Fetch financial statements from Google Finance

google-finance-fetch

#! /usr/bin/env ruby

require 'bigdecimal'
require 'csv'
require 'net/http'
require 'nokogiri'

class CompanyStats
  attr_reader :name

  def initialize(name)
    @name = name
    @values = {}
  end

  def add_value(key, val)
    @values[key] = val
  end

  def dump
    @values.each_pair do |k, v|
      puts "#{k}: #{v && v.to_s('F')}"
    end
  end

  def value_of(item)
    if v = @values[item]
      v.to_s('F')
    end
  end
end

class Fetcher
  def initialize
    @http = Net::HTTP.new('www.google.com', 443)
    @http.use_ssl = true
  end

  def fetch(name, fstype)
    path = "/finance?q=BVMF%3A#{name}"
    path += "&fstype=#{fstype}" if fstype

    response = @http.get(path)
    unless response.is_a?(Net::HTTPSuccess)
      return [false, response.code]
    end

    [true, response.body]
  end
end

class Parser
  def initialize(html)
    @doc = Nokogiri::HTML(html)
  end

protected
  def str_to_decimal(s)
    s = strip(s)
    s.nil? || s.empty? || s == '-' ? nil : BigDecimal(s.gsub(',', ''))
  end

  def strip(s)
    s.match(/^[\u00a0\s]*(.*?)[\u00a0\s]*$/)[1]
  end
end

class SummaryParser < Parser
  def parse(stats)
    price = @doc.xpath('//span[@class="pr"]')
    stats.add_value('Price', str_to_decimal(price.first.text))

    snap = {}
    @doc.xpath('//div[@class="snap-panel"]//tr').each do |row|
      cols = row.xpath('./td').map { |x| x.text }
      snap[strip(cols[0])] = cols[1]
    end

    stats.add_value('P/E', str_to_decimal(snap['P/E']))
    stats.add_value('Market capitalization', snap_to_decimal(snap['Mkt cap']))
  end

  def valid?
    @doc.xpath('//div[@id="market-data-div"]').size > 0
  end

private
  def multiplier(s)
    { 'M' => 1e6, 'B' => 1e9 }[s]
  end

  def snap_to_decimal(s)
    if m = s.match(/^(.+)([MB])$/)
      str_to_decimal(m[1]) * multiplier(m[2])
    end
  end
end

class FinancialsParser < Parser
  def parse(stats)
    ['inc', 'bal', 'cas'].each do |s|
      table = '//div[@id="%s"]//table[@id="%s"]' % ["#{s}annualdiv", "fs-table"]
      @doc.xpath(table + '/tbody/tr').each do |row|
        cols = row.xpath('./td').map { |x| x.text.strip }
        val = str_to_decimal(cols[1])
        stats.add_value(cols[0], val && val * 1e6)
      end
    end
  end

  def valid?
    @doc.xpath('//div[@id="fs-type-tabs"]').size > 0
  end
end

class TableOutput
  def initialize(io, columns)
    @io = io
    @columns = columns

    @csv = CSV.new(io)
    @csv << [''] + columns
  end

  def add(stats)
    @csv << [stats.name] + @columns.map { |x| stats.value_of(x) }
  end

  def close
    @csv.close
  end
end

if __FILE__ == $0
  output = TableOutput.new(STDOUT, ['Total Revenue', 'P/E', 'Market capitalization'])
  begin
    fetcher = Fetcher.new

    while ARGV.size > 0
      ticker = ARGV.shift
      stats = CompanyStats.new(ticker)

      [[nil, SummaryParser], ['ii', FinancialsParser]].each do |(fstype, klass)|
        success, data = fetcher.fetch(ticker, fstype)
        unless success
          STDERR.puts("HTTP error while fetching #{ticker}: #{data}")
          next
        end

        parser = klass.new(data)
        unless parser.valid?
          STDERR.puts("Invalid data for #{ticker}")
          next
        end

        parser.parse(stats)
      end

      output.add(stats)
    end
  ensure
    output.close
  end
end