import type { Logger as PinoLogger } from "pino";
import { pino } from "pino";

import { pinoMixin as telemetryMixin } from "../telemetry/instrumentations/pino.js";

export type Logger = PinoLogger;
export type LogLevel = "fatal" | "error" | "warn" | "info" | "debug" | "trace";

export type CreateLogger = (serviceName: string) => Logger;

export function createMockLoggerProvider(): CreateLogger {
  return createLoggerProvider({
    config: { logLevel: "error" },
  });
}

export function createLoggerProvider({
  config,
}: {
  config: { logLevel: LogLevel };
}): CreateLogger {
  return function createLogger(serviceName: string): Logger {
    const logger = pino({
      name: "app",
      level: config.logLevel,
      formatters: {
        // format level as string instead of number
        level(label) {
          return { level: label };
        },
      },
      timestamp: pino.stdTimeFunctions.isoTime,
      hooks: {
        // reverse pino method so it goes logger.method(message, details) instead
        // of logger.method(details, message)
        logMethod(inputArguments: unknown[], method) {
          if (inputArguments.length >= 2) {
            const argument1 = inputArguments[0];
            const argument2 = inputArguments[1];
            Reflect.apply(method, this, [
              argument2,
              argument1,
              ...inputArguments.slice(2),
            ]);

            return;
          }

          method.apply(this, inputArguments as [string, ...unknown[]]);
        },
      },
      mixin: telemetryMixin,
    });

    return logger.child({
      serviceName,
    });
  };
}