import { isArray, isBoolean, isRecord } from './data/is'
import { jsonStringifySafe } from './data/json'
import { escapeRegExp } from './data/regexp'

const defaultSeparator = ','

export function csvStringify(data: any[], opt: {
  // header?: string[]
  separator?: string
  addBom?: boolean // option to add byte order mark for improved Excel support
} = {}): string {
  const { separator = defaultSeparator } = opt
  let body = ''
  if (opt.addBom)
    body = '\uFEFF'

  // Append the header row to the response if requested
  // if (header)
  //   body = `${header.join(separator)}\n`

  // Convert the data to a CSV-like structure
  for (let i = 0; i < data.length; i++) {
    body += `${data[i].map((field: string) => {
      if (field == null || field === '')
        return ''
      if (isBoolean(field))
        return field ? 1 : 0
      let s = String(field)
      if (isRecord(field) || isArray(field))
        s = jsonStringifySafe(field)
      if (s.includes('"') || s.includes('\n') || s.includes(separator))
        return `"${s.replace(/"/g, '""')}"`
      return s
    }).join(separator)}\n`
  }

  return body
}

export function csvParse(raw: string, opt: {
  separator?: string
} = {}) {
  // https://regex101.com/r/BCpKyV/1
  // eslint-disable-next-line regexp/no-unused-capturing-group, regexp/no-super-linear-backtracking, regexp/no-dupe-disjunctions, regexp/no-useless-non-capturing-group
  let rxOneValueWithSeparator = /("((?:(?:[^"]*?)(?:"")?)*)"|([^,;\t\n]*))([,;\t\n]|\r\n)/g
  if (opt.separator)
    rxOneValueWithSeparator = new RegExp(rxOneValueWithSeparator.source.replace(/',;\\t/g, escapeRegExp(opt.separator)), rxOneValueWithSeparator.flags)

  const lines: any[][] = []
  let row: any[] = []
  let m: any
  const text = `${raw.replace(/\r\n/g, '\n').trim()}\n`

  // eslint-disable-next-line no-cond-assign
  while (m = rxOneValueWithSeparator.exec(text)) {
    let value = m[2] ?? m[3] ?? ''
    value = value.replace(/""/g, '"')
    row.push(value)
    if (m[4] === '\n') {
      lines.push(row)
      row = []
    }
  }
  return lines
}

export function csvParseToObjects(raw: string, opt: {
  separator?: string
} = {}) {
  const lines = csvParse(raw, opt)
  const header = lines[0]
  return lines.slice(1).map(l =>
    Object.fromEntries (l.map((v, i) => [header[i], v])),
  )
}