class Reline::KeyStroke

def compress_meta_key(ary)
  return ary unless @config.convert_meta
  ary.inject([]) { |result, key|
    if result.size > 0 and result.last == "\e".ord
      result[result.size - 1] = Reline::Key.new(key, key | 0b10000000, true)
    else
      result << key
    end
    result
  }
end

def equal?(me, other)
  case me
  when Array
    compressed_me = compress_meta_key(me)
    compressed_other = compress_meta_key(other)
    compressed_me.size == compressed_other.size and [compressed_me, compressed_other].transpose.all?{ |i| equal?(i[0], i[1]) }
  when Integer
    if other.is_a?(Reline::Key)
      if other.combined_char == "\e".ord
        false
      else
        other.combined_char == me
      end
    else
      me == other
    end
  when Reline::Key
    if other.is_a?(Integer)
      me.combined_char == other
    else
      me == other
    end
  end
end

def expand(input)
  input = compress_meta_key(input)
  lhs = key_mapping.keys.select { |item| start_with?(input, item) }.sort_by(&:size).last
  return input unless lhs
  rhs = key_mapping[lhs]
  case rhs
  when String
    rhs_bytes = rhs.bytes
    expand(expand(rhs_bytes) + expand(input.drop(lhs.size)))
  when Symbol
    [rhs] + expand(input.drop(lhs.size))
  when Array
    rhs
  end
end

def initialize(config)
  @config = config
end

def key_mapping
  @config.key_bindings
end

def match_status(input)
  key_mapping.keys.select { |lhs|
    start_with?(lhs, input)
  }.tap { |it|
    return :matched  if it.size == 1 && equal?(it[0], input)
    return :matching if it.size == 1 && !equal?(it[0], input)
    return :matched  if it.max_by(&:size)&.size&.< input.size
    return :matching if it.size > 1
  }
  key_mapping.keys.select { |lhs|
    start_with?(input, lhs)
  }.tap { |it|
    return it.size > 0 ? :matched : :unmatched
  }
end

def start_with?(me, other)
  compressed_me = compress_meta_key(me)
  compressed_other = compress_meta_key(other)
  i = 0
  loop do
    my_c = compressed_me[i]
    other_c = compressed_other[i]
    other_is_last = (i + 1) == compressed_other.size
    me_is_last = (i + 1) == compressed_me.size
    if my_c != other_c
      if other_c == "\e".ord and other_is_last and my_c.is_a?(Reline::Key) and my_c.with_meta
        return true
      else
        return false
      end
    elsif other_is_last
      return true
    elsif me_is_last
      return false
    end
    i += 1
  end
end