session-ios/SessionMessagingKit/Open Groups/Types/PreparedSendData.swift

244 lines
10 KiB
Swift

// Copyright © 2023 Rangeproof Pty Ltd. All rights reserved.
import Foundation
import Combine
import SessionUtilitiesKit
// MARK: - ErasedPreparedSendData
public protocol ErasedPreparedSendData {
var endpoint: OpenGroupAPI.Endpoint { get }
var batchResponseTypes: [Decodable.Type] { get }
func encodeForBatchRequest(to encoder: Encoder) throws
}
// MARK: - PreparedSendData<R>
public extension OpenGroupAPI {
struct PreparedSendData<R>: ErasedPreparedSendData {
internal let request: URLRequest
internal let server: String
internal let publicKey: String
internal let originalType: Decodable.Type
internal let responseType: R.Type
internal let timeout: TimeInterval
fileprivate let responseConverter: ((ResponseInfoType, Any) throws -> R)
// The following types are needed for `BatchRequest` handling
private let method: HTTPMethod
private let path: String
public let endpoint: Endpoint
internal let batchEndpoints: [Endpoint]
public let batchResponseTypes: [Decodable.Type]
/// The `jsonBodyEncoder` is used to simplify the encoding for `BatchRequest`
private let jsonBodyEncoder: ((inout KeyedEncodingContainer<BatchRequest.Child.CodingKeys>, BatchRequest.Child.CodingKeys) throws -> ())?
private let b64: String?
private let bytes: [UInt8]?
internal init<T: Encodable>(
request: Request<T, Endpoint>,
urlRequest: URLRequest,
publicKey: String,
responseType: R.Type,
timeout: TimeInterval
) where R: Decodable {
self.request = urlRequest
self.server = request.server
self.publicKey = publicKey
self.originalType = responseType
self.responseType = responseType
self.timeout = timeout
self.responseConverter = { _, response in
guard let validResponse: R = response as? R else { throw HTTPError.invalidResponse }
return validResponse
}
// The following data is needed in this type for handling batch requests
self.method = request.method
self.endpoint = request.endpoint
self.path = request.urlPathAndParamsString
self.batchEndpoints = ((request.body as? BatchRequest)?
.requests
.map { $0.request.endpoint })
.defaulting(to: [])
self.batchResponseTypes = ((request.body as? BatchRequest)?
.requests
.flatMap { $0.request.batchResponseTypes })
.defaulting(to: [HTTP.BatchSubResponse<R>.self])
// Note: Need to differentiate between JSON, b64 string and bytes body values to ensure
// they are encoded correctly so the server knows how to handle them
switch request.body {
case let bodyString as String:
self.jsonBodyEncoder = nil
self.b64 = bodyString
self.bytes = nil
case let bodyBytes as [UInt8]:
self.jsonBodyEncoder = nil
self.b64 = nil
self.bytes = bodyBytes
default:
self.jsonBodyEncoder = { [body = request.body] container, key in
try container.encodeIfPresent(body, forKey: key)
}
self.b64 = nil
self.bytes = nil
}
}
private init<U: Decodable>(
request: URLRequest,
server: String,
publicKey: String,
originalType: U.Type,
responseType: R.Type,
timeout: TimeInterval,
responseConverter: @escaping (ResponseInfoType, Any) throws -> R,
method: HTTPMethod,
endpoint: Endpoint,
path: String,
batchEndpoints: [Endpoint],
batchResponseTypes: [Decodable.Type],
jsonBodyEncoder: ((inout KeyedEncodingContainer<BatchRequest.Child.CodingKeys>, BatchRequest.Child.CodingKeys) throws -> ())?,
b64: String?,
bytes: [UInt8]?
