# Copyright, 2017, by Samuel G. D. Williams. <http://www.codeotaku.com>
# 
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

require 'async/http/server'

module Falcon
	class Input
		def initialize(body)
			@body = body
			@chunks = []
			
			@index = 0
			@buffer = Async::IO::BinaryString.new
			@finished = false
		end
		
		def each(&block)
			return to_enum unless block_given?
			
			while chunk = read_next
				yield chunk
			end
			
			@closed = true
		end
		
		def rewind
			@index = 0
			@finished = false
			@buffer.clear
		end
		
		def read(length = nil, buffer = nil)
			if length
				fill_buffer(length) if @buffer.bytesize <= length
				
				return @buffer.slice!(0, length)
			else
				buffer ||= Async::IO::BinaryString.new
				
				buffer << @buffer
				@buffer.clear
				
				while chunk = read_next
					buffer << chunk
				end
				
				return buffer
			end
		end
		
		def eof?
			@finished and @buffer.empty?
		end
		
		def gets
			read
		end
		
		def close
			@body.finish
		end
		
		private
		
		def read_next
			return nil if @finished
			
			chunk = nil
			
			if @index < @chunks.count
				chunk = @chunks[@index]
				@index += 1
			else
				if chunk = @body.read
					@chunks << chunk
					@index += 1
				end
			end
			
			@finished = true if chunk.nil?
			
			return chunk
		end
		
		def fill_buffer(length)
			while @buffer.bytesize < length and chunk = read_next
				@buffer << chunk
			end
		end
	end
end