class Puma::Client

def above_http_content_limit(value)
  @http_content_length_limit&.< value
end

def call
  @hijacked = true
  env[HIJACK_IO] ||= @io
end

def can_close?
  # Allow connection to close if we're not in the middle of parsing a request.
  @parsed_bytes == 0
end

def close
  begin
    @io.close
  rescue IOError, Errno::EBADF
    Puma::Util.purge_interrupt_queue
  end
end

def closed?
  @to_io.closed?
end

def decode_chunk(chunk)
  if @partial_part_left > 0
    if @partial_part_left <= chunk.size
      if @partial_part_left > 2
        write_chunk(chunk[0..(@partial_part_left-3)]) # skip the \r\n
      end
      chunk = chunk[@partial_part_left..-1]
      @partial_part_left = 0
    else
      if @partial_part_left > 2
        if @partial_part_left == chunk.size + 1
          # Don't include the last \r
          write_chunk(chunk[0..(@partial_part_left-3)])
        else
          # don't include the last \r\n
          write_chunk(chunk)
        end
      end
      @partial_part_left -= chunk.size
      return false
    end
  end
  if @prev_chunk.empty?
    io = StringIO.new(chunk)
  else
    io = StringIO.new(@prev_chunk+chunk)
    @prev_chunk = ""
  end
  while !io.eof?
    line = io.gets
    if line.end_with?(CHUNK_VALID_ENDING)
      # Puma doesn't process chunk extensions, but should parse if they're
      # present, which is the reason for the semicolon regex
      chunk_hex = line.strip[/\A[^;]+/]
      if CHUNK_SIZE_INVALID.match? chunk_hex
        raise HttpParserError, "Invalid chunk size: '#{chunk_hex}'"
      end
      len = chunk_hex.to_i(16)
      if len == 0
        @in_last_chunk = true
        @body.rewind
        rest = io.read
        if rest.bytesize < CHUNK_VALID_ENDING_SIZE
          @buffer = nil
          @partial_part_left = CHUNK_VALID_ENDING_SIZE - rest.bytesize
          return false
        else
          # if the next character is a CRLF, set buffer to everything after that CRLF
          start_of_rest = if rest.start_with?(CHUNK_VALID_ENDING)
            CHUNK_VALID_ENDING_SIZE
          else # we have started a trailer section, which we do not support. skip it!
            rest.index(CHUNK_VALID_ENDING*2) + CHUNK_VALID_ENDING_SIZE*2
          end
          @buffer = rest[start_of_rest..-1]
          @buffer = nil if @buffer.empty?
          set_ready
          return true
        end
      end
      # Track the excess as a function of the size of the
      # header vs the size of the actual data. Excess can
      # go negative (and is expected to) when the body is
      # significant.
      # The additional of chunk_hex.size and 2 compensates
      # for a client sending 1 byte in a chunked body over
      # a long period of time, making sure that that client
      # isn't accidentally eventually punished.
      @excess_cr += (line.size - len - chunk_hex.size - 2)
      if @excess_cr >= MAX_CHUNK_EXCESS
        raise HttpParserError, "Maximum chunk excess detected"
      end
      len += 2
      part = io.read(len)
      unless part
        @partial_part_left = len
        next
      end
      got = part.size
      case
      when got == len
        # proper chunked segment must end with "\r\n"
        if part.end_with? CHUNK_VALID_ENDING
          write_chunk(part[0..-3]) # to skip the ending \r\n
        else
          raise HttpParserError, "Chunk size mismatch"
        end
      when got <= len - 2
        write_chunk(part)
        @partial_part_left = len - part.size
      when got == len - 1 # edge where we get just \r but not \n
        write_chunk(part[0..-2])
        @partial_part_left = len - part.size
      end
    else
      if @prev_chunk.size + chunk.size >= MAX_CHUNK_HEADER_SIZE
        raise HttpParserError, "maximum size of chunk header exceeded"
      end
      @prev_chunk = line
      return false
    end
  end
  if @in_last_chunk
    set_ready
    true
  else
    false
  end
end

def eagerly_finish
  return true if @ready
  return false unless @to_io.wait_readable(0)
  try_to_finish
end

def expect_proxy_proto=(val)
  if val
    if @read_header
      @read_proxy = true
    end
  else
    @read_proxy = false
  end
  @expect_proxy_proto = val
end

def finish(timeout)
  return if @ready
  @to_io.wait_readable(timeout) || timeout! until try_to_finish
end

