//
//  Copyright (c) 2023 Touch Instinct
//
//  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

public extension UIEdgeInsets {

    // MARK: - Factory methods

    static var nan: Self {
        .edges(.nan)
    }

    static func edges(_ insets: CGFloat) -> UIEdgeInsets {
        .init(top: insets, left: insets, bottom: insets, right: insets)
    }

    static func horizontal(_ insets: CGFloat) -> UIEdgeInsets {
        .init(top: .nan, left: insets, bottom: .nan, right: insets)
    }

    static func vertical(_ insets: CGFloat) -> UIEdgeInsets {
        .init(top: insets, left: .nan, bottom: insets, right: .nan)
    }

    static func horizontal(left: CGFloat = .nan, right: CGFloat = .nan) -> UIEdgeInsets {
        .init(top: .nan, left: left, bottom: .nan, right: right)
    }

    static func vertical(top: CGFloat = .nan, bottom: CGFloat = .nan) -> UIEdgeInsets {
        .init(top: top, left: .nan, bottom: bottom, right: .nan)
    }

    // MARK: - Instance methods

    func vertical(onNan defaultValue: CGFloat = .nan) -> CGFloat {
        add(\.top, to: \.bottom, of: self, onNan: defaultValue)
    }
    
    func horizontal(onNan defaultValue: CGFloat = .nan) -> CGFloat {
        add(\.left, to: \.right, of: self, onNan: defaultValue)
    }

    func horizontal(_ insets: CGFloat) -> UIEdgeInsets {
        .init(top: top, left: insets, bottom: bottom, right: insets)
    }

    func vertical(_ insets: CGFloat) -> UIEdgeInsets {
        .init(top: insets, left: left, bottom: insets, right: right)
    }

    func horizontal(left: CGFloat = .nan, right: CGFloat = .nan) -> UIEdgeInsets {
        .init(top: top, left: left, bottom: bottom, right: right)
    }

    func vertical(top: CGFloat = .nan, bottom: CGFloat = .nan) -> UIEdgeInsets {
        .init(top: top, left: left, bottom: bottom, right: right)
    }

    func replacingNan(with defaultValue: CGFloat) -> Self {
        .init(top: top.isFinite ? top : defaultValue,
              left: left.isFinite ? left : defaultValue,
              bottom: bottom.isFinite ? bottom : defaultValue,
              right: right.isFinite ? right : defaultValue)
    }

    func add(_ lhsKeyPath: KeyPath<Self, CGFloat>,
             to rhsKeyPath: KeyPath<Self, CGFloat>,
             of rhs: Self,
             onNan defaultValue: CGFloat = .nan) -> CGFloat {

        let lhsValue = self[keyPath: lhsKeyPath]
        let rhsValue = rhs[keyPath: rhsKeyPath]

        switch (lhsValue.isFinite, rhsValue.isFinite) {
        case (true, true):
            return lhsValue + rhsValue
        case (true, false):
            return lhsValue
        case (false, true):
            return rhsValue
        case (false, false):
            return defaultValue
        }
    }
}