# redMine - project management software
# Copyright (C) 2006-2007  Jean-Philippe Lang
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

require 'redmine/scm/adapters/abstract_adapter'

module Redmine
  module Scm
    module Adapters
      class CvsAdapter < AbstractAdapter

        # CVS executable name
        CVS_BIN = Redmine::Configuration['scm_cvs_command'] || "cvs"

        # raised if scm command exited with error, e.g. unknown revision.
        class ScmCommandAborted < CommandFailed; end

        class << self
          def client_command
            @@bin    ||= CVS_BIN
          end

          def sq_bin
            @@sq_bin ||= shell_quote(CVS_BIN)
          end

          def client_version
            @@client_version ||= (scm_command_version || [])
          end

          def client_available
            client_version_above?([1, 12])
          end

          def scm_command_version
            scm_version = scm_version_from_command_line.dup
            if scm_version.respond_to?(:force_encoding)
              scm_version.force_encoding('ASCII-8BIT')
            end
            if m = scm_version.match(%r{\A(.*?)((\d+\.)+\d+)}m)
              m[2].scan(%r{\d+}).collect(&:to_i)
            end
          end

          def scm_version_from_command_line
            shellout("#{sq_bin} --version") { |io| io.read }.to_s
          end
        end

        # Guidelines for the input:
        #  url -> the project-path, relative to the cvsroot (eg. module name)
        #  root_url -> the good old, sometimes damned, CVSROOT
        #  login -> unnecessary
        #  password -> unnecessary too
        def initialize(url, root_url=nil, login=nil, password=nil,
                       path_encoding=nil)
          @url = url
          @login = login if login && !login.empty?
          @password = (password || "") if @login
          #TODO: better Exception here (IllegalArgumentException)
          raise CommandFailed if root_url.blank?
          @root_url = root_url
        end

        def root_url
          @root_url
        end

        def url
          @url
        end

        def info
          logger.debug "<cvs> info"
          Info.new({:root_url => @root_url, :lastrev => nil})
        end

        def get_previous_revision(revision)
          CvsRevisionHelper.new(revision).prevRev
        end

        # Returns an Entries collection
        # or nil if the given path doesn't exist in the repository
        # this method is used by the repository-browser (aka LIST)
        def entries(path=nil, identifier=nil)
          logger.debug "<cvs> entries '#{path}' with identifier '#{identifier}'"
          path_with_project="#{url}#{with_leading_slash(path)}"
          entries = Entries.new
          cmd_args = %w|rls -e|
          cmd_args << "-D" << time_to_cvstime_rlog(identifier) if identifier
          cmd_args << path_with_project
          scm_cmd(*cmd_args) do |io|
            io.each_line() do |line|
              fields = line.chop.split('/',-1)
              logger.debug(">>InspectLine #{fields.inspect}")
              if fields[0]!="D"
                time = nil
                # Thu Dec 13 16:27:22 2007
                time_l = fields[-3].split(' ')
                if time_l.size == 5 && time_l[4].length == 4
                  begin
                    time = Time.parse(
                             "#{time_l[1]} #{time_l[2]} #{time_l[3]} GMT #{time_l[4]}")
                  rescue
                  end
                end
                entries << Entry.new(
                 {
                  :name => fields[-5],
                  #:path => fields[-4].include?(path)?fields[-4]:(path + "/"+ fields[-4]),
                  :path => "#{path}/#{fields[-5]}",
                  :kind => 'file',
                  :size => nil,
                  :lastrev => Revision.new(
                      {
                        :revision => fields[-4],
                        :name => fields[-4],
                        :time => time,
                        :author => ''
                      })
                  })
              else
                entries << Entry.new(
                 {
                  :name => fields[1],
                  :path => "#{path}/#{fields[1]}",
                  :kind => 'dir',
                  :size => nil,
                  :lastrev => nil
                 })
              end
            end
          end
          entries.sort_by_name
        rescue ScmCommandAborted
          nil
        end

        STARTLOG="----------------------------"
        ENDLOG  ="============================================================================="

