# frozen_string_literal: true

# Redmine - project management software
# Copyright (C) 2006-2017  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/sort_criteria'

class QueryColumn
  attr_accessor :name, :sortable, :groupable, :totalable, :default_order
  include Redmine::I18n

  def initialize(name, options={})
    self.name = name
    self.sortable = options[:sortable]
    self.groupable = options[:groupable] || false
    if groupable == true
      self.groupable = name.to_s
    end
    self.totalable = options[:totalable] || false
    self.default_order = options[:default_order]
    @inline = options.key?(:inline) ? options[:inline] : true
    @caption_key = options[:caption] || "field_#{name}".to_sym
    @frozen = options[:frozen]
  end

  def caption
    case @caption_key
    when Symbol
      l(@caption_key)
    when Proc
      @caption_key.call
    else
      @caption_key
    end
  end

  # Returns true if the column is sortable, otherwise false
  def sortable?
    !@sortable.nil?
  end

  def sortable
    @sortable.is_a?(Proc) ? @sortable.call : @sortable
  end

  def inline?
    @inline
  end

  def frozen?
    @frozen
  end

  def value(object)
    object.send name
  end

  def value_object(object)
    object.send name
  end

  # Returns the group that object belongs to when grouping query results
  def group_value(object)
    value(object)
  end

  def css_classes
    name
  end
end

class TimestampQueryColumn < QueryColumn

  def groupable
    if @groupable
      Redmine::Database.timestamp_to_date(sortable, User.current.time_zone)
    end
  end

  def group_value(object)
    if time = value(object)
      User.current.time_to_date(time)
    end
  end
end

class QueryAssociationColumn < QueryColumn

  def initialize(association, attribute, options={})
    @association = association
    @attribute = attribute
    name_with_assoc = "#{association}.#{attribute}".to_sym
    super(name_with_assoc, options)
  end

  def value_object(object)
    if assoc = object.send(@association)
      assoc.send @attribute
    end
  end

  def css_classes
    @css_classes ||= "#{@association}-#{@attribute}"
  end
end

class QueryCustomFieldColumn < QueryColumn

  def initialize(custom_field, options={})
    self.name = "cf_#{custom_field.id}".to_sym
    self.sortable = custom_field.order_statement || false
    self.groupable = custom_field.group_statement || false
    self.totalable = options.key?(:totalable) ? !!options[:totalable] : custom_field.totalable?
    @inline = custom_field.full_width_layout? ? false : true
    @cf = custom_field
  end

  def caption
    @cf.name
  end

  def custom_field
    @cf
  end

  def value_object(object)
    if custom_field.visible_by?(object.project, User.current)
      cv = object.custom_values.select {|v| v.custom_field_id == @cf.id}
      cv.size > 1 ? cv.sort_by {|e| e.value.to_s} : cv.first
    else
      nil
    end
  end

  def value(object)
    raw = value_object(object)
    if raw.is_a?(Array)
      raw.map {|r| @cf.cast_value(r.value)}
    elsif raw
      @cf.cast_value(raw.value)
    else
      nil
    end
  end

  def css_classes
    @css_classes ||= "#{name} #{@cf.field_format}"
  end
end

class QueryAssociationCustomFieldColumn < QueryCustomFieldColumn

  def initialize(association, custom_field, options={})
    super(custom_field, options)
    self.name = "#{association}.cf_#{custom_field.id}".to_sym
    # TODO: support sorting/grouping by association custom field
    self.sortable = false
    self.groupable = false
    @association = association
  end

  def value_object(object)
    if assoc = object.send(@association)
      super(assoc)
    end
  end

  def css_classes
    @css_classes ||= "#{@association}_cf_#{@cf.id} #{@cf.field_format}"
  end
end

class QueryFilter
  include Redmine::I18n

  def initialize(field, options)
    @field = field.to_s
    @options = options
    @options[:name] ||= l(options[:label] || "field_#{field}".gsub(/_id$/, ''))
    # Consider filters with a Proc for values as remote by default
    @remote = options.key?(:remote) ? options[:remote] : options[:values].is_a?(Proc)
  end

  def [](arg)
    if arg == :values
      values
    else
      @options[arg]
    end
  end

  def values
    @values ||= begin
      values = @options[:values]
      if values.is_a?(Proc)
        values = values.call
      end
      values
    end
  end

  def remote
    @remote
  end
end

class Query < ActiveRecord::Base
  class StatementInvalid < ::ActiveRecord::StatementInvalid
  end

  include Redmine::SubclassFactory

  VISIBILITY_PRIVATE = 0
  VISIBILITY_ROLES   = 1
  VISIBILITY_PUBLIC  = 2

  belongs_to :project
  belongs_to :user
  has_and_belongs_to_many :roles, :join_table => "#{table_name_prefix}queries_roles#{table_name_suffix}", :foreign_key => "query_id"
  serialize :filters
  serialize :column_names
  serialize :sort_criteria, Array
  serialize :options, Hash

  validates_presence_of :name
  validates_length_of :name, :maximum => 255
  validates :visibility, :inclusion => { :in => [VISIBILITY_PUBLIC, VISIBILITY_ROLES, VISIBILITY_PRIVATE] }
  validate :validate_query_filters
  validate do |query|
    errors.add(:base, l(:label_role_plural) + ' ' + l('activerecord.errors.messages.blank')) if query.visibility == VISIBILITY_ROLES && roles.blank?
  end

  after_save do |query|
    if query.saved_change_to_visibility? && query.visibility != VISIBILITY_ROLES
      query.roles.clear
    end
  end

