import { SeverityNumber } from "@opentelemetry/api-logs";

/** Log severity levels in ascending order. */
export type LogLevel = "debug" | "info" | "warn" | "error" | "fatal";

/** Map from LogLevel to OTel SeverityNumber. */
export const SEVERITY_MAP: Record<LogLevel, SeverityNumber> = {
  debug: SeverityNumber.DEBUG,
  info: SeverityNumber.INFO,
  warn: SeverityNumber.WARN,
  error: SeverityNumber.ERROR,
  fatal: SeverityNumber.FATAL,
};

/** Attributes that can be attached to log records. */
export type LogAttributes = Record<string, unknown>;

/** Options for creating a logger. */
export interface CreateLoggerOptions {
  /** Service name (e.g., "atbb-appview"). */
  service: string;
  /** Service version (e.g., "0.1.0"). */
  version?: string;
  /** Deployment environment (e.g., "production", "development"). */
  environment?: string;
  /** Minimum log level. Defaults to "info". */
  level?: LogLevel;
}

/** Structured logger interface. */
export interface Logger {
  debug(message: string, attributes?: LogAttributes): void;
  info(message: string, attributes?: LogAttributes): void;
  warn(message: string, attributes?: LogAttributes): void;
  error(message: string, attributes?: LogAttributes): void;
  fatal(message: string, attributes?: LogAttributes): void;
  /** Create a child logger with additional base attributes. */
  child(attributes: LogAttributes): Logger;
  /** Shut down the underlying OTel LoggerProvider and release its resources. */
  shutdown(): Promise<void>;
}