staff_hours.rb

# Entries
# [
#   {
#     "id": 171009,
#     "worker_id": 10,
#     "record": "some work",
#     "worked_at": "2013-09-02",
#     "hours": 6,
#     "client_id": 11,
#     "project_id": 30,
#     "billable_status": "billable"
#   }
# ]
#
# Staff Hours
# {
#   "total": 9999,
#   "by_month": [
#     ["2016-04-15", 99]
#   ]
# }

require 'json'
require 'date'
require 'net/http'

module Config
  API_TOKEN = 'SOME_TOKEN'
  ENTRIES_URL = "http://brium.me/api/entries?access_token=#{API_TOKEN}"
  BEFORE_BRIUM_FILENAME = 'staff_hours_before_brium.json'
  STAFF_HOURS_FILENAME = 'staff_hours.json'
end

def update_staff_hours(entries_str)
  hours_before_brium = parse_json_file(Config::BEFORE_BRIUM_FILENAME) # Staff format
  hours_before_brium = keys_to_symbol(hours_before_brium)

  entries = JSON.parse(entries_str)
  hours_after_brium = process_entries(entries)

  staff_hours = merge_periods(hours_before_brium, hours_after_brium)
  staff_hours_json = staff_hours.to_json

  update_staff_hours_file(staff_hours_json)
end

def keys_to_symbol(h)
  h.inject({}) do |accum, (key, value)|
    accum[key.to_sym] = value
    accum
  end
end

def update_staff_hours_file(staff_hours_json)
  File.open(Config::STAFF_HOURS_FILENAME, 'w') do |f|
    f.truncate(0)
    f.write(staff_hours_json)
  end
end

def merge_periods(left, right)
  {
    total: left[:total] + right[:total],
    by_month: left[:by_month] + right[:by_month]
  }
end

def process_entries(entries)
  by_month = Hash.new 0
  total_hours = 0
  entries.each do |entry|
    hours = entry["hours"] 
    total_hours += hours
    date = Date.parse entry["worked_at"]
    date_key = "#{date.year}-#{date.month}-01"
    by_month[date_key.to_sym] += hours
  end

  by_month = by_month.to_a
  by_month = by_month.map do |value|
    date, hours = value
    [date, hours.to_i]
  end

  {total: total_hours, by_month: by_month}
end

def parse_json_file(filename)
  if !File.exist?(filename)
    raise "#{filename} doesn't exist."
  end

  file = File.open(filename, 'r')
  hash = JSON.parse file.read
  file.close
  hash
end


uri = URI.parse(Config::ENTRIES_URL)
response = Net::HTTP.get_response(uri)
if response.is_a? Net::HTTPSuccess
  update_staff_hours(response.body)
else
  puts "Request failed with a #{response.code}:\n #{response.body}"
end