/*
 * Copyright [2019] [Doric.Pub]
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
//
// Created by pengfei.zhou on 2019/10/23.
//

#import "DoricLayouts.h"
#import <objc/runtime.h>
#import "UIView+Doric.h"
#import "DoricExtensions.h"

static const void *kLayoutConfig = &kLayoutConfig;

@implementation UIView (DoricLayout)
@dynamic doricLayout;

- (void)setDoricLayout:(DoricLayout *)doricLayout {
    objc_setAssociatedObject(self, kLayoutConfig, doricLayout, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

- (DoricLayout *)doricLayout {
    DoricLayout *layout = objc_getAssociatedObject(self, kLayoutConfig);
    if (!layout) {
        layout = [DoricLayout new];
        layout.width = self.width;
        layout.height = self.height;
        layout.x = self.x;
        layout.y = self.y;
        layout.view = self;
        self.doricLayout = layout;
    }
    return layout;
}

@end

@interface DoricLayout ()
@property(nonatomic, assign) CGFloat contentWidth;
@property(nonatomic, assign) CGFloat contentHeight;
@property(nonatomic, assign) CGFloat measuredWidth;

@property(nonatomic, assign) CGFloat measuredHeight;
@property(nonatomic, assign) CGFloat measuredX;
@property(nonatomic, assign) CGFloat measuredY;
@property(nonatomic, assign) BOOL resolved;
@end

@implementation DoricLayout
- (instancetype)init {
    if (self = [super init]) {
        _widthSpec = DoricLayoutJust;
        _heightSpec = DoricLayoutJust;
        _maxWidth = -1;
        _maxHeight = -1;
    }
    return self;
}

- (void)apply {
    if (!CGAffineTransformEqualToTransform(self.view.transform, CGAffineTransformIdentity)) {
        return;
    }
    self.resolved = NO;
    [self measure:self.view.frame.size];
    [self layout];
    [self setFrame];
}

- (void)measure:(CGSize)targetSize {
    if (self.widthSpec == DoricLayoutMost) {
        self.measuredWidth = targetSize.width;
    } else {
        self.measuredWidth = self.width;
    }
    if (self.heightSpec == DoricLayoutMost) {
        self.measuredHeight = targetSize.height;
    } else {
        self.measuredHeight = self.height;
    }
    [self measureContent:CGSizeMake(
            self.measuredWidth - self.paddingLeft - self.paddingRight,
            self.measuredHeight - self.paddingTop - self.paddingBottom)];

    BOOL needRemeasure = NO;
    if (self.maxWidth >= 0) {
        if (self.measuredWidth > self.maxWidth) {
            self.measuredWidth = self.maxWidth;
            needRemeasure = YES;
        }
    }
    if (self.maxHeight > 0) {
        if (self.measuredHeight > self.maxHeight) {
            self.measuredHeight = self.maxHeight;
            needRemeasure = YES;
        }
    }
    if (needRemeasure) {
        [self measureContent:CGSizeMake(
                self.measuredWidth - self.paddingLeft - self.paddingRight,
                self.measuredHeight - self.paddingTop - self.paddingBottom)];
    }
    self.resolved = YES;
}

- (void)measureContent:(CGSize)targetSize {
    switch (self.layoutType) {
        case DoricStack: {
            [self measureStackContent:targetSize];
            break;
        }
        case DoricVLayout: {
            [self measureVLayoutContent:targetSize];
            break;
        }
        case DoricHLayout: {
            [self measureHLayoutContent:targetSize];
            break;
        }
        default: {
            [self measureUndefinedContent:targetSize];
            break;
        }
    }
}

- (void)layout {
    switch (self.layoutType) {
        case DoricStack: {
            [self layoutStack];
            break;
        }
        case DoricVLayout: {
            [self layoutVLayout];
            break;
        }
        case DoricHLayout: {
            [self layoutHLayout];
            break;
        }
        default: {
            break;
        }
    }
}

- (void)setFrame {
    [self.view.subviews forEach:^(__kindof UIView *obj) {
        [obj.doricLayout setFrame];
    }];
    self.view.width = self.measuredWidth;
    self.view.height = self.measuredHeight;
    self.view.x = self.measuredX;
    self.view.y = self.measuredY;
}

- (void)measureUndefinedContent:(CGSize)targetSize {
    CGSize measuredSize = [self.view sizeThatFits:targetSize];
    if (self.widthSpec == DoricLayoutFit) {
        self.measuredWidth = measuredSize.width + self.paddingLeft + self.paddingRight;
    }
    if (self.heightSpec == DoricLayoutFit) {
        self.measuredHeight = measuredSize.height + self.paddingTop + self.paddingBottom;
    }
}

- (CGFloat)takenWidth {
    return self.measuredWidth + self.marginLeft + self.marginRight;
}

- (CGFloat)takenHeight {
    return self.measuredHeight + self.marginTop + self.marginBottom;
}

