import AppKit

@MainActor
enum IconStyle {
    // Preserve the approved 22-point application artwork slot beside 14-point text.
    static func applicationSize(for font: NSFont) -> CGFloat {
        font.pointSize * (22.0 / 14.0)
    }

    static func symbolConfiguration(for font: NSFont) -> NSImage.SymbolConfiguration {
        .init(pointSize: font.pointSize, weight: .regular, scale: .medium)
    }

    static func symbol(_ name: String, for font: NSFont, accessibilityDescription: String? = nil) -> NSImage? {
        NSImage(systemSymbolName: name, accessibilityDescription: accessibilityDescription)?
            .withSymbolConfiguration(symbolConfiguration(for: font))
    }
}

/// A shared artwork slot: font-sized symbols or proportionally sized application/file icons.
@MainActor
final class IconView: NSImageView {
    init(font: NSFont) {
        super.init(frame: .zero)
        symbolConfiguration = IconStyle.symbolConfiguration(for: font)
        imageScaling = .scaleProportionallyDown
        setAccessibilityElement(false)
        translatesAutoresizingMaskIntoConstraints = false
        let size = IconStyle.applicationSize(for: font)
        NSLayoutConstraint.activate([
            widthAnchor.constraint(equalToConstant: size),
            heightAnchor.constraint(equalToConstant: size)
        ])
    }

    // SF Symbol optical insets must not enlarge the shared artwork slot.
    override var alignmentRectInsets: NSEdgeInsets { NSEdgeInsets(top: 0, left: 0, bottom: 0, right: 0) }

    required init?(coder: NSCoder) { fatalError("Conjure creates icons programmatically") }
}