  class_attribute :operators
  self.operators = {
    "="   => :label_equals,
    "!"   => :label_not_equals,
    "o"   => :label_open_issues,
    "c"   => :label_closed_issues,
    "!*"  => :label_none,
    "*"   => :label_any,
    ">="  => :label_greater_or_equal,
    "<="  => :label_less_or_equal,
    "><"  => :label_between,
    "<t+" => :label_in_less_than,
    ">t+" => :label_in_more_than,
    "><t+"=> :label_in_the_next_days,
    "t+"  => :label_in,
    "nd"  => :label_tomorrow,
    "t"   => :label_today,
    "ld"  => :label_yesterday,
    "nw"  => :label_next_week,
    "w"   => :label_this_week,
    "lw"  => :label_last_week,
    "l2w" => [:label_last_n_weeks, {:count => 2}],
    "nm"  => :label_next_month,
    "m"   => :label_this_month,
    "lm"  => :label_last_month,
    "y"   => :label_this_year,
    ">t-" => :label_less_than_ago,
    "<t-" => :label_more_than_ago,
    "><t-"=> :label_in_the_past_days,
    "t-"  => :label_ago,
    "~"   => :label_contains,
    "!~"  => :label_not_contains,
    "=p"  => :label_any_issues_in_project,
    "=!p" => :label_any_issues_not_in_project,
    "!p"  => :label_no_issues_in_project,
    "*o"  => :label_any_open_issues,
    "!o"  => :label_no_open_issues,
  }

  class_attribute :operators_by_filter_type
  self.operators_by_filter_type = {
    :list => [ "=", "!" ],
    :list_status => [ "o", "=", "!", "c", "*" ],
    :list_optional => [ "=", "!", "!*", "*" ],
    :list_subprojects => [ "*", "!*", "=", "!" ],
    :date => [ "=", ">=", "<=", "><", "<t+", ">t+", "><t+", "t+", "nd", "t", "ld", "nw", "w", "lw", "l2w", "nm", "m", "lm", "y", ">t-", "<t-", "><t-", "t-", "!*", "*" ],
    :date_past => [ "=", ">=", "<=", "><", ">t-", "<t-", "><t-", "t-", "t", "ld", "w", "lw", "l2w", "m", "lm", "y", "!*", "*" ],
    :string => [ "~", "=", "!~", "!", "!*", "*" ],
    :text => [  "~", "!~", "!*", "*" ],
    :integer => [ "=", ">=", "<=", "><", "!*", "*" ],
    :float => [ "=", ">=", "<=", "><", "!*", "*" ],
    :relation => ["=", "=p", "=!p", "!p", "*o", "!o", "!*", "*"],
    :tree => ["=", "~", "!*", "*"]
  }

  class_attribute :available_columns
  self.available_columns = []

  class_attribute :queried_class

  # Permission required to view the queries, set on subclasses.
  class_attribute :view_permission

  # Scope of queries that are global or on the given project
  scope :global_or_on_project, lambda {|project|
    where(:project_id => (project.nil? ? nil : [nil, project.id]))
  }

  scope :sorted, lambda {order(:name, :id)}

  # Scope of visible queries, can be used from subclasses only.
  # Unlike other visible scopes, a class methods is used as it
  # let handle inheritance more nicely than scope DSL.
  def self.visible(*args)
    if self == ::Query
      # Visibility depends on permissions for each subclass,
      # raise an error if the scope is called from Query (eg. Query.visible)
      raise Exception.new("Cannot call .visible scope from the base Query class, but from subclasses only.")
    end

    user = args.shift || User.current
    base = Project.allowed_to_condition(user, view_permission, *args)
    scope = joins("LEFT OUTER JOIN #{Project.table_name} ON #{table_name}.project_id = #{Project.table_name}.id").
      where("#{table_name}.project_id IS NULL OR (#{base})")

    if user.admin?
      scope.where("#{table_name}.visibility <> ? OR #{table_name}.user_id = ?", VISIBILITY_PRIVATE, user.id)
    elsif user.memberships.any?
      scope.where("#{table_name}.visibility = ?" +
        " OR (#{table_name}.visibility = ? AND #{table_name}.id IN (" +
          "SELECT DISTINCT q.id FROM #{table_name} q" +
          " INNER JOIN #{table_name_prefix}queries_roles#{table_name_suffix} qr on qr.query_id = q.id" +
          " INNER JOIN #{MemberRole.table_name} mr ON mr.role_id = qr.role_id" +
          " INNER JOIN #{Member.table_name} m ON m.id = mr.member_id AND m.user_id = ?" +
          " INNER JOIN #{Project.table_name} p ON p.id = m.project_id AND p.status <> ?" +
          " WHERE q.project_id IS NULL OR q.project_id = m.project_id))" +
        " OR #{table_name}.user_id = ?",
        VISIBILITY_PUBLIC, VISIBILITY_ROLES, user.id, Project::STATUS_ARCHIVED, user.id)
    elsif user.logged?
      scope.where("#{table_name}.visibility = ? OR #{table_name}.user_id = ?", VISIBILITY_PUBLIC, user.id)
    else
      scope.where("#{table_name}.visibility = ?", VISIBILITY_PUBLIC)
    end
  end

  # Returns true if the query is visible to +user+ or the current user.
  def visible?(user=User.current)
    return true if user.admin?
    return false unless project.nil? || user.allowed_to?(self.class.view_permission, project)
    case visibility
    when VISIBILITY_PUBLIC
      true
    when VISIBILITY_ROLES
      if project
        (user.roles_for_project(project) & roles).any?
      else
        user.memberships.joins(:member_roles).where(:member_roles => {:role_id => roles.map(&:id)}).any?
      end
    else
      user == self.user
    end
  end

  def is_private?
    visibility == VISIBILITY_PRIVATE
  end

  def is_public?
    !is_private?
  end

  # Returns true if the query is available for all projects
  def is_global?
    new_record? ? project_id.nil? : project_id_in_database.nil?
  end

  def queried_table_name
    @queried_table_name ||= self.class.queried_class.table_name
  end

