# 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 'active_record'
require 'iconv'
require 'pp'

namespace :redmine do
  desc 'MediaWiki migration script'
  task :migrate_from_mediawiki => :environment do
    
    module MWMigrate

      class MWText < ActiveRecord::Base
        set_table_name :text
        set_primary_key :old_id
      end

      class MWRev < ActiveRecord::Base
        set_table_name :revision
        set_primary_key :rev_id
        belongs_to :page, :class_name => "MWPage", :foreign_key => :rev_page
        belongs_to :text, :class_name => "MWText", :foreign_key => :rev_text_id
      end

      class MWPage < ActiveRecord::Base
        set_table_name :page
        set_primary_key :page_id
        has_many :revisions, :class_name => "MWRev", :foreign_key => :rev_page, :order => "rev_timestamp DESC"
      end

      def self.find_or_create_user(email, project_member = false)
        u = User.find_by_mail(email)
        if !u
          u = User.find_by_mail(@@mw_default_user)
        end
        if(!u)
          # Create a new user if not found
          mail = email[0,limit_for(User, 'mail')]
          mail = "#{mail}@fortna.com" unless mail.include?("@")
          name = email[0,email.index("@")];
          u = User.new :firstname => name[0,limit_for(User, 'firstname')].gsub(/[^\w\s\'\-]/i, '-'),
                       :lastname => '-',
                       :mail => mail.gsub(/[^-@a-z0-9\.]/i, '-')
          u.login = email[0,limit_for(User, 'login')].gsub(/[^a-z0-9_\-@\.]/i, '-')
          u.password = 'bugzilla'
          u.admin = false
          # finally, a default user is used if the new user is not valid
          puts "Created User: "+ u.to_yaml
          u = User.find(:first) unless u.save
        else
#          puts "Found User: " + u.to_yaml
        end
        # Make sure he is a member of the project
##        if project_member && !u.member_of?(@target_project)
##          role = ROLE_MAPPING['developer']
##          Member.create(:user => u, :project => @target_project, :role => role)
##          u.reload
##        end
        u
      end
      
      
      # Basic wiki syntax conversion
      def self.convert_wiki_text(text)
        # Titles
        text = text.gsub(/^(\=+)\s*([^=]+)\s*\=+\s*$/) {|s| "\nh#{$1.length}. #{$2}\n"}

        # Internal links
        text = text.gsub(/\[\[(.*)\s+\|(.*)\]\]/) {|s| "[[#{$1}|#{$2}]]"}

        # External Links
        text = text.gsub(/\[(http[^\s]+)\s+([^\]]+)\]/) {|s| "\"#{$2}\":#{$1}"}
        text = text.gsub(/\[(http[^\s]+)\]/) {|s| "#{$1}"}

        # Highlighting
        text = text.gsub(/'''''([^\s])/, '_*\1')
        text = text.gsub(/([^\s])'''''/, '\1*_')
        text = text.gsub(/'''([^\s])/, '*\1')
        text = text.gsub(/([^\s])'''/, '\1*')
        text = text.gsub(/''([^\s])/, '_*\1')
        text = text.gsub(/([^\s])''/, '\1*_')

        # code
        text = text.gsub(/((^ [^\n]*\n)+)/m) { |s| "<pre>\n#{$1}</pre>\n" }
#        text = text.gsub(/(^\n^ .*?$)/m) { |s| "<pre><code>#{$1}" }
#        text = text.gsub(/(^ .*?\n)\n/m) { |s| "#{$1}</pre></code>\n" }

        # Tables
        # Half-assed attempt
        # First strip off the table formatting
        text = text.gsub(/^\![^\|]*/, '')
        text = text.gsub(/^\{\|[^\|]*$/, '{|')

