Function generate_excalidraw

src-tauri/src/services/chat_service.rs:1094–1165

Generate Excalidraw elements from a text prompt using the LLM.

(
    db: &SqlitePool,
    prompt: &str,
    existing_elements: Option<&str>,
    provider_id: Option<&str>,
    model_id: Option<&str>,
)

/// Generate Excalidraw elements from a text prompt using the LLM.
pub async fn generate_excalidraw(
    db: &SqlitePool,
    prompt: &str,
    existing_elements: Option<&str>,
    provider_id: Option<&str>,
    model_id: Option<&str>,
) -> AppResult<String> {
    let provider = provider_service::get_provider_for_chat(db, provider_id).await?;
    let model = model_id.unwrap_or(&provider.model);

    let mut messages = vec![
        serde_json::json!({"role": "system", "content": EXCALIDRAW_SYSTEM_PROMPT}),
    ];

    // If there are existing elements, include them so AI can edit
    if let Some(elements) = existing_elements {
        messages.push(serde_json::json!({
            "role": "user",
            "content": format!("Here are the current canvas elements:\n{}\n\nIMPORTANT: When I ask you to modify something, return ALL elements (modified + unmodified). Keep all existing element IDs, positions, and properties unless I specifically ask to change them.", elements)
        }));
        messages.push(serde_json::json!({
            "role": "assistant",
            "content": "I understand. I'll return the complete set of elements, only modifying what you ask for while preserving everything else exactly as-is."
        }));
    }

    messages.push(serde_json::json!({"role": "user", "content": prompt}));

    let client = http_client::request_client()?;
    let endpoint = format!("{}/chat/completions", provider.base_url.trim_end_matches('/'));

    let payload = serde_json::json!({
        "model": model,
        "messages": messages,
        "temperature": 0.3,
        "max_tokens": 4000,
        "stream": false,
    });

    let mut request = client
        .post(&endpoint)
        .header(CONTENT_TYPE, "application/json")
        .json(&payload);

    if let Some(key) = provider.api_key.as_deref().filter(|k| !k.trim().is_empty()) {
        request = request.header(AUTHORIZATION, format!("Bearer {key}"));
    }

    let response = request.send().await?;
    if !response.status().is_success() {
        let status = response.status();
        let body = response.text().await.unwrap_or_default();
        return Err(AppError::Http(format!("{status}: {body}")));
    }

    let body: Value = response.json().await?;
    let content = body["choices"][0]["message"]["content"]
        .as_str()