  # Builds the query from the given params
  def build_from_params(params, defaults={})
    if params[:fields] || params[:f]
      self.filters = {}
      add_filters(params[:fields] || params[:f], params[:operators] || params[:op], params[:values] || params[:v])
    else
      available_filters.each_key do |field|
        add_short_filter(field, params[field]) if params[field]
      end
    end

    query_params = params[:query] || defaults || {}
    self.group_by = params[:group_by] || query_params[:group_by] || self.group_by
    self.column_names = params[:c] || query_params[:column_names] || self.column_names
    self.totalable_names = params[:t] || query_params[:totalable_names] || self.totalable_names
    self.sort_criteria = params[:sort] || query_params[:sort_criteria] || self.sort_criteria
    self
  end

  # Builds a new query from the given params and attributes
  def self.build_from_params(params, attributes={})
    new(attributes).build_from_params(params)
  end

  def as_params
    if new_record?
      params = {}
      filters.each do |field, options|
        params[:f] ||= []
        params[:f] << field
        params[:op] ||= {}
        params[:op][field] = options[:operator]
        params[:v] ||= {}
        params[:v][field] = options[:values]
      end
      params[:c] = column_names
      params[:group_by] = group_by.to_s if group_by.present?
      params[:t] = totalable_names.map(&:to_s) if totalable_names.any?
      params[:sort] = sort_criteria.to_param
      params[:set_filter] = 1
      params
    else
      {:query_id => id}
    end
  end

  def validate_query_filters
    filters.each_key do |field|
      if values_for(field)
        case type_for(field)
        when :integer
          add_filter_error(field, :invalid) if values_for(field).detect {|v| v.present? && !/\A[+-]?\d+(,[+-]?\d+)*\z/.match?(v) }
        when :float
          add_filter_error(field, :invalid) if values_for(field).detect {|v| v.present? && !/\A[+-]?\d+(\.\d*)?\z/.match?(v) }
        when :date, :date_past
          case operator_for(field)
          when "=", ">=", "<=", "><"
            add_filter_error(field, :invalid) if values_for(field).detect {|v|
              v.present? && (!/\A\d{4}-\d{2}-\d{2}(T\d{2}((:)?\d{2}){0,2}(Z|\d{2}:?\d{2})?)?\z/.match?(v) || parse_date(v).nil?)
            }
          when ">t-", "<t-", "t-", ">t+", "<t+", "t+", "><t+", "><t-"
            add_filter_error(field, :invalid) if values_for(field).detect {|v| v.present? && !/^\d+$/.match?(v) }
          end
        end
      end

      add_filter_error(field, :blank) unless
          # filter requires one or more values
          (values_for(field) and !values_for(field).first.blank?) or
          # filter doesn't require any value
          ["o", "c", "!*", "*", "nd", "t", "ld", "nw", "w", "lw", "l2w", "nm", "m", "lm", "y", "*o", "!o"].include? operator_for(field)
    end if filters
  end

  def add_filter_error(field, message)
    m = label_for(field) + " " + l(message, :scope => 'activerecord.errors.messages')
    errors.add(:base, m)
  end

  def editable_by?(user)
    return false unless user
    # Admin can edit them all and regular users can edit their private queries
    return true if user.admin? || (is_private? && self.user_id == user.id)
    # Members can not edit public queries that are for all project (only admin is allowed to)
    is_public? && !is_global? && user.allowed_to?(:manage_public_queries, project)
  end

  def trackers
    @trackers ||= (project.nil? ? Tracker.all : project.rolled_up_trackers).visible.sorted
  end

  # Returns a hash of localized labels for all filter operators
  def self.operators_labels
    operators.inject({}) {|h, operator| h[operator.first] = l(*operator.last); h}
  end

  # Returns a representation of the available filters for JSON serialization
  def available_filters_as_json
    json = {}
    available_filters.each do |field, filter|
      options = {:type => filter[:type], :name => filter[:name]}
      options[:remote] = true if filter.remote

      if has_filter?(field) || !filter.remote
        options[:values] = filter.values
        if options[:values] && values_for(field)
          missing = Array(values_for(field)).select(&:present?) - options[:values].map(&:last)
          if missing.any? && respond_to?(method = "find_#{field}_filter_values")
            options[:values] += send(method, missing)
          end
        end
      end
      json[field] = options.stringify_keys
    end
    json
  end

  def all_projects
    @all_projects ||= Project.visible.to_a
  end

  def all_projects_values
    return @all_projects_values if @all_projects_values

    values = []
    Project.project_tree(all_projects) do |p, level|
      prefix = (level > 0 ? ('--' * level + ' ') : '')
      values << ["#{prefix}#{p.name}", p.id.to_s]
    end
    @all_projects_values = values
  end

  def project_values
    project_values = []
    if User.current.logged? && User.current.memberships.any?
      project_values << ["<< #{l(:label_my_projects).downcase} >>", "mine"]
    end
    project_values += all_projects_values
    project_values
  end

  def subproject_values
    project.descendants.visible.collect{|s| [s.name, s.id.to_s] }
  end

  def principals
    @principal ||= begin
      principals = []
      if project
        principals += Principal.member_of(project).visible
        unless project.leaf?
          principals += Principal.member_of(project.descendants.visible).visible
        end
      else
        principals += Principal.member_of(all_projects).visible
      end
      principals.uniq!
      principals.sort!
      principals.reject! {|p| p.is_a?(GroupBuiltin)}
      principals
    end
  end

  def users
    principals.select {|p| p.is_a?(User)}
  end

  def author_values
    author_values = []
    author_values << ["<< #{l(:label_me)} >>", "me"] if User.current.logged?
    author_values += users.sort_by(&:status).collect{|s| [s.name, s.id.to_s, l("status_#{User::LABEL_BY_STATUS[s.status]}")] }
    author_values
  end

  def assigned_to_values
    assigned_to_values = []
    assigned_to_values << ["<< #{l(:label_me)} >>", "me"] if User.current.logged?
    assigned_to_values += (Setting.issue_group_assignment? ? principals : users).sort_by(&:status).collect{|s| [s.name, s.id.to_s, l("status_#{User::LABEL_BY_STATUS[s.status]}")] }
    assigned_to_values
  end

  def fixed_version_values
    versions = []
    if project
      versions = project.shared_versions.to_a
    else
      versions = Version.visible.to_a
    end
    Version.sort_by_status(versions).collect{|s| ["#{s.project.name} - #{s.name}", s.id.to_s, l("version_status_#{s.status}")] }
  end

