module Octopress
  module Deploy
    class Git

      def initialize(options={})
        @options     = options
        @repo        = @options[:git_url]
        @branch      = @options[:git_branch]   || 'master'
        @remote      = @options[:remote]       || 'deploy'
        @remote_path = @options[:remote_path]  || ''
        @remote_path = @remote_path.sub(/^\//,'') #remove leading slash
        @site_dir    = File.expand_path(@options[:site_dir])  || '_site'
        @deploy_dir  = File.expand_path(@options[:deploy_dir] || '.deploy')
        @pull_dir    = @options[:dir]
        abort "Deploy Failed: Configure a git_url in #{@options[:config_file]} before deploying.".red if @repo.nil?
      end

      # Initialize, pull, copy and deploy.
      #
      def push
        init_repo
        puts "Syncing #{@site_dir.sub(`pwd`.strip+'/', '')} files to #{@repo}."
        FileUtils.cd @deploy_dir do
          git_pull
          clean_deploy
          copy_site
          git_push
        end
      end

      def pull
        `git clone -b #{@branch} #{@repo} #{@pull_dir}`
      end

      # Check to see if local deployment dir is configured to deploy.
      #
      def check_repo
        if Dir.exist? @deploy_dir
          FileUtils.cd @deploy_dir do
            return `git remote -v`.include? @repo
          end
        end
      end

      def self.default_config(options={})
        config = <<-CONFIG
#{"git_url: #{options[:git_url]}".ljust(40)}  # remote repository url, e.g. git@github.com:username/repo_name

# Note on git_branch:
# If using GitHub project pages, set the branch to 'gh-pages'.
# For GitHub user/organization pages or Heroku, set the branch to 'master'.
#
#{"git_branch: #{options[:git_branch] || 'master'}".ljust(40)}  # Git branch where static site files are commited

CONFIG
        config << "\n# " unless options[:remote_path]
        config << "#{"remote_path: #{options[:remote_path]}".ljust(38)}  # Destination directory"
      end

      # If necessary create deploy directory and initialize it with deployment remote.
      #
      def init_repo
        return if check_repo
        FileUtils.mkdir_p @deploy_dir
        FileUtils.cd @deploy_dir do
          if Dir[@deploy_dir+'/*'].empty?

            # initialize the repository and add the remote.
            #
            `git init; git remote add #{@remote} #{@repo}`

            # Attempt to pull from the remote.
            #
            if git_pull
              `git branch -m #{@branch}`

            # If no branch exists on remote, create one locally.
            else
              `echo "initialize deploy repo" > _`
              `git add .; git commit -m 'initial commit'`
              `git branch -m #{@branch}`
              `git rm _; git add -u; git commit -m 'cleanup'`
            end
          end
        end
      end

      def git_push
        `git push #{@remote} #{@branch}`
      end

      # Attempt to pull from the remote branch
      #
      def git_pull
        if `git branch -a` =~ /remotes\/#{@remote}\/#{@branch}/ ||
           `git ls-remote #{@remote}` =~ /refs\/heads\/#{@branch}/
             `git pull #{@remote} #{@branch}`
        end
      end

      # Remove files in deploy dir, ensuring a 1:1 site files deployment.
      #
      def clean_deploy
        FileUtils.rm_rf(Dir.glob('*'), secure: true)
      end

      # Copy site files into deploy dir.
      #
      def copy_site
        target_dir = File.join(@deploy_dir, @remote_path).sub(/\/$/,'')
        FileUtils.cp_r @site_dir + '/.', target_dir
        message = "Site updated at: #{Time.now.utc}"
        `git add --all :/; git commit -m '#{message}'`
      end
    end
  end
end