ThemeManager-TargetActionStorage.swift

import Foundation

fileprivate var associatedKey = "ThemerTargetActionStorage"

final class TargetActionStorage<Theme: ThemeProtocol> {
    private var targetActions: [AnyTargetActionWrapper<Theme>] = []

    static func setup(for target: Any) -> TargetActionStorage {
        let storage = TargetActionStorage()
        objc_setAssociatedObject(
            target,
            &associatedKey,
            storage,
            .OBJC_ASSOCIATION_RETAIN_NONATOMIC
        )
        return storage
    }

    static func get(for target: Any) -> TargetActionStorage? {
        return objc_getAssociatedObject(target, &associatedKey)
            .map { $0 as! TargetActionStorage }
    }

    func register<Target: AnyObject>(
        target: Target,
        action: @escaping (Target) -> (Theme) -> (),
        initialTheme: Theme
    ) {
        let ta = AnyTargetActionWrapper(target: target, action: action)
        targetActions.append(ta)
        ta.applyTheme(initialTheme)
    }

    func applyTheme(_ theme: Theme) {
        targetActions.forEach {
            $0.applyTheme(theme)
        }
    }
}