Introduce the new index chat settings

crates/milli/src/update/chat.rs

@@ -0,0 +1,45 @@
+use deserr::Deserr;
+use serde::{Deserialize, Serialize};
+use utoipa::ToSchema;
+
+use crate::index::ChatConfig;
+use crate::prompt::{default_max_bytes, PromptData};
+use crate::update::Setting;
+
+#[derive(Debug, Clone, Default, Serialize, Deserialize, PartialEq, Eq, Deserr, ToSchema)]
+#[serde(deny_unknown_fields, rename_all = "camelCase")]
+#[deserr(deny_unknown_fields, rename_all = camelCase)]
+pub struct ChatSettings {
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    #[deserr(default)]
+    #[schema(value_type = Option<String>)]
+    pub description: Setting<String>,
+
+    /// A liquid template used to render documents to a text that can be embedded.
+    ///
+    /// Meillisearch interpolates the template for each document and sends the resulting text to the embedder.
+    /// The embedder then generates document vectors based on this text.
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    #[deserr(default)]
+    #[schema(value_type = Option<String>)]
+    pub document_template: Setting<String>,
+
+    /// Rendered texts are truncated to this size. Defaults to 400.
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    #[deserr(default)]
+    #[schema(value_type = Option<usize>)]
+    pub document_template_max_bytes: Setting<usize>,
+}
+
+impl From<ChatConfig> for ChatSettings {
+    fn from(config: ChatConfig) -> Self {
+        let ChatConfig { description, prompt: PromptData { template, max_bytes } } = config;
+        ChatSettings {
+            description: Setting::Set(description),
+            document_template: Setting::Set(template),
+            document_template_max_bytes: Setting::Set(
+                max_bytes.unwrap_or(default_max_bytes()).get(),
+            ),
+        }
+    }
+}