        # Now congeal the rows
        while( text.gsub!(/(\|-.*)\n(\|\w.*)$/m, '\1\2'))
        end

        # Now congeal the headers
        while( text.gsub!(/(\{\|.*)\n(\|\w.*)$/m, '\1\2'))
        end

        # format the headers properly
        while( text.gsub!(/(\{\|.*)\|([^_].*)$/, '\1|_. \2'))
        end

        # get rid of leading '{|'
        text = text.gsub(/^\{\|(.*)$/) { |s| "table(stdtbl)\n#{$1}|" }

        # get rid of leading '|-'
        text = text.gsub(/^\|-(.*)$/, '\1|')

        # get rid of trailing '|}'
        text = text.gsub(/^\|\}.*$/, '')

        # Internal Links
        text = text.gsub(/\[\[Image:([^\s]+)\]\]/) { |s| "!#{$1}!" }

        # Wiki page separator ':'
        while( text.gsub!(/(\[\[\s*\w+):(\w+)/, '\1_\2') )
        end

        text
      end
    
      def self.migrate
        establish_connection

        # Quick database test
        pages = MWPage.count
                
        migrated_wiki_edits = 0

        puts "No wiki defined" unless @target_project.wiki
        wiki = @target_project.wiki || 
               Wiki.new(:project => @target_project, 
                        :start_page => @target_project.name)

  
        # Wiki      
        puts "Migrating #{mw_page_title}, 1 of #{pages} pages"
        pages = MWPage.find(:all, 
                            :conditions => ["page_title = ?", mw_page_title])

        if((pages.size > 0) && (@@mw_whole_namespace == "y" || @@mw_whole_namespace == "Y"))
          pages = MWPage.find(:all,
                              :conditions => ["page_namespace = ?", pages[0].page_namespace])
        end

        pages.each do |page|
          print "Translate #{page.page_title} (y/N)? "
          next unless STDIN.gets.match(/^[yY]$/i)  

          STDOUT.flush
          new_title = page.page_title.gsub(/:/, "_")
          p = wiki.find_or_new_page(new_title)
          p.content = WikiContent.new(:page => p) if p.new_record?
          p.content.text = convert_wiki_text(page.revisions[0].text.old_text)
          p.content.author = User.find_by_mail(@@mw_default_user)
          p.content.comments = page.revisions[0].rev_comment
          puts "Record: " + p.content.to_s
          puts "  Text: " + p.content.text
          print "Save translated page (y/N)? "
          next unless STDIN.gets.match(/^[yY]$/i)  

          p.new_record? ? p.save : p.content.save
          migrated_wiki_edits += 1 unless p.content.new_record?
        end
       
        puts
        puts "Wiki edits:      #{migrated_wiki_edits}/#{MWPage.count}"
      end
      
      def self.limit_for(klass, attribute)
        klass.columns_hash[attribute.to_s].limit
      end
      
      def self.encoding(charset)
        @ic = Iconv.new('UTF-8', charset)
      rescue Iconv::InvalidEncoding
        puts "Invalid encoding!"
        return false
      end
      
      def self.set_mw_directory(path)
        @@bz_directory = path
        raise "This directory doesn't exist!" unless File.directory?(path)
        @@bz_directory
      rescue Exception => e
        puts e
        return false
      end

      def self.mw_directory
        @@mw_directory
      end

      def self.set_mw_adapter(adapter)
        return false if adapter.blank?
        raise "Unknown adapter: #{adapter}!" unless %w(sqlite sqlite3 mysql postgresql).include?(adapter)
        # If adapter is sqlite or sqlite3, make sure that mw.db exists
        raise "#{mw_db_path} doesn't exist!" if %w(sqlite sqlite3).include?(adapter) && !File.exist?(mw_db_path)
        @@mw_adapter = adapter
      rescue Exception => e
        puts e
        return false
      end
      
      def self.set_mw_db_host(host)
        return nil if host.blank?
        @@mw_db_host = host
      end

      def self.set_mw_db_port(port)
        return nil if port.to_i == 0
        @@mw_db_port = port.to_i
      end
      
      def self.set_mw_db_socket(sock)
        @@mw_db_socket = sock
      end
      
      def self.set_mw_db_name(name)
        return nil if name.blank?
        @@mw_db_name = name
      end

      def self.set_mw_db_username(username)
        @@mw_db_username = username
      end
      
      def self.set_mw_db_password(password)
        @@mw_db_password = password
      end
      
      def self.set_mw_default_user(username)
        @@mw_default_user = username
      end

      def self.set_mw_page_title(name)
        @@mw_page_title = name
      end

      def self.set_mw_whole_namespace(flag)
        @@mw_whole_namespace = flag
      end

