chore: import upstream snapshot with attribution

cpp/json_ffi/openai_api_protocol.h

@@ -0,0 +1,208 @@
+/*!
+ *  Copyright (c) 2023-2025 by Contributors
+ * \file json_ffi/openai_api_protocol.h
+ * \brief The header of OpenAI API Protocol in MLC LLM.
+ */
+#ifndef MLC_LLM_JSON_FFI_OPENAI_API_PROTOCOL_H
+#define MLC_LLM_JSON_FFI_OPENAI_API_PROTOCOL_H
+
+#include <tvm/ffi/extra/json.h>
+
+#include <ctime>
+#include <optional>
+#include <random>
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+#include "../serve/config.h"
+#include "../support/result.h"
+
+namespace mlc {
+namespace llm {
+namespace json_ffi {
+
+using serve::DebugConfig;
+using serve::ResponseFormat;
+
+enum class Type { text, json_object, function };
+enum class FinishReason { stop, length, tool_calls, error };
+
+inline std::string GenerateUUID(size_t length) {
+  auto randchar = []() -> char {
+    const char charset[] =
+        "0123456789"
+        "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+        "abcdefghijklmnopqrstuvwxyz";
+    const size_t max_index = (sizeof(charset) - 1);
+    return charset[rand() % max_index];
+  };
+  std::string str(length, 0);
+  std::generate_n(str.begin(), length, randchar);
+  return str;
+}
+
+class ChatFunction {
+ public:
+  std::optional<std::string> description = std::nullopt;
+  std::string name;
+  // Todo: change to std::vector<std::pair<std::string, std::string>>?
+  std::unordered_map<std::string, std::string>
+      parameters;  // Assuming parameters are string key-value pairs
+
+  static Result<ChatFunction> FromJSON(const tvm::ffi::json::Object& json);
+  tvm::ffi::json::Object AsJSON() const;
+};
+
+class ChatTool {
+ public:
+  Type type = Type::function;
+  ChatFunction function;
+
+  static Result<ChatTool> FromJSON(const tvm::ffi::json::Object& json);
+  tvm::ffi::json::Object AsJSON() const;
+};
+
+class ChatFunctionCall {
+ public:
+  std::string name;
+  std::optional<std::unordered_map<std::string, std::string>> arguments =
+      std::nullopt;  // Assuming arguments are string key-value pairs
+
+  static Result<ChatFunctionCall> FromJSON(const tvm::ffi::json::Object& json);
+  tvm::ffi::json::Object AsJSON() const;
+};
+
+class ChatToolCall {
+ public:
+  std::string id = "call_" + GenerateUUID(8);
+  Type type = Type::function;
+  ChatFunctionCall function;
+
+  static Result<ChatToolCall> FromJSON(const tvm::ffi::json::Object& json);
+  tvm::ffi::json::Object AsJSON() const;
+};
+
+class ChatCompletionMessageContent {
+ public:
+  ChatCompletionMessageContent() = default;
+
+  ChatCompletionMessageContent(std::nullopt_t) {}  // NOLINT(*)
+
+  ChatCompletionMessageContent(std::string text) : text_(text) {}  // NOLINT(*)
+
+  ChatCompletionMessageContent(
+      std::vector<std::unordered_map<std::string, std::string>> parts)  // NOLINT(*)
+      : parts_(parts) {}
+
+  bool IsNull() const { return !IsText() && !IsParts(); }
+
+  bool IsText() const { return text_.operator bool(); }
+
+  bool IsParts() const { return parts_.operator bool(); }
+
+  const std::string& Text() const { return text_.value(); }
+
+  const std::vector<std::unordered_map<std::string, std::string>>& Parts() const {
+    return parts_.value();
+  }
+
+ private:
+  /*! \brief used to store text content */
+  std::optional<std::string> text_;
+  std::optional<std::vector<std::unordered_map<std::string, std::string>>> parts_;
+};
+
+class ChatCompletionMessage {
+ public:
+  ChatCompletionMessageContent content =
+      std::nullopt;  // Assuming content is a list of string key-value pairs
+  std::string role;
+  std::optional<std::string> name = std::nullopt;
+  std::optional<std::vector<ChatToolCall>> tool_calls = std::nullopt;
+  std::optional<std::string> tool_call_id = std::nullopt;
+
+  static Result<ChatCompletionMessage> FromJSON(const tvm::ffi::json::Object& json);
+  tvm::ffi::json::Object AsJSON() const;
+};
+
+class ChatCompletionRequest {
+ public:
+  std::vector<ChatCompletionMessage> messages;
+  std::optional<std::string> model = std::nullopt;
+  std::optional<double> frequency_penalty = std::nullopt;
+  std::optional<double> presence_penalty = std::nullopt;
+  bool logprobs = false;
+  int top_logprobs = 0;
+  std::optional<std::vector<std::pair<int, float>>> logit_bias = std::nullopt;
+  std::optional<int> max_tokens = std::nullopt;
+  int n = 1;
+  std::optional<int> seed = std::nullopt;
+  std::optional<std::vector<std::string>> stop = std::nullopt;
+  bool stream = false;
+  std::optional<double> temperature = std::nullopt;
+  std::optional<double> top_p = std::nullopt;
+  std::optional<std::vector<ChatTool>> tools = std::nullopt;
+  std::optional<std::string> tool_choice = std::nullopt;
+  std::optional<std::string> user = std::nullopt;
+  bool ignore_eos = false;
+  std::optional<ResponseFormat> response_format = std::nullopt;
+  std::optional<DebugConfig> debug_config = std::nullopt;
+
+  /*! \brief Parse and create a ChatCompletionRequest instance from the given JSON string. */
+  static Result<ChatCompletionRequest> FromJSON(const std::string& json_str);
+
+  // TODO: check_penalty_range, check_logit_bias, check_logprobs
+};
+
+class ChatCompletionResponseChoice {
+ public:
+  std::optional<FinishReason> finish_reason;
+  int index = 0;
+  ChatCompletionMessage message;
+  // TODO: logprobs
+
+  tvm::ffi::json::Object AsJSON() const;
+};
+
+class ChatCompletionStreamResponseChoice {
+ public:
+  std::optional<FinishReason> finish_reason;
+  int index = 0;
+  ChatCompletionMessage delta;
+  // TODO: logprobs
+
+  tvm::ffi::json::Object AsJSON() const;
+};
+
+class ChatCompletionResponse {
+ public:
+  std::string id;
+  std::vector<ChatCompletionResponseChoice> choices;
+  int created = static_cast<int>(std::time(nullptr));
+  std::string model;
+  std::string system_fingerprint;
+  std::string object = "chat.completion";
+  // TODO: usage_info
+
+  tvm::ffi::json::Object AsJSON() const;
+};
+
+class ChatCompletionStreamResponse {
+ public:
+  std::string id;
+  std::vector<ChatCompletionStreamResponseChoice> choices;
+  int created = static_cast<int>(std::time(nullptr));
+  std::string model;
+  std::string system_fingerprint;
+  std::string object = "chat.completion.chunk";
+  std::optional<tvm::ffi::json::Value> usage;
+
+  tvm::ffi::json::Object AsJSON() const;
+};
+
+}  // namespace json_ffi
+}  // namespace llm
+}  // namespace mlc
+
+#endif  // MLC_LLM_JSON_FFI_OPENAI_API_PROTOCOL_H