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

   This file is part of the JUCE 7 technical preview.
   Copyright (c) 2022 - Raw Material Software Limited

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

   For the technical preview this file cannot be licensed commercially.

   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
{

//==============================================================================
static NSMutableArray* createAllowedTypesArray (const StringArray& filters)
{
    if (filters.size() == 0)
        return nil;

    NSMutableArray* filterArray = [[[NSMutableArray alloc] init] autorelease];

    for (int i = 0; i < filters.size(); ++i)
    {
        // From OS X 10.6 you can only specify allowed extensions, so any filters containing wildcards
        // must be of the form "*.extension"
        jassert (filters[i] == "*"
                 || (filters[i].startsWith ("*.") && filters[i].lastIndexOfChar ('*') == 0));
        const String f (filters[i].replace ("*.", ""));

        if (f == "*")
            return nil;

        [filterArray addObject: juceStringToNS (f)];
    }

    return filterArray;
}

//==============================================================================
class FileChooser::Native     : public Component,
                                public FileChooser::Pimpl
{
public:
    Native (FileChooser& fileChooser, int flags, FilePreviewComponent* previewComponent)
        : owner (fileChooser), preview (previewComponent),
          selectsDirectories ((flags & FileBrowserComponent::canSelectDirectories)   != 0),
          selectsFiles       ((flags & FileBrowserComponent::canSelectFiles)         != 0),
          isSave             ((flags & FileBrowserComponent::saveMode)               != 0),
          selectMultiple     ((flags & FileBrowserComponent::canSelectMultipleItems) != 0)
    {
        setBounds (0, 0, 0, 0);
        setOpaque (true);

        static DelegateClass delegateClass;
        static SafeSavePanel safeSavePanel;
        static SafeOpenPanel safeOpenPanel;

        panel = isSave ? [safeSavePanel.createInstance() init]
                       : [safeOpenPanel.createInstance() init];

        delegate = [delegateClass.createInstance() init];
        object_setInstanceVariable (delegate, "cppObject", this);

        [panel setDelegate: delegate];

        filters.addTokens (owner.filters.replaceCharacters (",:", ";;"), ";", String());
        filters.trim();
        filters.removeEmptyStrings();

        auto* nsTitle = juceStringToNS (owner.title);
        [panel setTitle: nsTitle];
        [panel setReleasedWhenClosed: YES];

        JUCE_BEGIN_IGNORE_WARNINGS_GCC_LIKE ("-Wdeprecated-declarations")
        [panel setAllowedFileTypes: createAllowedTypesArray (filters)];
        JUCE_END_IGNORE_WARNINGS_GCC_LIKE

        if (! isSave)
        {
            auto* openPanel = static_cast<NSOpenPanel*> (panel);

            [openPanel setCanChooseDirectories: selectsDirectories];
            [openPanel setCanChooseFiles: selectsFiles];
            [openPanel setAllowsMultipleSelection: selectMultiple];
            [openPanel setResolvesAliases: YES];
            [openPanel setMessage: nsTitle]; // equivalent to the title bar since 10.11

            if (owner.treatFilePackagesAsDirs)
                [openPanel setTreatsFilePackagesAsDirectories: YES];
        }

        if (preview != nullptr)
        {
            nsViewPreview = [[NSView alloc] initWithFrame: makeNSRect (preview->getLocalBounds())];
            [panel setAccessoryView: nsViewPreview];

            preview->addToDesktop (0, (void*) nsViewPreview);
            preview->setVisible (true);

            if (@available (macOS 10.11, *))
            {
                if (! isSave)
                {
                    auto* openPanel = static_cast<NSOpenPanel*> (panel);
                    [openPanel setAccessoryViewDisclosed: YES];
                }
            }
        }

        if (isSave || selectsDirectories)
            [panel setCanCreateDirectories: YES];

        [panel setLevel: NSModalPanelWindowLevel];

        if (owner.startingFile.isDirectory())
        {
            startingDirectory = owner.startingFile.getFullPathName();
        }
        else
        {
            startingDirectory = owner.startingFile.getParentDirectory().getFullPathName();
            filename = owner.startingFile.getFileName();
        }

        [panel setDirectoryURL: createNSURLFromFile (startingDirectory)];
        [panel setNameFieldStringValue: juceStringToNS (filename)];
    }

    ~Native() override
    {
        exitModalState (0);

        if (preview != nullptr)
            preview->removeFromDesktop();

        removeFromDesktop();

        if (panel != nil)
        {
            [panel setDelegate: nil];

            if (nsViewPreview != nil)
            {
                [panel setAccessoryView: nil];
                [nsViewPreview release];
            }

            [panel close];
        }

        if (delegate != nil)
            [delegate release];
    }

    void launch() override
    {
        if (panel != nil)
        {
            setAlwaysOnTop (juce_areThereAnyAlwaysOnTopWindows());
            addToDesktop (0);

            enterModalState (true);

            MessageManager::callAsync ([ref = SafePointer<Native> (this)]
            {
                if (ref == nullptr)
                    return;

