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

   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.

   By using JUCE, you agree to the terms of both the JUCE 5 End-User License
   Agreement and JUCE 5 Privacy Policy (both updated and effective as of the
   27th April 2017).

   End User License Agreement: www.juce.com/juce-5-licence
   Privacy Policy: www.juce.com/juce-5-privacy-policy

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

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

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

#if JUCE_MAC

struct WebViewKeyEquivalentResponder : public ObjCClass<WebView>
{
    WebViewKeyEquivalentResponder() : ObjCClass<WebView> ("WebViewKeyEquivalentResponder_")
    {
        addMethod (@selector (performKeyEquivalent:), performKeyEquivalent, @encode (BOOL), "@:@");
        registerClass();
    }

private:
    static BOOL performKeyEquivalent (id self, SEL selector, NSEvent* event)
    {
        NSResponder* first = [[self window] firstResponder];
        if (([event modifierFlags] & NSDeviceIndependentModifierFlagsMask) == NSCommandKeyMask)
        {
            if ([[event charactersIgnoringModifiers] isEqualToString:@"x"]) return [NSApp sendAction:@selector(cut:)       to:first from:self];
            if ([[event charactersIgnoringModifiers] isEqualToString:@"c"]) return [NSApp sendAction:@selector(copy:)      to:first from:self];
            if ([[event charactersIgnoringModifiers] isEqualToString:@"v"]) return [NSApp sendAction:@selector(paste:)     to:first from:self];
            if ([[event charactersIgnoringModifiers] isEqualToString:@"a"]) return [NSApp sendAction:@selector(selectAll:) to:first from:self];
        }

        objc_super s = { self, [WebView class] };
        return ObjCMsgSendSuper<BOOL, NSEvent*> (&s, selector, event);
    }
};

struct DownloadClickDetectorClass  : public ObjCClass<NSObject>
{
    DownloadClickDetectorClass()  : ObjCClass<NSObject> ("JUCEWebClickDetector_")
    {
        addIvar<WebBrowserComponent*> ("owner");

        addMethod (@selector (webView:decidePolicyForNavigationAction:request:frame:decisionListener:),
                   decidePolicyForNavigationAction, "v@:@@@@@");
        addMethod (@selector (webView:decidePolicyForNewWindowAction:request:newFrameName:decisionListener:),
                   decidePolicyForNewWindowAction, "v@:@@@@@");
        addMethod (@selector (webView:didFinishLoadForFrame:), didFinishLoadForFrame, "v@:@@");
        addMethod (@selector (webView:didFailLoadWithError:forFrame:),  didFailLoadWithError,  "v@:@@@");
        addMethod (@selector (webView:didFailProvisionalLoadWithError:forFrame:),  didFailLoadWithError,  "v@:@@@");
        addMethod (@selector (webView:willCloseFrame:), willCloseFrame, "v@:@@");
        addMethod (@selector (webView:runOpenPanelForFileButtonWithResultListener:allowMultipleFiles:), runOpenPanel, "v@:@@", @encode (BOOL));

        registerClass();
    }

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

private:
    static String getOriginalURL (NSDictionary* actionInformation)
    {
        if (NSURL* url = [actionInformation valueForKey: nsStringLiteral ("WebActionOriginalURLKey")])
            return nsStringToJuce ([url absoluteString]);

        return {};
    }

    static void decidePolicyForNavigationAction (id self, SEL, WebView*, NSDictionary* actionInformation,
                                                 NSURLRequest*, WebFrame*, id<WebPolicyDecisionListener> listener)
    {
        if (getOwner (self)->pageAboutToLoad (getOriginalURL (actionInformation)))
            [listener use];
        else
            [listener ignore];
    }

    static void decidePolicyForNewWindowAction (id self, SEL, WebView*, NSDictionary* actionInformation,
                                                NSURLRequest*, NSString*, id<WebPolicyDecisionListener> listener)
    {
        getOwner (self)->newWindowAttemptingToLoad (getOriginalURL (actionInformation));
        [listener ignore];
    }

