# Redmine plugin for Document Management System "Features"
#
# Copyright (C) 2011   Vít Jonáš <vit.jonas@gmail.com>
#
# 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.

begin
  require 'xapian'
  $xapian_bindings_available = true
rescue LoadError
  Rails.logger.info 'REDMAIN_XAPIAN ERROR: No Ruby bindings for Xapian installed !!. PLEASE install Xapian search engine interface for Ruby.'
  $xapian_bindings_available = false
end

class DmsfFile < ActiveRecord::Base
  unloadable

  include RedmineDmsf::Lockable
 
  belongs_to :project
  belongs_to :folder, :class_name => 'DmsfFolder', :foreign_key => 'dmsf_folder_id'
  belongs_to :deleted_by_user, :class_name => 'User', :foreign_key => 'deleted_by_user_id'
  has_many :revisions, :class_name => 'DmsfFileRevision', :foreign_key => 'dmsf_file_id',
    :order => "#{DmsfFileRevision.table_name}.major_version DESC, #{DmsfFileRevision.table_name}.minor_version DESC, #{DmsfFileRevision.table_name}.updated_at DESC", 
    :dependent => :destroy
  has_many :locks, :class_name => 'DmsfLock', :foreign_key => 'entity_id',
    :order => "#{DmsfLock.table_name}.updated_at DESC",
    :conditions => {:entity_type => 0},
    :dependent => :destroy  
  has_many :referenced_links, :class_name => 'DmsfLink', :foreign_key => 'target_id', 
    :conditions => {:target_type => DmsfFile.model_name}, :dependent => :destroy

  scope :visible, lambda {|*args| where(DmsfFile.visible_condition(args.shift || User.current, *args)).readonly(false)}
  
  validates :name, :presence => true
  validates_format_of :name, :with => DmsfFolder.invalid_characters,
    :message => l(:error_contains_invalid_character)
  
  validate :validates_name_uniqueness 
  
  def self.visible_condition(user, options = {})
    query = DmsfFile.where(:deleted => false)
    query.where_values.map {|v| v.respond_to?(:to_sql) ? v.to_sql : v.to_s}.join(' AND ')
  end

  def validates_name_uniqueness
    existing_file = DmsfFile.visible.find_file_by_name(self.project, self.folder, self.name)
    errors.add(:name, l('activerecord.errors.messages.taken')) unless
      existing_file.nil? || existing_file.id == self.id
  end
  
  acts_as_event :title => Proc.new {|o| "#{o.title} - #{o.name}"},
                :description => Proc.new {|o| o.description },
                :url => Proc.new {|o| {:controller => 'dmsf_files', :action => 'show', :id => o}},
                :datetime => Proc.new {|o| o.updated_at },
                :author => Proc.new {|o| o.last_revision.user }
    
  @@storage_path = nil

  def self.storage_path
    self.storage_path = Setting.plugin_redmine_dmsf['dmsf_storage_directory'].strip unless @@storage_path    
    Dir.mkdir(@@storage_path) unless File.exists?(@@storage_path)    
    @@storage_path
  end

  # Lets introduce a write for storage path, that way we can also 
  # better interact from test-cases etc
  def self.storage_path=(obj)
    @@storage_path = obj
  end
  
  def self.project_root_files(project)
    visible.where(:project_id => project.id, :dmsf_folder_id => nil).order('name ASC')
  end
  
  def self.find_file_by_name(project, folder, name)        
    where(
      :project_id => project, 
      :dmsf_folder_id => folder ? folder.id : nil, 
      :name => name).visible.first
  end

  def last_revision
    unless @last_revision
      @last_revision = deleted ? self.revisions.first : self.revisions.visible.first    
    end
    @last_revision
  end
  
  def set_last_revision(new_revision)
    @last_revision = new_revision
  end

  def delete
    if locked_for_user?
      errors[:base] << l(:error_file_is_locked)
      return false 
    end
    begin
      if Setting.plugin_redmine_dmsf['dmsf_really_delete_files']     
        self.revisions.visible.each {|r| r.delete(true)}
        self.destroy
      else
        # Revisions of a deleted file SHOULD be deleted too
        self.revisions.visible.each {|r| r.delete }
        self.deleted = true
        self.deleted_by_user = User.current
        save
      end
    rescue Exception => e
      errors[:base] << e.message
      return false
    end
  end
  
