class Precompile2git

# File lib/precompile2git.rb, line 10
def initialize
  @project_dir = Dir.getwd

  @logger = Logger.new(STDOUT)

  config = YAML.load_file(@project_dir + "/config/precompile2git.yml")
  config["precompile2git"].each { |key, value| instance_variable_set("@#{key}", value) }

  git_opts = @log_git ? { :log => @logger } : {}

  @g = Git.open(@project_dir , git_opts)

  @g.config('user.name', @user_name) if @user_name
  @g.config('user.email', @user_email) if @user_email
end

# File lib/precompile2git.rb, line 28
def commit_and_push
  begin
    @g.add('.')
    @g.commit_all("Assets precompilation")
  rescue Git::GitExecuteError => e
    @logger.error("Could not commit. This can occur if there was nothing to commit. Git error: " +  e.inspect)
  end

  begin
    @g.push("origin", @compiled_branch)
  rescue Git::GitExecuteError => e
    @logger.error("Could not push changes. Git error: " + e.inspect)
  end

  
end

# File lib/precompile2git.rb, line 64
def precompile
  begin
    if @precompilation_process_pid

      @logger.info("A precompilation has been launched before. Killing any rake task that may be still running...")

      begin
        pids = Process.descendant_processes(@precompilation_process_pid)

        pids.each do |pid|
          @logger.info("Killing pid:" + pid.to_s)
          Process.kill(9, pid)
        end
      rescue Exception => e
        @logger.info("Something went wrong when killing running processes: " + e.to_s)
      end
    end


    @precompilation_process_pid = fork do
      @logger.info("Precompiler: Starting assets precompilation...")

      system('bundle install > ' + @commands_log_file + '; RAILS_ENV=' + @rails_env + ' rake assets:precompile  > ' + @commands_log_file + ';')

      @logger.info("Precompiler: Precompilation done. Committing and pushing")

      commit_and_push

      @logger.info("Precompiler: Pushed to main branch. Ready to deploy!")

      @precompilation_process_pid = nil
    end

  rescue Exception => e
    @logger.info "Something went wrong in precompilation process: " + e.to_s
  end
end

# File lib/precompile2git.rb, line 47
def start
  @logger.info("Syncing repo.")

  sync_and_merge

  @logger.info("Syncing done, running first precompilation.")

  precompile

  @logger.info("Precompilation process started, start watching.")

  @watch_thread = watch_repo(5)
  @watch_thread.join
end

# File lib/precompile2git.rb, line 122
def sync_and_merge
  sync_with_origin(@uncompiled_branch)
  sync_with_origin(@compiled_branch)
  
  @g.merge(@uncompiled_branch, nil)
end

# File lib/precompile2git.rb, line 104
def sync_with_origin( branch_name )
  locals = @g.branches.local.map{ |b| b.to_s }
  
  @g.reset_hard

  if locals.include?(branch_name)
    @g.checkout(branch_name)
  else
    @g.checkout("origin/" + branch_name, { :new_branch => branch_name } )
  end
  
  @g.reset_hard("origin/" + branch_name)
  @g.pull("origin", branch_name)
end

# File lib/precompile2git.rb, line 131
def up_to_date?
  begin
    @g.fetch

    # log should be empty if no updates
    log = @g.log.between(@uncompiled_branch, "origin/" + @uncompiled_branch)

    return log.size == 0

  rescue Exception => e
    @logger.error("Could not check repository state. ")
    return true
  end
end

# File lib/precompile2git.rb, line 149
def watch_repo(interval)
  Thread.new do
    loop do
      start_time = Time.now

      begin
        up_to_date = up_to_date?
        
        unless up_to_date 
          @logger.info("New commits found, precompiling.")
        
          sync_and_merge

          precompile
        end

      rescue Git::GitExecuteError => e
        @logger.error("Something went wrong with Git : " + e.to_s)
      end

      elapsed = Time.now - start_time
      sleep( [ interval - elapsed, 0].max )
    end
  end
end