New revision of the Assistant Panel (#10870)

This is a crate only addition of a new version of the AssistantPanel.
We'll be putting this behind a feature flag while we iron out the new
experience.

Release Notes:

- N/A

---------

Co-authored-by: Nathan Sobo <nathan@zed.dev>
Co-authored-by: Antonio Scandurra <me@as-cii.com>
Co-authored-by: Conrad Irwin <conrad@zed.dev>
Co-authored-by: Marshall Bowers <elliott.codes@gmail.com>
Co-authored-by: Antonio Scandurra <antonio@zed.dev>
Co-authored-by: Nate Butler <nate@zed.dev>
Co-authored-by: Nate Butler <iamnbutler@gmail.com>
Co-authored-by: Max Brunsfeld <maxbrunsfeld@gmail.com>
Co-authored-by: Max <max@zed.dev>

crates/open_ai/src/open_ai.rs

@@ -1,6 +1,7 @@
 use anyhow::{anyhow, Context, Result};
 use futures::{io::BufReader, stream::BoxStream, AsyncBufReadExt, AsyncReadExt, StreamExt};
 use serde::{Deserialize, Serialize};
+use serde_json::{Map, Value};
 use std::{convert::TryFrom, future::Future};
 use util::http::{AsyncBody, HttpClient, Method, Request as HttpRequest};
 
@@ -12,6 +13,7 @@ pub enum Role {
     User,
     Assistant,
     System,
+    Tool,
 }
 
 impl TryFrom<String> for Role {
@@ -22,6 +24,7 @@ impl TryFrom<String> for Role {
             "user" => Ok(Self::User),
             "assistant" => Ok(Self::Assistant),
             "system" => Ok(Self::System),
+            "tool" => Ok(Self::Tool),
             _ => Err(anyhow!("invalid role '{value}'")),
         }
     }
@@ -33,6 +36,7 @@ impl From<Role> for String {
             Role::User => "user".to_owned(),
             Role::Assistant => "assistant".to_owned(),
             Role::System => "system".to_owned(),
+            Role::Tool => "tool".to_owned(),
         }
     }
 }
@@ -91,18 +95,88 @@ pub struct Request {
     pub stream: bool,
     pub stop: Vec<String>,
     pub temperature: f32,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub tool_choice: Option<String>,
+    #[serde(skip_serializing_if = "Vec::is_empty")]
+    pub tools: Vec<ToolDefinition>,
+}
+
+#[derive(Debug, Serialize)]
+pub struct FunctionDefinition {
+    pub name: String,
+    pub description: Option<String>,
+    pub parameters: Option<Map<String, Value>>,
+}
+
+#[derive(Serialize, Debug)]
+#[serde(tag = "type", rename_all = "snake_case")]
+pub enum ToolDefinition {
+    #[allow(dead_code)]
+    Function { function: FunctionDefinition },
 }
 
 #[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
-pub struct RequestMessage {
-    pub role: Role,
-    pub content: String,
+#[serde(tag = "role", rename_all = "lowercase")]
+pub enum RequestMessage {
+    Assistant {
+        content: Option<String>,
+        #[serde(default, skip_serializing_if = "Vec::is_empty")]
+        tool_calls: Vec<ToolCall>,
+    },
+    User {
+        content: String,
+    },
+    System {
+        content: String,
+    },
+    Tool {
+        content: String,
+        tool_call_id: String,
+    },
 }
 
 #[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
-pub struct ResponseMessage {
+pub struct ToolCall {
+    pub id: String,
+    #[serde(flatten)]
+    pub content: ToolCallContent,
+}
+
+#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
+#[serde(tag = "type", rename_all = "lowercase")]
+pub enum ToolCallContent {
+    Function { function: FunctionContent },
+}
+
+#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
+pub struct FunctionContent {
+    pub name: String,
+    pub arguments: String,
+}
+
+#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
+pub struct ResponseMessageDelta {
     pub role: Option<Role>,
     pub content: Option<String>,
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub tool_calls: Vec<ToolCallChunk>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
+pub struct ToolCallChunk {
+    pub index: usize,
+    pub id: Option<String>,
+
+    // There is also an optional `type` field that would determine if a
+    // function is there. Sometimes this streams in with the `function` before
+    // it streams in the `type`
+    pub function: Option<FunctionChunk>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
+pub struct FunctionChunk {
+    pub name: Option<String>,
+    pub arguments: Option<String>,
 }
 
 #[derive(Deserialize, Debug)]
@@ -115,7 +189,7 @@ pub struct Usage {
 #[derive(Deserialize, Debug)]
 pub struct ChoiceDelta {
     pub index: u32,
-    pub delta: ResponseMessage,
+    pub delta: ResponseMessageDelta,
     pub finish_reason: Option<String>,
 }