    static void didFinishLoadForFrame (id self, SEL, WebView* sender, WebFrame* frame)
    {
        if ([frame isEqual: [sender mainFrame]])
        {
            NSURL* url = [[[frame dataSource] request] URL];
            getOwner (self)->pageFinishedLoading (nsStringToJuce ([url absoluteString]));
        }
    }

    static void didFailLoadWithError (id self, SEL, WebView* sender, NSError* error, WebFrame* frame)
    {
        if ([frame isEqual: [sender mainFrame]] && error != nullptr && [error code] != NSURLErrorCancelled)
        {
            String errorString (nsStringToJuce ([error localizedDescription]));

            bool proceedToErrorPage = getOwner (self)->pageLoadHadNetworkError (errorString);

            // WebKit doesn't have an internal error page, so make a really simple one ourselves
            if (proceedToErrorPage)
                getOwner(self)->goToURL (String ("data:text/plain;charset=UTF-8,") + errorString);
        }
    }

    static void willCloseFrame (id self, SEL, WebView*, WebFrame*)
    {
        getOwner (self)->windowCloseRequest();
    }

    static void runOpenPanel (id, SEL, WebView*, id<WebOpenPanelResultListener> resultListener, BOOL allowMultipleFiles)
    {
       #if JUCE_MODAL_LOOPS_PERMITTED
        FileChooser chooser (TRANS("Select the file you want to upload..."),
                             File::getSpecialLocation (File::userHomeDirectory), "*");

        if (allowMultipleFiles ? chooser.browseForMultipleFilesToOpen()
                               : chooser.browseForFileToOpen())
        {
            for (auto& f : chooser.getResults())
                [resultListener chooseFilename: juceStringToNS (f.getFullPathName())];
        }
       #else
        ignoreUnused (resultListener, allowMultipleFiles);
        jassertfalse; // Can't use this without modal loops being enabled!
       #endif
    }
};

#else

} // (juce namespace)

//==============================================================================
@interface WebViewTapDetector  : NSObject<UIGestureRecognizerDelegate>
{
}

- (BOOL) gestureRecognizer: (UIGestureRecognizer*) gestureRecognizer
         shouldRecognizeSimultaneouslyWithGestureRecognizer: (UIGestureRecognizer*) otherGestureRecognizer;
@end

@implementation WebViewTapDetector

- (BOOL) gestureRecognizer: (UIGestureRecognizer*) gestureRecognizer
         shouldRecognizeSimultaneouslyWithGestureRecognizer: (UIGestureRecognizer*) otherGestureRecognizer
{
    ignoreUnused (gestureRecognizer, otherGestureRecognizer);
    return YES;
}

@end

//==============================================================================
@interface WebViewURLChangeDetector : NSObject<UIWebViewDelegate>
{
    juce::WebBrowserComponent* ownerComponent;
}

- (WebViewURLChangeDetector*) initWithWebBrowserOwner: (juce::WebBrowserComponent*) ownerComponent;
- (BOOL) webView: (UIWebView*) webView shouldStartLoadWithRequest: (NSURLRequest*) request
                                                   navigationType: (UIWebViewNavigationType) navigationType;
- (void) webViewDidFinishLoad: (UIWebView*) webView;
@end

@implementation WebViewURLChangeDetector

- (WebViewURLChangeDetector*) initWithWebBrowserOwner: (juce::WebBrowserComponent*) ownerComp
{
    [super init];
    ownerComponent = ownerComp;
    return self;
}

- (BOOL) webView: (UIWebView*) webView shouldStartLoadWithRequest: (NSURLRequest*) request
                                                   navigationType: (UIWebViewNavigationType) navigationType
{
    ignoreUnused (webView, navigationType);
    return ownerComponent->pageAboutToLoad (nsStringToJuce (request.URL.absoluteString));
}

