/*
 * 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_WASM)
#elif defined(DISTRHO_OS_WINDOWS)
# define WIN32_LEAN_AND_MEAN
# include <windows.h>
#else
# define ILDAEIL_X11
# include <X11/Xlib.h>
# include <X11/Xutil.h>
# include <pthread.h>
#endif

#include "PluginHostWindow.hpp"

START_NAMESPACE_DGL

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

    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),
          subview(nullptr),
#elif defined(DISTRHO_OS_WASM)
#elif defined(DISTRHO_OS_WINDOWS)
          pluginWindow(nullptr),
#else
          display(nullptr),
          pluginWindow(0),
#endif
          xOffset(0),
          yOffset(0),
          lookingForChildren(false)
    {
#if defined(DISTRHO_OS_HAIKU)
#elif defined(DISTRHO_OS_MAC)
        view = [[NSView new]retain];
        DISTRHO_SAFE_ASSERT_RETURN(view != nullptr,)
        [view setAutoresizingMask:NSViewNotSizable];
        [view setAutoresizesSubviews:NO];
        [view setHidden:YES];
        [(NSView*)parentWindowId addSubview:view];
#elif defined(DISTRHO_OS_WASM)
#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_WASM)
#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)
        subview = nullptr;
        return view;
#elif defined(DISTRHO_OS_WASM)
        return nullptr;
#elif defined(DISTRHO_OS_WINDOWS)
        pluginWindow = nullptr;
        return (void*)parentWindowId;
#else
        pluginWindow = 0;
        return (void*)parentWindowId;
#endif
    }

    bool hide()
    {
#if defined(DISTRHO_OS_HAIKU)
#elif defined(DISTRHO_OS_MAC)
        if (view != nullptr)
        {
            [view setHidden:YES];
            [NSOpenGLContext clearCurrentContext];
            return true;
        }
#elif defined(DISTRHO_OS_WASM)
#elif defined(DISTRHO_OS_WINDOWS)
        if (pluginWindow != nullptr)
        {
            ShowWindow(pluginWindow, SW_HIDE);
            pluginWindow = nullptr;
            return true;
        }
#else
        if (pluginWindow != 0)
        {
            XUnmapWindow(display, pluginWindow);
            XSync(display, True);
            pluginWindow = 0;
            return true;
        }
#endif
        return false;
    }

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

            if (subview == nullptr)
            {
                for (NSView* subview2 in [view subviews])
                {
                    subview = subview2;
                    break;
                }
            }
#elif defined(DISTRHO_OS_WASM)
#elif defined(DISTRHO_OS_WINDOWS)
            if (pluginWindow == nullptr)
                pluginWindow = FindWindowExA((::HWND)parentWindowId, nullptr, nullptr, nullptr);
#else
            if (display == nullptr)
                return;

            if (pluginWindow == 0)
            {
                ::Window rootWindow, parentWindow;
                ::Window* childWindows = nullptr;
                uint numChildren = 0;

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

                if (numChildren > 0 && childWindows != nullptr)
                {
                    // pick last child, needed for NTK based UIs which do not delete/remove previous windows.
                    //sadly this breaks ildaeil-within-ildaeil recursion.. :(
                    pluginWindow = childWindows[numChildren - 1];
                    XFree(childWindows);
                }
            }
#endif
        }

#if defined(DISTRHO_OS_HAIKU)
#elif defined(DISTRHO_OS_MAC)
        if (subview != nullptr)
        {
            const double scaleFactor = [[[view window] screen] backingScaleFactor];
            const NSSize size = [subview frame].size;
            const double width = size.width;
            const double height = size.height;

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

            if (width > 1.0 && height > 1.0)
            {
                lookingForChildren = false;
                [view setFrameSize:size];
                [view setHidden:NO];
                [view setNeedsDisplay:YES];
                pluginWindowCallbacks->pluginWindowResized(width * scaleFactor, height * scaleFactor);
            }
        }
#elif defined(DISTRHO_OS_WASM)
#elif defined(DISTRHO_OS_WINDOWS)
        if (pluginWindow != nullptr)
        {
            int width = 0;
            int height = 0;

            RECT rect;
            if (GetWindowRect(pluginWindow, &rect))
            {
                width = rect.right - rect.left;
                height = rect.bottom - rect.top;
            }

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

            if (width > 1 && height > 1)
            {
                lookingForChildren = false;
                SetWindowPos(pluginWindow, 0, xOffset, yOffset, 0, 0,
                             SWP_NOACTIVATE | SWP_NOSIZE | SWP_NOOWNERZORDER | SWP_NOZORDER);
                pluginWindowCallbacks->pluginWindowResized(width, height);
            }
        }
#else
        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;
                    }
                }
            }

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

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

        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_WASM)
#elif defined(DISTRHO_OS_WINDOWS)
        // unused
        (void)width;
        (void)height;
#else
        // unused
        (void)width;
        (void)height;
#endif
        xOffset = x;
        yOffset = y;
    }
};

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

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

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

bool PluginHostWindow::hide()
{
    return 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