) {
self.request = request
self.server = server
self.publicKey = publicKey
self.originalType = originalType
self.responseType = responseType
self.timeout = timeout
self.responseConverter = responseConverter
// The following data is needed in this type for handling batch requests
self.method = method
self.endpoint = endpoint
self.path = path
self.batchEndpoints = batchEndpoints
self.batchResponseTypes = batchResponseTypes
self.jsonBodyEncoder = jsonBodyEncoder
self.b64 = b64
self.bytes = bytes
}
// MARK: - ErasedPreparedSendData
public func encodeForBatchRequest(to encoder: Encoder) throws {
var container: KeyedEncodingContainer<BatchRequest.Child.CodingKeys> = encoder.container(keyedBy: BatchRequest.Child.CodingKeys.self)
// Exclude request signature headers (not used for sub-requests)
let batchRequestHeaders: [String: String] = (request.allHTTPHeaderFields ?? [:])
.filter { key, _ in
key.lowercased() != HTTPHeader.sogsPubKey.lowercased() &&
key.lowercased() != HTTPHeader.sogsTimestamp.lowercased() &&
key.lowercased() != HTTPHeader.sogsNonce.lowercased() &&
key.lowercased() != HTTPHeader.sogsSignature.lowercased()
}
if !batchRequestHeaders.isEmpty {
try container.encode(batchRequestHeaders, forKey: .headers)
}
try container.encode(method, forKey: .method)
try container.encode(path, forKey: .path)
try jsonBodyEncoder?(&container, .json)
try container.encodeIfPresent(b64, forKey: .b64)
try container.encodeIfPresent(bytes, forKey: .bytes)
}
}
}
public extension OpenGroupAPI.PreparedSendData {
func map<O>(transform: @escaping (ResponseInfoType, R) throws -> O) -> OpenGroupAPI.PreparedSendData<O> {
return OpenGroupAPI.PreparedSendData(
request: request,
server: server,
publicKey: publicKey,
originalType: originalType,
responseType: O.self,
timeout: timeout,
responseConverter: { info, response in
let validResponse: R = try responseConverter(info, response)
return try transform(info, validResponse)
},
method: method,
endpoint: endpoint,
path: path,
batchEndpoints: batchEndpoints,
batchResponseTypes: batchResponseTypes,
jsonBodyEncoder: jsonBodyEncoder,
b64: b64,
bytes: bytes
)
}
}
// MARK: - Convenience
public extension Publisher where Output == (ResponseInfoType, Data?), Failure == Error {
func decoded<R>(
with preparedData: OpenGroupAPI.PreparedSendData<R>,
using dependencies: Dependencies
) -> AnyPublisher<(ResponseInfoType, R), Error> {
self
.tryMap { responseInfo, maybeData -> (ResponseInfoType, R) in
// Depending on the 'originalType' we need to process the response differently
let targetData: Any = try {
switch preparedData.originalType {
case is OpenGroupAPI.BatchResponse.Type:
let responses: [Decodable] = try HTTP.BatchResponse.decodingResponses(
from: maybeData,
as: preparedData.batchResponseTypes,
requireAllResults: true,
using: dependencies
)
return OpenGroupAPI.BatchResponse(
info: responseInfo,
data: Swift.zip(preparedData.batchEndpoints, responses)
.reduce(into: [:]) { result, next in
result[next.0] = next.1
}
)
case is NoResponse.Type: return NoResponse()
case is Optional<Data>.Type: return maybeData as Any
case is Data.Type: return try maybeData ?? { throw HTTPError.parsingFailed }()
case is _OptionalProtocol.Type:
guard let data: Data = maybeData else { return maybeData as Any }
return try preparedData.originalType.decoded(from: data, using: dependencies)
default:
guard let data: Data = maybeData else { throw HTTPError.parsingFailed }
return try preparedData.originalType.decoded(from: data, using: dependencies)
}
}()
// Generate and return the converted data
let convertedData: R = try preparedData.responseConverter(responseInfo, targetData)
return (responseInfo, convertedData)
}
.eraseToAnyPublisher()
}
}
// MARK: - _OptionalProtocol
/// This protocol should only be used within this file and is used to distinguish between `Any.Type` and `Optional<Any>.Type` as
/// it seems that `is Optional<Any>.Type` doesn't work nicely but this protocol works nicely as long as the case is under any explicit
/// `Optional<T>` handling that we need
private protocol _OptionalProtocol {}
extension Optional: _OptionalProtocol {}