use crate::types::*;
use super::{ChatMessage, LLM, LLMOptions, LLMResult};
use serde_json::json;
use std::future::Future;
use std::pin::Pin;
#[derive(Debug, Clone)]
pub enum CohereModel {
Command,
CommandR,
CommandLight,
CommandNightly,
}
impl CohereModel {
fn as_str(&self) -> &'static str {
match self {
CohereModel::Command => "command",
CohereModel::CommandR => "command-r",
CohereModel::CommandLight => "command-light",
CohereModel::CommandNightly => "command-nightly",
}
}
}
impl From<CohereModel> for String {
fn from(model: CohereModel) -> Self {
model.as_str().to_string()
}
}
pub struct Cohere {
api_key: String,
model: CohereModel,
base_url: String,
client: reqwest::Client,
default_options: LLMOptions,
}
impl Cohere {
pub fn new(api_key: String) -> Self {
Self {
api_key,
model: CohereModel::Command,
base_url: "https://api.cohere.ai/v1".to_string(),
client: reqwest::Client::new(),
default_options: LLMOptions::default(),
}
}
pub fn with_model(mut self, model: CohereModel) -> Self {
self.model = model;
self
}
pub fn command(self) -> Self {
self.with_model(CohereModel::Command)
}
pub fn command_r(self) -> Self {
self.with_model(CohereModel::CommandR)
}
pub fn command_light(self) -> Self {
self.with_model(CohereModel::CommandLight)
}
pub fn with_temperature(mut self, temperature: f32) -> Self {
self.default_options.temperature = Some(temperature);
self
}
pub fn with_max_tokens(mut self, max_tokens: u32) -> Self {
self.default_options.max_tokens = Some(max_tokens);
self
}
pub fn with_top_p(mut self, top_p: f32) -> Self {
self.default_options.top_p = Some(top_p);
self
}
pub fn with_top_k(mut self, top_k: u32) -> Self {
self.default_options.top_k = Some(top_k);
self
}
pub fn with_base_url(mut self, base_url: &str) -> Self {
self.base_url = base_url.to_string();
self
}
async fn chat_completion(
&self,
messages: &[ChatMessage],
options: &LLMOptions,
) -> Result<String> {
let model_name: String = self.model.clone().into();
let chat_history: Vec<serde_json::Value> = messages
.iter()
.take(messages.len().saturating_sub(1))
.map(|m| {
json!({
"role": m.role,
"message": m.content,
})
})
.collect();
let last_message = messages.last().ok_or_else(|| {
LangHubError::LLMError("No messages provided".to_string())
})?;
let mut request_body = json!({
"model": model_name,
"message": last_message.content,
"chat_history": chat_history,
});
if let Some(temp) = options.temperature.or(self.default_options.temperature) {
request_body["temperature"] = json!(temp);
}
if let Some(max_tokens) = options.max_tokens.or(self.default_options.max_tokens) {
request_body["max_tokens"] = json!(max_tokens);
}
if let Some(top_p) = options.top_p.or(self.default_options.top_p) {
request_body["p"] = json!(top_p);
}
if let Some(top_k) = options.top_k.or(self.default_options.top_k) {
request_body["k"] = json!(top_k);
}
if let Some(stop) = options
.stop_sequences
.as_ref()
.or(self.default_options.stop_sequences.as_ref())
{
request_body["stop_sequences"] = json!(stop);
}
let response = self
.client
.post(format!("{}/chat", self.base_url))
.header("Authorization", format!("Bearer {}", self.api_key))
.header("Content-Type", "application/json")
.json(&request_body)
.send()
.await
.map_err(|e| LangHubError::LLMError(format!("Cohere request error: {}", e)))?;
if !response.status().is_success() {
let status = response.status();
let error_text = response.text().await.unwrap_or_default();
return Err(LangHubError::LLMError(format!(
"Cohere API error ({}): {}",
status, error_text
)));
}
let json: serde_json::Value = response
.json()
.await
.map_err(|e| LangHubError::LLMError(format!("JSON parse error: {}", e)))?;
let text = json["text"]
.as_str()
.ok_or_else(|| {
LangHubError::ParseError("Missing 'text' field in response".to_string())
})?
.to_string();
Ok(text)
}
}
impl LLM for Cohere {
fn generate(
&self,
prompt: &str,
) -> Pin<Box<dyn Future<Output = Result<LLMResult>> + Send + '_>> {
let prompt = prompt.to_string();
let options = self.default_options.clone();
Box::pin(async move {
let messages = vec![ChatMessage::user(&prompt)];
let text = self.chat_completion(&messages, &options).await?;
Ok(LLMResult {
text,
metadata: None,
})
})
}
fn generate_with_options(
&self,
prompt: &str,
options: LLMOptions,
) -> Pin<Box<dyn Future<Output = Result<LLMResult>> + Send + '_>> {
let prompt = prompt.to_string();
Box::pin(async move {
let messages = vec![ChatMessage::user(&prompt)];
let text = self.chat_completion(&messages, &options).await?;
Ok(LLMResult {
text,
metadata: None,
})
})
}
fn chat(
&self,
messages: Vec<ChatMessage>,
) -> Pin<Box<dyn Future<Output = Result<LLMResult>> + Send + '_>> {
Box::pin(async move {
let text = self
.chat_completion(&messages, &LLMOptions::default())
.await?;
Ok(LLMResult {
text,
metadata: None,
})
})
}
fn get_model_name(&self) -> &str {
match self.model {
CohereModel::Command => "cohere-command",
CohereModel::CommandR => "cohere-command-r",
CohereModel::CommandLight => "cohere-command-light",
CohereModel::CommandNightly => "cohere-command-nightly",
}
}
fn get_provider_name(&self) -> &str {
match self.model {
CohereModel::Command => "Cohere-Command",
CohereModel::CommandR => "Cohere-Command-R",
CohereModel::CommandLight => "Cohere-Command-Light",
CohereModel::CommandNightly => "Cohere-Command-Nightly",
}
}
fn get_provider_enum(&self) -> ModelProvider {
ModelProvider::Cohere
}
fn supports_function_calling(&self) -> bool {
true
}
fn supports_json_mode(&self) -> bool {
true
}
fn max_context_length(&self) -> Option<usize> {
match self.model {
CohereModel::Command => Some(4096),
CohereModel::CommandR => Some(128000),
CohereModel::CommandLight => Some(4096),
CohereModel::CommandNightly => Some(4096),
}
}
}