//
//  Toast.swift
//  PaiaiDataKit
//
//  Created by FFIB on 2019/1/21.
//  Copyright © 2019 FFIB. All rights reserved.
//

import UIKit

private let globalInstance = Toast()

public class Toast {
    public enum ToastType {
        case text(String)
        case image(UIImage?)
        case imageWithText(UIImage?, String)
        case activityIndicator(String?)
    }

    public enum PresentationStyle {
        case center
        case custom(animator: ToastAnimator)

        var animator: ToastAnimator {
            switch self {
            case .center:
                return FadeToastAnimator()
            case let .custom(animator):
                return animator
            }
        }
    }

    public enum AnimationDuration {
        case none
        case duration(TimeInterval)
    }

    public struct Config {
        public init() {}

        public var toastType: ToastType = .text("")
        public var presentationStyle: PresentationStyle = .center
        public var duration: AnimationDuration = .duration(1)
        public var option: ToastOption = .default

        public static var `default`: Config {
            return Config()
        }
    }

    private var _toastView: ToastView?
    private var _config: Config = .default
    private var _task: DispatchWorkItem?
}

/// MARK: - APIS
public extension Toast {
    func show(config: Config = .default, in view: UIView? = UIApplication.shared.keyWindow) {
        self._config = config
        if _toastView == nil {
            let toastView = ToastView(option: config.option, type: config.toastType)
            view?.addSubview(toastView)
            _toastView = toastView
            showAnimation()
        } else {
            if case let .duration(interval) = config.duration {
                if let task = _task {
                    _ = task.wait(timeout: .now() + interval)
                } else {
                    self._task = DispatchWorkItem(block: {
                        self.hideAnimation()
                    })
                    DispatchQueue.main.asyncAfter(deadline: .now() + interval, execute: self._task!)
                }
            } else {
                _task?.cancel()
                _task = nil
            }

            _toastView?.option = config.option
            _toastView?.toastType = config.toastType
            _toastView?.switchToast()
        }
    }

    func show(message: String, in view: UIView? = UIApplication.shared.keyWindow) {
        var config = Config()
        config.toastType = .text(message)
        show(config: config, in: view)
    }

    func show(image: UIImage?, in view: UIView? = UIApplication.shared.keyWindow) {
        var config = Config()
        config.toastType = .image(image)
        show(config: config, in: view)
    }

    func show(message: String, image: UIImage?, in view: UIView? = UIApplication.shared.keyWindow) {
        var config = Config()
        config.toastType = .imageWithText(image, message)
        show(config: config, in: view)
    }

    func showActivity(message: String?, in view: UIView? = UIApplication.shared.keyWindow) {
        var config = Config()
        config.toastType = .activityIndicator(message)
        config.duration = .none
        show(config: config, in: view)
    }

    func hide() {
        hideAnimation()
    }

    private func showAnimation() {
        guard let toastView = _toastView else { return }
        _config.presentationStyle.animator.toastIn(in: toastView) {[weak self] _ in
            guard let `self` = self else { return }
            switch self._config.duration {
            case .none:
                break
            case let .duration(interval):
                self._task = DispatchWorkItem(block: {
                    self.hideAnimation()
                })
                DispatchQueue.main.asyncAfter(deadline: .now() + interval, execute: self._task!)
            }
        }
    }

    private func hideAnimation() {
        guard let toastView = _toastView else { return }
        _config.presentationStyle.animator.toastOut(in: toastView) {[weak self] (_) in
            guard let `self` = self else { return }
            self.clear()
        }
    }

    private func clear() {
        _toastView?.removeFromSuperview()
        _toastView = nil
        _task = nil
    }
}

/// MARK: - Static APIS
public extension Toast {
    static var share: Toast {
        return globalInstance
    }

    static func show(config: Config = .default, in view: UIView? = UIApplication.shared.keyWindow) {
        globalInstance.show(config: config, in: view)
    }

    static func show(message: String, in view: UIView? = UIApplication.shared.keyWindow) {
        globalInstance.show(message: message, in: view)
    }

    static func show(image: UIImage?, in view: UIView? = UIApplication.shared.keyWindow) {
        globalInstance.show(image: image, in: view)
    }

    static func show(message: String, image: UIImage?, in view: UIView? = UIApplication.shared.keyWindow) {
        globalInstance.show(message: message, image: image, in: view)
    }

    static func showActivity(message: String?, in view: UIView? = UIApplication.shared.keyWindow) {
        globalInstance.showActivity(message: message, in: view)
    }

    static func hide() {
        globalInstance.hide()
    }
}