//
//  AudioSectionView.swift
//  XIONControlPanel
//

import UIKit

final class AudioSectionView: UIView
{
    var mixerSettingsHandler: (() -> Void)?
    var bottomContentInset: CGFloat = 0.0
    {
        didSet
        {
            if oldValue != bottomContentInset {
                setNeedsLayout()
            }
        }
    }

    private let _label = UILabel(frame: .zero)
    private let _mixerSettingsButton = AudioActionButton(type: .custom)

    override init(frame: CGRect)
    {
        super.init(frame: frame)

        _label.font = UIFont(name: "Orbitron-Medium", size: 14.0)
        _label.text = "audio"
        _label.textColor = .white.withAlphaComponent(0.8)
        addSubview(_label)

        _mixerSettingsButton.setTitle("MIXER SETTINGS", for: .normal)
        _mixerSettingsButton.titleLabel?.font = UIFont(name: "Orbitron-Medium", size: 21.0)
        _mixerSettingsButton.setTitleColor(.white, for: .normal)
        _mixerSettingsButton.accessibilityIdentifier = "audio.mixerSettings"
        _mixerSettingsButton.accessibilityLabel = "Mixer Settings"
        _mixerSettingsButton.addTarget(self, action: #selector(_showMixerSettings), for: .touchUpInside)
        addSubview(_mixerSettingsButton)
    }

    required init?(coder: NSCoder)
    {
        fatalError("unsupported")
    }

    override func layoutSubviews()
    {
        super.layoutSubviews()

        let labelSpacing: CGFloat = 8.0
        let labelSize = _label.sizeThatFits(bounds.size)
        _label.frame = CGRect(
            x: 0.0,
            y: 0.0,
            width: labelSize.width,
            height: labelSize.height
        )
        _mixerSettingsButton.frame = CGRect(
            x: 0.0,
            y: _label.frame.maxY + labelSpacing,
            width: bounds.width,
            height: max(
                0.0,
                bounds.height - _label.frame.height - labelSpacing - bottomContentInset
            )
        )
    }

    static func preferredHeight(forWidth width: CGFloat) -> CGFloat
    {
        let cellsPerRow: CGFloat
        switch width {
        case 500.0...:
            cellsPerRow = 4.0
        case 400.0..<500.0:
            cellsPerRow = 3.0
        default:
            cellsPerRow = 2.0
        }

        let cellSpacing: CGFloat = 5.0
        let cellDimension = floor(
            (width / cellsPerRow) - ((cellSpacing * (cellsPerRow - 1.0)) / cellsPerRow)
        )
        let buttonHeight = rint(cellDimension / 1.5)
        return 17.0 + 8.0 + buttonHeight
    }

    @objc private func _showMixerSettings()
    {
        mixerSettingsHandler?()
    }
}

private final class AudioActionButton: UIButton
{
    private static let normalBackgroundColor = UIColor(white: 0.2, alpha: 1.0)
    private static let highlightedBackgroundColor = UIColor(white: 0.8, alpha: 1.0)

    override init(frame: CGRect)
    {
        super.init(frame: frame)
        backgroundColor = Self.normalBackgroundColor
        accessibilityTraits = .button
    }

    required init?(coder: NSCoder)
    {
        fatalError("unsupported")
    }

    override var isHighlighted: Bool
    {
        didSet
        {
            if isHighlighted {
                backgroundColor = Self.highlightedBackgroundColor
            } else {
                UIView.animate(
                    withDuration: 0.35,
                    delay: 0.0,
                    options: [.allowUserInteraction, .beginFromCurrentState],
                    animations: {
                        self.backgroundColor = Self.normalBackgroundColor
                    },
                    completion: nil
                )
            }
        }
    }
}