def in_data_phase
  !(@read_header || @read_proxy)
end

def initialize(io, env=nil)
  @io = io
  @to_io = io.to_io
  @io_buffer = IOBuffer.new
  @proto_env = env
  @env = env&.dup
  @parser = HttpParser.new
  @parsed_bytes = 0
  @read_header = true
  @read_proxy = false
  @ready = false
  @body = nil
  @body_read_start = nil
  @buffer = nil
  @tempfile = nil
  @timeout_at = nil
  @requests_served = 0
  @hijacked = false
  @http_content_length_limit = nil
  @http_content_length_limit_exceeded = false
  @peerip = nil
  @peer_family = nil
  @listener = nil
  @remote_addr_header = nil
  @expect_proxy_proto = false
  @body_remain = 0
  @in_last_chunk = false
  # need unfrozen ASCII-8BIT, +'' is UTF-8
  @read_buffer = String.new # rubocop: disable Performance/UnfreezeString
end

def inspect
  "#<Puma::Client:0x#{object_id.to_s(16)} @ready=#{@ready.inspect}>"
end

def io_ok?
  @to_io.is_a?(::BasicSocket) && !closed?
end

def peer_family
  return @peer_family if @peer_family
  @peer_family ||= begin
                     @io.local_address.afamily
                   rescue
                     Socket::AF_INET
                   end
end

def peerip
  return @peerip if @peerip
  if @remote_addr_header
    hdr = (@env[@remote_addr_header] || @io.peeraddr.last).split(/[\s,]/).first
    @peerip = hdr
    return hdr
  end
  @peerip ||= @io.peeraddr.last
end

def read_body
  if @chunked_body
    return read_chunked_body
  end
  # Read an odd sized chunk so we can read even sized ones
  # after this
  remain = @body_remain
  if remain > CHUNK_SIZE
    want = CHUNK_SIZE
  else
    want = remain
  end
  begin
    chunk = @io.read_nonblock(want, @read_buffer)
  rescue IO::WaitReadable
    return false
  rescue SystemCallError, IOError
    raise ConnectionError, "Connection error detected during read"
  end
  # No chunk means a closed socket
  unless chunk
    @body.close
    @buffer = nil
    set_ready
    raise EOFError
  end
  remain -= @body.write(chunk)
  if remain <= 0
    @body.rewind
    @buffer = nil
    set_ready
    return true
  end
  @body_remain = remain
  false
end

def read_chunked_body
  while true
    begin
      chunk = @io.read_nonblock(4096, @read_buffer)
    rescue IO::WaitReadable
      return false
    rescue SystemCallError, IOError
      raise ConnectionError, "Connection error detected during read"
    end
    # No chunk means a closed socket
    unless chunk
      @body.close
      @buffer = nil
      set_ready
      raise EOFError
    end
    if decode_chunk(chunk)
      @env[CONTENT_LENGTH] = @chunked_content_length.to_s
      return true
    end
  end
end

def reset(fast_check=true)
  @parser.reset
  @io_buffer.reset
  @read_header = true
  @read_proxy = !!@expect_proxy_proto
  @env = @proto_env.dup
  @body = nil
  @tempfile = nil
  @parsed_bytes = 0
  @ready = false
  @body_remain = 0
  @peerip = nil if @remote_addr_header
  @in_last_chunk = false
  @http_content_length_limit_exceeded = false
  if @buffer
    return false unless try_to_parse_proxy_protocol
    @parsed_bytes = @parser.execute(@env, @buffer, @parsed_bytes)
    if @parser.finished?
      return setup_body
    elsif @parsed_bytes >= MAX_HEADER
      raise HttpParserError,
        "HEADER is longer than allowed, aborting client early."
    end
    return false
  else
    begin
      if fast_check && @to_io.wait_readable(FAST_TRACK_KA_TIMEOUT)
        return try_to_finish
      end
    rescue IOError
      # swallow it
    end
  end
end

def set_ready
  if @body_read_start
    @env['puma.request_body_wait'] = Process.clock_gettime(Process::CLOCK_MONOTONIC, :float_millisecond) - @body_read_start
  end
  @requests_served += 1
  @ready = true
end

def set_timeout(val)
  @timeout_at = Process.clock_gettime(Process::CLOCK_MONOTONIC) + val
end

