const fs = require('fs')
const yaml = require('js-yaml')
const chproc = require('child_process')


/**
 * Delete all files in a directory
 *
 * @param dirPath : string
 */
function rmInDir(dirPath) {
  let files

  console.log(`\x1b[32m[Clean]\x1b[m ${dirPath}`)

  try {
    files = fs.readdirSync(dirPath)
  } catch (e) {
    return
  }

  if (files.length > 0) {
    for (let i = 0; i < files.length; i++) {
      let filePath = dirPath + '/' + files[i]

      if (filePath.endsWith('.gitignore') || filePath.endsWith('.gitkeep'))
        continue // preserve special files

      if (fs.statSync(filePath).isFile())
        fs.unlinkSync(filePath)
      else
        rmInDir(filePath)
    }
  }
}

/**
 * Copy a file
 *
 * @param src : string
 * @param dest : string
 * @param verbose : boolean, default true
 * @returns {boolean}
 */
function cp(src, dest, verbose=true) {
  if (!fs.existsSync(src)) {
    return false;
  }

  if (verbose) console.log(`\x1b[32m[Copy]\x1b[m ${src} -> ${dest}`)
  let data = fs.readFileSync(src);
  fs.writeFileSync(dest, data);
  return true
}

/**
 * Write with automatic encoding to JSON or YAML
 *
 * @param path : string
 * @param content : object|string
 */
function fwrite(path, content) {
  let towrite = content
  let format = 'plain'

  if (typeof towrite !== 'string') {
    if (path.endsWith('.json')) {
      towrite = JSON.stringify(towrite, null, 4)
      format = 'json'
    }
    else if (path.endsWith('.yaml') || path.endsWith('.yml')) {
      towrite = yaml.safeDump(towrite)
      format = 'yaml'
    }
    else {
      throw `Can't figure out data encoding (at ${path})`
    }
  }

  console.log(`\x1b[32m[Writing]\x1b[m ${path} (${format})`)
  fs.writeFileSync(path, towrite)
}

/**
 * Read with automatic decoding from JSON or YAML
 *
 * @param path : string
 * @return string|object|array
 */
function fread(path) {
  let content = fs.readFileSync(path, 'utf-8')
  let format = 'plain'

  if (path.endsWith('.json')) {
    content = JSON.parse(content)
    format = 'json'
  } else if (path.endsWith('.yaml') || path.endsWith('.yml')) {
    content = yaml.safeLoad(content)
    format = 'yaml'
  }

  console.log(`\x1b[32m[Reading]\x1b[m ${path} (${format})`)
  return content
}

/**
 * Test if a file exists
 *
 * @param path : string
 * @returns {boolean} exists
 */
function exists (path) {
  return fs.existsSync(path)
}


/**
 * Delete a file
 *
 * @param path : string
 * @returns {boolean} success
 */
function rm (path) {
  if (!exists(path)) {
    return false
  }

  fs.unlinkSync(path)
  return true
}

/**
 * Execute a command
 *
 * @param command
 * @param cwd
 */
function exec (command, cwd='.') {
  return chproc.execSync(command, {
    cwd: cwd,
    stdio: [0,1,2]
  })
}

module.exports = {
  rmInDir,
  cp,
  fwrite,
  fread,
  exists,
  rm,
  exec,
  abort: (msg) => {
    console.log(`\x1b[31;1m${msg}\x1b[m`)
    process.exit()
  }
}