  # Returns a scope of issue statuses that are available as columns for filters
  def issue_statuses_values
    if project
      statuses = project.rolled_up_statuses
    else
      statuses = IssueStatus.all.sorted
    end
    statuses.collect{|s| [s.name, s.id.to_s]}
  end

  def watcher_values
    watcher_values = [["<< #{l(:label_me)} >>", "me"]]
    watcher_values += users.sort_by(&:status).collect{|s| [s.name, s.id.to_s, l("status_#{User::LABEL_BY_STATUS[s.status]}")] } if User.current.allowed_to?(:view_issue_watchers, self.project)
    watcher_values
  end

  # Returns a scope of issue custom fields that are available as columns or filters
  def issue_custom_fields
    if project
      project.rolled_up_custom_fields
    else
      IssueCustomField.all
    end
  end

  # Returns a scope of project statuses that are available as columns or filters
  def project_statuses_values
    [
      [l(:project_status_active), "#{Project::STATUS_ACTIVE}"],
      [l(:project_status_closed), "#{Project::STATUS_CLOSED}"]
    ]
  end

  # Adds available filters
  def initialize_available_filters
    # implemented by sub-classes
  end
  protected :initialize_available_filters

  # Adds an available filter
  def add_available_filter(field, options)
    @available_filters ||= ActiveSupport::OrderedHash.new
    @available_filters[field] = QueryFilter.new(field, options)
    @available_filters
  end

  # Removes an available filter
  def delete_available_filter(field)
    if @available_filters
      @available_filters.delete(field)
    end
  end

  # Return a hash of available filters
  def available_filters
    unless @available_filters
      initialize_available_filters
      @available_filters ||= {}
    end
    @available_filters
  end

  def add_filter(field, operator, values=nil)
    # values must be an array
    return unless values.nil? || values.is_a?(Array)
    # check if field is defined as an available filter
    if available_filters.has_key? field
      filters[field] = {:operator => operator, :values => (values || [''])}
    end
  end

  def add_short_filter(field, expression)
    return unless expression && available_filters.has_key?(field)
    field_type = available_filters[field][:type]
    operators_by_filter_type[field_type].sort.reverse.detect do |operator|
      next unless expression =~ /^#{Regexp.escape(operator)}(.*)$/
      values = $1
      add_filter field, operator, values.present? ? values.split('|') : ['']
    end || add_filter(field, '=', expression.to_s.split('|'))
  end

  # Add multiple filters using +add_filter+
  def add_filters(fields, operators, values)
    if fields.present? && operators.present?
      fields.each do |field|
        add_filter(field, operators[field], values && values[field])
      end
    end
  end

  def has_filter?(field)
    filters and filters[field]
  end

  def type_for(field)
    available_filters[field][:type] if available_filters.has_key?(field)
  end

  def operator_for(field)
    has_filter?(field) ? filters[field][:operator] : nil
  end

  def values_for(field)
    has_filter?(field) ? filters[field][:values] : nil
  end

  def value_for(field, index=0)
    (values_for(field) || [])[index]
  end

  def label_for(field)
    label = available_filters[field][:name] if available_filters.has_key?(field)
    label ||= queried_class.human_attribute_name(field, :default => field)
  end

  def self.add_available_column(column)
    self.available_columns << (column) if column.is_a?(QueryColumn)
  end

  # Returns an array of columns that can be used to group the results
  def groupable_columns
    available_columns.select {|c| c.groupable}
  end

  # Returns a Hash of columns and the key for sorting
  def sortable_columns
    available_columns.inject({}) {|h, column|
      h[column.name.to_s] = column.sortable
      h
    }
  end

  def columns
    # preserve the column_names order
    cols = (has_default_columns? ? default_columns_names : column_names).collect do |name|
       available_columns.find { |col| col.name == name }
    end.compact
    available_columns.select(&:frozen?) | cols
  end

  def inline_columns
    columns.select(&:inline?)
  end

  def block_columns
    columns.reject(&:inline?)
  end

  def available_inline_columns
    available_columns.select(&:inline?)
  end

  def available_block_columns
    available_columns.reject(&:inline?)
  end

  def available_totalable_columns
    available_columns.select(&:totalable)
  end

  def default_columns_names
    []
  end

  def default_totalable_names
    []
  end

  def column_names=(names)
    if names
      names = names.select {|n| n.is_a?(Symbol) || !n.blank? }
      names = names.collect {|n| n.is_a?(Symbol) ? n : n.to_sym }
      if names.delete(:all_inline)
        names = available_inline_columns.map(&:name) | names
      end
      # Set column_names to nil if default columns
      if names == default_columns_names
        names = nil
      end
    end
    write_attribute(:column_names, names)
  end

  def has_column?(column)
    name = column.is_a?(QueryColumn) ? column.name : column
    columns.detect {|c| c.name == name}
  end

  def has_custom_field_column?
    columns.any? {|column| column.is_a? QueryCustomFieldColumn}
  end

  def has_default_columns?
    column_names.nil? || column_names.empty?
  end

  def totalable_columns
    names = totalable_names
    available_totalable_columns.select {|column| names.include?(column.name)}
  end

  def totalable_names=(names)
    if names
      names = names.select(&:present?).map {|n| n.is_a?(Symbol) ? n : n.to_sym}
    end
    options[:totalable_names] = names
  end

  def totalable_names
    options[:totalable_names] || default_totalable_names || []
  end

  def default_sort_criteria
    []
  end

  def sort_criteria=(arg)
    c = Redmine::SortCriteria.new(arg)
    write_attribute(:sort_criteria, c.to_a)
    c
  end

  def sort_criteria
    c = read_attribute(:sort_criteria)
    if c.blank?
      c = default_sort_criteria
    end
    Redmine::SortCriteria.new(c)
  end

  def sort_criteria_key(index)
    sort_criteria[index].try(:first)
  end

  def sort_criteria_order(index)
    sort_criteria[index].try(:last)
  end

  def sort_clause
    if clause = sort_criteria.sort_clause(sortable_columns)
      clause.map {|c| Arel.sql c}
    end
  end

