openai_interface/chat/

mod.rs

//! # Chat Completions API Module
//!
//! This module provides components shared by many submodules.

use std::str::FromStr;

use serde::{Deserialize, Serialize};

use crate::errors::OapiError;

pub mod create;
pub mod delete;
pub mod retrieve;
pub mod update;

/// The service tier used for processing the request.
///
/// This enum represents the different service tiers that can be specified when
/// making a request to the API. Each tier corresponds to different performance
/// characteristics and pricing models.
#[derive(Debug, Serialize, Deserialize, Clone)]
#[serde(rename_all = "lowercase")]
pub enum ServiceTier {
    /// Automatically select the service tier based on project settings.
    Auto,
    /// Use the default service tier with standard pricing and performance.
    Default,
    /// Use the flex service tier for flexible processing requirements.
    Flex,
    /// Use the scale service tier for scalable processing needs.
    Scale,
    /// Use the priority service tier for high-priority requests.
    Priority,
}

#[derive(Debug, Deserialize)]
pub struct ChatCompletion {
    /// A unique identifier for the chat completion.
    pub id: String,
    /// A list of chat completion choices. Can be more than one
    /// if `n` is greater than 1.
    pub choices: Vec<Choice>,
    /// The Unix timestamp (in seconds) of when the chat completion was created.
    pub created: u64,
    /// The model used for the chat completion.
    pub model: String,
    /// Specifies the processing type used for serving the request.
    ///
    /// - If set to 'auto', then the request will be processed with the service tier
    ///   configured in the Project settings. Unless otherwise configured, the Project
    ///   will use 'default'.
    /// - If set to 'default', then the request will be processed with the standard
    ///   pricing and performance for the selected model.
    /// - If set to '[flex](https://platform.openai.com/docs/guides/flex-processing)' or
    ///   '[priority](https://openai.com/api-priority-processing/)', then the request
    ///   will be processed with the corresponding service tier.
    /// - When not set, the default behavior is 'auto'.
    ///
    /// When the `service_tier` parameter is set, the response body will include the
    /// `service_tier` value based on the processing mode actually used to serve the
    /// request. This response value may be different from the value set in the
    /// parameter.
    pub service_tier: Option<ServiceTier>,
    /// The system fingerprint used for the chat completion.
    /// Can be used in conjunction with the `seed` request parameter to understand when
    /// backend changes have been made that might impact determinism.
    pub system_fingerprint: Option<String>,
    /// The object type, which is always `chat.completion`.
    pub object: ChatCompletionObject,
    /// Usage statistics for the completion request.
    pub usage: Option<CompletionUsage>,
}

/// The object type, which is always `chat.completion`.
#[derive(Debug, Deserialize)]
pub enum ChatCompletionObject {
    /// The object type is always `chat.completion`.
    #[serde(rename = "chat.completion")]
    ChatCompletion,
}

#[derive(Debug, Deserialize)]
pub struct Choice {
    /// The reason the model stopped generating tokens.
    ///
    /// This will be `stop` if the model hit a natural stop point or a provided stop
    /// sequence, `length` if the maximum number of tokens specified in the request was
    /// reached, `content_filter` if content was omitted due to a flag from our content
    /// filters, `tool_calls` if the model called a tool, or `function_call`
    /// (deprecated) if the model called a function.
    pub finish_reason: FinishReason,
    /// The index of the choice in the list of choices.
    pub index: usize,
    /// Log probability information for the choice.
    pub logprobs: Option<ChoiceLogprobs>,
    /// A chat completion message generated by the model.
    pub message: ChatCompletionMessage,
}

#[derive(Debug, Deserialize, PartialEq)]
#[serde(rename_all = "snake_case")]
pub enum FinishReason {
    Length,
    Stop,
    ToolCalls,
    FunctionCall,
    ContentFilter,
    /// This choice can only be found in the manual of DeepSeek
    InsufficientSystemResource,
}

