/*
 * The MIT License (MIT)
 *
 * Copyright (C) 2017, Daniel Dahan and CosmicMind, Inc. <http://cosmicmind.com>.
 * All rights reserved.
 *
 * Original Inspiration & Author
 * Copyright (c) 2016 Luke Zhao <me@lkzhao.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

import UIKit

class SourcePreprocessor: MotionCorePreprocessor {
    /**
     Processes the transitionary views.
     - Parameter fromViews: An Array of UIViews.
     - Parameter toViews: An Array of UIViews.
     */
    override func process(fromViews: [UIView], toViews: [UIView]) {
        for fv in fromViews {
            guard let motionIdentifier = context[fv]?.motionIdentifier, let tv = context.destinationView(for: motionIdentifier) else {
                continue
            }
            
            prepare(view: fv, for: tv)
        }
        
        for tv in toViews {
            guard let motionIdentifier = context[tv]?.motionIdentifier, let fv = context.sourceView(for: motionIdentifier) else {
                continue
            }
            
            prepare(view: tv, for: fv)
        }
    }
}

fileprivate extension SourcePreprocessor {
    /**
     Prepares a given view for a target view.
     - Parameter view: A UIView.
     - Parameter for targetView: A UIView.
     */
    func prepare(view: UIView, for targetView: UIView) {
        let targetPos = context.container.convert(targetView.layer.position, from: targetView.superview!)
        let targetTransform = context.container.layer.flatTransformTo(layer: targetView.layer)
        
        var state = context[view]!

        /**
         Use global coordinate space since over target position is 
         converted from the global container
         */
        state.coordinateSpace = .global
        
        state.position = targetPos
        state.transform = targetTransform

        // Remove incompatible options.
        state.size = nil
        
        if view.bounds.size != targetView.bounds.size {
            state.size = targetView.bounds.size
        }

        if view.layer.cornerRadius != targetView.layer.cornerRadius {
            state.cornerRadius = targetView.layer.cornerRadius
        }
        
        if view.layer.shadowColor != targetView.layer.shadowColor {
            state.shadowColor = targetView.layer.shadowColor
        }
        
        if view.layer.shadowOpacity != targetView.layer.shadowOpacity {
            state.shadowOpacity = targetView.layer.shadowOpacity
        }
        
        if view.layer.shadowOffset != targetView.layer.shadowOffset {
            state.shadowOffset = targetView.layer.shadowOffset
        }
        
        if view.layer.shadowRadius != targetView.layer.shadowRadius {
            state.shadowRadius = targetView.layer.shadowRadius
        }
        
        if view.layer.shadowPath != targetView.layer.shadowPath {
            state.shadowPath = targetView.layer.shadowPath
        }
        
        if view.layer.contentsRect != targetView.layer.contentsRect {
            state.contentsRect = targetView.layer.contentsRect
        }
        
        if view.layer.contentsScale != targetView.layer.contentsScale {
            state.contentsScale = targetView.layer.contentsScale
        }
        
        context[view] = state
    }
}
