feat: support RAG (#560)

* feat: support RAG

* support more embeddings models and implement concurrent embedding api

* show the progress of addings paths

* ignore embedding context when saving message

* embedding model max_chunk_size => default_chunk_size

* support pdf and pandoc formats (docx, epub, ipynb)

1 files changed, 58 insertions, 11 deletions

diff --git a/src/client/cohere.rs b/src/client/cohere.rs
index e0a5eec..69c343b 100644
--- a/src/client/cohere.rs
+++ b/src/client/cohere.rs
@@ -1,15 +1,12 @@
-use super::{
-    catch_error, extract_system_message, json_stream, message::*, ChatCompletionsData,
-    ChatCompletionsOutput, Client, CohereClient, ExtraConfig, Model, ModelData, ModelPatches,
-    PromptAction, PromptKind, SseHandler, ToolCall,
-};
+use super::*;
 
-use anyhow::{bail, Result};
+use anyhow::{bail, Context, Result};
 use reqwest::{Client as ReqwestClient, RequestBuilder};
 use serde::Deserialize;
 use serde_json::{json, Value};
 
-const API_URL: &str = "https://api.cohere.ai/v1/chat";
+const CHAT_COMPLETIONS_API_URL: &str = "https://api.cohere.ai/v1/chat";
+const EMBEDDINGS_API_URL: &str = "https://api.cohere.ai/v1/embed";
 
 #[derive(Debug, Clone, Deserialize, Default)]
 pub struct CohereConfig {
@@ -35,11 +32,38 @@ impl CohereClient {
         let api_key = self.get_api_key()?;
 
         let mut body = build_chat_completions_body(data, &self.model)?;
-        self.patch_request_body(&mut body);
+        self.patch_chat_completions_body(&mut body);
 
-        let url = API_URL;
+        let url = CHAT_COMPLETIONS_API_URL;
 
-        debug!("Cohere Request: {url} {body}");
+        debug!("Cohere Chat Completions Request: {url} {body}");
+
+        let builder = client.post(url).bearer_auth(api_key).json(&body);
+
+        Ok(builder)
+    }
+
+    fn embeddings_builder(
+        &self,
+        client: &ReqwestClient,
+        data: EmbeddingsData,
+    ) -> Result<RequestBuilder> {
+        let api_key = self.get_api_key()?;
+
+        let input_type = match data.query {
+            true => "search_query",
+            false => "search_document",
+        };
+
+        let body = json!({
+            "model": self.model.name(),
+            "texts": data.texts,
+            "input_type": input_type,
+        });
+
+        let url = EMBEDDINGS_API_URL;
+
+        debug!("Cohere Embeddings Request: {url} {body}");
 
         let builder = client.post(url).bearer_auth(api_key).json(&body);
 
@@ -47,7 +71,12 @@ impl CohereClient {
     }
 }
 
-impl_client_trait!(CohereClient, chat_completions, chat_completions_streaming);
+impl_client_trait!(
+    CohereClient,
+    chat_completions,
+    chat_completions_streaming,
+    embeddings
+);
 
 async fn chat_completions(builder: RequestBuilder) -> Result<ChatCompletionsOutput> {
     let res = builder.send().await?;
@@ -100,6 +129,24 @@ async fn chat_completions_streaming(
     Ok(())
 }
 
+async fn embeddings(
+    builder: RequestBuilder,
+) -> Result<EmbeddingsOutput> {
+    let res = builder.send().await?;
+    let status = res.status();
+    let data: Value = res.json().await?;
+    if !status.is_success() {
+        catch_error(&data, status.as_u16())?;
+    }
+    let res_body: EmbeddingsResBody = serde_json::from_value(data).context("Invalid request data")?;
+    Ok(res_body.embeddings)
+}
+
+#[derive(Deserialize)]
+struct EmbeddingsResBody {
+    embeddings: Vec<Vec<f32>>,
+}
+
 fn build_chat_completions_body(data: ChatCompletionsData, model: &Model) -> Result<Value> {
     let ChatCompletionsData {
         mut messages,