FontBuilder.swift

//
//  FontBuilder.swift
//  Eject
//
//  Created by Brian King on 10/19/16.
//  Copyright © 2016 Brian King. All rights reserved.
//

import Foundation

struct FontBuilder: Builder {
    func lookupSize(name: String) -> String {
        switch name {
        case "button":
            return "15"
        default:
            return "\(name) -- log a bug with this value!"
        }
    }

    func buildElement(attributes: inout [String: String], document: XIBDocument, parent: Reference?) throws -> Reference? {
        guard let parent = parent else { throw XIBParser.Error.needParent }
        let key = try attributes.removeRequiredValue(forKey: "key")
        let pointSize = try attributes.removeValue(forKey: "pointSize") ?? lookupSize(name: try attributes.removeRequiredValue(forKey: "size"))
        let value: String
        attributes.removeValue(forKey: "family")

        // Not sure why, but the IB specifies a private key. Fix it up.
        if let type = attributes.removeValue(forKey: "type") {
            value = ".\(type)Font(ofSize: \(pointSize))"
        }
        else if let name = attributes.removeValue(forKey: "name") {
            value = "UIFont(name: \"\(name)\", size: \(pointSize))"
        }
        else {
            throw XIBParser.Error.unknown(attributes: attributes)
        }

        try document.addVariableConfiguration(
            for: parent.identifier,
            attribute: key,
            value: BasicValue(value: value)
        )
        return parent
    }
}