//
//  CustomSegmentedControl.swift
//  SuperBoss
//
//  Created by STENIO FREITAS on 19/08/17.
//  Copyright © 2017 Stenio Wagner. All rights reserved.
//

import UIKit

class CustomSegmentedControl: UIControl {

    var selectorTextColor: UIColor = .white
    var selectorColor: UIColor = .darkGray
    var selector: UIView!

    var borderColor: UIColor = .yellow
    var borderWidth: CGFloat = 1
    var textColor: UIColor = .lightGray

    let buttonTitles = ["Podcasts", "Vídeos"]
    var buttons = [UIButton]()

    override func draw(_ rect: CGRect) {
        layer.cornerRadius = frame.height / 2
    }

    func updateViews() {
        subviews.forEach { $0.removeFromSuperview() }

        buttons.removeAll()

        setupButtons(buttonTitles)

        buttons[0].setTitleColor(selectorTextColor, for: .normal)

        setupSelector(numberOfTitles: buttonTitles.count)

        setupStackView()
    }

    func setupButtons(_ buttonTitles: [String]) {
        for buttonTitle in buttonTitles {
            let button = UIButton(type: .system)

            button.setTitle(buttonTitle, for: .normal)
            button.setTitleColor(textColor, for: .normal)
            button.addTarget(self, action: #selector(onSegmentedControlChanged(buttonClicked:)), for: .touchUpInside)

            buttons.append(button)
        }
    }

    func setupSelector(numberOfTitles: Int) {
        let selectorWidth = frame.width / CGFloat(numberOfTitles)

        selector = UIView(frame: CGRect(x: 0, y: 0, width: Int(selectorWidth), height: Int(frame.height)))
        selector.layer.cornerRadius = frame.height / 2
        selector.backgroundColor = selectorColor

        addSubview(selector)
    }

    func setupStackView() {
        let stackView = UIStackView(arrangedSubviews: buttons)

        stackView.axis = .horizontal
        stackView.alignment = .fill
        stackView.distribution = .fillProportionally

        addSubview(stackView)

        stackView.translatesAutoresizingMaskIntoConstraints = false

        stackView.topAnchor.constraint(equalTo: self.topAnchor).isActive = true
        stackView.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true
        stackView.leftAnchor.constraint(equalTo: self.leftAnchor).isActive = true
        stackView.rightAnchor.constraint(equalTo: self.rightAnchor).isActive = true
    }

    func onSegmentedControlChanged(buttonClicked: UIButton) {
        for (buttonIndex, button) in buttons.enumerated() {
            button.setTitleColor(textColor, for: .normal)

            if button == buttonClicked {
                animateSegmentedControlChange(buttonTargetIndex: buttonIndex)
                button.setTitleColor(selectorTextColor, for: .normal)
            }
        }
    }

    func animateSegmentedControlChange(buttonTargetIndex: Int) {
        let selectorStartPosition = frame.width / CGFloat(buttons.count) * CGFloat(buttonTargetIndex)

        UIView.animate(withDuration: 0.3, animations: {
            self.selector.frame.origin.x = selectorStartPosition
        })
    }
}