rig-core 0.10.0

//! OpenRouter Inference API client and Rig integration
//!
//! # Example
//! ```
//! use rig::providers::openrouter;
//!
//! let client = openrouter::Client::new("YOUR_API_KEY");
//!
//! let llama_3_1_8b = client.completion_model(openrouter::LLAMA_3_1_8B);
//! ```

use crate::{
    agent::AgentBuilder,
    completion::{self, CompletionError, CompletionRequest},
    extractor::ExtractorBuilder,
    json_utils,
    providers::openai::Message,
    OneOrMany,
};
use schemars::JsonSchema;
use serde::{Deserialize, Serialize};
use serde_json::json;

use super::openai::AssistantContent;

// ================================================================
// Main openrouter Client
// ================================================================
const OPENROUTER_API_BASE_URL: &str = "https://openrouter.ai/api/v1";

#[derive(Clone)]
pub struct Client {
    base_url: String,
    http_client: reqwest::Client,
}

impl Client {
    /// Create a new OpenRouter client with the given API key.
    pub fn new(api_key: &str) -> Self {
        Self::from_url(api_key, OPENROUTER_API_BASE_URL)
    }

    /// Create a new OpenRouter client with the given API key and base API URL.
    pub fn from_url(api_key: &str, base_url: &str) -> Self {
        Self {
            base_url: base_url.to_string(),
            http_client: reqwest::Client::builder()
                .default_headers({
                    let mut headers = reqwest::header::HeaderMap::new();
                    headers.insert(
                        "Authorization",
                        format!("Bearer {}", api_key)
                            .parse()
                            .expect("Bearer token should parse"),
                    );
                    headers
                })
                .build()
                .expect("OpenRouter reqwest client should build"),
        }
    }

    /// Create a new openrouter client from the `openrouter_API_KEY` environment variable.
    /// Panics if the environment variable is not set.
    pub fn from_env() -> Self {
        let api_key = std::env::var("OPENROUTER_API_KEY").expect("OPENROUTER_API_KEY not set");
        Self::new(&api_key)
    }

    fn post(&self, path: &str) -> reqwest::RequestBuilder {
        let url = format!("{}/{}", self.base_url, path).replace("//", "/");
        self.http_client.post(url)
    }

    /// Create a completion model with the given name.
    ///
    /// # Example
    /// ```
    /// use rig::providers::openrouter::{Client, self};
    ///
    /// // Initialize the openrouter client
    /// let openrouter = Client::new("your-openrouter-api-key");
    ///
    /// let llama_3_1_8b = openrouter.completion_model(openrouter::LLAMA_3_1_8B);
    /// ```
    pub fn completion_model(&self, model: &str) -> CompletionModel {
        CompletionModel::new(self.clone(), model)
    }

    /// Create an agent builder with the given completion model.
    ///
    /// # Example
    /// ```
    /// use rig::providers::openrouter::{Client, self};
    ///
    /// // Initialize the Eternal client
    /// let openrouter = Client::new("your-openrouter-api-key");
    ///
    /// let agent = openrouter.agent(openrouter::LLAMA_3_1_8B)
    ///    .preamble("You are comedian AI with a mission to make people laugh.")
    ///    .temperature(0.0)
    ///    .build();
    /// ```
    pub fn agent(&self, model: &str) -> AgentBuilder<CompletionModel> {
        AgentBuilder::new(self.completion_model(model))
    }

    /// Create an extractor builder with the given completion model.
    pub fn extractor<T: JsonSchema + for<'a> Deserialize<'a> + Serialize + Send + Sync>(
        &self,
        model: &str,
    ) -> ExtractorBuilder<T, CompletionModel> {
        ExtractorBuilder::new(self.completion_model(model))
    }
}

#[derive(Debug, Deserialize)]
struct ApiErrorResponse {
    message: String,
}

#[derive(Debug, Deserialize)]
#[serde(untagged)]
enum ApiResponse<T> {
    Ok(T),
    Err(ApiErrorResponse),
}

#[derive(Clone, Debug, Deserialize)]
pub struct Usage {
    pub prompt_tokens: usize,
    pub completion_tokens: usize,
    pub total_tokens: usize,
}

impl std::fmt::Display for Usage {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(
            f,
            "Prompt tokens: {} Total tokens: {}",
            self.prompt_tokens, self.total_tokens
        )
    }
}

// ================================================================
// OpenRouter Completion API
// ================================================================
/// The `qwen/qwq-32b` model. Find more models at <https://openrouter.ai/models>.
pub const QWEN_QWQ_32B: &str = "qwen/qwq-32b";
/// The `anthropic/claude-3.7-sonnet` model. Find more models at <https://openrouter.ai/models>.
pub const CLAUDE_3_7_SONNET: &str = "anthropic/claude-3.7-sonnet";
/// The `perplexity/sonar-pro` model. Find more models at <https://openrouter.ai/models>.
pub const PERPLEXITY_SONAR_PRO: &str = "perplexity/sonar-pro";
/// The `google/gemini-2.0-flash-001` model. Find more models at <https://openrouter.ai/models>.
pub const GEMINI_FLASH_2_0: &str = "google/gemini-2.0-flash-001";

