//
//  ToastView.swift
//  PaiaiDataKit
//
//  Created by FFIB on 16/7/21.
//  Copyright © 2016年 FFIB. All rights reserved.
//

import UIKit

class ToastView: UIView {

    var option: ToastOption
    var toastType: Toast.ToastType

    fileprivate var stackView = UIStackView(arrangedSubviews: [])
    fileprivate var visualView: UIVisualEffectView
    fileprivate var label: UILabel?
    fileprivate var imageView: UIImageView?
    fileprivate var activityIndicatorView: UIActivityIndicatorView?

    fileprivate var text: String?
    fileprivate var image: UIImage?
    fileprivate var isActivity: Bool = false

    fileprivate var padding = UIEdgeInsets(top: 24, left: 24, bottom: 24, right: 24)

    init(option: ToastOption, type: Toast.ToastType) {
        self.option = option
        self.toastType = type
        let effect = UIBlurEffect(style: .dark)
        self.visualView = UIVisualEffectView(effect: effect)
        super.init(frame: CGRect.zero)
        initProperty()
    }

    required init(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    private func initProperty() {
        layer.cornerRadius = 5
        layer.masksToBounds = true

        stackView.axis = .vertical
        stackView.alignment = .center
        stackView.distribution = .equalSpacing
        stackView.spacing = 12
    }

    public func switchToast() {
        clear()
        setToast()
        constructStackViewHierarchy()
        activateConstraints()
    }

    override func didMoveToWindow() {
        setToast()

        addSubview(visualView)

        constructStackViewHierarchy()
        activateConstraints()
    }

    private func clear() {
        image = nil
        isActivity = false
        text = nil
        let arrangedSubviews = stackView.arrangedSubviews
        arrangedSubviews.forEach {
            stackView.removeArrangedSubview($0)
            $0.removeFromSuperview()
        }
        stackView.removeFromSuperview()
    }

    private func setToast() {
        switch toastType {
        case let .text(str):
            text = str
        case let .image(img):
            image = img
        case let .imageWithText(img, str):
            image = img
            text = str
        case let .activityIndicator(str):
            text = str
            isActivity = true
        }
    }
}

/// construct view and layout
fileprivate extension ToastView {

    func constructStackViewHierarchy() {
        addSubview(stackView)

        if image != nil {
            imageView = makeImageView()

            stackView.addArrangedSubview(imageView!)
        }

        if isActivity {
            activityIndicatorView = makeActivityIndicatorView()
            stackView.addArrangedSubview(activityIndicatorView!)
        }

        if text != nil {
            label = makeLabel()
            stackView.addArrangedSubview(label!)
        }
    }

    func activateConstraints() {
        activateConstraintsImage()
        activateConstraintsIndicator()
        activateConstraintsText()
        activateConstraintsStackView()
        activateConstraintsVisualView()
        activateConstraintsContentView()
    }

    func activateConstraintsStackView() {
        stackView.translatesAutoresizingMaskIntoConstraints = false

        NSLayoutConstraint.activate([
            stackView.topAnchor.constraint(equalTo: topAnchor, constant: padding.top),
            stackView.bottomAnchor.constraint(equalTo: bottomAnchor, constant: -padding.bottom),
            stackView.leadingAnchor.constraint(equalTo: leadingAnchor, constant: padding.left),
            stackView.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -padding.right)
            ])
    }

    func activateConstraintsImage() {
        guard let imageView = imageView else { return }

        imageView.translatesAutoresizingMaskIntoConstraints = false

        NSLayoutConstraint.activate([
            imageView.widthAnchor.constraint(equalToConstant: 50),
            imageView.heightAnchor.constraint(equalToConstant: 50)
            ])
    }

    func activateConstraintsIndicator() {
        guard let activityIndicatorView = activityIndicatorView else { return }

        activityIndicatorView.startAnimating()
    }

    func activateConstraintsText() {
        guard let label = label else { return }

        let windowSize = UIScreen.main.bounds.size

        label.translatesAutoresizingMaskIntoConstraints = false

        NSLayoutConstraint.activate([
            widthAnchor.constraint(lessThanOrEqualToConstant: windowSize.width - 52)
            ])
    }

    func activateConstraintsContentView() {
        guard let val = superview else { return }

        translatesAutoresizingMaskIntoConstraints = false

        NSLayoutConstraint.activate([
            centerXAnchor.constraint(equalTo: val.centerXAnchor),
            centerYAnchor.constraint(equalTo: val.centerYAnchor)
            ])
    }

    func activateConstraintsVisualView() {
        visualView.translatesAutoresizingMaskIntoConstraints = false

        NSLayoutConstraint.activate([
            visualView.topAnchor.constraint(equalTo: topAnchor),
            visualView.leadingAnchor.constraint(equalTo: leadingAnchor),
            visualView.widthAnchor.constraint(equalTo: widthAnchor),
            visualView.heightAnchor.constraint(equalTo: heightAnchor)
            ])
    }
}

fileprivate extension ToastView {
    func makeLabel() -> UILabel {
        let label = UILabel()
        label.text = text
        label.numberOfLines = 0
        label.font = option.font
        label.textAlignment = .center
        label.textColor = option.tintColor
        label.sizeToFit()

        return label
    }

    func makeImageView() -> UIImageView {
        let imageView = UIImageView()
        imageView.image = image

        return imageView
    }

    func makeActivityIndicatorView() -> UIActivityIndicatorView {
        let activity = UIActivityIndicatorView(style: .whiteLarge)

        return activity
    }
}