/// Fields that are not supported yet:
/// - _audio_: If the audio output modality is requested, this object contains
/// data about the audio response from the model.
/// [Learn more from OpenAI](https://platform.openai.com/docs/guides/audio).
#[derive(Debug, Deserialize)]
pub struct ChatCompletionMessage {
    /// The role of the author of this message. This shall always
    /// be ResponseRole::Assistant
    pub role: ResponseRole,
    /// The contents of the message.
    pub content: Option<String>,
    pub reasoning_content: Option<String>,
    /// The tool calls generated by the model, such as function calls.
    /// Tool calls deserialization is not supported yet.
    pub tool_calls: Option<Vec<ChatCompletionMessageToolCall>>,
}

#[derive(Debug, Deserialize)]
#[serde(tag = "type", rename_all = "snake_case")]
pub enum ChatCompletionMessageToolCall {
    /// The type of the tool. Currently, only `function` is supported.
    /// The field { type = "function" } is added automatically.
    Function {
        /// The ID of the tool call.
        id: String,
        /// The function that the model called.
        function: String, // function type
    },
    /// The type of the tool. Always `custom`.
    /// The field { type = "custom" } is added automatically.
    Custom {
        /// The id of the tool call.
        id: String,
        /// The custom tool that the model called.
        custom: MessageToolCallCustom,
    },
}

#[derive(Debug, Deserialize)]
pub struct MessageToolCallCustom {
    /// The input for the custom tool call generated by the model.
    pub input: String,
    /// The name of the custom tool to call.
    pub name: String,
}

#[derive(Debug, Deserialize)]
pub struct MessageToolCallFunction {
    /// The arguments to call the function with, as generated by the model in JSON
    /// format. Note that the model does not always generate valid JSON, and may
    /// hallucinate parameters not defined by your function schema. Validate the
    /// arguments in your code before calling your function.
    pub arguments: String,
    /// The name of the function to call.
    pub name: String,
}

#[derive(Debug, Deserialize)]
#[serde(rename_all = "snake_case")]
pub enum ResponseRole {
    /// The role of the response message is always assistant.
    Assistant,
}

#[derive(Debug, Deserialize)]
pub struct ChoiceLogprobs {
    /// A list of message content tokens with log probability information.
    pub content: Option<Vec<TokenLogProb>>,
    /// Only found in DeepSeek's manual.
    pub reasoning_content: Option<Vec<TokenLogProb>>,
    /// A list of message refusal tokens with log probability information.
    pub refusal: Option<Vec<TokenLogProb>>,
}

#[derive(Debug, Deserialize)]
pub struct TokenLogProb {
    /// The token.
    pub token: String,
    /// The log probability of this token, if it is within the top 20 most likely
    /// tokens. Otherwise, the value `-9999.0` is used to signify that the token is very
    /// unlikely.
    pub logprob: f32,
    /// A list of integers representing the UTF-8 bytes representation of the token.
    ///
    /// Useful in instances where characters are represented by multiple tokens and
    /// their byte representations must be combined to generate the correct text
    /// representation. Can be `null` if there is no bytes representation for the token.
    pub bytes: Option<Vec<u8>>,
    /// List of the most likely tokens and their log probability, at this token
    /// position. In rare cases, there may be fewer than the number of requested
    /// `top_logprobs` returned.
    pub top_logprobs: Vec<TopLogprob>,
}

#[derive(Debug, Deserialize)]
pub struct TopLogprob {
    /// The token.
    pub token: String,
    /// A list of integers representing the UTF-8 bytes representation of the token.
    ///
    /// Useful in instances where characters are represented by multiple tokens and
    /// their byte representations must be combined to generate the correct text
    /// representation. Can be `null` if there is no bytes representation for the token.
    pub logprob: f32,
    /// List of the most likely tokens and their log probability, at this token
    /// position. In rare cases, there may be fewer than the number of requested
    /// `top_logprobs` returned.
    pub bytes: Option<Vec<u8>>,
}

#[derive(Debug, Deserialize)]
pub struct CompletionUsage {
    /// Number of tokens in the generated completion.
    pub completion_tokens: usize,
    /// Number of tokens in the prompt.
    pub prompt_tokens: usize,

