//
//  Copyright (c) 2021 Open Whisper Systems. All rights reserved.
//

import UIKit
import SignalMessaging

@objc
public class OWSButton: UIButton {

    @objc
    public var block: () -> Void = { }

    @objc
    public var dimsWhenHighlighted = false

    public override var isHighlighted: Bool {
        didSet {
            guard dimsWhenHighlighted else { return }
            alpha = isHighlighted ? 0.4 : 1
        }
    }

    // MARK: -

    @objc
    public init(block: @escaping () -> Void = { }) {
        super.init(frame: .zero)

        self.block = block
        addTarget(self, action: #selector(didTap), for: .touchUpInside)
    }

    @objc
    public init(title: String, block: @escaping () -> Void = { }) {
        super.init(frame: .zero)

        self.block = block
        addTarget(self, action: #selector(didTap), for: .touchUpInside)
        setTitle(title, for: .normal)
    }

    @objc
    public init(imageName: String,
         tintColor: UIColor?,
         block: @escaping () -> Void = { }) {
        super.init(frame: .zero)

        self.block = block
        addTarget(self, action: #selector(didTap), for: .touchUpInside)

        setImage(imageName: imageName)
        self.tintColor = tintColor
    }

    @objc
    public func setImage(imageName: String?) {
        guard let imageName = imageName else {
            setImage(nil, for: .normal)
            return
        }
        if let image = UIImage(named: imageName) {
            setImage(image.withRenderingMode(.alwaysTemplate), for: .normal)
        } else {
            owsFailDebug("Missing asset: \(imageName)")
        }
    }

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

    // MARK: - Common Style Reuse

    @objc
    public class func sendButton(imageName: String, block: @escaping () -> Void) -> OWSButton {
        let button = OWSButton(imageName: imageName, tintColor: .white, block: block)

        let buttonWidth: CGFloat = 40
        button.layer.cornerRadius = buttonWidth / 2
        button.autoSetDimensions(to: CGSize(square: buttonWidth))

        button.backgroundColor = .ows_accentBlue

        return button
    }

    /// Mimics a UIBarButtonItem of type .cancel, but with a shadow.
    @objc
    public class func shadowedCancelButton(block: @escaping () -> Void) -> OWSButton {
        let cancelButton = OWSButton(title: CommonStrings.cancelButton, block: block)
        cancelButton.setTitleColor(.white, for: .normal)
        if let titleLabel = cancelButton.titleLabel {
            titleLabel.font = UIFont.systemFont(ofSize: 18.0)
            titleLabel.layer.shadowColor = UIColor.black.cgColor
            titleLabel.setShadow()
        } else {
            owsFailDebug("Missing titleLabel.")
        }
        cancelButton.sizeToFit()
        return cancelButton
    }

    @objc
    public class func navigationBarButton(imageName: String, block: @escaping () -> Void) -> OWSButton {
        let button = OWSButton(imageName: imageName, tintColor: .white, block: block)
        button.layer.shadowColor = UIColor.black.cgColor
        button.layer.shadowRadius = 2
        button.layer.shadowOpacity = 0.66
        button.layer.shadowOffset = .zero
        return button
    }

    // MARK: -

    @objc
    func didTap() {
        block()
    }
}