/*
 * DISTRHO Ildaeil Plugin
 * Copyright (C) 2021 Filipe Coelho <falktx@falktx.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * For a full copy of the GNU General Public License see the LICENSE file.
 */

#include "src/DistrhoDefines.h"

#if defined(DISTRHO_OS_HAIKU)
#elif defined(DISTRHO_OS_MAC)
# import <Cocoa/Cocoa.h>
#elif defined(DISTRHO_OS_WINDOWS)
#else
# define ILDAEIL_X11
# include <X11/Xlib.h>
# include <X11/Xutil.h>
# include <pthread.h>
#endif

#include "PluginHostWindow.hpp"

#ifdef DISTRHO_OS_MAC
@interface IldaeilPluginView : NSView
- (void)resizeWithOldSuperviewSize:(NSSize)oldSize;
@end
@implementation IldaeilPluginView
- (void)resizeWithOldSuperviewSize:(NSSize)oldSize
{
    [super resizeWithOldSuperviewSize:oldSize];
}
@end
#endif

START_NAMESPACE_DGL

#if defined(DISTRHO_OS_HAIKU)
#elif defined(DISTRHO_OS_MAC)
#elif defined(DISTRHO_OS_WINDOWS)
#else
static pthread_mutex_t gErrorMutex = PTHREAD_MUTEX_INITIALIZER;
static bool gErrorTriggered = false;
static int ildaeilErrorHandler(Display*, XErrorEvent*)
{
    gErrorTriggered = true;
    return 0;
}
#endif

struct PluginHostWindow::PrivateData
{
    Window& parentWindow;
    const uintptr_t parentWindowId;
    Callbacks* const pluginWindowCallbacks;

#if defined(DISTRHO_OS_HAIKU)
#elif defined(DISTRHO_OS_MAC)
    IldaeilPluginView* view;
#elif defined(DISTRHO_OS_WINDOWS)
#else
    ::Display* display;
    ::Window pluginWindow;
    uint xOffset, yOffset;
#endif

    bool lookingForChildren;

    PrivateData(Window& pw, Callbacks* const cbs)
        : parentWindow(pw),
          parentWindowId(pw.getNativeWindowHandle()),
          pluginWindowCallbacks(cbs),
#if defined(DISTRHO_OS_HAIKU)
#elif defined(DISTRHO_OS_MAC)
          view(nullptr),
#elif defined(DISTRHO_OS_WINDOWS)
#else
          display(nullptr),
          pluginWindow(0),
          xOffset(0),
          yOffset(0),
#endif
          lookingForChildren(false)
    {
#if defined(DISTRHO_OS_HAIKU)
#elif defined(DISTRHO_OS_MAC)
        view = [[IldaeilPluginView new]retain];
        DISTRHO_SAFE_ASSERT_RETURN(view != nullptr,)

        [view setAutoresizingMask:NSViewNotSizable];
        [view setAutoresizesSubviews:YES];
        [view setHidden:YES];
        [(NSView*)parentWindowId addSubview:view];
#elif defined(DISTRHO_OS_WINDOWS)
#else
        display = XOpenDisplay(nullptr);
        DISTRHO_SAFE_ASSERT_RETURN(display != nullptr,)
#endif
    }

    ~PrivateData()
    {
#if defined(DISTRHO_OS_HAIKU)
#elif defined(DISTRHO_OS_MAC)
        if (view != nullptr)
            [view release];
#elif defined(DISTRHO_OS_WINDOWS)
#else
        if (display != nullptr)
            XCloseDisplay(display);
#endif
    }

    void* attachAndGetWindowHandle()
    {
        lookingForChildren = true;
#if defined(DISTRHO_OS_HAIKU)
        return nullptr;
#elif defined(DISTRHO_OS_MAC)
        return view;
#elif defined(DISTRHO_OS_WINDOWS)
        return nullptr;
#else
        pluginWindow = 0;
        return (void*)parentWindowId;
#endif
    }

    void hide()
    {
#if defined(DISTRHO_OS_HAIKU)
#elif defined(DISTRHO_OS_MAC)
        if (view != nullptr)
            [view setHidden:YES];
#elif defined(DISTRHO_OS_WINDOWS)
#else
        pluginWindow = 0;
#endif
    }