- (void)measureStackContent:(CGSize)targetSize {
    CGFloat contentWidth = 0, contentHeight = 0;
    for (__kindof UIView *subview in self.view.subviews) {
        DoricLayout *layout = subview.doricLayout;
        if (layout.disabled) {
            continue;
        }
        [layout measure:targetSize];
        contentWidth = MAX(contentWidth, layout.takenWidth);
        contentHeight = MAX(contentHeight, layout.takenHeight);
    }
    if (self.widthSpec == DoricLayoutFit) {
        self.measuredWidth = contentWidth + self.paddingLeft + self.paddingRight;
    }

    if (self.heightSpec == DoricLayoutFit) {
        self.measuredHeight = contentHeight + self.paddingTop + self.paddingBottom;
    }

    self.contentWidth = contentWidth;

    self.contentHeight = contentHeight;
}

- (void)measureVLayoutContent:(CGSize)targetSize {
    CGFloat contentWidth = 0, contentHeight = 0, contentWeight = 0;
    BOOL had = NO;
    for (__kindof UIView *subview in self.view.subviews) {
        DoricLayout *layout = subview.doricLayout;
        if (layout.disabled) {
            continue;
        }
        had = YES;
        [layout measure:CGSizeMake(targetSize.width, targetSize.height - contentHeight)];
        contentWidth = MAX(contentWidth, layout.takenWidth);
        contentHeight += layout.takenHeight + self.spacing;
        contentWeight += layout.weight;
    }

    if (had) {
        contentHeight -= self.spacing;
    }

    if (contentWeight > 0) {
        CGFloat remaining = targetSize.height - contentHeight;
        contentWidth = 0;
        for (__kindof UIView *subview in self.view.subviews) {
            DoricLayout *layout = subview.doricLayout;
            if (layout.disabled) {
                continue;
            }
            layout.measuredHeight += remaining / contentWeight * layout.weight;
            //Need Remeasure
            [layout measureContent:CGSizeMake(
                    layout.measuredWidth - layout.paddingLeft - layout.paddingRight,
                    layout.measuredHeight - layout.paddingTop - layout.paddingBottom)];
            contentWidth = MAX(contentWidth, layout.takenWidth);
        }
        contentHeight = targetSize.height;
    }

    if (self.widthSpec == DoricLayoutFit) {
        self.measuredWidth = contentWidth + self.paddingLeft + self.paddingRight;
    }

    if (self.heightSpec == DoricLayoutFit) {
        self.measuredHeight = contentHeight + self.paddingTop + self.paddingBottom;
    }

    self.contentWidth = contentWidth;

    self.contentHeight = contentHeight;
}

- (void)measureHLayoutContent:(CGSize)targetSize {
    CGFloat contentWidth = 0, contentHeight = 0, contentWeight = 0;;
    BOOL had = NO;
    for (__kindof UIView *subview in self.view.subviews) {
        DoricLayout *layout = subview.doricLayout;
        if (layout.disabled) {
            continue;
        }
        had = YES;
        [layout measure:CGSizeMake(targetSize.width - contentWidth, targetSize.height)];
        contentWidth += layout.takenWidth + self.spacing;
        contentHeight = MAX(contentHeight, layout.takenHeight);
        contentWeight += layout.weight;
    }

    if (had) {
        contentWidth -= self.spacing;
    }

    if (contentWeight > 0) {
        CGFloat remaining = targetSize.width - contentWidth;
        contentHeight = 0;
        for (__kindof UIView *subview in self.view.subviews) {
            DoricLayout *layout = subview.doricLayout;
            if (layout.disabled) {
                continue;
            }
            layout.measuredWidth += remaining / contentWeight * layout.weight;
            //Need Remeasure
            [layout measureContent:CGSizeMake(
                    layout.measuredWidth - layout.paddingLeft - layout.paddingRight,
                    layout.measuredHeight - layout.paddingTop - layout.paddingBottom)];
            contentHeight = MAX(contentHeight, layout.takenHeight);
        }
        contentWidth = targetSize.width;
    }

    if (self.widthSpec == DoricLayoutFit) {
        self.measuredWidth = contentWidth + self.paddingLeft + self.paddingRight;
    }

    if (self.heightSpec == DoricLayoutFit) {
        self.measuredHeight = contentHeight + self.paddingTop + self.paddingBottom;
    }

    self.contentWidth = contentWidth;

    self.contentHeight = contentHeight;
}

- (void)layoutStack {
    for (__kindof UIView *subview in self.view.subviews) {
        DoricLayout *layout = subview.doricLayout;
        if (layout.disabled) {
            continue;
        }
        [layout layout];
        DoricGravity gravity = layout.alignment;
        if ((gravity & DoricGravityLeft) == DoricGravityLeft) {
            layout.measuredX = self.paddingLeft;
        } else if ((gravity & DoricGravityRight) == DoricGravityRight) {
            layout.measuredX = self.measuredWidth - self.paddingRight - layout.measuredWidth;
        } else if ((gravity & DoricGravityCenterX) == DoricGravityCenterX) {
            layout.measuredX = self.measuredWidth / 2 - layout.measuredWidth / 2;
        } else {
            if (layout.marginLeft || layout.marginRight) {
                layout.measuredX = self.paddingLeft;
            } else {
                layout.measuredX = layout.x;
            }
        }
        if ((gravity & DoricGravityTop) == DoricGravityTop) {
            layout.measuredY = self.paddingTop;
        } else if ((gravity & DoricGravityBottom) == DoricGravityBottom) {
            layout.measuredY = self.measuredHeight - self.paddingBottom - layout.measuredHeight;
        } else if ((gravity & DoricGravityCenterY) == DoricGravityCenterY) {
            layout.measuredY = self.measuredHeight / 2 - layout.measuredHeight / 2;
        } else {
            if (layout.marginTop || layout.marginBottom) {
                layout.measuredY = self.paddingTop;
            } else {
                layout.measuredY = layout.y;
            }
        }