  # Returns the SQL sort order that should be prepended for grouping
  def group_by_sort_order
    if column = group_by_column
      order = (sort_criteria.order_for(column.name) || column.default_order || 'asc').try(:upcase)
      Array(column.sortable).map {|s| Arel.sql("#{s} #{order}")}
    end
  end

  # Returns true if the query is a grouped query
  def grouped?
    !group_by_column.nil?
  end

  def group_by_column
    groupable_columns.detect {|c| c.groupable && c.name.to_s == group_by}
  end

  def group_by_statement
    group_by_column.try(:groupable)
  end

  def project_statement
    project_clauses = []
    active_subprojects_ids = []

    active_subprojects_ids = project.descendants.active.map(&:id) if project
    if active_subprojects_ids.any?
      if has_filter?("subproject_id")
        case operator_for("subproject_id")
        when '='
          # include the selected subprojects
          ids = [project.id] + values_for("subproject_id").map(&:to_i)
          project_clauses << "#{Project.table_name}.id IN (%s)" % ids.join(',')
        when '!'
          # exclude the selected subprojects
          ids = [project.id] + active_subprojects_ids - values_for("subproject_id").map(&:to_i)
          project_clauses << "#{Project.table_name}.id IN (%s)" % ids.join(',')
        when '!*'
          # main project only
          project_clauses << "#{Project.table_name}.id = %d" % project.id
        else
          # all subprojects
          project_clauses << "#{Project.table_name}.lft >= #{project.lft} AND #{Project.table_name}.rgt <= #{project.rgt}"
        end
      elsif Setting.display_subprojects_issues?
        project_clauses << "#{Project.table_name}.lft >= #{project.lft} AND #{Project.table_name}.rgt <= #{project.rgt}"
      else
        project_clauses << "#{Project.table_name}.id = %d" % project.id
      end
    elsif project
      project_clauses << "#{Project.table_name}.id = %d" % project.id
    end
    project_clauses.any? ? project_clauses.join(' AND ') : nil
  end

  def statement
    # filters clauses
    filters_clauses = []
    filters.each_key do |field|
      next if field == "subproject_id"
      v = values_for(field).clone
      next unless v and !v.empty?
      operator = operator_for(field)

      # "me" value substitution
      if %w(assigned_to_id author_id user_id watcher_id updated_by last_updated_by).include?(field)
        if v.delete("me")
          if User.current.logged?
            v.push(User.current.id.to_s)
            v += User.current.group_ids.map(&:to_s) if field == 'assigned_to_id'
          else
            v.push("0")
          end
        end
      end

      if field == 'project_id'
        if v.delete('mine')
          v += User.current.memberships.map(&:project_id).map(&:to_s)
        end
      end

      if field =~ /^cf_(\d+)\.cf_(\d+)$/
        filters_clauses << sql_for_chained_custom_field(field, operator, v, $1, $2)
      elsif field =~ /cf_(\d+)$/
        # custom field
        filters_clauses << sql_for_custom_field(field, operator, v, $1)
      elsif field =~ /^cf_(\d+)\.(.+)$/
        filters_clauses << sql_for_custom_field_attribute(field, operator, v, $1, $2)
      elsif respond_to?(method = "sql_for_#{field.tr('.','_')}_field")
        # specific statement
        filters_clauses << send(method, field, operator, v)
      else
        # regular field
        filters_clauses << '(' + sql_for_field(field, operator, v, queried_table_name, field) + ')'
      end
    end if filters and valid?

    if (c = group_by_column) && c.is_a?(QueryCustomFieldColumn)
      # Excludes results for which the grouped custom field is not visible
      filters_clauses << c.custom_field.visibility_by_project_condition
    end

    filters_clauses << project_statement
    filters_clauses.reject!(&:blank?)

    filters_clauses.any? ? filters_clauses.join(' AND ') : nil
  end

  # Returns the result count by group or nil if query is not grouped
  def result_count_by_group
    grouped_query do |scope|
      scope.count
    end
  end

  # Returns the sum of values for the given column
  def total_for(column)
    total_with_scope(column, base_scope)
  end

  # Returns a hash of the sum of the given column for each group,
  # or nil if the query is not grouped
  def total_by_group_for(column)
    grouped_query do |scope|
      total_with_scope(column, scope)
    end
  end

  def totals
    totals = totalable_columns.map {|column| [column, total_for(column)]}
    yield totals if block_given?
    totals
  end

  def totals_by_group
    totals = totalable_columns.map {|column| [column, total_by_group_for(column)]}
    yield totals if block_given?
    totals
  end

  def css_classes
    s = sort_criteria.first
    if s.present?
      key, asc = s
      "sort-by-#{key.to_s.dasherize} sort-#{asc}"
    end
  end

  private

  def grouped_query(&block)
    r = nil
    if grouped?
      r = yield base_group_scope
      c = group_by_column
      if c.is_a?(QueryCustomFieldColumn)
        r = r.keys.inject({}) {|h, k| h[c.custom_field.cast_value(k)] = r[k]; h}
      end
    end
    r
  rescue ::ActiveRecord::StatementInvalid => e
    raise StatementInvalid.new(e.message)
  end