- (void) webViewDidFinishLoad: (UIWebView*) webView
{
    ownerComponent->pageFinishedLoading (nsStringToJuce (webView.request.URL.absoluteString));
}
@end

namespace juce {

#endif

//==============================================================================
class WebBrowserComponent::Pimpl
                                   #if JUCE_MAC
                                    : public NSViewComponent
                                   #else
                                    : public UIViewComponent
                                   #endif
{
public:
    Pimpl (WebBrowserComponent* owner)
    {
       #if JUCE_MAC
        static WebViewKeyEquivalentResponder webviewClass;
        webView = (WebView*) webviewClass.createInstance();

        webView = [webView initWithFrame: NSMakeRect (0, 0, 100.0f, 100.0f)
                               frameName: nsEmptyString()
                               groupName: nsEmptyString()];
        setView (webView);

        static DownloadClickDetectorClass cls;
        clickListener = [cls.createInstance() init];
        DownloadClickDetectorClass::setOwner (clickListener, owner);
        [webView setPolicyDelegate: clickListener];
        [webView setFrameLoadDelegate: clickListener];
        [webView setUIDelegate: clickListener];
       #else
        webView = [[UIWebView alloc] initWithFrame: CGRectMake (0, 0, 1.0f, 1.0f)];
        setView (webView);

        tapDetector = [[WebViewTapDetector alloc] init];
        urlDetector = [[WebViewURLChangeDetector alloc] initWithWebBrowserOwner: owner];
        gestureRecogniser = nil;
        webView.delegate = urlDetector;
       #endif
    }

    ~Pimpl()
    {
       #if JUCE_MAC
        [webView setPolicyDelegate: nil];
        [webView setFrameLoadDelegate: nil];
        [webView setUIDelegate: nil];
        [clickListener release];
       #else
        webView.delegate = nil;
        [webView removeGestureRecognizer: gestureRecogniser];
        [gestureRecogniser release];
        [tapDetector release];
        [urlDetector release];
       #endif

        setView (nil);
    }

    void goToURL (const String& url,
                  const StringArray* headers,
                  const MemoryBlock* postData)
    {
        stop();

        if (url.trimStart().startsWithIgnoreCase ("javascript:"))
        {
            [webView stringByEvaluatingJavaScriptFromString:
                juceStringToNS (url.fromFirstOccurrenceOf (":", false, false))];
        }
        else
        {
            NSString* urlString = juceStringToNS (url);

           #if (JUCE_MAC && (defined (__MAC_OS_X_VERSION_MIN_REQUIRED) && defined (__MAC_10_9) && __MAC_OS_X_VERSION_MIN_REQUIRED >= __MAC_10_9)) || (JUCE_IOS && (defined (__IPHONE_OS_VERSION_MIN_REQUIRED) && defined (__IPHONE_7_0) && __IPHONE_OS_VERSION_MIN_REQUIRED >= __IPHONE_7_0))
            urlString = [urlString stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]];
           #else
            urlString = [urlString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
           #endif
            NSMutableURLRequest* r
                = [NSMutableURLRequest requestWithURL: [NSURL URLWithString: urlString]
                                          cachePolicy: NSURLRequestUseProtocolCachePolicy
                                      timeoutInterval: 30.0];

            if (postData != nullptr && postData->getSize() > 0)
            {
                [r setHTTPMethod: nsStringLiteral ("POST")];
                [r setHTTPBody: [NSData dataWithBytes: postData->getData()
                                               length: postData->getSize()]];
            }

            if (headers != nullptr)
            {
                for (int i = 0; i < headers->size(); ++i)
                {
                    const String headerName  ((*headers)[i].upToFirstOccurrenceOf (":", false, false).trim());
                    const String headerValue ((*headers)[i].fromFirstOccurrenceOf (":", false, false).trim());

                    [r setValue: juceStringToNS (headerValue)
                       forHTTPHeaderField: juceStringToNS (headerName)];
                }
            }

           #if JUCE_MAC
            [[webView mainFrame] loadRequest: r];
           #else
            [webView loadRequest: r];
           #endif

