class Reline::Unicode

# File lib/reline/unicode.rb, line 98
def self.calculate_width(str, allow_escape_code = false)
  if allow_escape_code
    width = 0
    rest = str.encode(Encoding::UTF_8)
    in_zero_width = false
    rest.scan(WIDTH_SCANNER) do |non_printing_start, non_printing_end, csi, osc, gc|
      case
      when non_printing_start
        in_zero_width = true
      when non_printing_end
        in_zero_width = false
      when csi, osc
      when gc
        unless in_zero_width
          width += get_mbchar_width(gc)
        end
      end
    end
    width
  else
    str.encode(Encoding::UTF_8).grapheme_clusters.inject(0) { |w, gc|
      w + get_mbchar_width(gc)
    }
  end
end

# File lib/reline/unicode.rb, line 387
def self.common_prefix(list, ignore_case: false)
  return '' if list.empty?

  common_prefix_gcs = list.first.grapheme_clusters
  list.each do |item|
    gcs = item.grapheme_clusters
    common_prefix_gcs = common_prefix_gcs.take_while.with_index do |gc, i|
      ignore_case ? gc.casecmp?(gcs[i]) : gc == gcs[i]
    end
  end
  common_prefix_gcs.join
end

# File lib/reline/unicode.rb, line 292
def self.ed_transpose_words(line, byte_pointer)
  gcs = line.byteslice(0, byte_pointer).grapheme_clusters
  pos = gcs.size
  gcs += line.byteslice(byte_pointer..).grapheme_clusters
  pos += 1 while pos < gcs.size && !word_character?(gcs[pos])
  if pos == gcs.size # 'aaa  bbb [cursor] '
    pos -= 1 while pos > 0 && !word_character?(gcs[pos - 1])
    second_word_end = gcs.size
  else # 'aaa  [cursor]bbb'
    pos += 1 while pos < gcs.size && word_character?(gcs[pos])
    second_word_end = pos
  end
  pos -= 1 while pos > 0 && word_character?(gcs[pos - 1])
  second_word_start = pos
  pos -= 1 while pos > 0 && !word_character?(gcs[pos - 1])
  first_word_end = pos
  pos -= 1 while pos > 0 && word_character?(gcs[pos - 1])
  first_word_start = pos

  [first_word_start, first_word_end, second_word_start, second_word_end].map do |idx|
    gcs.take(idx).sum(&:bytesize)
  end
end

# File lib/reline/unicode.rb, line 278
def self.em_backward_word(line, byte_pointer)
  gcs = line.byteslice(0, byte_pointer).grapheme_clusters.reverse
  nonwords = gcs.take_while { |c| !word_character?(c) }
  words = gcs.drop(nonwords.size).take_while { |c| word_character?(c) }
  nonwords.sum(&:bytesize) + words.sum(&:bytesize)
end

# File lib/reline/unicode.rb, line 285
def self.em_big_backward_word(line, byte_pointer)
  gcs = line.byteslice(0, byte_pointer).grapheme_clusters.reverse
  spaces = gcs.take_while { |c| space_character?(c) }
  nonspaces = gcs.drop(spaces.size).take_while { |c| !space_character?(c) }
  spaces.sum(&:bytesize) + nonspaces.sum(&:bytesize)
end

# File lib/reline/unicode.rb, line 264
def self.em_forward_word(line, byte_pointer)
  gcs = line.byteslice(byte_pointer..).grapheme_clusters
  nonwords = gcs.take_while { |c| !word_character?(c) }
  words = gcs.drop(nonwords.size).take_while { |c| word_character?(c) }
  nonwords.sum(&:bytesize) + words.sum(&:bytesize)
end

# File lib/reline/unicode.rb, line 271
def self.em_forward_word_with_capitalization(line, byte_pointer)
  gcs = line.byteslice(byte_pointer..).grapheme_clusters
  nonwords = gcs.take_while { |c| !word_character?(c) }
  words = gcs.drop(nonwords.size).take_while { |c| word_character?(c) }
  [nonwords.sum(&:bytesize) + words.sum(&:bytesize), nonwords.join + words.join.capitalize]
end

# File lib/reline/unicode.rb, line 44
def self.escape_for_print(str)
  str.chars.map! { |gr|
    case gr
    when -"\n"
      gr
    when -"\t"
      -'  '
    else
      EscapedPairs[gr.ord] || gr
    end
  }.join
end

