const _ = require("lodash")
const dayjs = require("dayjs")
const colors = require("colors/safe")
const fs = require("node:fs/promises")

/////////////////////////////////////////////////////////////////////////

const LEVELS = {debug: 10, info: 20, warn: 30, error: 40}
const DEFAULT_LEVEL = "info"

// level configured from settings (see settings.js); env LOG_LEVEL overrides it
let settingsLevel = null

module.exports = {
   debug: msg => log("DEBUG", msg),
   info: msg => log("INFO", msg),
   warn: msg => log("WARN", msg),
   error: msg => log("ERROR", msg),
   setLevel,
   level: currentLevel,
}

/////////////////////////////////////////////////////////////////////////

/**
 * Set the level from settings. The LOG_LEVEL env var still takes precedence.
 */
function setLevel (level) {
   settingsLevel = level ? level.toString().trim().toLowerCase() : null
}

/**
 * Resolve the active log level: LOG_LEVEL env var > settings level > "info".
 */
function currentLevel () {
   const level = process.env.LOG_LEVEL || settingsLevel || DEFAULT_LEVEL
   return level.toString().trim().toLowerCase()
}

function log (level, msg) {
   const threshold = currentLevel()
   if (threshold === "silent" || threshold === "off") return
   if (LEVELS[level.toLowerCase()] < (LEVELS[threshold] ?? LEVELS[DEFAULT_LEVEL])) return

   if (!_.isString(msg)) {
      if (msg.message) {
         msg = msg.message
      }
      else {
         try {
            msg = JSON.stringify(msg)
         } catch (ex) {
            msg = msg?.toString()
         }
      }
   }
   level = _.padEnd(level, 5)
   level = format(level.toLowerCase())
   let message = `${level} ${dayjs().format("DD.MM.YYYY HH:mm:ss")} - ${msg}`
   console.log(message)
   return fs.appendFile("log.log", message + "\n")
}

function format (level) {
   switch (level.trim()) {
      case "info":
         return colors.green(level.toUpperCase())
      case "warn":
         return colors.blue(level.toUpperCase())
      case "error":
         return colors.red(level.toUpperCase())
      case "debug":
         return colors.grey(level.toUpperCase())
   }
   return level
}