full backend rewrite.

calling this v0.4.0

backend/src/svc/llm_service.rs

@@ -0,0 +1,89 @@
+#[derive(Clone)]
+pub struct LlmService;
+
+
+static LMSTUDIO_URL: LazyLock<Option<String>> = LazyLock::new(|| env::var("LMSTUDIO_URL").ok());
+static LMSTUDIO_MODEL: LazyLock<Option<String>> = LazyLock::new(|| env::var("LMSTUDIO_MODEL").ok());
+
+impl LlmService {
+
+	pub fn new() -> Self {
+		Self {}
+	}
+
+	pub fn enabled(&self) -> bool {
+		LMSTUDIO_URL.is_some()
+	}
+
+	pub async fn query(&self, message: &ChatMsg) -> ApiResult<ChatMsg> {
+		let Some(url) = LMSTUDIO_URL.clone() else {
+			return Err(AppError::internal("AI not enabled!"))
+		};
+
+		let model = LMSTUDIO_MODEL.clone().unwrap_or_else(|| "gpt-oss-20b".into());
+
+		let client = reqwest::Client::new();
+
+		// Build the request body
+		let payload = LlmRequest {
+			model, // whatever model you run locally
+			messages: vec![Message {
+				role: "user".into(),
+				content: message.text.clone(),
+			}],
+		};
+
+		// POST to lm‑studio (default 127.0.0.1:1234)
+		let resp = client
+			.post(url)
+			.json(&payload)
+			.send()
+			.await
+			.map_err(|_| AppError::internal("Failed to make request to LLM server"))?;
+
+		// The API returns a JSON with `choices[].message.content`
+		#[derive(Deserialize)]
+		struct LlmResponse {
+			choices: Vec<Choice>,
+		}
+		#[derive(Deserialize)]
+		struct Choice {
+			message: Message,
+		}
+
+		let llm_resp: LlmResponse = resp
+			.json()
+			.await
+			.map_err(|_| AppError::internal("Failed to parse LLM response"))?;
+
+		Ok(ChatMsg {
+			display_name: Some(String::from("llm")),
+			user_id: 0,
+			text: llm_resp.choices[0].message.content.clone(),
+			timestamp: chrono::Utc::now(),
+		})
+	}
+}
+
+use std::env;
+use std::sync::LazyLock;
+// src/llm.rs
+use serde::{Deserialize, Serialize};
+
+use crate::api::chat::ChatMsg;
+use crate::error::{ApiResult, AppError};
+use crate::svc::chat_svc::ChatService;
+
+#[derive(Serialize)]
+struct LlmRequest {
+	model: String,
+	messages: Vec<Message>,
+}
+
+#[derive(Serialize, Deserialize)]
+struct Message {
+	role: String, // "user" or "assistant"
+	content: String,
+}
+
+