central_back_xls_test.rb

require 'open-uri'
require 'simple-spreadsheet'
require 'thread'
require 'fileutils'

require 'byebug'

DATA_URI = URI('https://www.bancentral.gov.do/tasas_cambio/TASA_DOLAR_REFERENCIA_MC.XLS')

# yields file
def get_data(url, &block)
	mutex       = Mutex.new
	file_length = 0

	opts = {}

	# This lambda gets called once. The argument is the
	# length of the file as per the HTTP header sent by
	# the server.
	opts[:content_length_proc] = lambda do|len|
			file_length = len
			mutex.lock
	end

	# This lambda could be called multiple times. Each time,
	# it passes the actual number of bytes downloaded.
	opts[:progress_proc] = lambda do|delta|
			mutex.unlock if delta >= file_length
	end

	open(url, opts) do|file|

		# Attempts to grab the lock and waits if it isn't available
		# We want to wait if the file isn't fully downloaded.
		mutex.lock

		block.call(file)
	end
end

hsh = nil

get_data(DATA_URI) do|file|
	path = "#{file.path}.xls"

	FileUtils.mv(file.path, path)

	xls  = SimpleSpreadsheet::Workbook.read(path)

	xls.selected_sheet = xls.sheets.first

	row  = xls.last_row

	hsh = {
		buying_rate:  xls.cell(row, 4),
		selling_rate: xls.cell(row, 5)
	}
end

p hsh