harn-serve 0.10.129

use crate::DispatchError;

/// Translate a VM-level error into the dispatcher's typed error.
///
/// Three signals get hoisted out of `Generic` so adapters can render
/// each correctly:
///
/// * `ErrorCategory::Cancelled` — caller-initiated cancel (HTTP 499).
/// * `ErrorCategory::BudgetExceeded` — a `@budget(...)` ceiling fired
///   (HTTP 429, `code = "budget_exceeded"`).
/// * the owned missing-tenant auth diagnostic retains its actionable text;
///   every other auth error remains value-free at this boundary.
/// * everything else → `Execution` (HTTP 500).
pub(super) fn classify_vm_error(error: harn_vm::VmError) -> DispatchError {
    let category = harn_vm::error_to_category(&error);
    if matches!(category, harn_vm::ErrorCategory::Auth)
        && matches!(
            &error,
            harn_vm::VmError::CategorizedError { message, .. }
                if message == harn_vm::harness_tenant::MISSING_TENANT_MESSAGE
        )
    {
        return DispatchError::Execution(
            harn_vm::harness_tenant::MISSING_TENANT_MESSAGE.to_string(),
        );
    }
    let message = harn_vm::tool_registry::tool_runtime_error_summary(&error);
    match category {
        harn_vm::ErrorCategory::Cancelled => DispatchError::Cancelled(message),
        harn_vm::ErrorCategory::BudgetExceeded => DispatchError::BudgetExceeded {
            category: budget_category_from_error(&error)
                .unwrap_or_else(|| "llm_cost_usd".to_string()),
            message,
        },
        _ => DispatchError::Execution(message),
    }
}

/// Best-effort attempt to recover the specific budget dimension that
/// fired (one of `llm_cost_usd`, `llm_tokens`, `mcp_calls`,
/// `pg_queries`) from a `VmError` so per-class rejection telemetry stays
/// accurate. The structured form (`VmError::Thrown(Dict)` — the
/// preflight LLM check and the mcp/pg call-count guards) carries it as
/// the `limit` field. The LLM cost/token guards raise the categorised
/// mid-call variant instead, where we disambiguate on the message.
pub(super) fn budget_category_from_error(error: &harn_vm::VmError) -> Option<String> {
    match error {
        harn_vm::VmError::Thrown(harn_vm::VmValue::Dict(d)) => {
            let harn_vm::VmValue::String(limit) = d.get("limit")? else {
                return None;
            };
            let limit = limit.as_str();
            matches!(
                limit,
                "llm_cost_usd" | "llm_tokens" | "mcp_calls" | "pg_queries"
            )
            .then(|| limit.to_string())
        }
        harn_vm::VmError::CategorizedError { message, .. } if message.contains("LLM") => {
            if message.contains("token") {
                Some("llm_tokens".to_string())
            } else {
                Some("llm_cost_usd".to_string())
            }
        }
        _ => None,
    }
}