/*
 * Copyright (C) 2015 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#import "config.h"
#import "WKViewLayoutStrategy.h"

#if PLATFORM(MAC)

#import "WKViewInternal.h"
#import "WebPageProxy.h"
#import <WebCore/MachSendRight.h>
#import <WebCore/QuartzCoreSPI.h>

using namespace WebCore;
using namespace WebKit;

@interface WKViewViewSizeLayoutStrategy : WKViewLayoutStrategy
@end

@interface WKViewFixedSizeLayoutStrategy : WKViewLayoutStrategy
@end

@interface WKViewDynamicSizeComputedFromViewScaleLayoutStrategy : WKViewLayoutStrategy
@end

@interface WKViewDynamicSizeWithMinimumViewSizeLayoutStrategy : WKViewLayoutStrategy {
    BOOL _isWaitingForCommit;
    BOOL _hasPendingLayout;
    CGFloat _lastCommittedViewScale;
}
@end

@interface WKViewDynamicSizeComputedFromMinimumDocumentSizeLayoutStrategy : WKViewLayoutStrategy
@end

@implementation WKViewLayoutStrategy

+ (instancetype)layoutStrategyWithPage:(WebPageProxy&)page view:(WKView *)wkView mode:(WKLayoutMode)mode
{
    WKViewLayoutStrategy *strategy;

    switch (mode) {
    case kWKLayoutModeFixedSize:
        strategy = [[WKViewFixedSizeLayoutStrategy alloc] initWithPage:page view:wkView mode:mode];
        break;
    case kWKLayoutModeDynamicSizeComputedFromViewScale:
        strategy = [[WKViewDynamicSizeComputedFromViewScaleLayoutStrategy alloc] initWithPage:page view:wkView mode:mode];
        break;
    case kWKLayoutModeDynamicSizeWithMinimumViewSize:
        strategy = [[WKViewDynamicSizeWithMinimumViewSizeLayoutStrategy alloc] initWithPage:page view:wkView mode:mode];
        break;
    case kWKLayoutModeDynamicSizeComputedFromMinimumDocumentSize:
        strategy = [[WKViewDynamicSizeComputedFromMinimumDocumentSizeLayoutStrategy alloc] initWithPage:page view:wkView mode:mode];
        break;
    case kWKLayoutModeViewSize:
    default:
        strategy = [[WKViewViewSizeLayoutStrategy alloc] initWithPage:page view:wkView mode:mode];
        break;
    }

    [strategy updateLayout];

    return [strategy autorelease];
}

- (instancetype)initWithPage:(WebPageProxy&)page view:(WKView *)wkView mode:(WKLayoutMode)mode
{
    self = [super init];

    if (!self)
        return nil;

    _page = &page;
    _wkView = wkView;
    _layoutMode = mode;

    return self;
}

- (void)willDestroyView:(WKView *)view
{
    _page = nullptr;
    _wkView = nil;
}

- (WKLayoutMode)layoutMode
{
    return _layoutMode;
}

- (void)updateLayout
{
}

- (void)disableFrameSizeUpdates
{
    _frameSizeUpdatesDisabledCount++;
}

- (void)enableFrameSizeUpdates
{
    if (!_frameSizeUpdatesDisabledCount)
        return;

    if (!(--_frameSizeUpdatesDisabledCount))
        [self didChangeFrameSize];
}

- (BOOL)frameSizeUpdatesDisabled
{
    return _frameSizeUpdatesDisabledCount > 0;
}

- (void)didChangeViewScale
{
}

- (void)didChangeMinimumViewSize
{
}

- (void)willStartLiveResize
{
}

- (void)didEndLiveResize
{
}

- (void)didChangeFrameSize
{
    if ([self frameSizeUpdatesDisabled])
        return;

    if (_wkView.shouldClipToVisibleRect)
        [_wkView _updateViewExposedRect];
    [_wkView _setDrawingAreaSize:_wkView.frame.size];
}

- (void)willChangeLayoutStrategy
{
}

@end

@implementation WKViewViewSizeLayoutStrategy

- (instancetype)initWithPage:(WebPageProxy&)page view:(WKView *)wkView mode:(WKLayoutMode)mode
{
    self = [super initWithPage:page view:wkView mode:mode];

    if (!self)
        return nil;

    page.setUseFixedLayout(false);

    return self;
}

- (void)updateLayout
{
}

@end

@implementation WKViewFixedSizeLayoutStrategy

- (instancetype)initWithPage:(WebPageProxy&)page view:(WKView *)wkView mode:(WKLayoutMode)mode
{
    self = [super initWithPage:page view:wkView mode:mode];

    if (!self)
        return nil;

    page.setUseFixedLayout(true);

    return self;
}

- (void)updateLayout
{
}

@end

@implementation WKViewDynamicSizeComputedFromViewScaleLayoutStrategy

- (instancetype)initWithPage:(WebPageProxy&)page view:(WKView *)wkView mode:(WKLayoutMode)mode
{
    self = [super initWithPage:page view:wkView mode:mode];

    if (!self)
        return nil;

    page.setUseFixedLayout(true);

    return self;
}

- (void)updateLayout
{
    CGFloat inverseScale = 1 / _page->viewScaleFactor();
    [_wkView _setFixedLayoutSize:CGSizeMake(_wkView.frame.size.width * inverseScale, _wkView.frame.size.height * inverseScale)];
}

