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

import UIKit

class ToastView: UIView {
    
    fileprivate var option: ToastOption
    fileprivate var toastType: Toast.ToastType
    
    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 topView: UIView?
    fileprivate var bottomView: UIView?
    fileprivate var padding = UIEdgeInsets(top: 12, left: 12, bottom: 12, right: 12)
    
    
    init(option: ToastOption, type: Toast.ToastType) {
        self.option = option
        self.toastType = type
        super.init(frame: CGRect.zero)
        
        initProperty()
    }
    
    @available(*, unavailable, message: "Loading this view from a nib is unsupported")
    public required init?(coder aDecoder: NSCoder) {
        fatalError("Loading this view from a nib is unsupported")
    }
    
    private func initProperty() {
        alpha = 0
        layer.cornerRadius = 5
        backgroundColor = option.backgroundColor
    }
    
    override func didMoveToWindow() {
        switch toastType {
        case let .text(t):
            text = t
        case let .image(i):
            image = i
        case let .imageWithText(i, t):
            image = i
            text = t
        case let .activityIndicator(t):
            text = t
            isActivity = true
        }
        
        constructViewHierarchy()
        activateConstraints()
    }
}

/// construct view and layout
fileprivate extension ToastView {
    
    func constructViewHierarchy() {
        if image != nil {
            imageView = makeImageView()
            addSubview(imageView!)
        }
        
        if isActivity {
            activityIndicatorView = makeActivityIndicatorView()
            addSubview(activityIndicatorView!)
        }
        
        if text != nil {
            label = makeLabel()
            addSubview(label!)
        }
    }
    
    func activateConstraints() {
        activateConstraintsImage()
        activateConstraintsIndicator()
        activateConstraintsText()
        activateConstraintsContentView()
    }
    
    func activateConstraintsImage() {
        guard let imageView = imageView else { return }
        
        imageView.translatesAutoresizingMaskIntoConstraints = false
        
        NSLayoutConstraint.activate([
            imageView.widthAnchor.constraint(equalToConstant: 50),
            imageView.heightAnchor.constraint(equalToConstant: 50),
            imageView.centerXAnchor.constraint(equalTo: centerXAnchor),
            imageView.topAnchor.constraint(equalTo: topAnchor, constant: padding.top)
            ])
        
        topView = imageView
    }
    
    func activateConstraintsIndicator() {
        guard let activityIndicatorView = activityIndicatorView else { return }
        
        activityIndicatorView.translatesAutoresizingMaskIntoConstraints = false
        
        NSLayoutConstraint.activate([
            activityIndicatorView.centerXAnchor.constraint(equalTo: centerXAnchor),
            activityIndicatorView.topAnchor.constraint(equalTo: topAnchor, constant: padding.top)
            ])
        
        topView = activityIndicatorView
        activityIndicatorView.startAnimating()
    }
    
    func activateConstraintsText() {
        guard let label = label else { return }
        
        let windowSize = UIScreen.main.bounds.size
        
        label.translatesAutoresizingMaskIntoConstraints = false
        
        NSLayoutConstraint.activate([
            label.centerXAnchor.constraint(equalTo: centerXAnchor),
            widthAnchor.constraint(lessThanOrEqualToConstant: windowSize.width - 52),
            label.bottomAnchor.constraint(equalTo: bottomAnchor, constant: -padding.bottom),
            label.leadingAnchor.constraint(equalTo: leadingAnchor, constant: padding.left),
            label.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -padding.right),
            label.topAnchor.constraint(equalTo: topView?.bottomAnchor ?? topAnchor, constant: 6),
            ])
        
        if (text?.count ?? 0) <= 3 {
            
        } else {
            NSLayoutConstraint.activate([
                ])
        }
        
        if topView != nil {
            NSLayoutConstraint.activate([
                label.widthAnchor.constraint(greaterThanOrEqualTo: heightAnchor)
                ])
        }
        
        bottomView = label
    }
    
    func activateConstraintsContentView() {
        guard let v = superview else { return }
        translatesAutoresizingMaskIntoConstraints = false
        
        NSLayoutConstraint.activate([
            centerXAnchor.constraint(equalTo: v.centerXAnchor),
            centerYAnchor.constraint(equalTo: v.centerYAnchor)
            ])
        
        if topView == nil {
            NSLayoutConstraint.activate([
                bottomView!.topAnchor.constraint(equalTo: topAnchor, constant: padding.top)
                ])
        } else if bottomView == nil {
            NSLayoutConstraint.activate([
                topView!.bottomAnchor.constraint(equalTo: bottomAnchor, constant: -padding.bottom),
                topView!.leadingAnchor.constraint(equalTo: leadingAnchor, constant: padding.left),
                topView!.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -padding.right)
                ])
        }
    }
}

fileprivate extension ToastView {
    func makeLabel() -> UILabel {
        let l = UILabel()
        l.text = text
        l.numberOfLines = 0
        l.font = option.font
        l.textAlignment = .center
        l.textColor = option.tintColor
        
        return l
    }
    
    func makeImageView() -> UIImageView {
        let i = UIImageView()
        i.image = image
        
        return i
    }
    
    func makeActivityIndicatorView() -> UIActivityIndicatorView {
        let a = UIActivityIndicatorView(style: .white)
        
        return a
    }
}