import path from 'path'
import fs from 'fs/promises'
import { spawn } from 'child_process'
import { fileURLToPath, pathToFileURL } from 'url'

export default class Util {
  constructor(root_import_meta_url) {
    this._root_import_meta_url = root_import_meta_url
  }

  getPathFromRoot(add) {
    const __dirname = path.dirname(fileURLToPath(this._root_import_meta_url));
    return path.join(__dirname,'./', add)
  }

  getUrlFromRoot(add) {
    return path.join(this._root_import_meta_url,'../', add)
  }

  getExtension(filename) {
    let extension = path.extname(filename)
    if (filename.indexOf('.tar.') > 0) {
      return '.tar' + extension
    }
    return extension
  }

  getAppNames(config) {
    let out = []
    let keys = Object.keys(config)
    for (let key of keys) {
      if (typeof(config[key]) !== 'object' || config[key] == null) continue
      if (typeof(config[key].port) !== 'number' || !config[key].port) continue
      if (typeof(config[key].provider) !== 'string' || !config[key].provider) continue

      out.push(key)
    }
    return out
  }

  get7zipExecutable() {
    const util = new Util(import.meta.url)
    if (process.platform === 'win32') {
      return util.getPathFromRoot('../bin/7za.exe')
    }
    return util.getPathFromRoot('../bin/7zas')
  }

  verifyConfig(config) {
    if (!config.name) throw new Error('name is missing in config.json')
    if (this.getAppNames(config).length === 0) throw new Error('no application was found in config')
    if (config.debugPort != null && (typeof(config.debugPort) !== 'number' || !config.debugPort)) throw new Error('debugPort in config not a valid number')
  }
  
  extractFile(file, stream = function() {}) {
    return this.runCommand(this.get7zipExecutable(), ['x', file], path.dirname(file), stream)
      .then(() => {
        if (!file.indexOf('.tar.')) return

        let tarFile = file.slice(0, file.lastIndexOf('.'))
        return fs.stat(tarFile)
          .catch(function() { return null })
          .then((stat) => {
            if (!stat) return
            return this.extractFile(tarFile)
              .then(function() { return fs.rm(tarFile, { force: true }) })
          })
      })
  }

  runCommand(command, options = [], folder = null, stream = function() {}) {
    return new Promise(function(res, rej) {
      stream(`[Command] ${folder ? folder : ''}${command} ${options.join(' ')}\n`)
      let processor = spawn(command, options, {
        shell: true,
        cwd: folder,
      })
      let timeOuter = setInterval(function() {
        processor.stdin.write('n\n')
      }, 250)
      processor.stdout.on('data', function(data) {
        stream(data.toString())
      })
      processor.stderr.on('data', function(data) {
        stream(data.toString())
      })
      processor.on('error', function(err) {
        clearInterval(timeOuter)
        rej(err)
      })
      processor.on('exit', function (code) {
        clearInterval(timeOuter)
        if (code !== 0) {
          return rej(new Error('Program returned error code: ' + code))
        }
        res(code)
      })
    })
  }
}