UIKitAction.swift

//
//  Copyright 2020 PLAID, Inc.
//
//  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
//
//      https://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.
//

import UIKit

/// 画像を生成して返す関数を表す型です。
public typealias ImageProvider = () -> UIImage?

/// Actionの生成を行う列挙型です。
public enum ActionFactory {
    /// Actionを返します。<br>
    ///
    /// view / viewController / targetText が全て nil の場合は初期化に失敗して nil を返します。<br>
    /// アクションIDにはアプリ再起動時も変化しない一意なIDを設定してください。
    ///
    /// - Parameter actionName: アクション名
    /// - Parameter view: UIView
    /// - Parameter viewController: UIViewController
    /// - Parameter targetText: ターゲット文字列（Viewコンポーネントのタイトルなどを設定します。）
    /// - Parameter actionId: アクションID
    /// - Parameter imageProvider: 操作ログに添付する画像を返す関数（ペアリング時の操作ログ送信でのみ利用されます。）
    /// - Returns: ActionProtocol
    public static func createForUIKit(
        actionName: String,
        view: UIView?,
        viewController: UIViewController?,
        targetText: String?,
        actionId: String?,
        imageProvider: ImageProvider? = nil
    ) -> ActionProtocol? {
        UIKitAction(
            actionName,
            view: UIKitAction.AppropriateViewDetector(view: view)?.detect(),
            viewController: viewController,
            targetText: targetText,
            actionId: actionId,
            imageProvider: imageProvider
        )
    }
}

/// UIKit用のアクションを表現する型です。
internal protocol UIKitActionProtocol: ActionProtocol {
    /// UIViewを返します
    var view: UIView? { get }

    /// UIViewControllerを返します
    var viewController: UIViewController? { get }

    /// View名を返します
    var viewName: String? { get }

    /// ViewController名を返します
    var viewControllerName: String? { get }
}

extension UIKitActionProtocol {
    /// スクリーン名を返します
    var screenName: String? {
        viewName
    }

    /// Viewホスト名を返します
    var screenHostName: String? {
        viewControllerName
    }
}

internal struct UIKitAction: UIKitActionProtocol {
    static let ignoreActions = ["handlePan:", "handlePanGesture:", "handlePinchGesture:",
                                "handleTouchMonitor:", "handleTiltGesture:", "observerGestureHandler:"]
    var action: String
    var view: UIView?
    var viewController: UIViewController?
    var targetText: String?
    var actionId: String?
    var imageProvider: ImageProvider?

    var viewName: String? {
        guard let view = view else {
            return nil
        }
        return String(describing: type(of: view))
    }

    var viewControllerName: String? {
        guard let viewController = viewController else {
            return nil
        }
        return String(describing: type(of: viewController))
    }

    init?(_ action: String, view: UIView?, viewController: UIViewController?, targetText: String? = nil, actionId: String? = nil, imageProvider: ImageProvider? = nil) {
        guard UIKitAction.validate(actoionName: action, view: view, viewController: viewController, targetText: targetText) else {
            return nil
        }

        self.action = action
        self.view = view
        self.viewController = viewController
        self.targetText = targetText
        self.actionId = actionId
        self.imageProvider = imageProvider ?? Self.defaultImageProvider(view: view, viewController: viewController)
    }

    static func defaultImageProvider(view: UIView?, viewController: UIViewController?) -> ImageProvider {
        { Inspector.takeSnapshot(with: view) ?? Inspector.takeSnapshot(with: viewController?.view) }
    }

    private static func validate(actoionName: String, view: UIView?, viewController: UIViewController?, targetText: String?) -> Bool {
        if UIKitAction.ignoreActions.contains(actoionName) {
            return false
        }
        if view == nil && viewController == nil && targetText == nil {
            return false
        }
        return true
    }

    func image() -> UIImage? {
        imageProvider?()
    }
}

extension UIKitAction {
    /// Viewの階層情報を連結してactionIdとして返す。（例: UIButton0UIView0UIView）
    static func actionId(view: UIView?) -> String? {
        guard view != nil else {
            return nil
        }

        var actionId = ""
        var targetView = view
        while let tView = targetView {
            if let superView = tView.superview {
                actionId.append(String(describing: type(of: tView)))
                if let index = superView.subviews.firstIndex(where: { $0.isEqual(tView) }) {
                    actionId.append(String(index))
                    targetView = superView
                }
            } else {
                actionId.append(String(describing: type(of: tView)))
                targetView = nil
            }
        }
        return actionId
    }

    /// actionIdからView階層のパスを示すindex配列を返す。（例: UIView1UIView0UIViewからは、[0,1]が返される）
    static func viewPathIndices(actionId: String?) -> [Int] {
        guard let actionId = actionId else {
            return []
        }
        let indices = actionId.components(separatedBy: CharacterSet.decimalDigits.inverted).compactMap { Int($0) }
        return indices.reversed()
    }
}

extension UIKitAction {
    struct AppropriateViewDetector {
        var view: UIView

        init?(view: UIView?) {
            guard let view = view else {
                return nil
            }
            self.view = view
        }

        /// View階層を探索してビジュアルトラッキングの発火条件として扱いやすい親Viewがあれば返す。（UITableViewCellなど）
        /// 発火条件として扱いやすい親Viewがなければ、保持しているviewを返す。
        func detect() -> UIView? {
            if isAppropriateView {
                return view
            }

            func _detect(from view: UIView) -> UIView? {
                var targetView: UIView? = view
                while let tView = targetView {
                    switch targetView {
                    case is UITableViewCell, is UICollectionViewCell, is UIPickerView, is UINavigationBar:
                        return tView

                    default:
                        targetView = tView.superview
                    }
                }
                return view
            }

            return _detect(from: view)
        }

        var isAppropriateView: Bool {
            switch view {
            case is UIScrollView, is UITableViewCell, is UICollectionViewCell, is UIPickerView, is UINavigationBar:
                return true

            case is UILabel, is UIImageView:
                let gestureRecognizers = view.gestureRecognizers ?? []
                return gestureRecognizers.contains { $0.isEnabled }

            case let view as UIControl where view.isUserInteractionEnabled && view.isEnabled:
                return true

            default:
                return false
            }
        }
    }
}

extension UIKitAction: CustomStringConvertible {
    public var description: String {
        let cls = String(describing: type(of: self))
        let values = [
            "action": action,
            "view": viewName ?? "",
            "view_controller": viewControllerName ?? "",
            "target_text": targetText ?? "",
            "action_id": actionId ?? ""
        ]
        return "<\(cls): \(values)>"
    }
}