import { context as otelContext, trace } from "@opentelemetry/api";
import pino, { type Logger as PinoLogger } from "pino";
const DEFAULT_SERVICE_NAME = "discord-mcp";
const DEFAULT_LOG_LEVEL = "info";
const SECRET_REDACT_PATHS = [
"token",
"*.token",
"authorization",
"*.authorization",
"headers.authorization",
"DISCORD_TOKEN",
"DISCORD_CLIENT_SECRET",
];
type LogStyle = "pretty" | "json";
type LogStyleDecision = {
style: LogStyle;
source: "env" | "auto";
};
function parseBoolean(value: string | undefined, fallback: boolean): boolean {
if (value === undefined) {
return fallback;
}
const normalized = value.trim().toLowerCase();
if (normalized === "1" || normalized === "true" || normalized === "yes") {
return true;
}
if (normalized === "0" || normalized === "false" || normalized === "no") {
return false;
}
return fallback;
}
function isDevelopmentRun(): boolean {
const lifecycle = process.env.npm_lifecycle_event?.toLowerCase() || "";
return process.env.NODE_ENV === "development" || lifecycle.startsWith("dev");
}
function resolveLogStyleDecision(): LogStyleDecision {
const raw = process.env.LOG_STYLE?.trim().toLowerCase();
if (raw === "pretty" || raw === "json") {
return {
style: raw,
source: "env",
};
}
const style = process.stderr.isTTY || isDevelopmentRun() ? "pretty" : "json";
return {
style,
source: "auto",
};
}
function buildPrettyTransport() {
return pino.transport({
target: "pino-pretty",
options: {
colorize: parseBoolean(process.env.LOG_COLOR, process.stderr.isTTY),
singleLine: true,
levelFirst: true,
translateTime: false,
ignore: "pid,hostname,time",
messageFormat:
"{if module}{module} {end}{msg}{if trace_id} trace={trace_id} span={span_id}{end}",
},
});
}
function buildTraceContextBindings(): Record<string, string> {
const span = trace.getSpan(otelContext.active());
if (!span) {
return {};
}
const spanContext = span.spanContext();
if (!spanContext.traceId || !spanContext.spanId) {
return {};
}
return {
trace_id: spanContext.traceId,
span_id: spanContext.spanId,
};
}
function normalizeLogLevel(value: string | undefined): string {
const normalized = value?.trim().toLowerCase();
if (
normalized === "fatal" ||
normalized === "error" ||
normalized === "warn" ||
normalized === "info" ||
normalized === "debug" ||
normalized === "trace"
) {
return normalized;
}
return DEFAULT_LOG_LEVEL;
}
const serviceName = process.env.OTEL_SERVICE_NAME || DEFAULT_SERVICE_NAME;
const logStyleDecision = resolveLogStyleDecision();
const logStyle = logStyleDecision.style;
const baseLogger = pino(
{
level: normalizeLogLevel(process.env.LOG_LEVEL),
enabled: parseBoolean(process.env.ENABLE_LOGGING, true),
timestamp: false,
base: {
service: serviceName,
},
redact: {
paths: SECRET_REDACT_PATHS,
censor: "[REDACTED]",
},
mixin: buildTraceContextBindings,
},
logStyle === "pretty" ? buildPrettyTransport() : undefined,
);
if (baseLogger.isLevelEnabled("debug")) {
baseLogger.debug(
{
logStyle: logStyleDecision.style,
source: logStyleDecision.source,
isTTY: process.stderr.isTTY,
lifecycleEvent: process.env.npm_lifecycle_event,
nodeEnv: process.env.NODE_ENV,
},
"logger_style_selected",
);
}
export function getRuntimeLogger(): PinoLogger {
return baseLogger;
}
export function getModuleLogger(moduleName: string): PinoLogger {
return baseLogger.child({
module: moduleName,
});
}