  def total_with_scope(column, scope)
    unless column.is_a?(QueryColumn)
      column = column.to_sym
      column = available_totalable_columns.detect {|c| c.name == column}
    end
    if column.is_a?(QueryCustomFieldColumn)
      custom_field = column.custom_field
      send "total_for_custom_field", custom_field, scope
    else
      send "total_for_#{column.name}", scope
    end
  rescue ::ActiveRecord::StatementInvalid => e
    raise StatementInvalid.new(e.message)
  end

  def base_scope
    raise "unimplemented"
  end

  def base_group_scope
    base_scope.
      joins(joins_for_order_statement(group_by_statement)).
      group(group_by_statement)
  end

  def total_for_custom_field(custom_field, scope, &block)
    total = custom_field.format.total_for_scope(custom_field, scope)
    total = map_total(total) {|t| custom_field.format.cast_total_value(custom_field, t)}
    total
  end

  def map_total(total, &block)
    if total.is_a?(Hash)
      total.each_key {|k| total[k] = yield total[k]}
    else
      total = yield total
    end
    total
  end

  def sql_for_custom_field(field, operator, value, custom_field_id)
    db_table = CustomValue.table_name
    db_field = 'value'
    filter = @available_filters[field]
    return nil unless filter
    if filter[:field].format.target_class && filter[:field].format.target_class <= User
      if value.delete('me')
        value.push User.current.id.to_s
      end
    end
    not_in = nil
    if operator == '!'
      # Makes ! operator work for custom fields with multiple values
      operator = '='
      not_in = 'NOT'
    end
    customized_key = "id"
    customized_class = queried_class
    if field =~ /^(.+)\.cf_/
      assoc = $1
      customized_key = "#{assoc}_id"
      customized_class = queried_class.reflect_on_association(assoc.to_sym).klass.base_class rescue nil
      raise "Unknown #{queried_class.name} association #{assoc}" unless customized_class
    end
    where = sql_for_field(field, operator, value, db_table, db_field, true)
    if /[<>]/.match?(operator)
      where = "(#{where}) AND #{db_table}.#{db_field} <> ''"
    end
    "#{queried_table_name}.#{customized_key} #{not_in} IN (" +
      "SELECT #{customized_class.table_name}.id FROM #{customized_class.table_name}" +
      " LEFT OUTER JOIN #{db_table} ON #{db_table}.customized_type='#{customized_class}' AND #{db_table}.customized_id=#{customized_class.table_name}.id AND #{db_table}.custom_field_id=#{custom_field_id}" +
      " WHERE (#{where}) AND (#{filter[:field].visibility_by_project_condition}))"
  end

  def sql_for_chained_custom_field(field, operator, value, custom_field_id, chained_custom_field_id)
    not_in = nil
    if operator == '!'
      # Makes ! operator work for custom fields with multiple values
      operator = '='
      not_in = 'NOT'
    end

    filter = available_filters[field]
    target_class = filter[:through].format.target_class

    "#{queried_table_name}.id #{not_in} IN (" +
      "SELECT customized_id FROM #{CustomValue.table_name}" +
      " WHERE customized_type='#{queried_class}' AND custom_field_id=#{custom_field_id}" +
      "  AND CAST(CASE value WHEN '' THEN '0' ELSE value END AS decimal(30,0)) IN (" +
      "  SELECT customized_id FROM #{CustomValue.table_name}" +
      "  WHERE customized_type='#{target_class}' AND custom_field_id=#{chained_custom_field_id}" +
      "  AND #{sql_for_field(field, operator, value, CustomValue.table_name, 'value')}))"

  end

  def sql_for_custom_field_attribute(field, operator, value, custom_field_id, attribute)
    attribute = 'effective_date' if attribute == 'due_date'
    not_in = nil
    if operator == '!'
      # Makes ! operator work for custom fields with multiple values
      operator = '='
      not_in = 'NOT'
    end

    filter = available_filters[field]
    target_table_name = filter[:field].format.target_class.table_name

    "#{queried_table_name}.id #{not_in} IN (" +
      "SELECT customized_id FROM #{CustomValue.table_name}" +
      " WHERE customized_type='#{queried_class}' AND custom_field_id=#{custom_field_id}" +
      "  AND CAST(CASE value WHEN '' THEN '0' ELSE value END AS decimal(30,0)) IN (" +
      "  SELECT id FROM #{target_table_name} WHERE #{sql_for_field(field, operator, value, filter[:field].format.target_class.table_name, attribute)}))"
  end

