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

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2020 - Raw Material Software Limited

   You may use this code under the terms of the GPL v3
   (see www.gnu.org/licenses).

   For this technical preview, this file is not subject to commercial licensing.

   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
{

class FileChooser::Native    : private Component,
                               public FileChooser::Pimpl
{
public:
    Native (FileChooser& fileChooser, int flags)
        : owner (fileChooser)
    {
        String firstFileExtension;

        static FileChooserDelegateClass cls;
        delegate.reset ([cls.createInstance() init]);
        FileChooserDelegateClass::setOwner (delegate.get(), this);

        auto utTypeArray = createNSArrayFromStringArray (getUTTypesForWildcards (owner.filters, firstFileExtension));

        if ((flags & FileBrowserComponent::saveMode) != 0)
        {
            auto currentFileOrDirectory = owner.startingFile;

            UIDocumentPickerMode pickerMode = currentFileOrDirectory.existsAsFile()
                                                ? UIDocumentPickerModeExportToService
                                                : UIDocumentPickerModeMoveToService;

            if (! currentFileOrDirectory.existsAsFile())
            {
                auto filename = getFilename (currentFileOrDirectory, firstFileExtension);
                auto tmpDirectory = File::createTempFile ("JUCE-filepath");

                if (tmpDirectory.createDirectory().wasOk())
                {
                    currentFileOrDirectory = tmpDirectory.getChildFile (filename);
                    currentFileOrDirectory.replaceWithText ("");
                }
                else
                {
                    // Temporary directory creation failed! You need to specify a
                    // path you have write access to. Saving will not work for
                    // current path.
                    jassertfalse;
                }
            }

            auto url = [[NSURL alloc] initFileURLWithPath: juceStringToNS (currentFileOrDirectory.getFullPathName())];
            controller.reset ([[UIDocumentPickerViewController alloc] initWithURL: url
                                                                           inMode: pickerMode]);
            [url release];
        }
        else
        {
            controller.reset ([[UIDocumentPickerViewController alloc] initWithDocumentTypes: utTypeArray
                                                                                      inMode: UIDocumentPickerModeOpen]);
        }

        [controller.get() setDelegate: delegate.get()];
        [controller.get() setModalTransitionStyle: UIModalTransitionStyleCrossDissolve];

        setOpaque (false);

        if (SystemStats::isRunningInAppExtensionSandbox())
        {
            if (fileChooser.parent != nullptr)
            {
                [controller.get() setModalPresentationStyle:UIModalPresentationFullScreen];

                auto chooserBounds = fileChooser.parent->getBounds();
                setBounds (chooserBounds);

                setAlwaysOnTop (true);
                fileChooser.parent->addAndMakeVisible (this);
            }
            else
            {
                // Opening a native top-level window in an AUv3 is not allowed (sandboxing). You need to specify a
                // parent component (for example your editor) to parent the native file chooser window. To do this
                // specify a parent component in the FileChooser's constructor!
                jassert (fileChooser.parent != nullptr);
            }
        }
        else
        {
            auto chooserBounds = Desktop::getInstance().getDisplays().getMainDisplay().userArea;
            setBounds (chooserBounds);

            setAlwaysOnTop (true);
            addToDesktop (0);
        }
    }

    ~Native() override
    {
        exitModalState (0);
    }

    void launch() override
    {
        enterModalState (true, nullptr, true);
    }

    void runModally() override
    {
       #if JUCE_MODAL_LOOPS_PERMITTED
        runModalLoop();
       #endif
    }

private:
    //==============================================================================
    void parentHierarchyChanged() override
    {
        auto* newPeer = dynamic_cast<UIViewComponentPeer*> (getPeer());

        if (peer != newPeer)
        {
            peer = newPeer;

            if (auto* parentController = peer->controller)
                [parentController showViewController: controller.get() sender: parentController];
        }
    }

    //==============================================================================
    static StringArray getUTTypesForWildcards (const String& filterWildcards, String& firstExtension)
    {
        auto filters = StringArray::fromTokens (filterWildcards, ";", "");
        StringArray result;

        firstExtension = {};

        if (! filters.contains ("*") && filters.size() > 0)
        {
            for (auto filter : filters)
            {
                if (filter.isEmpty())
                    continue;

                // iOS only supports file extension wild cards
                jassert (filter.upToLastOccurrenceOf (".", true, false) == "*.");

                auto fileExtension = filter.fromLastOccurrenceOf (".", false, false);
                auto fileExtensionCF = fileExtension.toCFString();

                if (firstExtension.isEmpty())
                    firstExtension = fileExtension;

                auto tag = UTTypeCreatePreferredIdentifierForTag (kUTTagClassFilenameExtension, fileExtensionCF, nullptr);

                if (tag != nullptr)
                {
                    result.add (String::fromCFString (tag));
                    CFRelease (tag);
                }

