AmigoHelper.swift

//
//  AmigoHelper.swift
//
//  Created by Zaid Crowe on 04/01/2018.
//  Copyright © 2018 Team Extension. All rights reserved.
//

import Foundation

class AmigoHelper {
    
    enum AmigoError: Error {
        case CantCreateUpdateJSON
        case GetDataEncodingWrong
    }
    
    static func loadAmigo (amigoWebView: UIWebView, apiKey: String) {
        let checkAmigoExists = "typeof Amigo.load"
        if let amigoExists = amigoWebView.stringByEvaluatingJavaScript(from: checkAmigoExists) {
            if(amigoExists == "function"){
                amigoWebView.stringByEvaluatingJavaScript(from: "Amigo.load()")
            } else {
                amigoWebView.stringByEvaluatingJavaScript(from: "(function amigo(i,n,j,e,c,t){i.amigoConfig={apiKey:'"+apiKey+"'};c=n.createElement(j);c.async=1;c.src=e+'?api_key='+encodeURIComponent(i.amigoConfig.apiKey);t=n.getElementsByTagName(j)[0];t.parentNode.insertBefore(c,t)}(window,document,'script','https://private-dat.herokuapp.com/static/amigo-loader.js'));")
            }
        }
    }
    
    static func updateData (amigoData: Dictionary<String, Any>, amigoWebView: UIWebView, apiKey: String) throws {
        let theJSONData = try JSONSerialization.data(withJSONObject: amigoData, options: .prettyPrinted)
        guard let amigoDataJSONText = String(data: theJSONData, encoding: String.Encoding.ascii) else {
            throw(AmigoError.CantCreateUpdateJSON)
        }
        amigoWebView.stringByEvaluatingJavaScript(from: "amigoData = \""+amigoDataJSONText+"\"")
        loadAmigo(amigoWebView: amigoWebView, apiKey: apiKey)
    }
    
    static func getData (amigoWebView: UIWebView, apiKey: String) throws -> Dictionary<String, Any> {
        loadAmigo(amigoWebView: amigoWebView, apiKey: apiKey)
        
        let amigoDataString: String = amigoWebView.stringByEvaluatingJavaScript(from: "amigoData")!
        guard let amigoData = amigoDataString.data(using: .utf8) else {
            throw(AmigoError.GetDataEncodingWrong)
        }
        
        let amigoDict = try JSONSerialization.jsonObject(with: amigoData, options: []) as? [String: Any]
        return amigoDict ?? [:]
    }
}

    static func updateData (amigoData: Dictionary<String, Any>, amigoWebView: UIWebView, apiKey: String) throws {
        let theJSONData = try JSONSerialization.data(withJSONObject: amigoData, options: .prettyPrinted)
        guard let amigoDataJSONText = String(data: theJSONData, encoding: String.Encoding.ascii) else {
            // Can throw an error here if you'd like.
            return
        }
        amigoWebView.stringByEvaluatingJavaScript(from: "amigoData = \""+amigoDataJSONText+"\"")
        loadAmigo(amigoWebView: amigoWebView, apiKey: apiKey)
    }

    static func getData (amigoWebView: UIWebView, apiKey: String) throws -> Dictionary<String, Any> {
        loadAmigo(amigoWebView: amigoWebView, apiKey: apiKey)

        // Don't bang! unless you know that it will NEVER be nil, or your app will crash at runtime
        // alternatively, you could guard, or if you know it'll never fail then ! is fine.
        let amigoDataString: String = amigoWebView.stringByEvaluatingJavaScript(from: "amigoData")!

        guard let amigoData = amigoDataString.data(using: .utf8) else {
            // Throwing an error would be smart here instead
            return [:]
        }

        let amigoDict = try JSONSerialization.jsonObject(with: amigoData, options: []) as? [String: Any]
        return amigoDict ?? [:]
    }