Swift Class Method Swizzle

swift_swizzle

//
//  LHNetworking+Endpoint.swift
//  magellan
//
//  Created by Ivan Bruel on 09/04/15.
//  Copyright (c) 2015 Passworks S.A. All rights reserved.
//

import Foundation
import Lighthouse

extension LHNetworking {
    public override class func initialize() {
        struct Static {
            static var token: dispatch_once_t = 0
        }
        
        // make sure this isn't a subclass
        if self !== LHNetworking.self {
            return
        }
        
        dispatch_once(&Static.token) {
            let originalSelector = Selector("endpoint")
            let swizzledSelector = Selector("lh_endpoint")
            
            if let klass: AnyClass = object_getClass(self) {
                
                let originalMethod = class_getClassMethod(klass, originalSelector)
                let swizzledMethod = class_getClassMethod(klass, swizzledSelector)
                
                
                let didAddMethod = class_addMethod(klass, originalSelector, method_getImplementation(swizzledMethod), method_getTypeEncoding(swizzledMethod))
                
                if didAddMethod {
                    class_replaceMethod(klass, swizzledSelector, method_getImplementation(originalMethod), method_getTypeEncoding(originalMethod))
                } else {
                    method_exchangeImplementations(originalMethod, swizzledMethod);
                }
            }
        }
    }
    
    // MARK: - Method Swizzling
    class func lh_endpoint() -> String! {
        let environmentDictionary = NSProcessInfo.processInfo().environment
        if let endpoint = environmentDictionary["ENDPOINT"] as? String {
            println("returning custom endpoint \(endpoint)")
            return endpoint
        }
        return self.lh_endpoint()
    }
}