#!/usr/bin/env ruby
require 'rubygems'
gem 'instrumental_agent'
require 'instrumental_agent'

token = ENV["INSTRUMENTAL_TOKEN"] || ARGV[0]

if !token 
  puts 'Usage: gitstrumental API_TOKEN'
  exit 1
end

lines = `git log --format="REC %at %h '%cn'" --numstat`.chomp.split(/\n+/).reject(&:empty?)
branch = File.basename(`git symbolic-ref HEAD`.chomp).gsub(/[^a-z0-9]/i, "_")
if fetch_url = `git remote show origin`.chomp.split(/\n+/).grep(/Fetch URL:/).first
  repo = File.basename(fetch_url.split("/").last, ".git")
else
  repo = File.basename(Dir.pwd, ".git")
end
prolog = [repo, branch].join(".")
I = Instrumental::Agent.new(token)
curstat = {}
lines.each do |line|
  if line =~ /^REC/
    if !curstat.empty?
      name, ts, changes = curstat[:name], curstat[:timestamp], curstat[:changes]
      I.increment("git.#{prolog}.commits.#{name}", 1, ts)

      adds, deletes = changes.reduce do |prev, pair|
        [prev[0] + pair[0], prev[1] + pair[1]]
      end
      I.increment("git.#{prolog}.commits.#{name}.add", adds, ts)
      I.increment("git.#{prolog}.commits.#{name}.delete", deletes, ts)
      I.increment("git.#{prolog}.num_commits", 1, ts)
    end
    rec, ts, hash, *name_parts = line.split(" ")
    name = name_parts.join(" ").gsub(/^'([^']+)'$/, "\\1").gsub(/[^a-z0-9]/i, "_")
    curstat = {
      :name => name,
      :timestamp => ts.to_i,
      :hash => hash,
      :changes => []
    }
  else
    adds, deletes, file = line.split(/\s+/)
    curstat[:changes] << [
      adds.to_i, deletes.to_i
    ]
  end
end