/// A openrouter completion object.
///
/// For more information, see this link: <https://docs.openrouter.xyz/reference/create_chat_completion_v1_chat_completions_post>
#[derive(Debug, Deserialize)]
pub struct CompletionResponse {
    pub id: String,
    pub object: String,
    pub created: u64,
    pub model: String,
    pub choices: Vec<Choice>,
    pub system_fingerprint: Option<String>,
    pub usage: Option<Usage>,
}

impl From<ApiErrorResponse> for CompletionError {
    fn from(err: ApiErrorResponse) -> Self {
        CompletionError::ProviderError(err.message)
    }
}

impl TryFrom<CompletionResponse> for completion::CompletionResponse<CompletionResponse> {
    type Error = CompletionError;

    fn try_from(response: CompletionResponse) -> Result<Self, Self::Error> {
        let choice = response.choices.first().ok_or_else(|| {
            CompletionError::ResponseError("Response contained no choices".to_owned())
        })?;

        let content = match &choice.message {
            Message::Assistant {
                content,
                tool_calls,
                ..
            } => {
                let mut content = content
                    .iter()
                    .map(|c| match c {
                        AssistantContent::Text { text } => completion::AssistantContent::text(text),
                        AssistantContent::Refusal { refusal } => {
                            completion::AssistantContent::text(refusal)
                        }
                    })
                    .collect::<Vec<_>>();

                content.extend(
                    tool_calls
                        .iter()
                        .map(|call| {
                            completion::AssistantContent::tool_call(
                                &call.function.name,
                                &call.function.name,
                                call.function.arguments.clone(),
                            )
                        })
                        .collect::<Vec<_>>(),
                );
                Ok(content)
            }
            _ => Err(CompletionError::ResponseError(
                "Response did not contain a valid message or tool call".into(),
            )),
        }?;

        let choice = OneOrMany::many(content).map_err(|_| {
            CompletionError::ResponseError(
                "Response contained no message or tool call (empty)".to_owned(),
            )
        })?;

        Ok(completion::CompletionResponse {
            choice,
            raw_response: response,
        })
    }
}

#[derive(Debug, Deserialize)]
pub struct Choice {
    pub index: usize,
    pub native_finish_reason: Option<String>,
    pub message: Message,
    pub finish_reason: Option<String>,
}

#[derive(Clone)]
pub struct CompletionModel {
    client: Client,
    /// Name of the model (e.g.: deepseek-ai/DeepSeek-R1)
    pub model: String,
}

impl CompletionModel {
    pub fn new(client: Client, model: &str) -> Self {
        Self {
            client,
            model: model.to_string(),
        }
    }
}

impl completion::CompletionModel for CompletionModel {
    type Response = CompletionResponse;

    #[cfg_attr(feature = "worker", worker::send)]
    async fn completion(
        &self,
        completion_request: CompletionRequest,
    ) -> Result<completion::CompletionResponse<CompletionResponse>, CompletionError> {
        // Add preamble to chat history (if available)
        let mut full_history: Vec<Message> = match &completion_request.preamble {
            Some(preamble) => vec![Message::system(preamble)],
            None => vec![],
        };

        // Convert prompt to user message
        let prompt: Vec<Message> = completion_request.prompt_with_context().try_into()?;

        // Convert existing chat history
        let chat_history: Vec<Message> = completion_request
            .chat_history
            .into_iter()
            .map(|message| message.try_into())
            .collect::<Result<Vec<Vec<Message>>, _>>()?
            .into_iter()
            .flatten()
            .collect();

        // Combine all messages into a single history
        full_history.extend(chat_history);
        full_history.extend(prompt);

        let request = json!({
            "model": self.model,
            "messages": full_history,
            "temperature": completion_request.temperature,
        });

        let response = self
            .client
            .post("/chat/completions")
            .json(
                &if let Some(params) = completion_request.additional_params {
                    json_utils::merge(request, params)
                } else {
                    request
                },
            )
            .send()
            .await?;

        if response.status().is_success() {
            match response.json::<ApiResponse<CompletionResponse>>().await? {
                ApiResponse::Ok(response) => {
                    tracing::info!(target: "rig",
                        "OpenRouter completion token usage: {:?}",
                        response.usage.clone().map(|usage| format!("{usage}")).unwrap_or("N/A".to_string())
                    );

                    response.try_into()
                }
                ApiResponse::Err(err) => Err(CompletionError::ProviderError(err.message)),
            }
        } else {
            Err(CompletionError::ProviderError(response.text().await?))
        }
    }
}