  # Helper method to generate the WHERE sql for a +field+, +operator+ and a +value+
  def sql_for_field(field, operator, value, db_table, db_field, is_custom_filter=false)
    sql = ''
    case operator
    when "="
      if value.any?
        case type_for(field)
        when :date, :date_past
          sql = date_clause(db_table, db_field, parse_date(value.first), parse_date(value.first), is_custom_filter)
        when :integer
          int_values = value.first.to_s.scan(/[+-]?\d+/).map(&:to_i).join(",")
          if int_values.present?
            if is_custom_filter
              sql = "(#{db_table}.#{db_field} <> '' AND CAST(CASE #{db_table}.#{db_field} WHEN '' THEN '0' ELSE #{db_table}.#{db_field} END AS decimal(30,3)) IN (#{int_values}))"
            else
              sql = "#{db_table}.#{db_field} IN (#{int_values})"
            end
          else
            sql = "1=0"
          end
        when :float
          if is_custom_filter
            sql = "(#{db_table}.#{db_field} <> '' AND CAST(CASE #{db_table}.#{db_field} WHEN '' THEN '0' ELSE #{db_table}.#{db_field} END AS decimal(30,3)) BETWEEN #{value.first.to_f - 1e-5} AND #{value.first.to_f + 1e-5})"
          else
            sql = "#{db_table}.#{db_field} BETWEEN #{value.first.to_f - 1e-5} AND #{value.first.to_f + 1e-5}"
          end
        else
          sql = queried_class.send(:sanitize_sql_for_conditions, ["#{db_table}.#{db_field} IN (?)", value])
        end
      else
        # IN an empty set
        sql = "1=0"
      end
    when "!"
      if value.any?
        sql = queried_class.send(:sanitize_sql_for_conditions, ["(#{db_table}.#{db_field} IS NULL OR #{db_table}.#{db_field} NOT IN (?))", value])
      else
        # NOT IN an empty set
        sql = "1=1"
      end
    when "!*"
      sql = "#{db_table}.#{db_field} IS NULL"
      sql += " OR #{db_table}.#{db_field} = ''" if (is_custom_filter || [:text, :string].include?(type_for(field)))
    when "*"
      sql = "#{db_table}.#{db_field} IS NOT NULL"
      sql += " AND #{db_table}.#{db_field} <> ''" if is_custom_filter
    when ">="
      if [:date, :date_past].include?(type_for(field))
        sql = date_clause(db_table, db_field, parse_date(value.first), nil, is_custom_filter)
      else
        if is_custom_filter
          sql = "(#{db_table}.#{db_field} <> '' AND CAST(CASE #{db_table}.#{db_field} WHEN '' THEN '0' ELSE #{db_table}.#{db_field} END AS decimal(30,3)) >= #{value.first.to_f})"
        else
          sql = "#{db_table}.#{db_field} >= #{value.first.to_f}"
        end
      end
    when "<="
      if [:date, :date_past].include?(type_for(field))
        sql = date_clause(db_table, db_field, nil, parse_date(value.first), is_custom_filter)
      else
        if is_custom_filter
          sql = "(#{db_table}.#{db_field} <> '' AND CAST(CASE #{db_table}.#{db_field} WHEN '' THEN '0' ELSE #{db_table}.#{db_field} END AS decimal(30,3)) <= #{value.first.to_f})"
        else
          sql = "#{db_table}.#{db_field} <= #{value.first.to_f}"
        end
      end
    when "><"
      if [:date, :date_past].include?(type_for(field))
        sql = date_clause(db_table, db_field, parse_date(value[0]), parse_date(value[1]), is_custom_filter)
      else
        if is_custom_filter
          sql = "(#{db_table}.#{db_field} <> '' AND CAST(CASE #{db_table}.#{db_field} WHEN '' THEN '0' ELSE #{db_table}.#{db_field} END AS decimal(30,3)) BETWEEN #{value[0].to_f} AND #{value[1].to_f})"
        else
          sql = "#{db_table}.#{db_field} BETWEEN #{value[0].to_f} AND #{value[1].to_f}"
        end
      end
    when "o"
      sql = "#{queried_table_name}.status_id IN (SELECT id FROM #{IssueStatus.table_name} WHERE is_closed=#{self.class.connection.quoted_false})" if field == "status_id"
    when "c"
      sql = "#{queried_table_name}.status_id IN (SELECT id FROM #{IssueStatus.table_name} WHERE is_closed=#{self.class.connection.quoted_true})" if field == "status_id"
    when "><t-"
      # between today - n days and today
      sql = relative_date_clause(db_table, db_field, - value.first.to_i, 0, is_custom_filter)
    when ">t-"
      # >= today - n days
      sql = relative_date_clause(db_table, db_field, - value.first.to_i, nil, is_custom_filter)
    when "<t-"
      # <= today - n days
      sql = relative_date_clause(db_table, db_field, nil, - value.first.to_i, is_custom_filter)
    when "t-"
      # = n days in past
      sql = relative_date_clause(db_table, db_field, - value.first.to_i, - value.first.to_i, is_custom_filter)
    when "><t+"
      # between today and today + n days
      sql = relative_date_clause(db_table, db_field, 0, value.first.to_i, is_custom_filter)
    when ">t+"
      # >= today + n days
      sql = relative_date_clause(db_table, db_field, value.first.to_i, nil, is_custom_filter)
    when "<t+"
      # <= today + n days
      sql = relative_date_clause(db_table, db_field, nil, value.first.to_i, is_custom_filter)
    when "t+"
      # = today + n days
      sql = relative_date_clause(db_table, db_field, value.first.to_i, value.first.to_i, is_custom_filter)
    when "t"
      # = today
      sql = relative_date_clause(db_table, db_field, 0, 0, is_custom_filter)
    when "ld"
      # = yesterday
      sql = relative_date_clause(db_table, db_field, -1, -1, is_custom_filter)
    when "nd"
      # = tomorrow
      sql = relative_date_clause(db_table, db_field, 1, 1, is_custom_filter)
    when "w"
      # = this week
      first_day_of_week = l(:general_first_day_of_week).to_i
      day_of_week = User.current.today.cwday
      days_ago = (day_of_week >= first_day_of_week ? day_of_week - first_day_of_week : day_of_week + 7 - first_day_of_week)
      sql = relative_date_clause(db_table, db_field, - days_ago, - days_ago + 6, is_custom_filter)
    when "lw"
      # = last week
      first_day_of_week = l(:general_first_day_of_week).to_i
      day_of_week = User.current.today.cwday
      days_ago = (day_of_week >= first_day_of_week ? day_of_week - first_day_of_week : day_of_week + 7 - first_day_of_week)
      sql = relative_date_clause(db_table, db_field, - days_ago - 7, - days_ago - 1, is_custom_filter)
    when "l2w"
      # = last 2 weeks
      first_day_of_week = l(:general_first_day_of_week).to_i
      day_of_week = User.current.today.cwday
      days_ago = (day_of_week >= first_day_of_week ? day_of_week - first_day_of_week : day_of_week + 7 - first_day_of_week)
      sql = relative_date_clause(db_table, db_field, - days_ago - 14, - days_ago - 1, is_custom_filter)
    when "nw"
      # = next week
      first_day_of_week = l(:general_first_day_of_week).to_i
      day_of_week = User.current.today.cwday
      from = -(day_of_week >= first_day_of_week ? day_of_week - first_day_of_week : day_of_week + 7 - first_day_of_week) + 7
      sql = relative_date_clause(db_table, db_field, from, from + 6, is_custom_filter)
    when "m"
      # = this month
      date = User.current.today
      sql = date_clause(db_table, db_field, date.beginning_of_month, date.end_of_month, is_custom_filter)
    when "lm"
      # = last month
      date = User.current.today.prev_month
      sql = date_clause(db_table, db_field, date.beginning_of_month, date.end_of_month, is_custom_filter)
    when "nm"
      # = next month
      date = User.current.today.next_month
      sql = date_clause(db_table, db_field, date.beginning_of_month, date.end_of_month, is_custom_filter)
    when "y"
      # = this year
      date = User.current.today
      sql = date_clause(db_table, db_field, date.beginning_of_year, date.end_of_year, is_custom_filter)
    when "~"
      sql = sql_contains("#{db_table}.#{db_field}", value.first)
    when "!~"
      sql = sql_contains("#{db_table}.#{db_field}", value.first, false)
    else
      raise "Unknown query operator #{operator}"
    end