        # Returns all revisions found between identifier_from and identifier_to
        # in the repository. both identifier have to be dates or nil.
        # these method returns nothing but yield every result in block
        def revisions(path=nil, identifier_from=nil, identifier_to=nil, options={}, &block)
          logger.debug "<cvs> revisions path:'#{path}',identifier_from #{identifier_from}, identifier_to #{identifier_to}"

          path_with_project="#{url}#{with_leading_slash(path)}"
          cmd_args = %w|rlog|
          cmd_args << "-d" << ">#{time_to_cvstime_rlog(identifier_from)}" if identifier_from 
          cmd_args << path_with_project
          scm_cmd(*cmd_args) do |io|
            state="entry_start"
            
            commit_log=String.new
            revision=nil
            date=nil
            author=nil
            entry_path=nil
            entry_name=nil
            file_state=nil
            branch_map=nil
            
            io.each_line() do |line|
              
              if state!="revision" && /^#{ENDLOG}/ =~ line
                commit_log=String.new
                revision=nil
                state="entry_start"
              end
              
              if state=="entry_start"
                branch_map=Hash.new
                if /^RCS file: #{Regexp.escape(root_url_path)}\/#{Regexp.escape(path_with_project)}(.+),v$/ =~ line
                  entry_path = normalize_cvs_path($1)
                  entry_name = normalize_path(File.basename($1))
                  logger.debug("Path #{entry_path} <=> Name #{entry_name}")
                elsif /^head: (.+)$/ =~ line
                  entry_headRev = $1 #unless entry.nil?
                elsif /^symbolic names:/ =~ line
                  state="symbolic" #unless entry.nil?
                elsif /^#{STARTLOG}/ =~ line
                  commit_log=String.new
                  state="revision"
                end  
                next
              elsif state=="symbolic"
                if /^(.*):\s(.*)/ =~ (line.strip) 
                  branch_map[$1]=$2
                else
                  state="tags"
                  next
                end          
              elsif state=="tags"
                if /^#{STARTLOG}/ =~ line
                  commit_log = ""
                  state="revision"
                elsif /^#{ENDLOG}/ =~ line
                  state="head"
                end
                next
              elsif state=="revision"
                if /^#{ENDLOG}/ =~ line || /^#{STARTLOG}/ =~ line
                  if revision

                    revHelper=CvsRevisionHelper.new(revision)
                    revBranch="HEAD"
                    
                    branch_map.each() do |branch_name,branch_point|
                      if revHelper.is_in_branch_with_symbol(branch_point)
                        revBranch=branch_name
                      end
                    end
                    
                    logger.debug("********** YIELD Revision #{revision}::#{revBranch}")
                    
                    yield Revision.new({
                      :time => date,
                      :author => author,
                      :message=>commit_log.chomp,
                      :paths => [{
                        :revision => revision,
                        :branch=> revBranch,
                        :path=>entry_path,
                        :name=>entry_name,
                        :kind=>'file',
                        :action=>file_state
                      }]
                    })
                  end

                  commit_log=String.new
                  revision=nil
                  
                  if /^#{ENDLOG}/ =~ line
                    state="entry_start"
                  end
                  next
                end

                if /^branches: (.+)$/ =~ line
                  #TODO: version.branch = $1
                elsif /^revision (\d+(?:\.\d+)+).*$/ =~ line
                  revision = $1   
                elsif /^date:\s+(\d+.\d+.\d+\s+\d+:\d+:\d+)/ =~ line
                  date      = Time.parse($1)
                  author    = /author: ([^;]+)/.match(line)[1]
                  file_state     = /state: ([^;]+)/.match(line)[1]
                  #TODO: linechanges only available in CVS.... maybe a feature our SVN implementation. i'm sure, they are
                  #    useful for stats or something else
                  #                linechanges =/lines: \+(\d+) -(\d+)/.match(line)
                  #                unless linechanges.nil?
                  #                  version.line_plus  = linechanges[1]
                  #                  version.line_minus = linechanges[2]
                  #                else
                  #                  version.line_plus  = 0
                  #                  version.line_minus = 0
                  #                end
                else
                  commit_log << line unless line =~ /^\*\*\* empty log message \*\*\*/
                end
              end
            end
          end
        rescue ScmCommandAborted
          Revisions.new
        end

        def diff(path, identifier_from, identifier_to=nil)
          logger.debug "<cvs> diff path:'#{path}',identifier_from #{identifier_from}, identifier_to #{identifier_to}"
          path_with_project="#{url}#{with_leading_slash(path)}"
          cmd = "#{self.class.sq_bin} -d #{shell_quote root_url} rdiff -u -r#{identifier_to} -r#{identifier_from} #{shell_quote path_with_project}"
          diff = []
          shellout(cmd) do |io|
            io.each_line do |line|
              diff << line
            end
          end
          return nil if $? && $?.exitstatus != 0
          diff
        end

