'use strict'

var trim = require('trim')
var repeat = require('repeat-string')
var getIndent = require('./get-indentation')

module.exports = indentation

var tab = '\t'
var lineFeed = '\n'
var space = ' '
var exclamationMark = '!'

// Remove the minimum indent from every line in `value`.  Supports both tab,
// spaced, and mixed indentation (as well as possible).
function indentation(value, maximum) {
  var values = value.split(lineFeed)
  var position = values.length + 1
  var minIndent = Infinity
  var matrix = []
  var index
  var indentation
  var stops
  var padding

  values.unshift(repeat(space, maximum) + exclamationMark)

  while (position--) {
    indentation = getIndent(values[position])

    matrix[position] = indentation.stops

    if (trim(values[position]).length === 0) {
      continue
    }

    if (indentation.indent) {
      if (indentation.indent > 0 && indentation.indent < minIndent) {
        minIndent = indentation.indent
      }
    } else {
      minIndent = Infinity

      break
    }
  }

  if (minIndent !== Infinity) {
    position = values.length

    while (position--) {
      stops = matrix[position]
      index = minIndent

      while (index && !(index in stops)) {
        index--
      }

      if (
        trim(values[position]).length !== 0 &&
        minIndent &&
        index !== minIndent
      ) {
        padding = tab
      } else {
        padding = ''
      }

      values[position] =
        padding + values[position].slice(index in stops ? stops[index] + 1 : 0)
    }
  }

  values.shift()

  return values.join(lineFeed)
}