    // These two fields seem to be DeepSeek specific.
    /// Number of tokens in the prompt that hits the context cache.
    pub prompt_cache_hit_tokens: Option<usize>,
    /// Number of tokens in the prompt that misses the context cache.
    pub prompt_cache_miss_tokens: Option<usize>,

    /// Total number of tokens used in the request (prompt + completion).
    pub total_tokens: usize,
    /// Breakdown of tokens used in a completion.
    pub completion_tokens_details: Option<CompletionTokensDetails>,
    /// Breakdown of tokens used in the prompt.
    pub prompt_tokens_details: Option<PromptTokensDetails>,
}

#[derive(Debug, Deserialize)]
pub struct CompletionTokensDetails {
    /// When using Predicted Outputs, the number of tokens in the prediction that
    /// appeared in the completion.
    pub accepted_prediction_tokens: Option<usize>,
    /// Audio input tokens generated by the model.
    pub audio_tokens: Option<usize>,
    /// Tokens generated by the model for reasoning.
    pub reasoning_tokens: Option<usize>,
    /// When using Predicted Outputs, the number of tokens in the prediction that did
    /// not appear in the completion. However, like reasoning tokens, these tokens are
    /// still counted in the total completion tokens for purposes of billing, output,
    /// and context window limits.
    pub rejected_prediction_tokens: Option<usize>,
}

#[derive(Debug, Deserialize)]
pub struct PromptTokensDetails {
    /// Audio input tokens present in the prompt.
    pub audio_tokens: Option<usize>,
    /// Cached tokens present in the prompt.
    pub cached_tokens: Option<usize>,
}

impl FromStr for ChatCompletion {
    type Err = crate::errors::OapiError;

    fn from_str(content: &str) -> Result<Self, Self::Err> {
        let parse_result: Result<ChatCompletion, _> = serde_json::from_str(content)
            .map_err(|e| OapiError::DeserializationError(e.to_string()));
        parse_result
    }
}

#[cfg(test)]
mod test {
    use super::*;

    #[test]
    fn no_streaming_example_deepseek() {
        let json = r#"{
          "id": "30f6413a-a827-4cf3-9898-f13a8634b798",
          "object": "chat.completion",
          "created": 1757944111,
          "model": "deepseek-chat",
          "choices": [
            {
              "index": 0,
              "message": {
                "role": "assistant",
                "content": "Hello! How can I help you today? 😊"
              },
              "logprobs": null,
              "finish_reason": "stop"
            }
          ],
          "usage": {
            "prompt_tokens": 10,
            "completion_tokens": 11,
            "total_tokens": 21,
            "prompt_tokens_details": {
              "cached_tokens": 0
            },
            "prompt_cache_hit_tokens": 0,
            "prompt_cache_miss_tokens": 10
          },
          "system_fingerprint": "fp_08f168e49b_prod0820_fp8_kvcache"
        }"#;

        let parsed = ChatCompletion::from_str(json);
        match parsed {
            Ok(_) => {}
            Err(e) => {
                panic!("Failed to deserialize: {}", e);
            }
        }
    }

    #[test]
    fn no_streaming_example_qwen() {
        let json = r#"{
            "choices": [
                {
                    "message": {
                        "role": "assistant",
                        "content": "我是阿里云开发的一款超大规模语言模型，我叫通义千问。"
                    },
                    "finish_reason": "stop",
                    "index": 0,
                    "logprobs": null
                }
            ],
            "object": "chat.completion",
            "usage": {
                "prompt_tokens": 3019,
                "completion_tokens": 104,
                "total_tokens": 3123,
                "prompt_tokens_details": {
                    "cached_tokens": 2048
                }
            },
            "created": 1735120033,
            "system_fingerprint": null,
            "model": "qwen-plus",
            "id": "chatcmpl-6ada9ed2-7f33-9de2-8bb0-78bd4035025a"
        }"#;

        let parsed = ChatCompletion::from_str(json);
        match parsed {
            Ok(_) => {}
            Err(e) => {
                panic!("Failed to deserialize: {}", e);
            }
        }
    }
}