- (void)didChangeViewScale
{
    [super didChangeViewScale];

    [self updateLayout];
}

- (void)didChangeFrameSize
{
    [super didChangeFrameSize];

    if ([_wkView frameSizeUpdatesDisabled])
        return;

    [self updateLayout];
}

@end

@implementation WKViewDynamicSizeWithMinimumViewSizeLayoutStrategy

- (instancetype)initWithPage:(WebPageProxy&)page view:(WKView *)wkView mode:(WKLayoutMode)mode
{
    self = [super initWithPage:page view:wkView mode:mode];

    if (!self)
        return nil;

    page.setUseFixedLayout(true);
    _lastCommittedViewScale = _page->viewScaleFactor();

    return self;
}

- (void)_updateTransientScale:(CGFloat)scale
{
    float topContentInset = _page->topContentInset();

    CGFloat relativeScale = scale / _lastCommittedViewScale;

    CATransform3D transform = CATransform3DMakeTranslation(0, topContentInset - (topContentInset * relativeScale), 0);
    transform = CATransform3DScale(transform, relativeScale, relativeScale, 1);

    _wkView._rootLayer.transform = transform;
}

- (void)updateLayout
{
    _hasPendingLayout = NO;

    CGFloat scale = 1;

    CGFloat minimumViewWidth = _wkView._minimumViewSize.width;
    CGFloat minimumViewHeight = _wkView._minimumViewSize.height;

    CGFloat fixedLayoutWidth = _wkView.frame.size.width;
    CGFloat fixedLayoutHeight = _wkView.frame.size.height;

    if (NSIsEmptyRect(_wkView.frame))
        return;

    if (_wkView.frame.size.width < minimumViewWidth) {
        scale = _wkView.frame.size.width / minimumViewWidth;
        fixedLayoutWidth = minimumViewWidth;
    }

    if (_wkView.frame.size.height < minimumViewHeight) {
        scale = std::min(_wkView.frame.size.height / minimumViewHeight, scale);
        fixedLayoutWidth = minimumViewHeight;
    }

    _page->setFixedLayoutSize(IntSize(fixedLayoutWidth, fixedLayoutHeight));

    [self _updateTransientScale:scale];

    if (_isWaitingForCommit) {
        _hasPendingLayout = YES;
        return;
    }

    if ([_wkView inLiveResize] && _lastCommittedViewScale == 1 && scale == 1 && _frameSizeUpdatesDisabledCount == 1) {
        // Send frame size updates if we're the only ones disabling them,
        // if we're not scaling down. That way, everything will behave like a normal
        // resize except in the critical section.
        if (_wkView.shouldClipToVisibleRect)
            [_wkView _updateViewExposedRect];
        [_wkView _setDrawingAreaSize:[_wkView frame].size];
        return;
    }

    if (_lastCommittedViewScale == scale)
        return;

    _isWaitingForCommit = YES;

#if PLATFORM(IOS) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
    RetainPtr<CAContext> context = [_wkView.layer context];
    RetainPtr<WKViewDynamicSizeWithMinimumViewSizeLayoutStrategy> retainedSelf = self;
    _page->scaleViewAndUpdateGeometryFenced(scale, IntSize(_wkView.frame.size), [retainedSelf, context, scale] (const WebCore::MachSendRight& fencePort, CallbackBase::Error error) {
        if (error != CallbackBase::Error::None)
            return;

        [context setFencePort:fencePort.sendRight() commitHandler:[retainedSelf, scale] {
            WKViewDynamicSizeWithMinimumViewSizeLayoutStrategy *layoutStrategy = retainedSelf.get();
            layoutStrategy->_lastCommittedViewScale = scale;
            [layoutStrategy _updateTransientScale:scale];
            layoutStrategy->_isWaitingForCommit = NO;

            if (layoutStrategy->_hasPendingLayout)
                [layoutStrategy updateLayout];
        }];
    });
#else
    _page->scaleView(scale);
    _wkView._rootLayer.transform = CATransform3DIdentity;
#endif
}

- (void)didChangeMinimumViewSize
{
    [super didChangeMinimumViewSize];

    [self updateLayout];
}

- (void)willStartLiveResize
{
    [super willStartLiveResize];

    [_wkView disableFrameSizeUpdates];
}

- (void)didEndLiveResize
{
    [super didEndLiveResize];

    [self updateLayout];
    [_wkView enableFrameSizeUpdates];
}

- (void)didChangeFrameSize
{
    [super didChangeFrameSize];

    [self updateLayout];
}

- (void)willChangeLayoutStrategy
{
    _wkView._rootLayer.transform = CATransform3DIdentity;
    _page->scaleView(1);
}

@end

@implementation WKViewDynamicSizeComputedFromMinimumDocumentSizeLayoutStrategy

- (instancetype)initWithPage:(WebPageProxy&)page view:(WKView *)wkView mode:(WKLayoutMode)mode
{
    self = [super initWithPage:page view:wkView mode:mode];

    if (!self)
        return nil;

    _page->setShouldScaleViewToFitDocument(true);

    return self;
}

- (void)updateLayout
{
}

- (void)willChangeLayoutStrategy
{
    _page->setShouldScaleViewToFitDocument(false);
    _page->scaleView(1);
}

@end

#endif // PLATFORM(MAC)