  def title
    self.last_revision ? self.last_revision.title : self.name
  end
  
  def description
    self.last_revision ? self.last_revision.description : ''
  end
  
  def version
    self.last_revision ? self.last_revision.version : '0'
  end
  
  def workflow
    self.last_revision ? self.last_revision.workflow : nil
  end
  
  def size
    self.last_revision ? self.last_revision.size : 0
  end
  
  def dmsf_path
    path = self.folder.nil? ? [] : self.folder.dmsf_path
    path.push(self)
    path
  end
  
  def dmsf_path_str    
    self.dmsf_path.map { |element| element.title }.join('/')    
  end
  
  def notify?
    return true if self.notification
    return true if folder && folder.notify?
    return true if !folder && self.project.dmsf_notification
    return false
  end
  
  def notify_deactivate
    self.notification = false
    self.save!
  end
  
  def notify_activate
    self.notification = true
    self.save!
  end
  
  def display_name    
    return self.name    
  end
  
  # Returns an array of projects that current user can copy file to
  def self.allowed_target_projects_on_copy
    projects = []
    if User.current.admin?
      projects = Project.visible.all
    elsif User.current.logged?
      User.current.memberships.each {|m| projects << m.project if m.roles.detect {|r| r.allowed_to?(:file_manipulation)}}
    end
    projects
  end
  
  def move_to(project, folder)
    if self.locked_for_user?
      errors[:base] << l(:error_file_is_locked)
      return false 
    end
    
    new_revision = self.last_revision.clone    
    
    new_revision.folder = folder
    new_revision.project = folder ? folder.project : project
    new_revision.comment = l(:comment_moved_from, :source => "#{self.project.identifier}:#{self.dmsf_path_str}") 
    
    new_revision.custom_values = []
    self.last_revision.custom_values.each do |cv|
      new_revision.custom_values << CustomValue.new({:custom_field => cv.custom_field, :value => cv.value})
    end        
    
    # If the target project differs from the source project we must physically move the file
    if self.project != new_revision.project
      if File.exist? self.last_revision.disk_file
        FileUtils.mv self.last_revision.disk_file, new_revision.disk_file        
      end
    end

    self.folder = new_revision.folder
    self.project = new_revision.project

    self.save && new_revision.save        
  end
  
  def copy_to(project, folder)
    file = DmsfFile.new
    file.folder = folder
    file.project = folder ? folder.project : project
    file.name = self.name
    file.notification = Setting.plugin_redmine_dmsf['dmsf_default_notifications'].present?

    if file.save && self.last_revision
      new_revision = self.last_revision.clone
      new_revision.file = file
      new_revision.folder = folder
      new_revision.project = folder ? folder.project : project
      new_revision.comment = l(:comment_copied_from, :source => "#{self.project.identifier}: #{self.dmsf_path_str}")
      
      new_revision.custom_values = []
      self.last_revision.custom_values.each do |cv|
        new_revision.custom_values << CustomValue.new({:custom_field => cv.custom_field, :value => cv.value})
      end

      unless new_revision.save
        file.delete
      else        
        # If the target project differs from the source project we must physically copy the file
        if project != self.project          
          if File.exist? self.last_revision.disk_file
            FileUtils.cp self.last_revision.disk_file, new_revision.disk_file
          end
        end
      end
    end
    
    return file
  end
  
  # To fullfill searchable module expectations
  def self.search(tokens, projects = nil, options = {})
    tokens = [] << tokens unless tokens.is_a?(Array)
    projects = [] << projects unless projects.nil? || projects.is_a?(Array)
    
    find_options = {:include => [:project,:revisions]}
    find_options[:order] = 'dmsf_files.updated_at ' + (options[:before] ? 'DESC' : 'ASC')
    
    limit_options = {}
    limit_options[:limit] = options[:limit] if options[:limit]
    if options[:offset]
      limit_options[:conditions] = '(dmsf_files.updated_at ' + (options[:before] ? '<' : '>') + "'#{connection.quoted_date(options[:offset])}')"
    end
    
