log.ts

/**
 * Logs are assigned a priority number.
 * Higher numbers are less important information.
 * Set your desired log level higher to get more info.
 *
 *  -1 nothing
 *   0 only errors
 *   1 also warnings
 *   2 also logs
 *   3 also debugs
 *
 * Logs also come from different "sources" which can
 * have different log level settings.
 *
 * Two ways to modify the log level settings:
 *
 * 1. Set an environment variable in the shell.
 *    This applies to all "sources" (can't be set individually)
 *         EARTHSTAR_LOG_LEVEL=2 npm run test
 *
 * 2. Use setLogLevels() to globally modify the levels:
 *         setLogLevels({ sync: 2 });
 *
 * The environment variable wins over the numbers set by setLogLevels.
 */

//================================================================================
// TYPES

type LogSource = string;

export enum LogLevel {
  None = -1,
  Error = 0, // default
  Warn = 1,
  Log = 2,
  Info = 3,
  Debug = 4, // most verbose
}
export const DEFAULT_LOG_LEVEL = LogLevel.Error;

type LogLevels = Record<LogSource, LogLevel>;

//================================================================================
// ENV VAR

/*
// get the single log level number from the environment, or undefined if not set
const readEnvLogLevel = (): LogLevel | undefined => {
    if (process?.env?.EARTHSTAR_LOG_LEVEL) {
        const parsed = parseInt(process.env.EARTHSTAR_LOG_LEVEL);
        if (isNaN(parsed)) { return undefined }
        if (parsed !== Math.floor(parsed)) { return undefined; }
        return parsed;
    }
    return undefined;
}

// apply env var setting
const ENV_LOG_LEVEL = readEnvLogLevel();
*/

//================================================================================
// GLOBAL SETTINGS

// make global singleton to hold log levels
let globalLogLevels: LogLevels = {
  // result is the min of (_env) and anything else
  _default: DEFAULT_LOG_LEVEL,
};

export function updateLogLevels(newLogLevels: LogLevels): void {
  globalLogLevels = {
    ...globalLogLevels,
    ...newLogLevels,
  };
}

export function setLogLevel(source: LogSource, level: LogLevel) {
  globalLogLevels[source] = level;
}

export function setDefaultLogLevel(level: LogLevel) {
  globalLogLevels._default = level;
}

export function getLogLevel(source: LogSource): LogLevel {
  if (source in globalLogLevels) {
    return globalLogLevels[source];
  } else {
    return globalLogLevels._default;
  }
}

export function getLogLevels(): LogLevels {
  return globalLogLevels;
}

//================================================================================
// Logger class

type LogColor =
  | "blue"
  | "aqua"
  | "darkcyan"
  | "cyan"
  | "dimgray"
  | "slategray"
  | "green"
  | "springgreen"
  | "grey"
  | "darkMagenta"
  | "magenta"
  | "red"
  | "orangeRed"
  | "salmon"
  | "lightsalmon"
  | "gold"
  | "yellow";

export class Logger {
  source: LogSource;
  color: LogColor | undefined = undefined;

  constructor(source: LogSource, color?: LogColor) {
    this.source = source;
    this.color = color || "aqua";
  }

  _print(level: LogLevel, showTag: boolean, indent: string, ...args: any[]) {
    if (level <= getLogLevel(this.source)) {
      if (showTag) {
        const tag = `[${this.source}]`;

        if (this.color !== undefined) {
          const tagArgs = [`%c ${tag}`, `color: ${this.color}`];
          console.log(indent, ...tagArgs, ...args);
        } else {
          console.log(indent, tag, ...args);
        }
      } else {
        console.log(indent, ...args);
      }
    }
  }

  error(...args: any[]) {
    this._print(LogLevel.Error, true, "!!", ...args);
  }
  warn(...args: any[]) {
    this._print(LogLevel.Warn, true, "! ", ...args);
  }
  log(...args: any[]) {
    this._print(LogLevel.Log, true, "  ", ...args);
  }
  info(...args: any[]) {
    this._print(LogLevel.Info, true, "    ", ...args);
  }
  debug(...args: any[]) {
    this._print(LogLevel.Debug, true, "      ", ...args);
  }

  blank() {
    this._print(LogLevel.Info, false, "");
  }
}