initial commit

ios_client/EncryptedChat/Network/ProtocolHandler.swift

@@ -0,0 +1,90 @@
+import Foundation
+
+/// Newline-delimited JSON protocol handler.
+/// Matches Python: protocol.py build_request, build_response, parse_message, encode_binary, decode_binary
+enum ProtocolHandler {
+
+    /// Build a request message (newline-terminated JSON).
+    /// Matches Python: build_request(msg_type, request_id=None, **kwargs)
+    static func buildRequest(type: String, requestId: String? = nil, params: [String: Any] = [:]) throws -> Data {
+        var msg: [String: Any] = ["type": type]
+        if let requestId = requestId {
+            msg["request_id"] = requestId
+        }
+        // Merge params into msg
+        for (key, value) in params {
+            msg[key] = value
+        }
+
+        let jsonData = try JSONSerialization.data(withJSONObject: msg)
+        guard jsonData.count < Constants.maxMessageBytes else {
+            throw NetworkError.messageTooLarge
+        }
+        return jsonData + Data([0x0A])  // newline
+    }
+
+    /// Build a response message (newline-terminated JSON).
+    static func buildResponse(type: String, status: String, data: [String: Any]? = nil, requestId: String? = nil) throws -> Data {
+        var msg: [String: Any] = ["type": type, "status": status]
+        if let data = data {
+            msg["data"] = data
+        }
+        if let requestId = requestId {
+            msg["request_id"] = requestId
+        }
+
+        let jsonData = try JSONSerialization.data(withJSONObject: msg)
+        guard jsonData.count < Constants.maxMessageBytes else {
+            throw NetworkError.messageTooLarge
+        }
+        return jsonData + Data([0x0A])
+    }
+
+    /// Parse a single protocol message from bytes.
+    /// Matches Python: parse_message(line)
+    static func parseMessage(_ data: Data) throws -> [String: Any] {
+        let trimmed = data.trimmingNewlines()
+        guard !trimmed.isEmpty else {
+            throw NetworkError.protocolError("Empty message")
+        }
+        guard let obj = try JSONSerialization.jsonObject(with: trimmed) as? [String: Any] else {
+            throw NetworkError.protocolError("Message is not a JSON object")
+        }
+        return obj
+    }
+
+    /// Encode bytes to base64 string.
+    /// Matches Python: encode_binary(data)
+    static func encodeBinary(_ data: Data) -> String {
+        data.base64EncodedString(options: [])
+    }
+
+    /// Decode base64 string to bytes.
+    /// Matches Python: decode_binary(data)
+    static func decodeBinary(_ string: String) throws -> Data {
+        guard let data = Data(base64Encoded: string, options: .ignoreUnknownCharacters) else {
+            throw CryptoError.invalidBase64
+        }
+        return data
+    }
+
+    /// Generate a new request ID (UUID string).
+    static func newRequestId() -> String {
+        UUID().uuidString
+    }
+}
+
+// MARK: - Data Helpers
+
+private extension Data {
+    func trimmingNewlines() -> Data {
+        var data = self
+        while let last = data.last, last == 0x0A || last == 0x0D {
+            data.removeLast()
+        }
+        while let first = data.first, first == 0x0A || first == 0x0D {
+            data.removeFirst()
+        }
+        return data
+    }
+}