def xml_tag_length(doc, tag_name)
  file = File.open("#{doc}", "r")
  count = 0
  file.each { |l| count += 1 if l.include?("</#{tag_name}>") }
  count
end

def invs_xml_split(path, n)
  doc = File.open(path)

  limit = xml_tag_length("#{path}", "INVOICE")

  count = 0
  new_doc_name = 0
  arr = []

  x = 0
  y = n
  doc.each do |line|
    if line.include?("<INVOICE DBOP=\"INS\" >")
      count += 1
      arr << line
    elsif line.include?("</INVOICE>") && (count == y || count == limit)
      arr << line
      File.open("#{new_doc_name}.XML", "a") do |f|
        arr.each { |element| f.write(element.to_s) }
      end
      arr = []
      lines = File.readlines("#{new_doc_name}.XML")
      File.open("#{new_doc_name}.XML", "a") { |f| f.write("</SALES_INVOICES>") } # if lines[-1].include?("</INVOICE>")
      File.open("#{new_doc_name}.XML", "r+") { |f| f.write("<?xml version=\"1.0\" encoding=\"ISO-8859-9\"?>\n<SALES_INVOICES>\n") } # if lines[0].include?("<INVOICE DBOP=\"INS\" >")
      new_doc_name += 1
      x += n
      y += n
    elsif count >= (x + 1) # || count == 0
      arr << line
    end
  end
  doc.close
end

invs_xml_split("/home/yasin/İndirilenler/Satıs_Faturaları.XML", 5000)