#-- encoding: UTF-8
#-- copyright
# OpenProject is a project management system.
# Copyright (C) 2012-2018 the OpenProject Foundation (OPF)
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License version 3.
#
# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
# Copyright (C) 2006-2017 Jean-Philippe Lang
# Copyright (C) 2010-2013 the ChiliProject Team
#
# 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.
#
# See docs/COPYRIGHT.rdoc for more details.
#++

class Member < ActiveRecord::Base
  belongs_to :user
  belongs_to :principal, foreign_key: 'user_id'
  has_many :member_roles, dependent: :destroy, autosave: true
  has_many :roles, through: :member_roles
  belongs_to :project

  validates_presence_of :project
  validates_uniqueness_of :user_id, scope: :project_id

  validate :validate_presence_of_role
  validate :validate_presence_of_principal

  before_destroy :remove_from_category_assignments
  after_destroy :unwatch_from_permission_change,
                if: ->(member) { member.prune_watchers_on_destruction != false }

  after_save :save_notification
  after_destroy :destroy_notification

  scope :of, ->(project) {
    where(project_id: project)
  }

  def self.visible(user)
    where(project_id: Project.visible_by(user))
  end

  def name
    principal.name
  end

  def to_s
    name
  end

  # Set the roles for this member to the given roles_or_role_ids.
  # Inherited roles are left untouched.
  def assign_roles(roles_or_role_ids)
    do_assign_roles(roles_or_role_ids, false)
  end

  alias :base_role_ids= :role_ids=

  # Set the roles for this member to the given roles_or_role_ids, immediately
  # save the changes and destroy the member in case no role is left.
  # Inherited roles are left untouched.
  def assign_and_save_roles_and_destroy_member_if_none_left(roles_or_role_ids)
    do_assign_roles(roles_or_role_ids, true)
  end
  alias_method :role_ids=, :assign_and_save_roles_and_destroy_member_if_none_left

  # Add a role to the membership
  # Does not save the changes, the member must be saved afterwards for the role to be added.
  def add_role(role_or_role_id, inherited_from_id = nil)
    do_add_role(role_or_role_id, inherited_from_id, false)
  end

  # Add a role and save the change to the database
  def add_and_save_role(role_or_role_id, inherited_from_id = nil)
    do_add_role(role_or_role_id, inherited_from_id, true)
  end

  # Mark one of the member's roles for destruction
  #
  # Make sure to get the MemberRole instance from the member's association, otherwise the actual
  # destruction on save doesn't work.
  def mark_member_role_for_destruction(member_role)
    do_remove_member_role(member_role, false)
  end

  # Remove a role from a member
  # Destroys the member itself when no role is left afterwards
  #
  # Make sure to get the MemberRole instance from the member's association, otherwise the
  # destruction of the member, when the last MemberRole is destroyed, might not work.
  def remove_member_role_and_destroy_member_if_last(member_role, prune_watchers: true)
    do_remove_member_role(member_role, true, prune_watchers: prune_watchers)
  end

  def <=>(member)
    a = roles.sort.first
    b = member.roles.sort.first
    a == b ? (principal <=> member.principal) : (a <=> b)
  end

  def deletable?
    member_roles.detect(&:inherited_from).nil?
  end

  def include?(user)
    if principal.is_a?(Group)
      !user.nil? && user.groups.include?(principal)
    else
      self.user == user
    end
  end

  # remove category based auto assignments for this member
  #
  # Note: This logic is duplicated for mass deletion in `app/models/group/destroy.rb`.
  #       Accordingly it has to be changed there too should this bit change at all.
  def remove_from_category_assignments
    Category.where(['project_id = ? AND assigned_to_id = ?', project_id, user_id])
      .update_all 'assigned_to_id = NULL' if user
  end

  ##
  # Returns true if this user can be deleted as they have no other memberships
  # and haven't been activated yet. Only applies if the member is actually a user
  # as opposed to a group.
  def disposable?
    user && user.invited? && user.memberships.none? { |m| m.project_id != project_id }
  end

  protected

  attr_accessor :prune_watchers_on_destruction

  def destroy_if_no_roles_left!
    destroy if member_roles.empty? || member_roles.all? do |member_role|
      member_role.marked_for_destruction? || member_role.destroyed?
    end
  end

  def validate_presence_of_role
    if member_roles.empty?
      errors.add :base, :role_blank if roles.empty?
    else
      errors.add :base, :role_blank if member_roles.all? do |member_role|
        member_role.marked_for_destruction? || member_role.destroyed?
      end
    end
  end

  def validate_presence_of_principal
    errors.add :base, :principal_blank if principal.blank?
  end

  def do_add_role(role_or_role_id, inherited_from_id, save_immediately)
    id = (role_or_role_id.is_a? Role) ? role_or_role_id.id : role_or_role_id

    if save_immediately
      member_roles << MemberRole.new.tap do |member_role|
        member_role.role_id = id
        member_role.inherited_from = inherited_from_id
      end
    else
      member_roles.build.tap do |member_role|
        member_role.role_id = id
        member_role.inherited_from = inherited_from_id
      end
    end
  end

  # Set save_and_possibly_destroy to true to immediately save changes and destroy
  # when no roles are left.
  def do_assign_roles(roles_or_role_ids, save_and_possibly_destroy)
    # ensure we have integer ids
    ids = roles_or_role_ids.map { |r| (r.is_a? Role) ? r.id : r.to_i }

    # Keep inherited roles
    ids += member_roles.select { |mr| !mr.inherited_from.nil? }.map(&:role_id)

    new_role_ids = ids - role_ids
    # Add new roles
    # Do this before destroying them, otherwise the Member is destroyed due to not having any
    # Roles assigned via MemberRoles.
    new_role_ids.each do |id| do_add_role(id, nil, save_and_possibly_destroy) end

    # Remove roles (Rails' #role_ids= will not trigger MemberRole#on_destroy)
    member_roles_to_destroy = member_roles.select { |mr| !ids.include?(mr.role_id) }
    member_roles_to_destroy.each { |mr| do_remove_member_role(mr, save_and_possibly_destroy) }
  end

  def do_remove_member_role(member_role, destroy, prune_watchers: true)
    self.prune_watchers_on_destruction = prune_watchers

    # because we later on check whether all member_roles have been destroyed
    # (at least when we do destroy it) we have to work on the member_role
    # instance existing in the member_roles association.  Otherwise, while
    # representing the same db entry, the instances could be different and the
    # wrong instance might have the destroyed flag.
    to_destroy = member_roles.detect { |mr| mr.id == member_role.id }

    if destroy
      to_destroy.destroy_for_member
      destroy_if_no_roles_left!
    else
      to_destroy.mark_for_destruction
    end
    unwatch_from_permission_change if prune_watchers

    self.prune_watchers_on_destruction = true
  end

  private

  # Unwatch things that the user is no longer allowed to view inside project
  #
  # Note: This logic is duplicated for mass deletion in `app/models/group/destroy.rb`.
  #       Accordingly it has to be changed there too should this bit change at all.
  def unwatch_from_permission_change
    if user
      Watcher.prune(user: user, project_id: project.id)
    end
  end

  def save_notification
    ::OpenProject::Notifications.send(:member_updated, member: self)
  end

  def destroy_notification
    ::OpenProject::Notifications.send(:member_removed, member: self)
  end
end