/**
 * Structured logger for the OmniRoute plugin.
 *
 * Levels: error < warn < info < debug
 * Default: warn (matches current console.warn behavior)
 * Set via features.logLevel in plugin options.
 */

export type LogLevel = "error" | "warn" | "info" | "debug";

const LEVEL_ORDER: Record<LogLevel, number> = {
  error: 0,
  warn: 1,
  info: 2,
  debug: 3,
};

const TAG = "[omniroute-plugin]";

function shouldLog(current: LogLevel, target: LogLevel): boolean {
  return LEVEL_ORDER[current] >= LEVEL_ORDER[target];
}

let _level: LogLevel = "warn";

export function setLogLevel(level: LogLevel): void {
  _level = level;
}

export function getLogLevel(): LogLevel {
  return _level;
}

function fmt(level: LogLevel, msg: string, tag?: string): string {
  const prefix = tag ? `${TAG}${tag}` : TAG;
  return `${prefix} [${level.toUpperCase()}] ${msg}`;
}

function buildLogger(getLevel: () => LogLevel) {
  return {
    error(msg: string, ...args: unknown[]): void {
      if (shouldLog(getLevel(), "error")) console.error(fmt("error", msg), ...args);
    },
    warn(msg: string, ...args: unknown[]): void {
      if (shouldLog(getLevel(), "warn")) console.warn(fmt("warn", msg), ...args);
    },
    info(msg: string, ...args: unknown[]): void {
      if (shouldLog(getLevel(), "info")) console.warn(fmt("info", msg), ...args);
    },
    debug(msg: string, ...args: unknown[]): void {
      if (shouldLog(getLevel(), "debug")) console.warn(fmt("debug", msg), ...args);
    },
    /** Always emit regardless of level (for critical init breadcrumbs). */
    always(msg: string, ...args: unknown[]): void {
      console.warn(TAG, msg, ...args);
    },

    // ── Tagged child loggers ────────────────────────────────────────────
    child(tag: string) {
      return {
        error: (msg: string, ...args: unknown[]) =>
          shouldLog(getLevel(), "error") && console.error(fmt("error", msg, tag), ...args),
        warn: (msg: string, ...args: unknown[]) =>
          shouldLog(getLevel(), "warn") && console.warn(fmt("warn", msg, tag), ...args),
        info: (msg: string, ...args: unknown[]) =>
          shouldLog(getLevel(), "info") && console.warn(fmt("info", msg, tag), ...args),
        debug: (msg: string, ...args: unknown[]) =>
          shouldLog(getLevel(), "debug") && console.warn(fmt("debug", msg, tag), ...args),
      };
    },
  };
}

export type Logger = ReturnType<typeof buildLogger>;

/** Create an instance-scoped logger whose level cannot be changed by other plugin instances. */
export function createLogger(level: LogLevel): Logger {
  return buildLogger(() => level);
}

/** Backward-compatible module-global logger controlled by setLogLevel(). */
export const logger: Logger = buildLogger(() => _level);