/**
 * @param {string | TemplateStringsArray} strings
 * @param  {...unknown[]} values
 * @returns {string}
 */
export function dedent(strings, ...values) {
  const raw = typeof strings === 'string' ? [strings] : strings.raw
  const escapeSpecialCharacters = Array.isArray(strings)

  // first, perform interpolation
  let result = ''
  for (let i = 0; i < raw.length; i++) {
    let next = raw[i]

    if (next === undefined) {
      continue
    }

    if (escapeSpecialCharacters) {
      // handle escaped newlines, backticks, and interpolation characters
      next = next
        .replace(/\\\n[ \t]*/g, '')
        .replace(/\\`/g, '`')
        .replace(/\\\$/g, '$')
        .replace(/\\\{/g, '{')
    }

    result += next

    if (i < values.length) {
      result += values[i]
    }
  }

  // now strip indentation
  const lines = result.split('\n')
  let mindent = null
  for (const l of lines) {
    const m = l.match(/^(\s+)\S+/)
    if (m && m[1]) {
      const indent = m[1].length
      if (!mindent) {
        // this is the first indented line
        mindent = indent
      } else {
        mindent = Math.min(mindent, indent)
      }
    }
  }

  if (mindent !== null) {
    const m = mindent
    result = lines.map((l) => (l[0] === ' ' || l[0] === '\t' ? l.slice(m) : l)).join('\n')
  }

  // dedent eats leading and trailing whitespace too
  result = result.trim()
  if (escapeSpecialCharacters) {
    // handle escaped newlines at the end to ensure they don't get stripped too
    result = result.replace(/\\n/g, '\n')
  }

  return result
}