Share a gif on Twitter. Code adapted for Swift 3 and iOS 10

TwitterShare.swift

// MARK: - Twitter
    /*
     To upload a gif to Twitter, two different API calls are needed.
     One to upload the gif. The other, to append a comment to the gif.
     
     https://xcodenoobies.blogspot.com.ar/2016/01/how-to-using-slrequest-to-upload-image.html?showComment=1460489097793#c638358337669317406
     */
    static func twitterShare(from viewController: FinishVideoViewController, path: String) {
        
        let account = ACAccountStore()
        let accountType = account.accountType(withAccountTypeIdentifier: ACAccountTypeIdentifierTwitter)
        
        // Request access to Twitter
        account.requestAccessToAccounts(
            with: accountType,
            options: nil) { (granted, error) in
                
                if granted == true {
                    
                    guard let arrayOfAccounts = account.accounts(with: accountType) else { print("No array of accounts"); return }
                    
                    if arrayOfAccounts.count > 0 {
                        
                        guard let twitterAccount = arrayOfAccounts.first as? ACAccount else { print("No twitter account"); return }
                        
                        let gifURL = URL(fileURLWithPath: path)
                        guard let gifData: Data = NSData(contentsOf: gifURL) as Data? else { print("No Gif Data"); return }
                        
                        guard let postGifRequest = SocialHelper.getPostGifRequest(
                            twitterAccount: twitterAccount,
                            gifData: gifData) else { print("No post gif request"); return }
                        
                        // Post gif to Twitter
                        viewController.showProgressHUD(with: SocialHelper.gifUploadingMessage)
                        postGifRequest.perform(handler: { (responseData, urlResponse, error) in
                            
                            if let err = error {
                                print("Twitter error. Gif Request \(err)")
                                viewController.hideProgressHUD()
                                return
                            }
                            
                            guard let responseData = responseData else { print("No response data"); return }
                            
                            do {
                                
                                let json = try JSONSerialization.jsonObject(
                                    with: responseData,
                                    options: JSONSerialization.ReadingOptions(rawValue: UInt(0)))
                                
                                guard let jsonDict = json as? [String: Any] else {
                                    print("Error parsing json response")
                                    viewController.hideProgressHUD()
                                    return }
                                
                                guard let mediaID = jsonDict[SocialHelper.kTwitterMediaIdKey] as? String else { print("Error parsing mediaID"); return }
                                
                                guard let postCommentRequest = getPostCommentRequest(twitterAccount: twitterAccount, mediaID: mediaID) else { return }
                                
                                postCommentRequest.perform(handler: { (responseData, urlResponse, error) in
                                    viewController.hideProgressHUD()
                                    
                                    guard let _ = error else {
                                        print("Upload successful")
                                        DispatchQueue.main.async {
                                            viewController.showAlertWithMessage(message: SocialHelper.gifUploadSuccessMessage)
                                        }
                                        return
                                    }
                                    
                                    print("Upload failed")
                                    DispatchQueue.main.async {
                                        viewController.showAlertWithMessage(message: SocialHelper.gifUploadFailedMessage)
                                    }
                                })
                                
                            } catch {
                                print("JSONSerialization error")
                                viewController.hideProgressHUD()
                            }
                        })
                        
                    } else {
                        print("Array of accounts is empty")
                    }
                }
        }
    }

static func getPostGifRequest(twitterAccount: ACAccount, gifData: Data) -> SLRequest? {
        
        guard let gifRequestURL = URL(string: SocialHelper.twitterGifURL) else { print("No Request URL"); return nil }
        
        let postRequest = SLRequest(
            forServiceType: SLServiceTypeTwitter,
            requestMethod: SLRequestMethod.POST,
            url: gifRequestURL,
            parameters: nil)
        
        postRequest?.account = twitterAccount
        
        postRequest?.addMultipartData(
            gifData,
            withName: "media",
            type: "image/gif",
            filename: "showapp.gif")
        
        return postRequest
    }
    
    static func getPostCommentRequest(twitterAccount: ACAccount, mediaID: String) -> SLRequest? {
        
        let commentRequestURL = URL(string: SocialHelper.twitterCommentURL)
        
        let message = [
            SocialHelper.kTwitterStatusKey: SocialHelper.twitterShareText,
            SocialHelper.kTwitterMediaIdsKey: mediaID
        ]
        
        let postRequest2 = SLRequest(
            forServiceType: SLServiceTypeTwitter,
            requestMethod: SLRequestMethod.POST,
            url: commentRequestURL,
            parameters: message)
        
        postRequest2?.account = twitterAccount
        
        return postRequest2
    }