Upload photos to Mastodon

gistfile1.txt

func upload(user: User?, asset: PHAsset?) -> Future<Attachment, TendonError> {
	let promise = Promise<Attachment, TendonError>()
	guard let user = user else {
		promise.failure(TendonError.invalidUser)
		return promise.future
	}
	guard let asset = asset else {
		promise.failure(TendonError.argument)
		return promise.future
	}
	
	imageManager.requestImageData(for: asset, options: nil) { (imageData, _, orientation, info) in
		
		let urlString = user.serverName + "/api/v1/media"
		Alamofire.upload(multipartFormData: { (data) in
			data.append(imageData!, withName: "file", fileName: "\(UUID.init().uuidString).png", mimeType: "image/png") // png format!
		}, usingThreshold: UInt64.init(), to: URL(string: urlString)!, method: .post, headers: ["Authorization": "Bearer " + user.oauthToken], encodingCompletion: { (result) in
			switch result {
			case .success(let upload, _, _):
				upload.responseData(completionHandler: { (dataResponse) in
					guard
						let data = dataResponse.data,
						let jsonObject = try? JSONSerialization.jsonObject(with: data, options: [])
						else {
							promise.failure(TendonError.library)
							return
					}
					
					guard
						let httpResponse = dataResponse.response as? HTTPURLResponse,
						httpResponse.statusCode == 200
						else {
							let mastodonError = MastodonError(json: jsonObject)
							promise.failure(TendonError.library)
							return
					}
					
					promise.success(Attachment(from: jsonObject as! JSONDictionary)!)
				})
				break
			default:
				break
			}
		})
		
	}
	
	return promise.future
}