        if (!gravity) {
            gravity = DoricGravityLeft | DoricGravityTop;
        }
        if (layout.marginLeft && !((gravity & DoricGravityRight) == DoricGravityRight)) {
            layout.measuredX += layout.marginLeft;
        }
        if (layout.marginRight && !((gravity & DoricGravityLeft) == DoricGravityLeft)) {
            layout.measuredX -= layout.marginRight;
        }
        if (layout.marginTop && !((gravity & DoricGravityBottom) == DoricGravityBottom)) {
            layout.measuredY += layout.marginTop;
        }
        if (layout.marginBottom && !((gravity & DoricGravityTop) == DoricGravityTop)) {
            layout.measuredY -= layout.marginBottom;
        }
    }
}

- (void)layoutVLayout {
    CGFloat yStart = self.paddingTop;
    if ((self.gravity & DoricGravityTop) == DoricGravityTop) {
        yStart = self.paddingTop;
    } else if ((self.gravity & DoricGravityBottom) == DoricGravityBottom) {
        yStart = self.measuredHeight - self.contentHeight - self.paddingBottom;
    } else if ((self.gravity & DoricGravityCenterY) == DoricGravityCenterY) {
        yStart = (self.measuredHeight - self.contentHeight - self.paddingTop - self.paddingBottom) / 2 + self.paddingTop;
    }
    for (UIView *child in self.view.subviews) {
        DoricLayout *layout = child.doricLayout;
        if (layout.disabled) {
            continue;
        }
        [layout layout];
        DoricGravity gravity = layout.alignment | self.gravity;
        if ((gravity & DoricGravityLeft) == DoricGravityLeft) {
            layout.measuredX = self.paddingLeft;
        } else if ((gravity & DoricGravityRight) == DoricGravityRight) {
            layout.measuredX = self.measuredWidth - self.paddingRight - layout.measuredWidth;
        } else if ((gravity & DoricGravityCenterX) == DoricGravityCenterX) {
            layout.measuredX = self.measuredWidth / 2 - layout.measuredWidth / 2;
        } else {
            layout.measuredX = self.paddingLeft;
        }
        if (!gravity) {
            gravity = DoricGravityLeft;
        }
        if (layout.marginLeft && !((gravity & DoricGravityRight) == DoricGravityRight)) {
            layout.measuredX += layout.marginLeft;
        }
        if (layout.marginRight && !((gravity & DoricGravityLeft) == DoricGravityLeft)) {
            layout.measuredX -= layout.marginRight;
        }
        layout.measuredY = yStart + layout.marginTop;
        yStart += self.spacing + layout.takenHeight;
    }
}

- (void)layoutHLayout {
    CGFloat xStart = self.paddingLeft;
    if ((self.gravity & DoricGravityLeft) == DoricGravityLeft) {
        xStart = self.paddingLeft;
    } else if ((self.gravity & DoricGravityRight) == DoricGravityRight) {
        xStart = self.measuredWidth - self.contentWidth - self.paddingRight;
    } else if ((self.gravity & DoricGravityCenterX) == DoricGravityCenterX) {
        xStart = (self.measuredWidth - self.contentWidth - self.paddingLeft - self.paddingRight) / 2 + self.paddingLeft;
    }
    for (UIView *child in self.view.subviews) {
        DoricLayout *layout = child.doricLayout;
        if (layout.disabled) {
            continue;
        }
        [layout layout];

        DoricGravity gravity = layout.alignment | self.gravity;
        if ((gravity & DoricGravityTop) == DoricGravityTop) {
            layout.measuredY = self.paddingTop;
        } else if ((gravity & DoricGravityBottom) == DoricGravityBottom) {
            layout.measuredY = self.measuredHeight - self.paddingBottom - child.height;
        } else if ((gravity & DoricGravityCenterY) == DoricGravityCenterY) {
            layout.measuredY = self.measuredHeight / 2 - layout.measuredHeight / 2;
        } else {
            layout.measuredY = self.paddingTop;
        }
        if (!gravity) {
            gravity = DoricGravityTop;
        }
        if (layout.marginTop && !((gravity & DoricGravityBottom) == DoricGravityBottom)) {
            layout.measuredY += layout.marginTop;
        }
        if (layout.marginBottom && !((gravity & DoricGravityTop) == DoricGravityTop)) {
            layout.measuredY -= layout.marginBottom;
        }
        layout.measuredX = xStart + layout.marginLeft;
        xStart += self.spacing + layout.takenWidth;
    }
}

@end