const log = require('fancy-log')

/**
 * Validate whether all functions in math.js are documented in math.docs
 * we use the minified bundle to also check whether that bundle is valid.
 */
exports.validateEmbeddedDocs = function () {
  const math = require('../dist/math.min.js')
  let prop

  // names to ignore
  const ignore = [
    // functions not supported or relevant for the parser:
    'chain', 'print',
    'compile', 'parse', 'parser', // TODO: add embedded docs for compile, parse, and parser?
    'reviver', // TODO: add embedded docs for reviver?
    'apply', // FIXME: apply is not supported right now because of security concerns
    'eye', 'var', 'eval', 'typeof', // deprecated functions
    'addScalar', 'divideScalar', 'multiplyScalar', 'equalScalar'
  ]

  // test whether all functions are documented
  let undocumentedCount = 0
  for (prop in math.expression.mathWithTransform) {
    if (math.expression.mathWithTransform.hasOwnProperty(prop)) {
      const obj = math[prop]
      if (math['typeOf'](obj) !== 'Object') {
        try {
          if (ignore.indexOf(prop) === -1) {
            math.help(prop).toString()
          }
        } catch (err) {
          undocumentedCount++
          log('WARNING: Function ' + prop + ' is undocumented')
        }
      }
    }
  }

  // test whether there is documentation for non existing functions
  let nonExistingCount = 0
  const docs = math.docs
  for (prop in docs) {
    if (docs.hasOwnProperty(prop)) {
      if (math[prop] === undefined) {
        log('WARNING: Documentation for a non-existing function "' + prop + '"')
        nonExistingCount++
      }
    }
  }

  // done. Output results
  if (undocumentedCount === 0 && nonExistingCount === 0) {
    log('Validation successful: all functions are documented.')
  } else {
    log.error('Validation failed: not all functions are documented.')
  }

  return Promise.resolve()
}