import path from "path";
type LogLevel = "debug" | "info" | "warn" | "error" | "silent";
const levelOrder: Record<Exclude<LogLevel, "silent">, number> = {
debug: 10,
info: 20,
warn: 30,
error: 40,
};
function resolveLevel(): LogLevel {
const fromEnv = (process.env.MCP_LOG_LEVEL || "").toLowerCase();
if (fromEnv === "silent") return "silent";
if (fromEnv in levelOrder) return fromEnv as LogLevel;
// Fallback: enable debug if DEBUG includes 'swipl-mcp-server'
const dbg = process.env.DEBUG || "";
if (dbg.split(",").some((s) => s.trim().includes("swipl-mcp-server"))) return "debug";
return "warn";
}
let currentLevel: LogLevel = resolveLevel();
function shouldLog(target: Exclude<LogLevel, "silent">): boolean {
if (currentLevel === "silent") return false;
const cur = levelOrder[currentLevel as Exclude<LogLevel, "silent">] ?? 9999;
const tgt = levelOrder[target];
return cur <= tgt;
}
function fmt(level: string, msg: string) {
const ts = new Date().toISOString();
return `[swipl-mcp-server ${level}] ${ts} ${msg}`;
}
export const logger = {
setLevel(lvl: LogLevel) {
currentLevel = lvl;
},
debug(msg: string) {
if (shouldLog("debug")) console.error(fmt("debug", msg));
},
info(msg: string) {
if (shouldLog("info")) console.error(fmt("info", msg));
},
warn(msg: string) {
if (shouldLog("warn")) console.error(fmt("warn", msg));
},
error(msg: string) {
if (shouldLog("error")) console.error(fmt("error", msg));
},
// Helpers to avoid leaking sensitive details
redactPath(p: string): string {
try {
const rel = path.relative(process.cwd(), p);
return rel && !rel.startsWith("..") ? rel : path.basename(p);
} catch {
return "path";
}
},
redactPid(pid?: number | null): string {
return pid ? `pid:${String(pid).slice(0, 1)}**` : "pid:***";
},
};
