#!/usr/bin/env ruby
#
# An example hook script for the post-receive event
#
# This script is run after receive-pack has accepted a pack and the
# repository has been updated.  It is passed arguments in through stdin
# in the form
#  <oldrev> <newrev> <refname>
# For example:
#  aa453216d1b3e49e7f6f98441fa56946ddcd6a20 68f7abf4e6f922807889f52bc043ecd31b79f814 refs/heads/master

# This class is based on git contrib script post-receive-email

BREAKOUT_ROOT = ENV["BREAKOUT_ROOT"] || "/u/apps/breakout/current"

$:.unshift(BREAKOUT_ROOT + '/lib')

require "rubygems"
require "activesupport"

require File.join(BREAKOUT_ROOT, "config", "environments", "user_environment")

require "inifile"
require "changesets_client"

class GitPostReceiveHook
  attr_accessor :old_rev, :new_rev, :ref, :debug
  cattr_accessor :secret, :spaces_tool_id

  # Limit commits count in push
  LIMIT_COUNT = 100
  NULL_COMMIT_RE = /^0{40}$/

  def initialize(old_rev, new_rev, ref)
    self.old_rev = old_rev
    self.new_rev = new_rev
    self.ref = ref
    self.debug = false
  end 

  def go
    put_line '/'

    @change_type = if @old_rev =~ NULL_COMMIT_RE
                     :create
                   elsif @new_rev =~ NULL_COMMIT_RE
                     :delete
                   else
                     :update
                   end

    old_rev_type = new_rev_type = ""

    old_rev_type = `git cat-file -t #{@old_rev}`.chomp if @change_type != :create
    new_rev_type = `git cat-file -t #{@new_rev}`.chomp if @change_type != :delete

    if @debug
      put_line
      p @ref, @old_rev, @new_rev, @change_type, new_rev_type, old_rev_type
    end

    rev, rev_type = if @change_type == :create || @chage_type == :update
                      [@new_rev, new_rev_type]
                    else 
                      [@old_rev, old_rev_type]
                    end
    
    if @ref =~ /^refs\/heads\/(.+)$/
      @branch = $1

      if @change_type == :create 
        if old_rev_type == "" # New branch
          put_line '+'
          commits = load_commits @new_rev
          send_logs commits 
        elsif new_rev_type == "" # branch delete
          put_line '-'
        end
      elsif @change_type == :update
        commits = load_commits "#{@old_rev}..#{@new_rev}"
        send_logs commits
      end
    else
      raise "Not Implemented! TODO"
    end
  end

  def send_logs(logs)
    parsed_logs = parse_pretty_logs(logs)

    parsed_logs.each do |hash|
      params = {
        "tool_id" => 2, "spaces_tool_id" => @@spaces_tool_id, "secret_key" => @@secret,
        "username" => hash[:email], "comment" => hash[:comment], "external_id" => hash[:commit]
      }

      p params if debug

      begin
        ChangesetsClient.post(params)
      rescue Timeout::Error => e
        # Maybe we will serialize to disk and try later ?
      rescue => e1
        p e1
      end
    end
  end

  def load_commits(treeish)
    run "git rev-parse --not --branches | grep -v $(git rev-parse #{@branch}) | git rev-list --max-count=#{LIMIT_COUNT} --reverse --pretty --stdin #{treeish}"
  end

  def parse_pretty_logs(logs)
    rez = []
    commit = {}
    
    logs.each_line do |line|
      if line =~ /^commit ([0-9a-f]+)/i
        if commit.size > 0
          rez << commit
          commit = {}
        end

        commit[:commit] = $1
      elsif line =~ /^Author: (.+)$/i
        name, email = $1.split '<'
        email.tr! '>', ''
        commit[:name] = name.strip
        commit[:email] = email.strip
      elsif line =~ /^Date: (.+)$/i
        commit[:date] = $1.strip
      elsif line =~ /^\s{4}/
        commit[:comment] ||= ""
        commit[:comment] << line.strip << "\n"
      end
    end

    # push last commit
    rez << commit if commit.size > 0

    rez
  end

  def run(cmd)
    puts "$ #{cmd}" if @debug
    `#{cmd}`
  end

  def put_line(char = '*')
    puts char * 80 if @debug
  end
end

if __FILE__ == $0
  config = IniFile.new("breakout.ini")

  GitPostReceiveHook.secret = config["breakout"]["secretKey"]
  GitPostReceiveHook.spaces_tool_id = config["breakout"]["space_tool_id"]

  loop do
    line = $stdin.read
    break if !line || line.length == 0
    line.chomp

    old_rev, new_rev, ref = line.split(/ /, 3)

    gpr = GitPostReceiveHook.new(old_rev.chomp, new_rev.chomp, ref.chomp)
    gpr.debug = true if config['git'] && config['git']['debug'] 
    gpr.go
  end
end