      mattr_reader :mw_directory, :mw_adapter, :mw_db_host, :mw_db_port, :mw_db_name, :mw_db_username, :mw_db_password, :mw_db_socket, :mw_page_title, :mw_whole_namespace
      
     
      def self.mw_db_path; "#{mw_directory}/db/wiki.db" end
      def self.mw_attachments_directory; "#{mw_directory}/attachments" end

      def self.target_project_identifier(identifier)
        project = Project.find_by_identifier(identifier)
        if !project
          # create the target project
          project = Project.new :name => identifier.humanize,
                                :description => identifier.humanize
          project.identifier = identifier
          puts "Created Project: "+ project.to_s
          puts "Unable to create a project with identifier '#{identifier}'!" unless project.save
          # enable issues and wiki for the created project
          project.enabled_module_names = ['issue_tracking', 'wiki']
          project.trackers << TRACKER_BUG
          project.trackers << TRACKER_FEATURE
          project.trackers << TRACKER_SUPPORT
        else
          puts "Found Project: " + project.to_yaml
        end        
        @target_project = project.new_record? ? nil : project
      end
      
      
      def self.connection_params
        if %w(sqlite sqlite3).include?(mw_adapter)
          {:adapter => mw_adapter, 
           :database => mw_db_path}
        else
          {:adapter => mw_adapter,
           :database => mw_db_name,
           :host => mw_db_host,
           :port => mw_db_port,
           :socket => mw_db_socket,
           :username => mw_db_username,
           :password => mw_db_password}
        end
      end
      
      def self.establish_connection
        constants.each do |const|
          klass = const_get(const)
          next unless klass.respond_to? 'establish_connection'
          klass.establish_connection connection_params
        end
      end
      
    private
      def self.encode(text)
        @ic.iconv text
      rescue
        text
      end
    end
    
    puts
    puts "WARNING: a new project will be added to Redmine during this process."
    print "Are you sure you want to continue ? [y/N] "
    break unless STDIN.gets.match(/^[yY]$/i)  
    puts

    def prompt(text, options = {}, &block)
      default = options[:default] || ''
      while true
        print "#{text} [#{default}]: "
        value = STDIN.gets.chomp!
        value = default if value.blank?
        break if yield value
      end
    end
    
    DEFAULT_PORTS = {'mysql' => 3306, 'postgresl' => 5432}
    DEFAULT_SOCKETS = {'mysql' => '/var/lib/mysql/mysql.sock'}
    
    prompt('MW directory',:default => '/var/www/html/mediawiki-1.8.2') {|directory| MWMigrate.set_mw_directory directory}
    prompt('MW database adapter (sqlite, sqlite3, mysql, postgresql)', :default => 'mysql') {|adapter| MWMigrate.set_mw_adapter adapter}
    unless %w(sqlite sqlite3).include?(MWMigrate.mw_adapter)
      prompt('MW database host', :default => 'localhost') {|host| MWMigrate.set_mw_db_host host}
      prompt('MW database port', :default => DEFAULT_PORTS[MWMigrate.mw_adapter]) {|port| MWMigrate.set_mw_db_port port}
      prompt('MW database socket', :default => DEFAULT_SOCKETS[MWMigrate.mw_adapter]) {|sock| MWMigrate.set_mw_db_socket sock}
      prompt('MW database name', :default => 'wikidb') {|name| MWMigrate.set_mw_db_name name}
      prompt('MW database username', :default => 'wiki') {|username| MWMigrate.set_mw_db_username username}
      prompt('MW database password', :default => 'wikidb') {|password| MWMigrate.set_mw_db_password password}
    end
    prompt('MW database encoding', :default => 'UTF-8') {|encoding| MWMigrate.encoding encoding}
    prompt('Target project identifier', :default => 'CommCore') {|identifier| MWMigrate.target_project_identifier identifier}
    prompt('MW Page Title', :default => 'CommCore:Devel:XMLDB') {|identifier| MWMigrate.set_mw_page_title identifier}
    prompt('Page Author', :default => 'carlnygard@fortna.com') {|identifier| MWMigrate.set_mw_default_user identifier}
    prompt('Whole namespace (Y/n)?', :default => 'y') {|flag| MWMigrate.set_mw_whole_namespace flag}
    puts
    
    MWMigrate.migrate
  end
end