require 'vclog/adapters/abstract'

module VCLog

  module Adapters

    # SVN Adapter.
    #
    # NOTE: Unfortunately the SVN adapater is very slow. If hits the server
    # every time the 'svn log' command is issued. When generating a History
    # that's two hits for every tag. If anyone knows a better way please have
    # at it --maybe future versions of SVN will improve the situation.
    #
    class Svn < Abstract

      def initialize(root)
        begin
          require 'xmlsimple'
        rescue LoadError
          raise LoadError, "VCLog requires xml-simple for SVN support."
        end
        super(root)
      end

      # Extract changes.
      def extract_changes
        log = []

        xml = `svn log -v --xml`.strip

        commits = XmlSimple.xml_in(xml, {'KeyAttr' => 'rev'})
        commits = commits['logentry']

        commits.each do |com|
          rev  = com['revision']
          msg  = [com['msg']].flatten.compact.join('').strip
          who  = [com['author']].flatten.compact.join('').strip
          date = [com['date']].flatten.compact.join('').strip

          files = com['paths'].map{ |h| h['path'].map{ |y| y['content'] } }.flatten

          next if msg.empty?
          next if msg == "*** empty log message ***"

          date = Time.parse(date)

          log << Change.new(:id=>rev, :date=>date, :who=>who, :msg=>msg, :files=>files)
        end

        log
      end

      # Extract tags.
      def extract_tags
        list = []
        tagdir = tag_directory

        if tagdir
          tags = Dir.entries(tagdir).select{ |e| e.index('.') != 0 && e =~ /\d(.*)$/ }
        else
          tags = []
        end

        tags.each do |path|
          dir = File.join(tagdir, path)

          # using yaml, but maybe use xml instead?
          info = `svn info #{dir}`
          info = YAML.load(info)
          md = /(\d.*)$/.match(info['Path'])
          name = md ? md[1] : path
          date = info['Last Changed Date']
          who  = info['Last Changed Author']
          rev  = info['Revision']

          # get last commit
          xml = `svn log -l1 --xml #{dir}`
          commits = XmlSimple.xml_in(xml, {'KeyAttr' => 'rev'})
          commit = commits['logentry'].first

          msg  = [commit["msg"]].flatten.compact.join('').strip
          date = [commit["date"]].flatten.compact.join('').strip

          list << Tag.new(:name=>name, :id=>rev, :date=>date, :who=>who, :msg=>msg)
        end
        list
      end

      # This isn't perfect, but is there really anyway for it to be?
      # It ascends up the current directory tree looking for the 
      # best candidate for a tags directory.
      def tag_directory
        fnd = nil
        dir = root
        while dir != '/' do
          entries = Dir.entries(dir)
          if entries.include?('.svn')
            if entries.include?('tags')
              break(fnd = File.join(dir, 'tags'))
            else
              entries = entries.reject{ |e| e.index('.') == 0 }
              entries = entries.reject{ |e| e !~ /\d$/ }
              break(fnd = dir) unless entries.empty?
            end
          else
            break(fnd=nil)
          end
          dir = File.dirname(dir)
        end
        fnd
      end

      #
      def user
        @email ||= `svn propget svn:author`.strip
      end

      # TODO: Best solution to SVN email?
      def email
        @email ||= ENV['EMAIL']
      end

      #
      def repository
        info['Repository Root']
      end

      #
      def uuid
        info['Repository UUID']
      end

      # TODO: Need to effect svn tag date. How?
      def tag(ref, label, date, message)
        file = tempfile("message", message)

        Dir.chdir(root) do
          cmd = %[svn copy -r #{ref} -F "#{mfile.path}" . #{tag_directory}/#{label}]
          puts cmd if $DEBUG
          `#{cmd}` unless $DRYRUN
        end
      end

      private

      #
      def info
        @info ||= YAML.load(`svn info`.strip)
      end

    end

  end

end