class Async::HTTP::Body::File

def self.open(path, *args)
	self.new(::File.open(path, MODE), *args)
end

def close(error = nil)
	@file.close
	@remaining = 0
	
	super
end

def empty?
	@remaining == 0
end

def initialize(file, range = nil, block_size: BLOCK_SIZE)
	@file = file
	
	@block_size = block_size
	
	if range
		@file.seek(range.min)
		@offset = range.min
		@length = @remaining = range.size
	else
		@offset = 0
		@length = @remaining = @file.size
	end
end

def inspect
	"\#<#{self.class} file=#{@file.inspect} offset=#{@offset} remaining=#{@remaining}>"
end

def join
	return "" if @remaining == 0
	
	buffer = @file.read(@remaining)
	
	@remaining = 0
	
	return buffer
end

def read
	if @remaining > 0
		amount = [@remaining, @block_size].min
		
		if chunk = @file.read(amount)
			@remaining -= chunk.bytesize
			
			return chunk
		end
	end
end

def rewind
	@file.seek(@offset)
end