    columns = %w(dmsf_files.name dmsf_file_revisions.title dmsf_file_revisions.description)
    columns = ['dmsf_file_revisions.title'] if options[:titles_only]
            
    token_clauses = columns.collect {|column| "(LOWER(#{column}) LIKE ?)"}
    
    sql = (['(' + token_clauses.join(' OR ') + ')'] * tokens.size).join(options[:all_words] ? ' AND ' : ' OR ')
    find_options[:conditions] = [sql, * (tokens.collect {|w| "%#{w.downcase}%"} * token_clauses.size).sort]
    
    project_conditions = []
    project_conditions << (Project.allowed_to_condition(User.current, :view_dmsf_files))
    project_conditions << "#{DmsfFile.table_name}.project_id IN (#{projects.collect(&:id).join(',')})" unless projects.nil?
    
    results = []
    results_count = 0
    
    with_scope(:find => {:conditions => [project_conditions.join(' AND ') + " AND #{DmsfFile.table_name}.deleted = :false", {:false => false}]}) do
      with_scope(:find => find_options) do
        results_count = count(:all)
        results = find(:all, limit_options)
      end
    end
    
    if !options[:titles_only] && $xapian_bindings_available
      database = nil
      begin
        database = Xapian::Database.new(Setting.plugin_redmine_dmsf['dmsf_index_database'].strip)
      rescue
        Rails.logger.warn 'REDMAIN_XAPIAN ERROR: Xapian database is not properly set or initiated or is corrupted.'
      end

      unless database.nil?
        enquire = Xapian::Enquire.new(database)
        
        query_string = tokens.join(' ')
        qp = Xapian::QueryParser.new()
        stemmer = Xapian::Stem.new(Setting.plugin_redmine_dmsf['dmsf_stemming_lang'].strip)
        qp.stemmer = stemmer
        qp.database = database
        
        case Setting.plugin_redmine_dmsf['dmsf_stemming_strategy'].strip
          when 'STEM_NONE' 
            qp.stemming_strategy = Xapian::QueryParser::STEM_NONE
          when 'STEM_SOME'
            qp.stemming_strategy = Xapian::QueryParser::STEM_SOME
          when 'STEM_ALL'
            qp.stemming_strategy = Xapian::QueryParser::STEM_ALL
        end
      
        if options[:all_words]
          qp.default_op = Xapian::Query::OP_AND
        else  
          qp.default_op = Xapian::Query::OP_OR
        end
        
        query = qp.parse_query(query_string)
  
        enquire.query = query
        matchset = enquire.mset(0, 1000)
    
        if matchset
          matchset.matches.each {|m|
            docdata = m.document.data{url}
            dochash = Hash[*docdata.scan(/(url|sample|modtime|type|size)=\/?([^\n\]]+)/).flatten]
            filename = dochash['url']
            if filename
              dmsf_attrs = filename.scan(/^([^\/]+\/[^_]+)_([\d]+)_(.*)$/)
              id_attribute = 0
              id_attribute = dmsf_attrs[0][1] if dmsf_attrs.length > 0
              next if dmsf_attrs.length == 0 || id_attribute == 0
              next unless results.select{|f| f.id.to_s == id_attribute}.empty?
              
              dmsf_file = DmsfFile.where(limit_options[:conditions]).where(:id => id_attribute, :deleted => false).first
    
              if dmsf_file
                if options[:offset]
                  if options[:before]
                    next if dmsf_file.updated_at < options[:offset]
                  else
                    next if dmsf_file.updated_at > options[:offset]
                  end
                end
              
                allowed = User.current.allowed_to?(:view_dmsf_files, dmsf_file.project)
                project_included = false
                project_included = true unless projects
                unless project_included                  
                  projects.each do |x| 
                    if x.is_a?(ActiveRecord::Relation)
                      project_included = x.first.id == dmsf_file.project.id        
                    else
                      if dmsf_file.project
                        project_included = x[:id] == dmsf_file.project.id
                      else
                        project_included = false
                      end
                    end
                  end
                end
  
                if (allowed && project_included)
                  results.push(dmsf_file)
                  results_count += 1
                end
              end
            end
          }
        end
      end    
    end
    
    [results, results_count]
  end
  
end