    void idle()
    {
        if (lookingForChildren)
        {
#if defined(DISTRHO_OS_HAIKU)
#elif defined(DISTRHO_OS_MAC)
            if (view == nullptr)
                return;

            for (NSView* subview in [view subviews])
            {
                const double scaleFactor = [[[view window] screen] backingScaleFactor];
                const NSSize size = [subview frame].size;
                const double width = size.width;
                const double height = size.height;

                if (width <= 1 || height <= 1)
                    break;

                lookingForChildren = false;
                [view setFrameSize:size];
                [view setHidden:NO];
                [view setNeedsDisplay:YES];
                pluginWindowCallbacks->pluginWindowResized(width * scaleFactor, height * scaleFactor);
                break;
            }
#elif defined(DISTRHO_OS_WINDOWS)
#else
            if (pluginWindow == 0)
            {
                ::Window rootWindow, parentWindow;
                ::Window* childWindows = nullptr;
                uint numChildren = 0;

                XQueryTree(display, parentWindowId, &rootWindow, &parentWindow, &childWindows, &numChildren);

                if (numChildren > 0 && childWindows != nullptr)
                {
                    pluginWindow = childWindows[0];
                    XFree(childWindows);
                }
            }

            if (pluginWindow != 0)
            {
                int width = 0;
                int height = 0;

                XWindowAttributes attrs;
                memset(&attrs, 0, sizeof(attrs));

                pthread_mutex_lock(&gErrorMutex);
                const XErrorHandler oldErrorHandler = XSetErrorHandler(ildaeilErrorHandler);
                gErrorTriggered = false;

                if (XGetWindowAttributes(display, pluginWindow, &attrs) && ! gErrorTriggered)
                {
                    width = attrs.width;
                    height = attrs.height;
                }

                XSetErrorHandler(oldErrorHandler);
                pthread_mutex_unlock(&gErrorMutex);

                if (width == 0 && height == 0)
                {
                    XSizeHints sizeHints;
                    memset(&sizeHints, 0, sizeof(sizeHints));

                    if (XGetNormalHints(display, pluginWindow, &sizeHints))
                    {
                        if (sizeHints.flags & PSize)
                        {
                            width = sizeHints.width;
                            height = sizeHints.height;
                        }
                        else if (sizeHints.flags & PBaseSize)
                        {
                            width = sizeHints.base_width;
                            height = sizeHints.base_height;
                        }
                    }
                }

                d_stdout("child window bounds %u %u | offset %u %u", width, height, xOffset, yOffset);

                if (width > 1 && height > 1)
                {
                    lookingForChildren = false;
                    XMoveWindow(display, pluginWindow, xOffset, yOffset);
                    pluginWindowCallbacks->pluginWindowResized(width, height);
                }
            }
#endif
        }

#ifdef ILDAEIL_X11
        for (XEvent event; XPending(display) > 0;)
            XNextEvent(display, &event);
#endif
    }

    void setPositionAndSize(const uint x, const uint y, const uint width, const uint height)
    {
#if defined(DISTRHO_OS_HAIKU)
#elif defined(DISTRHO_OS_MAC)
        if (view != nullptr)
        {
            const double scaleFactor = [[[view window] screen] backingScaleFactor];
            [view setFrame:NSMakeRect(x / scaleFactor, y / scaleFactor, width / scaleFactor, height / scaleFactor)];
        }
#elif defined(DISTRHO_OS_WINDOWS)
#else
        xOffset = x;
        yOffset = y;
        // unused
        (void)width;
        (void)height;
#endif
    }
};

PluginHostWindow::PluginHostWindow(Window& parentWindow, Callbacks* const cbs)
  : pData(new PrivateData(parentWindow, cbs)) {}

PluginHostWindow::~PluginHostWindow()
{
    delete pData;
}

void* PluginHostWindow::attachAndGetWindowHandle()
{
    return pData->attachAndGetWindowHandle();
}

void PluginHostWindow::hide()
{
    pData->hide();
}

void PluginHostWindow::idle()
{
    pData->idle();
}

void PluginHostWindow::setPositionAndSize(const uint x, const uint y, const uint width, const uint height)
{
    pData->setPositionAndSize(x, y, width, height);
}

END_NAMESPACE_DGL