    return sql
  end

  # Returns a SQL LIKE statement with wildcards
  def sql_contains(db_field, value, match=true)
    queried_class.send :sanitize_sql_for_conditions,
      [Redmine::Database.like(db_field, '?', :match => match), "%#{value}%"]
  end

  # Adds a filter for the given custom field
  def add_custom_field_filter(field, assoc=nil)
    options = field.query_filter_options(self)

    filter_id = "cf_#{field.id}"
    filter_name = field.name
    if assoc.present?
      filter_id = "#{assoc}.#{filter_id}"
      filter_name = l("label_attribute_of_#{assoc}", :name => filter_name)
    end
    add_available_filter filter_id, options.merge({
      :name => filter_name,
      :field => field
    })
  end

  # Adds filters for custom fields associated to the custom field target class
  # Eg. having a version custom field "Milestone" for issues and a date custom field "Release date"
  # for versions, it will add an issue filter on Milestone'e Release date.
  def add_chained_custom_field_filters(field)
    klass = field.format.target_class
    if klass
      CustomField.where(:is_filter => true, :type => "#{klass.name}CustomField").each do |chained|
        options = chained.query_filter_options(self)

        filter_id = "cf_#{field.id}.cf_#{chained.id}"
        filter_name = chained.name

        add_available_filter filter_id, options.merge({
          :name => l(:label_attribute_of_object, :name => chained.name, :object_name => field.name),
          :field => chained,
          :through => field
        })
      end
    end
  end

  # Adds filters for the given custom fields scope
  def add_custom_fields_filters(scope, assoc=nil)
    scope.visible.where(:is_filter => true).sorted.each do |field|
      add_custom_field_filter(field, assoc)
      if assoc.nil?
        add_chained_custom_field_filters(field)

        if field.format.target_class && field.format.target_class == Version
          add_available_filter "cf_#{field.id}.due_date",
            :type => :date,
            :field => field,
            :name => l(:label_attribute_of_object, :name => l(:field_effective_date), :object_name => field.name)

          add_available_filter "cf_#{field.id}.status",
            :type => :list,
            :field => field,
            :name => l(:label_attribute_of_object, :name => l(:field_status), :object_name => field.name),
            :values => Version::VERSION_STATUSES.map{|s| [l("version_status_#{s}"), s] }
        end
      end
    end
  end

  # Adds filters for the given associations custom fields
  def add_associations_custom_fields_filters(*associations)
    fields_by_class = CustomField.visible.where(:is_filter => true).group_by(&:class)
    associations.each do |assoc|
      association_klass = queried_class.reflect_on_association(assoc).klass
      fields_by_class.each do |field_class, fields|
        if field_class.customized_class <= association_klass
          fields.sort.each do |field|
            add_custom_field_filter(field, assoc)
          end
        end
      end
    end
  end

  def quoted_time(time, is_custom_filter)
    if is_custom_filter
      # Custom field values are stored as strings in the DB
      # using this format that does not depend on DB date representation
      time.strftime("%Y-%m-%d %H:%M:%S")
    else
      self.class.connection.quoted_date(time)
    end
  end

  def date_for_user_time_zone(y, m, d)
    if tz = User.current.time_zone
      tz.local y, m, d
    else
      Time.local y, m, d
    end
  end

  # Returns a SQL clause for a date or datetime field.
  def date_clause(table, field, from, to, is_custom_filter)
    s = []
    if from
      if from.is_a?(Date)
        from = date_for_user_time_zone(from.year, from.month, from.day).yesterday.end_of_day
      else
        from = from - 1 # second
      end
      if self.class.default_timezone == :utc
        from = from.utc
      end
      s << ("#{table}.#{field} > '%s'" % [quoted_time(from, is_custom_filter)])
    end
    if to
      if to.is_a?(Date)
        to = date_for_user_time_zone(to.year, to.month, to.day).end_of_day
      end
      if self.class.default_timezone == :utc
        to = to.utc
      end
      s << ("#{table}.#{field} <= '%s'" % [quoted_time(to, is_custom_filter)])
    end
    s.join(' AND ')
  end

  # Returns a SQL clause for a date or datetime field using relative dates.
  def relative_date_clause(table, field, days_from, days_to, is_custom_filter)
    date_clause(table, field, (days_from ? User.current.today + days_from : nil), (days_to ? User.current.today + days_to : nil), is_custom_filter)
  end

  # Returns a Date or Time from the given filter value
  def parse_date(arg)
    if /\A\d{4}-\d{2}-\d{2}T/.match?(arg.to_s)
      Time.parse(arg) rescue nil
    else
      Date.parse(arg) rescue nil
    end
  end

  # Additional joins required for the given sort options
  def joins_for_order_statement(order_options)
    joins = []

    if order_options
      order_options.scan(/cf_\d+/).uniq.each do |name|
        column = available_columns.detect {|c| c.name.to_s == name}
        join = column && column.custom_field.join_for_order_statement
        if join
          joins << join
        end
      end
    end

    joins.any? ? joins.join(' ') : nil
  end
end