# typed: false

#--
# Copyright (c) 2007-2012 Nick Sieger.
# See the file README.txt included with the distribution for
# software license details.
#++

# Concatenate together multiple IO objects into a single, composite IO object
# for purposes of reading as a single stream.
#
# @example
#     crio = CompositeReadIO.new(StringIO.new('one'),
#                                StringIO.new('two'),
#                                StringIO.new('three'))
#     puts crio.read # => "onetwothree"
module Datadog
  module Core
    module Vendor
      module Multipart
        module Post
          class CompositeReadIO
            # Create a new composite-read IO from the arguments, all of which should
            # respond to #read in a manner consistent with IO.
            def initialize(*ios)
              @ios = ios.flatten
              @index = 0
            end

            # Read from IOs in order until `length` bytes have been received.
            def read(length = nil, outbuf = nil)
              got_result = false
              outbuf = outbuf ? outbuf.replace("") : ""

              while io = current_io
                if result = io.read(length)
                  got_result ||= !result.nil?
                  result.force_encoding("BINARY") if result.respond_to?(:force_encoding)
                  outbuf << result
                  length -= result.length if length
                  break if length == 0
                end
                advance_io
              end
              (!got_result && length) ? nil : outbuf
            end

            def rewind
              @ios.each { |io| io.rewind }
              @index = 0
            end

            private

            def current_io
              @ios[@index]
            end

            def advance_io
              @index += 1
            end
          end

          # Convenience methods for dealing with files and IO that are to be uploaded.
          class UploadIO
            attr_reader :content_type, :original_filename, :local_path, :io, :opts

            # Create an upload IO suitable for including in the params hash of a
            # Net::HTTP::Post::Multipart.
            #
            # Can take two forms. The first accepts a filename and content type, and
            # opens the file for reading (to be closed by finalizer).
            #
            # The second accepts an already-open IO, but also requires a third argument,
            # the filename from which it was opened (particularly useful/recommended if
            # uploading directly from a form in a framework, which often save the file to
            # an arbitrarily named RackMultipart file in /tmp).
            #
            # @example
            #     UploadIO.new("file.txt", "text/plain")
            #     UploadIO.new(file_io, "text/plain", "file.txt")
            def initialize(filename_or_io, content_type, filename = nil, opts = {})
              io = filename_or_io
              local_path = ""
              if io.respond_to? :read
                # in Ruby 1.9.2, StringIOs no longer respond to path
                # (since they respond to :length, so we don't need their local path, see parts.rb:41)
                local_path = filename_or_io.respond_to?(:path) ? filename_or_io.path : "local.path"
              else
                io = File.open(filename_or_io)
                local_path = filename_or_io
              end
              filename ||= local_path

              @content_type = content_type
              @original_filename = File.basename(filename)
              @local_path = local_path
              @io = io
              @opts = opts
            end

            def self.convert!(io, content_type, original_filename, local_path)
              raise ArgumentError, "convert! has been removed. You must now wrap IOs " \
                "using:\nUploadIO.new(filename_or_io, content_type, " \
                "filename=nil)\nPlease update your code."
            end

            def method_missing(*args)
              @io.send(*args)
            end

            def respond_to?(meth, include_all = false)
              @io.respond_to?(meth, include_all) || super(meth, include_all)
            end
          end
        end
      end
    end
  end
end