def setup_body
  @body_read_start = Process.clock_gettime(Process::CLOCK_MONOTONIC, :float_millisecond)
  if @env[HTTP_EXPECT] == CONTINUE
    # TODO allow a hook here to check the headers before
    # going forward
    @io << HTTP_11_100
    @io.flush
  end
  @read_header = false
  body = @parser.body
  te = @env[TRANSFER_ENCODING2]
  if te
    te_lwr = te.downcase
    if te.include? ','
      te_ary = te_lwr.split ','
      te_count = te_ary.count CHUNKED
      te_valid = te_ary[0..-2].all? { |e| ALLOWED_TRANSFER_ENCODING.include? e }
      if te_ary.last == CHUNKED && te_count == 1 && te_valid
        @env.delete TRANSFER_ENCODING2
        return setup_chunked_body body
      elsif te_count >= 1
        raise HttpParserError   , "#{TE_ERR_MSG}, multiple chunked: '#{te}'"
      elsif !te_valid
        raise HttpParserError501, "#{TE_ERR_MSG}, unknown value: '#{te}'"
      end
    elsif te_lwr == CHUNKED
      @env.delete TRANSFER_ENCODING2
      return setup_chunked_body body
    elsif ALLOWED_TRANSFER_ENCODING.include? te_lwr
      raise HttpParserError     , "#{TE_ERR_MSG}, single value must be chunked: '#{te}'"
    else
      raise HttpParserError501  , "#{TE_ERR_MSG}, unknown value: '#{te}'"
    end
  end
  @chunked_body = false
  cl = @env[CONTENT_LENGTH]
  if cl
    # cannot contain characters that are not \d, or be empty
    if CONTENT_LENGTH_VALUE_INVALID.match?(cl) || cl.empty?
      raise HttpParserError, "Invalid Content-Length: #{cl.inspect}"
    end
  else
    @buffer = body.empty? ? nil : body
    @body = EmptyBody
    set_ready
    return true
  end
  remain = cl.to_i - body.bytesize
  if remain <= 0
    @body = StringIO.new(body)
    @buffer = nil
    set_ready
    return true
  end
  if remain > MAX_BODY
    @body = Tempfile.new(Const::PUMA_TMP_BASE)
    @body.unlink
    @body.binmode
    @tempfile = @body
  else
    # The body[0,0] trick is to get an empty string in the same
    # encoding as body.
    @body = StringIO.new body[0,0]
  end
  @body.write body
  @body_remain = remain
  false
end

def setup_chunked_body(body)
  @chunked_body = true
  @partial_part_left = 0
  @prev_chunk = ""
  @excess_cr = 0
  @body = Tempfile.new(Const::PUMA_TMP_BASE)
  @body.unlink
  @body.binmode
  @tempfile = @body
  @chunked_content_length = 0
  if decode_chunk(body)
    @env[CONTENT_LENGTH] = @chunked_content_length.to_s
    return true
  end
end

def timeout
  [@timeout_at - Process.clock_gettime(Process::CLOCK_MONOTONIC), 0].max
end

def timeout!
  write_error(408) if in_data_phase
  raise ConnectionError
end

def try_to_finish
  if env[CONTENT_LENGTH] && above_http_content_limit(env[CONTENT_LENGTH].to_i)
    @http_content_length_limit_exceeded = true
  end
  if @http_content_length_limit_exceeded
    @buffer = nil
    @body = EmptyBody
    set_ready
    return true
  end
  return read_body if in_data_phase
  begin
    data = @io.read_nonblock(CHUNK_SIZE)
  rescue IO::WaitReadable
    return false
  rescue EOFError
    # Swallow error, don't log
  rescue SystemCallError, IOError
    raise ConnectionError, "Connection error detected during read"
  end
  # No data means a closed socket
  unless data
    @buffer = nil
    set_ready
    raise EOFError
  end
  if @buffer
    @buffer << data
  else
    @buffer = data
  end
  return false unless try_to_parse_proxy_protocol
  @parsed_bytes = @parser.execute(@env, @buffer, @parsed_bytes)
  if @parser.finished? && above_http_content_limit(@parser.body.bytesize)
    @http_content_length_limit_exceeded = true
  end
  if @parser.finished?
    return setup_body
  elsif @parsed_bytes >= MAX_HEADER
    raise HttpParserError,
      "HEADER is longer than allowed, aborting client early."
  end
  false
end

def try_to_parse_proxy_protocol
  if @read_proxy
    if @expect_proxy_proto == :v1
      if @buffer.include? "\r\n"
        if md = PROXY_PROTOCOL_V1_REGEX.match(@buffer)
          if md[1]
            @peerip = md[1].split(" ")[0]
          end
          @buffer = md.post_match
        end
        # if the buffer has a \r\n but doesn't have a PROXY protocol
        # request, this is just HTTP from a non-PROXY client; move on
        @read_proxy = false
        return @buffer.size > 0
      else
        return false
      end
    end
  end
  true
end

def write_chunk(str)
  @chunked_content_length += @body.write(str)
end

def write_error(status_code)
  begin
    @io << ERROR_RESPONSE[status_code]
  rescue StandardError
  end
end