# File lib/reline/unicode.rb, line 75
def self.get_mbchar_width(mbchar)
  ord = mbchar.ord
  if ord <= 0x1F # in EscapedPairs
    return 2
  elsif ord <= 0x7E # printable ASCII chars
    return 1
  end
  utf8_mbchar = mbchar.encode(Encoding::UTF_8)
  ord = utf8_mbchar.ord
  chunk_index = EastAsianWidth::CHUNK_LAST.bsearch_index { |o| ord <= o }
  size = EastAsianWidth::CHUNK_WIDTH[chunk_index]
  if size == -1
    Reline.ambiguous_width
  elsif size == 1 && utf8_mbchar.size >= 2
    second_char_ord = utf8_mbchar[1].ord
    # Halfwidth Dakuten Handakuten
    # Only these two character has Letter Modifier category and can be combined in a single grapheme cluster
    (second_char_ord == 0xFF9E || second_char_ord == 0xFF9F) ? 2 : 1
  else
    size
  end
end

# File lib/reline/unicode.rb, line 250
def self.get_next_mbchar_size(line, byte_pointer)
  grapheme = line.byteslice(byte_pointer..-1).grapheme_clusters.first
  grapheme ? grapheme.bytesize : 0
end

# File lib/reline/unicode.rb, line 255
def self.get_prev_mbchar_size(line, byte_pointer)
  if byte_pointer.zero?
    0
  else
    grapheme = line.byteslice(0..(byte_pointer - 1)).grapheme_clusters.last
    grapheme ? grapheme.bytesize : 0
  end
end

# File lib/reline/unicode.rb, line 57
def self.safe_encode(str, encoding)
  # Reline only supports utf-8 convertible string.
  converted = str.encode(encoding, invalid: :replace, undef: :replace)
  return converted if str.encoding == Encoding::UTF_8 || converted.encoding == Encoding::UTF_8 || converted.ascii_only?

  # This code is essentially doing the same thing as
  # `str.encode(utf8, **replace_options).encode(encoding, **replace_options)`
  # but also avoids unneccesary irreversible encoding conversion.
  converted.gsub(/\X/) do |c|
    c.encode(Encoding::UTF_8)
    c
  rescue Encoding::UndefinedConversionError
    '?'
  end
end

# File lib/reline/unicode.rb, line 412
def self.space_character?(s)
  s.match?(/\s/) if s
end

# File lib/reline/unicode.rb, line 125
def self.split_by_width(str, max_width)
  lines = split_line_by_width(str, max_width)
  [lines, lines.size]
end

# File lib/reline/unicode.rb, line 130
def self.split_line_by_width(str, max_width, encoding = str.encoding, offset: 0)
  lines = [String.new(encoding: encoding)]
  width = offset
  rest = str.encode(Encoding::UTF_8)
  in_zero_width = false
  seq = String.new(encoding: encoding)
  rest.scan(WIDTH_SCANNER) do |non_printing_start, non_printing_end, csi, osc, gc|
    case
    when non_printing_start
      in_zero_width = true
    when non_printing_end
      in_zero_width = false
    when csi
      lines.last << csi
      unless in_zero_width
        if csi == -"\e[m" || csi == -"\e[0m"
          seq.clear
        else
          seq << csi
        end
      end
    when osc
      lines.last << osc
      seq << osc unless in_zero_width
    when gc
      unless in_zero_width
        mbchar_width = get_mbchar_width(gc)
        if (width += mbchar_width) > max_width
          width = mbchar_width
          lines << seq.dup
        end
      end
      lines.last << gc
    end
  end
  # The cursor moves to next line in first
  if width == max_width
    lines << String.new(encoding: encoding)
  end
  lines
end

# File lib/reline/unicode.rb, line 172
def self.strip_non_printing_start_end(prompt)
  prompt.gsub(/\x01([^\x02]*)(?:\x02|\z)/) { $1 }
end

# File lib/reline/unicode.rb, line 181
def self.take_mbchar_range(str, start_col, width, cover_begin: false, cover_end: false, padding: false)
  chunk = String.new(encoding: str.encoding)

  end_col = start_col + width
  total_width = 0
  rest = str.encode(Encoding::UTF_8)
  in_zero_width = false
  chunk_start_col = nil
  chunk_end_col = nil
  has_csi = false
  rest.scan(WIDTH_SCANNER) do |non_printing_start, non_printing_end, csi, osc, gc|
    case
    when non_printing_start
      in_zero_width = true
    when non_printing_end
      in_zero_width = false
    when csi
      has_csi = true
      chunk << csi
    when osc
      chunk << osc
    when gc
      if in_zero_width
        chunk << gc
        next
      end

      mbchar_width = get_mbchar_width(gc)
      prev_width = total_width
      total_width += mbchar_width

