType* PropertiesFile::createProcessLock() const
{
    return options.processLock != nullptr ? new InterProcessLock::ScopedLockType (*options.processLock) : nullptr;
}

bool PropertiesFile::saveIfNeeded()
{
    const ScopedLock sl (getLock());
    return (! needsWriting) || save();
}

bool PropertiesFile::needsToBeSaved() const
{
    const ScopedLock sl (getLock());
    return needsWriting;
}

void PropertiesFile::setNeedsToBeSaved (const bool needsToBeSaved_)
{
    const ScopedLock sl (getLock());
    needsWriting = needsToBeSaved_;
}

bool PropertiesFile::save()
{
    const ScopedLock sl (getLock());

    stopTimer();

    if (options.doNotSave
         || file == File()
         || file.isDirectory()
         || ! file.getParentDirectory().createDirectory())
        return false;

    if (options.storageFormat == storeAsXML)
        return saveAsXml();

    return saveAsBinary();
}

bool PropertiesFile::loadAsXml()
{
    if (auto doc = parseXMLIfTagMatches (file, PropertyFileConstants::fileTag))
    {
        for (auto* e : doc->getChildWithTagNameIterator (PropertyFileConstants::valueTag))
        {
            auto name = e->getStringAttribute (PropertyFileConstants::nameAttribute);

            if (name.isNotEmpty())
                getAllProperties().set (name,
                                        e->getFirstChildElement() != nullptr
                                            ? e->getFirstChildElement()->toString (XmlElement::TextFormat().singleLine().withoutHeader())
                                            : e->getStringAttribute (PropertyFileConstants::valueAttribute));
        }

        return true;
    }

    return false;
}

bool PropertiesFile::saveAsXml()
{
    XmlElement doc (PropertyFileConstants::fileTag);
    auto& props = getAllProperties();

    for (int i = 0; i < props.size(); ++i)
    {
        auto* e = doc.createNewChildElement (PropertyFileConstants::valueTag);
        e->setAttribute (PropertyFileConstants::nameAttribute, props.getAllKeys() [i]);

        // if the value seems to contain xml, store it as such
        if (auto childElement = parseXML (props.getAllValues() [i]))
            e->addChildElement (childElement.release());
        else
            e->setAttribute (PropertyFileConstants::valueAttribute, props.getAllValues() [i]);
    }

    ProcessScopedLock pl (createProcessLock());

    if (pl != nullptr && ! pl->isLocked())
        return false; // locking failure

    if (doc.writeTo (file, {}))
    {
        needsWriting = false;
        return true;
    }

    return false;
}

bool PropertiesFile::loadAsBinary()
{
    FileInputStream fileStream (file);

    if (fileStream.openedOk())
    {
        auto magicNumber = fileStream.readInt();

        if (magicNumber == PropertyFileConstants::magicNumberCompressed)
        {
            SubregionStream subStream (&fileStream, 4, -1, false);
            GZIPDecompressorInputStream gzip (subStream);
            return loadAsBinary (gzip);
        }

        if (magicNumber == PropertyFileConstants::magicNumber)
            return loadAsBinary (fileStream);
    }

    return false;
}

bool PropertiesFile::loadAsBinary (InputStream& input)
{
    BufferedInputStream in (input, 2048);

    int numValues = in.readInt();

    while (--numValues >= 0 && ! in.isExhausted())
    {
        auto key = in.readString();
        auto value = in.readString();
        jassert (key.isNotEmpty());

        if (key.isNotEmpty())
            getAllProperties().set (key, value);
    }

    return true;
}

bool PropertiesFile::saveAsBinary()
{
    ProcessScopedLock pl (createProcessLock());

    if (pl != nullptr && ! pl->isLocked())
        return false; // locking failure

    TemporaryFile tempFile (file);

    {
        FileOutputStream out (tempFile.getFile());

        if (! out.openedOk())
            return false;

        if (options.storageFormat == storeAsCompressedBinary)
        {
            out.writeInt (PropertyFileConstants::magicNumberCompressed);
            out.flush();

            GZIPCompressorOutputStream zipped (out, 9);

            if (! writeToStream (zipped))
                return false;
        }
        else
        {
            // have you set up the storage option flags correctly?
            jassert (options.storageFormat == storeAsBinary);

            out.writeInt (PropertyFileConstants::magicNumber);

            if (! writeToStream (out))
                return false;
        }
    }

    if (! tempFile.overwriteTargetFileWithTemporary())
        return false;

    needsWriting = false;
    return true;
}

bool PropertiesFile::writeToStream (OutputStream& out)
{
    auto& props  = getAllProperties();
    auto& keys   = props.getAllKeys();
    auto& values = props.getAllValues();
    auto numProperties = props.size();

    if (! out.writeInt (numProperties))
        return false;

    for (int i = 0; i < numProperties; ++i)
    {
        if (! out.writeString (keys[i]))   return false;
        if (! out.writeString (values[i])) return false;
    }

    return true;
}

void PropertiesFile::timerCallback()
{
    saveIfNeeded();
}

void PropertiesFile::propertyChanged()
{
    sendChangeMessage();
    needsWriting = true;

    if (options.millisecondsBeforeSaving > 0)
        startTimer (options.millisecondsBeforeSaving);
    else if (options.millisecondsBeforeSaving == 0)
        saveIfNeeded();
}

} // namespace juce
