//! Tool usage patterns — detect dangerous or suspicious tool invocations.

/// Check whether a tool invocation matches a known dangerous pattern.
///
/// Returns a description of the risk if the pattern matches, or `None`
/// if the invocation appears safe.
pub fn check_dangerous_pattern(tool_name: &str, args: &serde_json::Value) -> Option<String> {
    match tool_name {
        "bash" => {
            let cmd = args.get("command").and_then(|v| v.as_str()).unwrap_or("");
            // Detect git push with --force
            if cmd.contains("git push") && cmd.contains("--force") {
                return Some(
                    "Force-pushing to git is destructive and may lose history".to_string(),
                );
            }
            // Detect rm -rf /
            if cmd.contains("rm -rf /") || cmd.contains("rm -rf /*") {
                return Some(
                    "Recursive deletion of the root filesystem is never allowed".to_string(),
                );
            }
        }
        "delete" => {
            let path = args.get("path").and_then(|v| v.as_str()).unwrap_or("");
            if path == "/" || path.starts_with("/etc") {
                return Some(format!("Deleting '{}' is too dangerous", path));
            }
        }
        _ => {
            tracing::debug!("no guard pattern registered for tool: {tool_name}");
        }
    }
    None
}