      if (cover_begin || padding ? total_width <= start_col : prev_width < start_col)
        # Current character haven't reached start_col yet
        next
      elsif padding && !cover_begin && prev_width < start_col && start_col < total_width
        # Add preceding padding. This padding might have background color.
        chunk << ' '
        chunk_start_col ||= start_col
        chunk_end_col = total_width
        next
      elsif (cover_end ? prev_width < end_col : total_width <= end_col)
        # Current character is in the range
        chunk << gc
        chunk_start_col ||= prev_width
        chunk_end_col = total_width
        break if total_width >= end_col
      else
        # Current character exceeds end_col
        if padding && end_col < total_width
          # Add succeeding padding. This padding might have background color.
          chunk << ' '
          chunk_start_col ||= prev_width
          chunk_end_col = end_col
        end
        break
      end
    end
  end
  chunk_start_col ||= start_col
  chunk_end_col ||= start_col
  if padding && chunk_end_col < end_col
    # Append padding. This padding should not include background color.
    chunk << "\e[0m" if has_csi
    chunk << ' ' * (end_col - chunk_end_col)
    chunk_end_col = end_col
  end
  [chunk, chunk_start_col, chunk_end_col - chunk_start_col]
end

# File lib/reline/unicode.rb, line 177
def self.take_range(str, start_col, max_width)
  take_mbchar_range(str, start_col, max_width).first
end

# File lib/reline/unicode.rb, line 378
def self.vi_backward_word(line, byte_pointer)
  gcs = line.byteslice(0, byte_pointer).grapheme_clusters.reverse
  spaces = gcs.take_while { |c| space_character?(c) }
  gcs.shift(spaces.size)
  start_with_word = word_character?(gcs.first)
  matched = gcs.take_while { |c| start_with_word ? word_character?(c) : !word_character?(c) && !space_character?(c) }
  spaces.sum(&:bytesize) + matched.sum(&:bytesize)
end

# File lib/reline/unicode.rb, line 333
def self.vi_big_backward_word(line, byte_pointer)
  gcs = line.byteslice(0, byte_pointer).grapheme_clusters.reverse
  spaces = gcs.take_while { |c| space_character?(c) }
  nonspaces = gcs.drop(spaces.size).take_while { |c| !space_character?(c) }
  spaces.sum(&:bytesize) + nonspaces.sum(&:bytesize)
end

# File lib/reline/unicode.rb, line 323
def self.vi_big_forward_end_word(line, byte_pointer)
  gcs = line.byteslice(byte_pointer..).grapheme_clusters
  first = gcs.shift(1)
  spaces = gcs.take_while { |c| space_character?(c) }
  nonspaces = gcs.drop(spaces.size).take_while { |c| !space_character?(c) }
  matched = spaces + nonspaces
  matched.pop
  first.sum(&:bytesize) + matched.sum(&:bytesize)
end

# File lib/reline/unicode.rb, line 316
def self.vi_big_forward_word(line, byte_pointer)
  gcs = line.byteslice(byte_pointer..).grapheme_clusters
  nonspaces = gcs.take_while { |c| !space_character?(c) }
  spaces = gcs.drop(nonspaces.size).take_while { |c| space_character?(c) }
  nonspaces.sum(&:bytesize) + spaces.sum(&:bytesize)
end

# File lib/reline/unicode.rb, line 400
def self.vi_first_print(line)
  gcs = line.grapheme_clusters
  spaces = gcs.take_while { |c| space_character?(c) }
  spaces.sum(&:bytesize)
end

# File lib/reline/unicode.rb, line 360
def self.vi_forward_end_word(line, byte_pointer)
  gcs = line.byteslice(byte_pointer..).grapheme_clusters
  return 0 if gcs.empty?
  return gcs.first.bytesize if gcs.size == 1

  start = gcs.shift
  skips = [start]
  if space_character?(start) || space_character?(gcs.first)
    spaces = gcs.take_while { |c| space_character?(c) }
    skips += spaces
    gcs.shift(spaces.size)
  end
  start_with_word = word_character?(gcs.first)
  matched = gcs.take_while { |c| start_with_word ? word_character?(c) : !word_character?(c) && !space_character?(c) }
  matched.pop
  skips.sum(&:bytesize) + matched.sum(&:bytesize)
end

# File lib/reline/unicode.rb, line 340
def self.vi_forward_word(line, byte_pointer, drop_terminate_spaces = false)
  gcs = line.byteslice(byte_pointer..).grapheme_clusters
  return 0 if gcs.empty?

  c = gcs.first
  matched =
    if word_character?(c)
      gcs.take_while { |c| word_character?(c) }
    elsif space_character?(c)
      gcs.take_while { |c| space_character?(c) }
    else
      gcs.take_while { |c| !word_character?(c) && !space_character?(c) }
    end

  return matched.sum(&:bytesize) if drop_terminate_spaces

  spaces = gcs.drop(matched.size).take_while { |c| space_character?(c) }
  matched.sum(&:bytesize) + spaces.sum(&:bytesize)
end

# File lib/reline/unicode.rb, line 406
def self.word_character?(s)
  s.encode(Encoding::UTF_8).match?(/\p{Word}/) if s
rescue Encoding::UndefinedConversionError
  false
end