           #if JUCE_IOS
            [webView setScalesPageToFit:YES];
           #endif
        }
    }

    void goBack()       { [webView goBack]; }
    void goForward()    { [webView goForward]; }

   #if JUCE_MAC
    void stop()         { [webView stopLoading: nil]; }
    void refresh()      { [webView reload: nil]; }
   #else
    void stop()         { [webView stopLoading]; }
    void refresh()      { [webView reload]; }
   #endif

    void mouseMove (const MouseEvent&)
    {
        // WebKit doesn't capture mouse-moves itself, so it seems the only way to make
        // them work is to push them via this non-public method..
        if ([webView respondsToSelector: @selector (_updateMouseoverWithFakeEvent)])
            [webView performSelector:    @selector (_updateMouseoverWithFakeEvent)];
    }

private:
   #if JUCE_MAC
    WebView* webView;
    id clickListener;
   #else
    UIWebView* webView;
    WebViewTapDetector* tapDetector;
    WebViewURLChangeDetector* urlDetector;
    UITapGestureRecognizer* gestureRecogniser;
   #endif
};

//==============================================================================
WebBrowserComponent::WebBrowserComponent (const bool unloadWhenHidden)
    : browser (nullptr),
      blankPageShown (false),
      unloadPageWhenBrowserIsHidden (unloadWhenHidden)
{
    setOpaque (true);

    addAndMakeVisible (browser = new Pimpl (this));
}

WebBrowserComponent::~WebBrowserComponent()
{
    deleteAndZero (browser);
}

//==============================================================================
void WebBrowserComponent::goToURL (const String& url,
                                   const StringArray* headers,
                                   const MemoryBlock* postData)
{
    lastURL = url;

    if (headers != nullptr)
        lastHeaders = *headers;
    else
        lastHeaders.clear();

    if (postData != nullptr)
        lastPostData = *postData;
    else
        lastPostData.reset();

    blankPageShown = false;

    browser->goToURL (url, headers, postData);
}

void WebBrowserComponent::stop()
{
    browser->stop();
}

void WebBrowserComponent::goBack()
{
    lastURL.clear();
    blankPageShown = false;
    browser->goBack();
}

void WebBrowserComponent::goForward()
{
    lastURL.clear();
    browser->goForward();
}

void WebBrowserComponent::refresh()
{
    browser->refresh();
}

//==============================================================================
void WebBrowserComponent::paint (Graphics&)
{
}

void WebBrowserComponent::checkWindowAssociation()
{
    if (isShowing())
    {
        reloadLastURL();

        if (blankPageShown)
            goBack();
    }
    else
    {
        if (unloadPageWhenBrowserIsHidden && ! blankPageShown)
        {
            // when the component becomes invisible, some stuff like flash
            // carries on playing audio, so we need to force it onto a blank
            // page to avoid this, (and send it back when it's made visible again).

            blankPageShown = true;
            browser->goToURL ("about:blank", 0, 0);
        }
    }
}

void WebBrowserComponent::reloadLastURL()
{
    if (lastURL.isNotEmpty())
    {
        goToURL (lastURL, &lastHeaders, &lastPostData);
        lastURL.clear();
    }
}

void WebBrowserComponent::parentHierarchyChanged()
{
    checkWindowAssociation();
}

void WebBrowserComponent::resized()
{
    browser->setSize (getWidth(), getHeight());
}

void WebBrowserComponent::visibilityChanged()
{
    checkWindowAssociation();
}

void WebBrowserComponent::focusGained (FocusChangeType)
{
}

void WebBrowserComponent::clearCookies()
{
    NSHTTPCookieStorage* storage = [NSHTTPCookieStorage sharedHTTPCookieStorage];

    if (NSArray* cookies = [storage cookies])
    {
        const NSUInteger n = [cookies count];

        for (NSUInteger i = 0; i < n; ++i)
            [storage deleteCookie: [cookies objectAtIndex: i]];
    }

    [[NSUserDefaults standardUserDefaults] synchronize];
}
