const fs = require('fs')
const path = require('path')
const util = require('util')

function inject (bot) {
  bot.commands = {
    commands: {},
    add,
    execute,
    info,
    isCommand,
    loadFromDir,
    isValid
  }

  bot.on('message', (player, message) => {
    if (!message.startsWith(bot.prefix)) { return }

    const args = message.slice(bot.prefix.length).split(' ')
    const command = args.shift().toLowerCase()

    if (!isCommand(command)) { return bot.core.run(`/tellraw @a ${JSON.stringify({ text: `Unknown command: ${bot.prefix}${command}`, color: bot.colors.error })}`) }

    bot.commands.execute(bot, command, player, args)
  })

  function add (command) {
    if (!isValid(command)) throw new Error('Invalid command', 'invalid_command')
    command.aliases.forEach(alias => (bot.commands.commands[alias.toLowerCase()] = command))
  }
  function loadFromDir (dirpath) {
    fs.readdirSync(dirpath).forEach(filename => {
      const filepath = path.resolve(dirpath, filename)
      if (!filepath.endsWith('js') || !fs.statSync(filepath).isFile()) return
      try {
        bot.commands.add(require(filepath))
      } catch (err) {
        bot.console.error('Error loading command ' + filepath + ': ' + util.inspect(err))
      }
    })
  }
  function info (command) {
    const info = bot.commands.commands[command] ?? command
    if (isValid(info)) { return info }
  }
  function isCommand (command) { return bot.commands.info(command) != null }
  async function execute (bot, command, player, args, ...custom) {
    const info = bot.commands.info(command)
    if (info == null) {
      bot.core.run('minecraft:tellraw @a ' + JSON.stringify({ text: 'Unknown command: ' + bot.prefix + command, color: bot.colors.error }))
      return
    }
    if (!info.enabled) {
      bot.core.run('minecraft:tellraw @a ' + JSON.stringify({ text: bot.prefix + command + 'is disabled', color: bot.colors.error }))
      return
    }
    if (info.permLevel > 0) {
      bot.core.run('minecraft:tellraw @a ' + JSON.stringify({ text: 'Trusted commands are currently disabled', color: bot.colors.error }))
      return
    }
    try {
      return await info.execute(bot, command, player, args, ...custom)
    } catch (err) {
      bot.console.error('Error executing command ' + command + ': ' + util.inspect(err))
      bot.core.run('minecraft:tellraw @a ' + JSON.stringify({ text: err.message, color: bot.colors.error }))
    }
  }
}

function isValid (command) {
  return command != null &&
  typeof command.execute === 'function' &&
  typeof command.name === 'string' &&
  typeof command.description === 'string' &&
  Array.isArray(command.usages) &&
  Array.isArray(command.aliases) &&
  typeof command.enabled === 'boolean' &&
  command.aliases.length > 0 &&
  typeof command.permLevel === 'number'
}

module.exports.bot = inject