feat!: add client.chat_stream() method

BREAKING CHANGE: You can't set the `stream` option for `client.chat*()`.

Either use `client.chat_stream()` if you want to use streams
or use `client.chat()` / `client.chat_async()` otherwise.

src/v1/chat_completion.rs

@@ -2,6 +2,25 @@ use serde::{Deserialize, Serialize};
 
 use crate::v1::{common, constants};
 
+// -----------------------------------------------------------------------------
+// Definitions
+
+#[derive(Clone, Debug, Deserialize, Serialize)]
+pub struct ChatMessage {
+    pub role: ChatMessageRole,
+    pub content: String,
+}
+
+#[derive(Clone, Debug, Eq, PartialEq, Deserialize, Serialize)]
+#[allow(non_camel_case_types)]
+pub enum ChatMessageRole {
+    assistant,
+    user,
+}
+
+// -----------------------------------------------------------------------------
+// Request
+
 #[derive(Debug)]
 pub struct ChatCompletionParams {
     pub tools: Option<String>,
@@ -9,7 +28,6 @@ pub struct ChatCompletionParams {
     pub max_tokens: Option<u32>,
     pub top_p: Option<f32>,
     pub random_seed: Option<u32>,
-    pub stream: Option<bool>,
     pub safe_prompt: Option<bool>,
 }
 impl Default for ChatCompletionParams {
@@ -20,7 +38,6 @@ impl Default for ChatCompletionParams {
             max_tokens: None,
             top_p: None,
             random_seed: None,
-            stream: None,
             safe_prompt: None,
         }
     }
@@ -28,7 +45,7 @@ impl Default for ChatCompletionParams {
 
 #[derive(Debug, Serialize, Deserialize)]
 pub struct ChatCompletionRequest {
-    pub messages: Vec<ChatCompletionMessage>,
+    pub messages: Vec<ChatMessage>,
     pub model: constants::Model,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub tools: Option<String>,
@@ -40,8 +57,7 @@ pub struct ChatCompletionRequest {
     pub top_p: Option<f32>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub random_seed: Option<u32>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub stream: Option<bool>,
+    pub stream: bool,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub safe_prompt: Option<bool>,
     // TODO Check this prop (seen in official Python client but not in API doc).
@@ -52,7 +68,8 @@ pub struct ChatCompletionRequest {
 impl ChatCompletionRequest {
     pub fn new(
         model: constants::Model,
-        messages: Vec<ChatCompletionMessage>,
+        messages: Vec<ChatMessage>,
+        stream: bool,
         options: Option<ChatCompletionParams>,
     ) -> Self {
         let ChatCompletionParams {
@@ -61,7 +78,6 @@ impl ChatCompletionRequest {
             max_tokens,
             top_p,
             random_seed,
-            stream,
             safe_prompt,
         } = options.unwrap_or_default();
 
@@ -79,6 +95,9 @@ impl ChatCompletionRequest {
     }
 }
 
+// -----------------------------------------------------------------------------
+// Response
+
 #[derive(Clone, Debug, Deserialize, Serialize)]
 pub struct ChatCompletionResponse {
     pub id: String,
@@ -86,28 +105,45 @@ pub struct ChatCompletionResponse {
     /// Unix timestamp (in seconds).
     pub created: u32,
     pub model: constants::Model,
-    pub choices: Vec<ChatCompletionChoice>,
+    pub choices: Vec<ChatCompletionResponseChoice>,
     pub usage: common::ResponseUsage,
 }
 
 #[derive(Clone, Debug, Deserialize, Serialize)]
-pub struct ChatCompletionChoice {
+pub struct ChatCompletionResponseChoice {
     pub index: u32,
-    pub message: ChatCompletionMessage,
+    pub message: ChatMessage,
     pub finish_reason: String,
     // TODO Check this prop (seen in API responses but undocumented).
     // pub logprobs: ???
 }
 
-#[derive(Clone, Debug, Deserialize, Serialize)]
-pub struct ChatCompletionMessage {
-    pub role: ChatCompletionMessageRole,
-    pub content: String,
+// -----------------------------------------------------------------------------
+// Stream
+
+#[derive(Debug, Deserialize)]
+pub struct ChatCompletionStreamChunk {
+    pub id: String,
+    pub object: String,
+    /// Unix timestamp (in seconds).
+    pub created: u32,
+    pub model: constants::Model,
+    pub choices: Vec<ChatCompletionStreamChunkChoice>,
+    // TODO Check this prop (seen in API responses but undocumented).
+    // pub usage: ???,
 }
 
-#[derive(Clone, Debug, Eq, PartialEq, Deserialize, Serialize)]
-#[allow(non_camel_case_types)]
-pub enum ChatCompletionMessageRole {
-    assistant,
-    user,
+#[derive(Debug, Deserialize)]
+pub struct ChatCompletionStreamChunkChoice {
+    pub index: u32,
+    pub delta: ChatCompletionStreamChunkChoiceDelta,
+    pub finish_reason: Option<String>,
+    // TODO Check this prop (seen in API responses but undocumented).
+    // pub logprobs: ???,
+}
+
+#[derive(Debug, Deserialize)]
+pub struct ChatCompletionStreamChunkChoiceDelta {
+    pub role: Option<ChatMessageRole>,
+    pub content: String,
 }