#--
# (c) Copyright 2007-2011 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.
#
# Usage:
#
#     crio = CompositeReadIO.new(StringIO.new('one'), StringIO.new('two'), StringIO.new('three'))
#     puts crio.read # => "onetwothree"
#  
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
  end

  # Read from the IO object, overlapping across underlying streams as necessary.
  def read(amount = nil, buf = nil)
    buffer = buf || ''
    done = if amount; nil; else ''; end
    partial_amount = amount

    loop do
      result = done

      while !@ios.empty? && (result = @ios.first.read(partial_amount)) == done
        @ios.shift
      end

      result.force_encoding("BINARY") if result.respond_to?(:force_encoding)
      buffer << result if result
      partial_amount -= result.length if partial_amount && result != done

      break if partial_amount && partial_amount <= 0
      break if result == done
    end

    if buffer.length > 0
      buffer
    else
      done
    end
  end
end

# Convenience methods for dealing with files and IO that are to be uploaded.
class UploadIO
  # 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.
  #
  #     UploadIO.new("file.txt", "text/plain")
  #     UploadIO.new(file_io, "text/plain", "file.txt")
  attr_reader :content_type, :original_filename, :local_path, :io

  def initialize(filename_or_io, content_type, filename = nil)
    io = filename_or_io
    local_path = ""
    if io.respond_to? :read
      local_path = filename_or_io.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
  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)
    @io.respond_to?(meth) || super(meth)
  end
end