                [ref->panel beginWithCompletionHandler: CreateObjCBlock (ref.getComponent(), &Native::finished)];

                if (ref->preview != nullptr)
                    ref->preview->toFront (true);
            });
        }
    }

    void runModally() override
    {
       #if JUCE_MODAL_LOOPS_PERMITTED
        ensurePanelSafe();

        std::unique_ptr<TemporaryMainMenuWithStandardCommands> tempMenu;

        if (JUCEApplicationBase::isStandaloneApp())
            tempMenu = std::make_unique<TemporaryMainMenuWithStandardCommands> (preview);

        jassert (panel != nil);
        auto result = [panel runModal];
        finished (result);
       #else
        jassertfalse;
       #endif
    }

    bool canModalEventBeSentToComponent (const Component* targetComponent) override
    {
        return TemporaryMainMenuWithStandardCommands::checkModalEvent (preview, targetComponent);
    }

private:
    //==============================================================================
    typedef NSObject<NSOpenSavePanelDelegate> DelegateType;

    static URL urlFromNSURL (NSURL* url)
    {
        const auto scheme = nsStringToJuce ([url scheme]);

        auto pathComponents = StringArray::fromTokens (nsStringToJuce ([url path]), "/", {});

        for (auto& component : pathComponents)
            component = URL::addEscapeChars (component, false);

        return { scheme + "://" + pathComponents.joinIntoString ("/") };
    }

    void finished (NSInteger result)
    {
        Array<URL> chooserResults;

        exitModalState (0);

        const auto okResult = []() -> NSInteger
        {
            if (@available (macOS 10.9, *))
                return NSModalResponseOK;

            JUCE_BEGIN_IGNORE_WARNINGS_GCC_LIKE ("-Wdeprecated-declarations")
            return NSFileHandlingPanelOKButton;
            JUCE_END_IGNORE_WARNINGS_GCC_LIKE
        }();

        if (panel != nil && result == okResult)
        {
            auto addURLResult = [&chooserResults] (NSURL* urlToAdd)
            {
                chooserResults.add (urlFromNSURL (urlToAdd));
            };

            if (isSave)
            {
                addURLResult ([panel URL]);
            }
            else
            {
                auto* openPanel = static_cast<NSOpenPanel*> (panel);
                auto urls = [openPanel URLs];

                for (unsigned int i = 0; i < [urls count]; ++i)
                    addURLResult ([urls objectAtIndex: i]);
            }
        }

        owner.finished (chooserResults);
    }

    BOOL shouldShowURL (const URL& urlToTest)
    {
        for (int i = filters.size(); --i >= 0;)
            if (urlToTest.getFileName().matchesWildcard (filters[i], true))
                return YES;

        const auto f = urlToTest.getLocalFile();
        return f.isDirectory()
                 && ! [[NSWorkspace sharedWorkspace] isFilePackageAtPath: juceStringToNS (f.getFullPathName())];
    }

    void panelSelectionDidChange (id sender)
    {
        jassert (sender == panel);
        ignoreUnused (sender);

        // NB: would need to extend FilePreviewComponent to handle the full list rather than just the first one
        if (preview != nullptr)
            preview->selectedFileChanged (File (getSelectedPaths()[0]));
    }

    StringArray getSelectedPaths() const
    {
        if (panel == nullptr)
            return {};

        StringArray paths;

        if (isSave)
        {
            paths.add (nsStringToJuce ([[panel URL] path]));
        }
        else
        {
            auto* urls = [static_cast<NSOpenPanel*> (panel) URLs];

            for (NSUInteger i = 0; i < [urls count]; ++i)
                paths.add (nsStringToJuce ([[urls objectAtIndex: i] path]));
        }

        return paths;
    }

    //==============================================================================
    FileChooser& owner;
    FilePreviewComponent* preview;
    NSView* nsViewPreview = nullptr;
    bool selectsDirectories, selectsFiles, isSave, selectMultiple;

    NSSavePanel* panel;
    DelegateType* delegate;

    StringArray filters;
    String startingDirectory, filename;

    void ensurePanelSafe()
    {
        // If you hit this, something (probably the plugin host) has modified the panel,
        // allowing the application to terminate while the panel's modal loop is running.
        // This is a very bad idea! Quitting from within the panel's modal loop may cause
        // your plugin/app destructor to run directly from within `runModally`, which will
        // dispose all app resources while they're still in use.
        // A safer alternative is to invoke the FileChooser with `launchAsync`, rather than
        // using the modal launchers.
        jassert ([panel preventsApplicationTerminationWhenModal]);
    }

    static BOOL preventsApplicationTerminationWhenModal (id, SEL) { return YES; }

    template <typename Base>
    struct SafeModalPanel : public ObjCClass<Base>
    {
        explicit SafeModalPanel (const char* name) : ObjCClass<Base> (name)
        {
            this->addMethod (@selector (preventsApplicationTerminationWhenModal),
                             preventsApplicationTerminationWhenModal);

            this->registerClass();
        }
    };

    struct SafeSavePanel : SafeModalPanel<NSSavePanel>
    {
        SafeSavePanel() : SafeModalPanel ("SaveSavePanel_") {}
    };

    struct SafeOpenPanel : SafeModalPanel<NSOpenPanel>
    {
        SafeOpenPanel() : SafeModalPanel ("SaveOpenPanel_") {}
    };

    //==============================================================================
    struct DelegateClass : public ObjCClass<DelegateType>
    {
        DelegateClass() : ObjCClass<DelegateType> ("JUCEFileChooser_")
        {
            addIvar<Native*> ("cppObject");

            addMethod (@selector (panel:shouldEnableURL:),   shouldEnableURL);
            addMethod (@selector (panelSelectionDidChange:), panelSelectionDidChange);

            addProtocol (@protocol (NSOpenSavePanelDelegate));

            registerClass();
        }

    private:
        static BOOL shouldEnableURL (id self, SEL, id /*sender*/, NSURL* url)
        {
            return getIvar<Native*> (self, "cppObject")->shouldShowURL (urlFromNSURL (url));
        }

        static void panelSelectionDidChange (id self, SEL, id sender)
        {
            getIvar<Native*> (self, "cppObject")->panelSelectionDidChange (sender);
        }
    };

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (Native)
};

std::shared_ptr<FileChooser::Pimpl> FileChooser::showPlatformDialog (FileChooser& owner, int flags,
                                                                     FilePreviewComponent* preview)
{
    return std::make_shared<FileChooser::Native> (owner, flags, preview);
}

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

}