Better chat settings management

crates/meilisearch/src/routes/settings/chat.rs

@@ -3,6 +3,7 @@ use actix_web::HttpResponse;
 use index_scheduler::IndexScheduler;
 use meilisearch_types::error::ResponseError;
 use meilisearch_types::keys::actions;
+use meilisearch_types::milli::update::Setting;
 use serde::{Deserialize, Serialize};
 
 use crate::extractors::authentication::policies::ActionPolicy;
@@ -35,37 +36,63 @@ async fn patch_settings(
         ActionPolicy<{ actions::CHAT_SETTINGS_UPDATE }>,
         Data<IndexScheduler>,
     >,
-    web::Json(chat_settings): web::Json<GlobalChatSettings>,
+    web::Json(new): web::Json<GlobalChatSettings>,
 ) -> Result<HttpResponse, ResponseError> {
-    let chat_settings = serde_json::to_value(chat_settings).unwrap();
-    index_scheduler.put_chat_settings(&chat_settings)?;
+    let old = match index_scheduler.chat_settings()? {
+        Some(value) => serde_json::from_value(value).unwrap(),
+        None => GlobalChatSettings::default(),
+    };
+
+    let settings = GlobalChatSettings {
+        source: new.source.or(old.source),
+        base_api: new.base_api.clone().or(old.base_api),
+        api_key: new.api_key.clone().or(old.api_key),
+        prompts: match (new.prompts, old.prompts) {
+            (Setting::NotSet, set) | (set, Setting::NotSet) => set,
+            (Setting::Set(_) | Setting::Reset, Setting::Reset) => Setting::Reset,
+            (Setting::Reset, Setting::Set(set)) => Setting::Set(set),
+            // If both are set we must merge the prompts settings
+            (Setting::Set(new), Setting::Set(old)) => Setting::Set(ChatPrompts {
+                system: new.system.or(old.system),
+                search_description: new.search_description.or(old.search_description),
+                search_q_param: new.search_q_param.or(old.search_q_param),
+                search_index_uid_param: new.search_index_uid_param.or(old.search_index_uid_param),
+                pre_query: new.pre_query.or(old.pre_query),
+            }),
+        },
+    };
+
+    let value = serde_json::to_value(settings).unwrap();
+    index_scheduler.put_chat_settings(&value)?;
     Ok(HttpResponse::Ok().finish())
 }
 
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(deny_unknown_fields, rename_all = "camelCase")]
 pub struct GlobalChatSettings {
-    pub source: String,
-    pub base_api: Option<String>,
-    pub api_key: Option<String>,
-    pub prompts: ChatPrompts,
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    pub source: Setting<String>,
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    pub base_api: Setting<String>,
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    pub api_key: Setting<String>,
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    pub prompts: Setting<ChatPrompts>,
 }
 
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(deny_unknown_fields, rename_all = "camelCase")]
 pub struct ChatPrompts {
-    pub system: String,
-    pub search_description: String,
-    pub search_q_param: String,
-    pub search_index_uid_param: String,
-    pub pre_query: String,
-}
-
-#[derive(Debug, Serialize, Deserialize)]
-#[serde(deny_unknown_fields, rename_all = "camelCase")]
-pub struct ChatIndexSettings {
-    pub description: String,
-    pub document_template: String,
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    pub system: Setting<String>,
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    pub search_description: Setting<String>,
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    pub search_q_param: Setting<String>,
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    pub search_index_uid_param: Setting<String>,
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    pub pre_query: Setting<String>,
 }
 
 const DEFAULT_SYSTEM_MESSAGE: &str = "You are a highly capable research assistant with access to powerful search tools. IMPORTANT INSTRUCTIONS:\
@@ -91,17 +118,26 @@ Selecting the right index ensures the most relevant results for the user query";
 impl Default for GlobalChatSettings {
     fn default() -> Self {
         GlobalChatSettings {
-            source: "openai".to_string(),
-            base_api: None,
-            api_key: None,
-            prompts: ChatPrompts {
-                system: DEFAULT_SYSTEM_MESSAGE.to_string(),
-                search_description: DEFAULT_SEARCH_IN_INDEX_TOOL_DESCRIPTION.to_string(),
-                search_q_param: DEFAULT_SEARCH_IN_INDEX_Q_PARAMETER_TOOL_DESCRIPTION.to_string(),
-                search_index_uid_param: DEFAULT_SEARCH_IN_INDEX_INDEX_PARAMETER_TOOL_DESCRIPTION
-                    .to_string(),
-                pre_query: "".to_string(),
-            },
+            source: Setting::Set("openAi".to_string()),
+            base_api: Setting::NotSet,
+            api_key: Setting::NotSet,
+            prompts: Setting::Set(ChatPrompts::default()),
+        }
+    }
+}
+
+impl Default for ChatPrompts {
+    fn default() -> Self {
+        ChatPrompts {
+            system: Setting::Set(DEFAULT_SYSTEM_MESSAGE.to_string()),
+            search_description: Setting::Set(DEFAULT_SEARCH_IN_INDEX_TOOL_DESCRIPTION.to_string()),
+            search_q_param: Setting::Set(
+                DEFAULT_SEARCH_IN_INDEX_Q_PARAMETER_TOOL_DESCRIPTION.to_string(),
+            ),
+            search_index_uid_param: Setting::Set(
+                DEFAULT_SEARCH_IN_INDEX_INDEX_PARAMETER_TOOL_DESCRIPTION.to_string(),
+            ),
+            pre_query: Setting::Set(Default::default()),
         }
     }
 }