        def cat(path, identifier=nil)
          identifier = (identifier) ? identifier : "HEAD"
          logger.debug "<cvs> cat path:'#{path}',identifier #{identifier}"
          path_with_project="#{url}#{with_leading_slash(path)}"
          cmd = "#{self.class.sq_bin} -d #{shell_quote root_url} co"
          cmd << " -D \"#{time_to_cvstime(identifier)}\"" if identifier
          cmd << " -p #{shell_quote path_with_project}"
          cat = nil
          shellout(cmd) do |io|
            io.binmode
            cat = io.read
          end
          return nil if $? && $?.exitstatus != 0
          cat
        end

        def annotate(path, identifier=nil)
          identifier = (identifier) ? identifier.to_i : "HEAD"
          logger.debug "<cvs> annotate path:'#{path}',identifier #{identifier}"
          path_with_project="#{url}#{with_leading_slash(path)}"
          cmd = "#{self.class.sq_bin} -d #{shell_quote root_url} rannotate -r#{identifier} #{shell_quote path_with_project}"
          blame = Annotate.new
          shellout(cmd) do |io|
            io.each_line do |line|
              next unless line =~ %r{^([\d\.]+)\s+\(([^\)]+)\s+[^\)]+\):\s(.*)$}
              blame.add_line($3.rstrip, Revision.new(:revision => $1, :author => $2.strip))
            end
          end
          return nil if $? && $?.exitstatus != 0
          blame
        end

        private

        # Returns the root url without the connexion string
        # :pserver:anonymous@foo.bar:/path => /path
        # :ext:cvsservername:/path => /path
        def root_url_path
          root_url.to_s.gsub(/^:.+:\d*/, '')
        end

        # convert a date/time into the CVS-format
        def time_to_cvstime(time)
          return nil if time.nil?
          return Time.now if time == 'HEAD'
          
          unless time.kind_of? Time
            time = Time.parse(time)
          end
          return time.strftime("%Y-%m-%d %H:%M:%S")
        end

        def time_to_cvstime_rlog(time)
          return nil if time.nil?
          t1 = time.clone.localtime
          return t1.strftime("%Y-%m-%d %H:%M:%S")
        end
          
        def normalize_cvs_path(path)
          normalize_path(path.gsub(/Attic\//,''))
        end
          
        def normalize_path(path)
          path.sub(/^(\/)*(.*)/,'\2').sub(/(.*)(,v)+/,'\1')
        end   

        def scm_cmd(*args, &block)
          full_args = [CVS_BIN, '-d', root_url]
          full_args += args
          ret = shellout(full_args.map { |e| shell_quote e.to_s }.join(' '), &block)
          if $? && $?.exitstatus != 0
            raise ScmCommandAborted, "cvs exited with non-zero status: #{$?.exitstatus}"
          end
          ret
        end
        private :scm_cmd
      end  

      class CvsRevisionHelper
        attr_accessor :complete_rev, :revision, :base, :branchid
        
        def initialize(complete_rev)
          @complete_rev = complete_rev
          parseRevision()
        end
    
        def branchPoint
          return @base
        end
      
        def branchVersion
          if isBranchRevision
            return @base+"."+@branchid
          end
          return @base
        end
      
        def isBranchRevision
          !@branchid.nil?
        end
        
        def prevRev
          unless @revision==0
            return buildRevision(@revision-1)
          end
          return buildRevision(@revision)    
        end
        
        def is_in_branch_with_symbol(branch_symbol)
          bpieces=branch_symbol.split(".")
          branch_start="#{bpieces[0..-3].join(".")}.#{bpieces[-1]}"
          return (branchVersion==branch_start)
        end
    
        private
        def buildRevision(rev)
          if rev== 0
            if @branchid.nil?
              @base+".0"
            else
              @base
            end
          elsif @branchid.nil? 
            @base+"."+rev.to_s
          else
            @base+"."+@branchid+"."+rev.to_s
          end
        end
        
        # Interpretiert die cvs revisionsnummern wie z.b. 1.14 oder 1.3.0.15
        def parseRevision()
          pieces=@complete_rev.split(".")
          @revision=pieces.last.to_i
          baseSize=1
          baseSize+=(pieces.size/2)
          @base=pieces[0..-baseSize].join(".")
          if baseSize > 2
            @branchid=pieces[-2]
          end     
        end
      end
    end
  end
end