//
//  FontStyle.swift
//  VDS
//
//  Created by Matt Bruce on 7/27/22.
//

import Foundation
import UIKit

/// Used in Classes that require Fonts
public protocol FontProtocol {
    var fontFileExtension: String { get }
    var fontName: String { get }
    static var allCases: [Self] { get }
}

extension FontProtocol {
    
    /// Registers the fonts used in the VDS Framework.
    public func register()  {
        guard let bundle = Bundle(identifier: "com.vzw.vds") else { return }
        Self.allCases.forEach{ font in
            if let url = bundle.url(forResource: font.fontName, withExtension: font.fontFileExtension){
                do{
                    try Self.register(from: url)
                } catch{
                    //TODO: error ("Font called \(font.fontName).\(font.fontFileExtension) couldn't be registered")
                }
            } else {
                //TODO: error ("Font for FontStyle: \(font) couldn't be found")
            }
        }
    }
    
    /// Registers a font from a fileLocation
    /// - Parameter url: URL of the file location.
    public static func register(from url: URL) throws {
        guard let fontDataProvider = CGDataProvider(url: url as CFURL) else {
            throw NSError(domain: "www.verizon.com", code: 123, userInfo: ["description":"Could not create font data provider for \(url)."])
        }
        let font = CGFont(fontDataProvider)
        var error: Unmanaged<CFError>?
        guard CTFontManagerRegisterGraphicsFont(font!, &error) else {
            throw error!.takeUnretainedValue()
        }
    }
    
    /// Returns a UIFont for the fontName and size given.
    /// - Parameters:
    ///   - size: Size of the font
    /// - Returns: UIFont for the fontName and Size.
    public func font(ofSize size: CGFloat) -> UIFont{
        DispatchQueue.once(block: { self.register() })
        guard let found = UIFont(name: self.fontName, size: size) else { return .systemFont(ofSize: size) }
        return found
    }
}

extension UIFont {
    public var scaledFont: UIFont {
        UIFontMetrics.default.scaledFont(for: self)
    }
}