//
// SnapKit
//
// Copyright (c) 2011-Present SnapKit Team - https://github.com/SnapKit
//
// 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.

#if os(iOS) || os(tvOS)
 import UIKit
#else
 import AppKit
#endif

public extension LayoutConstraint {
 
 override var description: String {
 var description = "<"
 
 description += descriptionForObject(self)
 
 if let firstItem = conditionalOptional(from: self.firstItem) {
 description += " \(descriptionForObject(firstItem))"
 }
 
 if self.firstAttribute != .notAnAttribute {
 description += ".\(descriptionForAttribute(self.firstAttribute))"
 }
 
 description += " \(descriptionForRelation(self.relation))"
 
 if let secondItem = self.secondItem {
 description += " \(descriptionForObject(secondItem))"
 }
 
 if self.secondAttribute != .notAnAttribute {
 description += ".\(descriptionForAttribute(self.secondAttribute))"
 }
 
 if self.multiplier != 1.0 {
 description += " * \(self.multiplier)"
 }
 
 if self.secondAttribute == .notAnAttribute {
 description += " \(self.constant)"
 } else {
 if self.constant > 0.0 {
 description += " + \(self.constant)"
 } else if self.constant < 0.0 {
 description += " - \(abs(self.constant))"
 }
 }
 
 if self.priority.rawValue != 1000.0 {
 description += " ^\(self.priority)"
 }
 
 description += ">"
 
 return description
 }
 
}

private func descriptionForRelation(_ relation: LayoutRelation) -> String {
 switch relation {
 case .equal: return "=="
 case .greaterThanOrEqual: return ">="
 case .lessThanOrEqual: return "<="
 #if swift(>=5.0)
 @unknown default: return "unknown"
 #endif
 }
}

private func descriptionForAttribute(_ attribute: LayoutAttribute) -> String {
 #if os(iOS) || os(tvOS)
 switch attribute {
 case .notAnAttribute: return "notAnAttribute"
 case .top: return "top"
 case .left: return "left"
 case .bottom: return "bottom"
 case .right: return "right"
 case .leading: return "leading"
 case .trailing: return "trailing"
 case .width: return "width"
 case .height: return "height"
 case .centerX: return "centerX"
 case .centerY: return "centerY"
 case .lastBaseline: return "lastBaseline"
 case .firstBaseline: return "firstBaseline"
 case .topMargin: return "topMargin"
 case .leftMargin: return "leftMargin"
 case .bottomMargin: return "bottomMargin"
 case .rightMargin: return "rightMargin"
 case .leadingMargin: return "leadingMargin"
 case .trailingMargin: return "trailingMargin"
 case .centerXWithinMargins: return "centerXWithinMargins"
 case .centerYWithinMargins: return "centerYWithinMargins"
 #if swift(>=5.0)
 @unknown default: return "unknown"
 #endif
 }
 #else
 switch attribute {
 case .notAnAttribute: return "notAnAttribute"
 case .top: return "top"
 case .left: return "left"
 case .bottom: return "bottom"
 case .right: return "right"
 case .leading: return "leading"
 case .trailing: return "trailing"
 case .width: return "width"
 case .height: return "height"
 case .centerX: return "centerX"
 case .centerY: return "centerY"
 case .lastBaseline: return "lastBaseline"
 case .firstBaseline: return "firstBaseline"
 #if swift(>=5.0)
 @unknown default: return "unknown"
 #endif
 }
 #endif
}

private func conditionalOptional<T>(from object: Optional<T>) -> Optional<T> {
 return object
}

private func conditionalOptional<T>(from object: T) -> Optional<T> {
 return Optional.some(object)
}

private func descriptionForObject(_ object: AnyObject) -> String {
 let pointerDescription = String(format: "%p", UInt(bitPattern: ObjectIdentifier(object)))
 var desc = ""
 
 desc += type(of: object).description()
 
 if let object = object as? ConstraintView {
 desc += ":\(object.snp.label() ?? pointerDescription)"
 } else if let object = object as? LayoutConstraint {
 desc += ":\(object.label ?? pointerDescription)"
 } else {
 desc += ":\(pointerDescription)"
 }
 
 if let object = object as? LayoutConstraint, let file = object.constraint?.sourceLocation.0, let line = object.constraint?.sourceLocation.1 {
 desc += "@\((file as NSString).lastPathComponent)#\(line)"
 }
 
 desc += ""
 return desc
}