bkp7 / mdprepare

const debug = require('debug')('mdprepare:processFile')

const {execSync} = require('child_process')

const fs = require('fs')

const os = require('os')

const path = require('path')

const h = require('./helpers.js')

export default function (filePath, clear) {

  // this function accepts a markdown filename and runs any mdprepare code which is embedded in that file

  debug(filePath)

  try {

    var txt = fs.readFileSync(filePath, 'utf8')

  } catch (err) {

    throw Error('file not found')

  }

  try {

    let p = processText(txt, clear, path.dirname(path.resolve(process.cwd(), filePath)))

    fs.writeFileSync(filePath, p)

  } catch (err) {

    throw Error('unable to write to file')

  }

  return true

}

export function processText (txt, clear, fileDirName) {

  let posn = 0

  let r = ''

  let x

  let y

  let t

  let frm

  let eolIsCRLF = (txt.indexOf('\r\n') !== -1)

  while (true) {

    x = h.findMdpCode(txt, posn)

    y = h.findMdpInsert(txt, posn)

    t = h.earlierOf(x, y)

    if (t.start === -1) {

      r = r + txt.substring(posn)

      break

    } else {

      r = r + txt.substring(posn, t.internalStart)

      frm = t.internalStart + t.internalLength

      analyseCommandString(t)

      if (t.info.cliCommand === 'ERROR: mdpInsert command not found') {

        // the mdpInsert command was not present so we don't insert or remove anything, just leave as is

        r = r + txt.substr(t.internalStart, t.internalLength)

      } else {

        if (clear !== true) {

          let insertText = t.prepend + runCliCmd(t.info.cliCommand, fileDirName)

          if (insertText.substr(-1) !== '\n' && t.postpend.length > 0) { insertText += '\n' }

          insertText += t.postpend

          r = r + h.replaceLineEndings(insertText, eolIsCRLF)

        }

        if (r.substr(-1) === '\n') {

          // we don't want to introduce 2 CRLFs or LFs so remove all lines between the start and end lines

          if (txt.substr(frm, 1) === '\r') { frm++ }

          /* istanbul ignore else  */

          if (txt.substr(frm, 1) === '\n') { frm++ }

        }

      }

      posn = t.start + t.length

      r = r + txt.substring(frm, posn)

    }

  }

  return r

}

function analyseCommandString (t) {

  // looks at the command string, checks it is a valid mdpInsert and populates .cli, .prepend and .postpend

  if (typeof t.info === 'undefined') { t.info = {} }

  let x = t.commandString.indexOf('mdpInsert ')

  if (x === -1) {

    t.info.cliCommand = 'ERROR: mdpInsert command not found'

    return

  }

  let regex = /mdpInsert ((`{3,}|~{3,})[^ ]*) /

  let regexResult = regex.exec(t.commandString)

  if (regexResult === null) {

    t.info.cliCommand = t.commandString.substr(x + 10)

    t.prepend = ''

    t.postpend = ''

  } else {

    t.info.cliCommand = t.commandString.substr(x + regexResult[0].length)

    t.prepend = regexResult[1] + '\n'

    t.postpend = regexResult[2]

  }

}

export function runCliCmd (str, wDirName) {

  // wDirName is either an absolute path or a relative path to the directory node was run from

  let cmd = crossPlatformCmds(str)

  try {

    return execSync(cmd, {cwd: wDirName})

  } catch (err) {

    return 'ERROR: ' + err.message

  }

}

function crossPlatformCmds (cmd) {

  // does limited cross platform translation of limited commands

  let r = cmd

  /* istanbul ignore if  */

  if (os.platform() === 'win32') {

    if (cmd.substr(0, 4) === 'cat ') {

      r = r.replace('cat ', 'type ')

      r = r.replace(/\//g, '\\')

    }

  }

  return r

}