class Reline::ANSI

# File reline/ansi.rb, line 180
def self.clear_screen
  @@output.write "\e[2J"
  @@output.write "\e[1;1H"
end

# File reline/ansi.rb, line 116
def self.cursor_pos
  begin
    res = ''
    m = nil
    @@input.raw do |stdin|
      @@output << "\e[6n"
      @@output.flush
      loop do
        c = stdin.getc
        next if c.nil?
        res << c
        m = res.match(/\e\[(?<row>\d+);(?<column>\d+)R/)
        break if m
      end
      (m.pre_match + m.post_match).chars.reverse_each do |ch|
        stdin.ungetc ch
      end
    end
    column = m[:column].to_i - 1
    row = m[:row].to_i - 1
  rescue Errno::ENOTTY
    begin
      buf = @@output.pread(@@output.pos, 0)
      row = buf.count("\n")
      column = buf.rindex("\n") ? (buf.size - buf.rindex("\n")) - 1 : 0
    rescue Errno::ESPIPE
      # Just returns column 1 for ambiguous width because this I/O is not
      # tty and can't seek.
      row = 0
      column = 1
    end
  end
  Reline::CursorPos.new(column, row)
end

# File reline/ansi.rb, line 197
def self.deprep(otio)
  int_handle = Signal.trap('INT', 'IGNORE')
  Signal.trap('INT', int_handle)
  Signal.trap('WINCH', @@old_winch_handler) if @@old_winch_handler
end

# File reline/ansi.rb, line 4
def self.encoding
  Encoding.default_external
end

# File reline/ansi.rb, line 171
def self.erase_after_cursor
  @@output.write "\e[K"
end

# File reline/ansi.rb, line 99
def self.get_screen_size
  s = @@input.winsize
  return s if s[0] > 0 && s[1] > 0
  s = [ENV["LINES"].to_i, ENV["COLUMNS"].to_i]
  return s if s[0] > 0 && s[1] > 0
  [24, 80]
rescue Errno::ENOTTY
  [24, 80]
end

# File reline/ansi.rb, line 70
def self.getc
  unless @@buf.empty?
    return @@buf.shift
  end
  until c = @@input.raw(intr: true, &:getbyte)
    sleep 0.1
  end
  (c == 0x16 && @@input.raw(min: 0, tim: 0, &:getbyte)) || c
rescue Errno::EIO
  # Maybe the I/O has been closed.
  nil
end

# File reline/ansi.rb, line 60
def self.input=(val)
  @@input = val
end

# File reline/ansi.rb, line 151
def self.move_cursor_column(x)
  @@output.write "\e[#{x + 1}G"
end

# File reline/ansi.rb, line 163
def self.move_cursor_down(x)
  if x > 0
    @@output.write "\e[#{x}B" if x > 0
  elsif x < 0
    move_cursor_up(-x)
  end
end

# File reline/ansi.rb, line 155
def self.move_cursor_up(x)
  if x > 0
    @@output.write "\e[#{x}A" if x > 0
  elsif x < 0
    move_cursor_down(-x)
  end
end

# File reline/ansi.rb, line 65
def self.output=(val)
  @@output = val
end

# File reline/ansi.rb, line 190
def self.prep
  retrieve_keybuffer
  int_handle = Signal.trap('INT', 'IGNORE')
  Signal.trap('INT', int_handle)
  nil
end

# File reline/ansi.rb, line 87
def self.retrieve_keybuffer
  begin
    result = select([@@input], [], [], 0.001)
    return if result.nil?
    str = @@input.read_nonblock(1024)
    str.bytes.each do |c|
      @@buf.push(c)
    end
  rescue EOFError
  end
end

# File reline/ansi.rb, line 175
def self.scroll_down(x)
  return if x.zero?
  @@output.write "\e[#{x}S"
end

# File reline/ansi.rb, line 109
def self.set_screen_size(rows, columns)
  @@input.winsize = [rows, columns]
  self
rescue Errno::ENOTTY
  self
end

# File reline/ansi.rb, line 186
def self.set_winch_handler(&handler)
  @@old_winch_handler = Signal.trap('WINCH', &handler)
end

# File reline/ansi.rb, line 83
def self.ungetc(c)
  @@buf.unshift(c)
end

# File reline/ansi.rb, line 8
def self.win?
  false
end