                CFRelease (fileExtensionCF);
            }
        }
        else
            result.add ("public.data");

        return result;
    }

    static String getFilename (const File& path, const String& fallbackExtension)
    {
        auto filename  = path.getFileNameWithoutExtension();
        auto extension = path.getFileExtension().substring (1);

        if (filename.isEmpty())
            filename = "Untitled";

        if (extension.isEmpty())
            extension = fallbackExtension;

        if (extension.isNotEmpty())
            filename += "." + extension;

        return filename;
    }

    //==============================================================================
    void didPickDocumentAtURL (NSURL* url)
    {
        bool isWriting = controller.get().documentPickerMode == UIDocumentPickerModeExportToService
                       | controller.get().documentPickerMode == UIDocumentPickerModeMoveToService;

        NSUInteger accessOptions = isWriting ? 0 : NSFileCoordinatorReadingWithoutChanges;

        auto* fileAccessIntent = isWriting
                               ? [NSFileAccessIntent writingIntentWithURL: url options: accessOptions]
                               : [NSFileAccessIntent readingIntentWithURL: url options: accessOptions];

        NSArray<NSFileAccessIntent*>* intents = @[fileAccessIntent];

        auto fileCoordinator = [[[NSFileCoordinator alloc] initWithFilePresenter: nil] autorelease];

        [fileCoordinator coordinateAccessWithIntents: intents queue: [NSOperationQueue mainQueue] byAccessor: ^(NSError* err)
        {
            Array<URL> chooserResults;

            if (err == nil)
            {
                [url startAccessingSecurityScopedResource];

                NSError* error = nil;

                NSData* bookmark = [url bookmarkDataWithOptions: 0
                                 includingResourceValuesForKeys: nil
                                                  relativeToURL: nil
                                                          error: &error];

                [bookmark retain];

                [url stopAccessingSecurityScopedResource];

                URL juceUrl (nsStringToJuce ([url absoluteString]));

                if (error == nil)
                {
                    setURLBookmark (juceUrl, (void*) bookmark);
                }
                else
                {
                    auto desc = [error localizedDescription];
                    ignoreUnused (desc);
                    jassertfalse;
                }

                chooserResults.add (juceUrl);
            }
            else
            {
                auto desc = [err localizedDescription];
                ignoreUnused (desc);
                jassertfalse;
            }

            owner.finished (chooserResults);
        }];
    }

    void pickerWasCancelled()
    {
        Array<URL> chooserResults;

        owner.finished (chooserResults);
        exitModalState (0);
    }

    //==============================================================================
    struct FileChooserDelegateClass  : public ObjCClass<NSObject<UIDocumentPickerDelegate>>
    {
        FileChooserDelegateClass()  : ObjCClass<NSObject<UIDocumentPickerDelegate>> ("FileChooserDelegate_")
        {
            addIvar<Native*> ("owner");

            addMethod (@selector (documentPicker:didPickDocumentAtURL:), didPickDocumentAtURL,       "v@:@@");
            addMethod (@selector (documentPickerWasCancelled:),          documentPickerWasCancelled, "v@:@");

            addProtocol (@protocol (UIDocumentPickerDelegate));

            registerClass();
        }

        static void setOwner (id self, Native* owner)   { object_setInstanceVariable (self, "owner", owner); }
        static Native* getOwner (id self)               { return getIvar<Native*> (self, "owner"); }

        //==============================================================================
        static void didPickDocumentAtURL (id self, SEL, UIDocumentPickerViewController*, NSURL* url)
        {
            auto picker = getOwner (self);

            if (picker != nullptr)
                picker->didPickDocumentAtURL (url);
        }

        static void documentPickerWasCancelled (id self, SEL, UIDocumentPickerViewController*)
        {
            auto picker = getOwner (self);

            if (picker != nullptr)
                picker->pickerWasCancelled();
        }
    };

    //==============================================================================
    FileChooser& owner;
    std::unique_ptr<NSObject<UIDocumentPickerDelegate>, NSObjectDeleter> delegate;
    std::unique_ptr<UIDocumentPickerViewController,     NSObjectDeleter> controller;
    UIViewComponentPeer* peer = nullptr;

    static FileChooserDelegateClass fileChooserDelegateClass;

    //==============================================================================
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (Native)
};

//==============================================================================
bool FileChooser::isPlatformDialogAvailable()
{
   #if JUCE_DISABLE_NATIVE_FILECHOOSERS
    return false;
   #else
    return true;
   #endif
}

FileChooser::Pimpl* FileChooser::showPlatformDialog (FileChooser& owner, int flags,
                                                     FilePreviewComponent*)
{
    return new FileChooser::Native (owner, flags);
}

} // namespace juce