#-- 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 UserMailer < BaseMailer
  helper :application, # for format_text
         :work_packages, # for css classes
         :custom_fields # for show_value
  helper IssuesHelper

  include OpenProject::LocaleHelper

  # wrap in a lambda to allow changing at run-time
  default from: Proc.new { Setting.mail_from }

  def test_mail(user)
    @welcome_url = url_for(controller: '/homescreen')

    headers['X-OpenProject-Type'] = 'Test'

    with_locale_for(user) do
      mail to: "\"#{user.name}\" <#{user.mail}>", subject: 'OpenProject Test'
    end
  end

  def work_package_added(user, journal, author)
    User.execute_as user do
      work_package = journal.journable.reload
      @issue = work_package # instance variable is used in the view
      @journal = journal

      set_work_package_headers(work_package)

      message_id work_package, user

      with_locale_for(user) do
        mail_for_author author, to: user.mail, subject: subject_for_work_package(work_package)
      end
    end
  end

  def work_package_updated(user, journal, author = User.current)
    User.execute_as user do
      work_package = journal.journable.reload

      # instance variables are used in the view
      @issue = work_package
      @journal = journal

      set_work_package_headers(work_package)

      message_id journal, user
      references work_package, user

      with_locale_for(user) do
        mail_for_author author, to: user.mail, subject: subject_for_work_package(work_package)
      end
    end
  end

  def work_package_watcher_added(work_package, user, watcher_setter)
    User.execute_as user do
      @issue = work_package
      @watcher_setter = watcher_setter

      set_work_package_headers(work_package)
      message_id work_package, user
      references work_package, user

      with_locale_for(user) do
        mail to: user.mail, subject: subject_for_work_package(work_package)
      end
    end
  end

  def password_lost(token)
    return unless token.user # token's can have no user

    @token = token
    @reset_password_url = url_for(controller: '/account',
                                  action:     :lost_password,
                                  token:      @token.value)

    open_project_headers 'Type' => 'Account'

    user = @token.user
    with_locale_for(user) do
      subject = t(:mail_subject_lost_password, value: Setting.app_title)
      mail to: user.mail, subject: subject
    end
  end

  def copy_project_failed(user, source_project, target_project_name, errors)
    @source_project = source_project
    @target_project_name = target_project_name
    @errors = errors

    open_project_headers 'Source-Project' => source_project.identifier,
                         'Author'         => user.login

    message_id source_project, user

    with_locale_for(user) do
      subject = I18n.t('copy_project.failed', source_project_name: source_project.name)

      mail to: user.mail, subject: subject
    end
  end

  def copy_project_succeeded(user, source_project, target_project, errors)
    @source_project = source_project
    @target_project = target_project
    @errors = errors

    open_project_headers 'Source-Project' => source_project.identifier,
                         'Target-Project' => target_project.identifier,
                         'Author'         => user.login

    message_id target_project, user

    with_locale_for(user) do
      subject = I18n.t('copy_project.succeeded', target_project_name: target_project.name)

      mail to: user.mail, subject: subject
    end
  end

  def news_added(user, news, author)
    @news = news

    open_project_headers 'Type'    => 'News'
    open_project_headers 'Project' => @news.project.identifier if @news.project

    message_id @news, user

    with_locale_for(user) do
      subject = "#{News.model_name.human}: #{@news.title}"
      subject = "[#{@news.project.name}] #{subject}" if @news.project
      mail_for_author author, to: user.mail, subject: subject
    end
  end

  def user_signed_up(token)
    return unless token.user

    @token = token
    @activation_url = url_for(controller: '/account',
                              action:     :activate,
                              token:      @token.value)

    open_project_headers 'Type' => 'Account'

    user = token.user
    with_locale_for(user) do
      subject = t(:mail_subject_register, value: Setting.app_title)
      mail to: user.mail, subject: subject
    end
  end

  def news_comment_added(user, comment, author)
    @comment = comment
    @news    = @comment.commented

    open_project_headers 'Project' => @news.project.identifier if @news.project

    message_id @comment, user
    references @news, user

    with_locale_for(user) do
      subject = "#{News.model_name.human}: #{@news.title}"
      subject = "Re: [#{@news.project.name}] #{subject}" if @news.project
      mail_for_author author, to: user.mail, subject: subject
    end
  end

  def wiki_content_added(user, wiki_content, author)
    @wiki_content = wiki_content

    open_project_headers 'Project'      => @wiki_content.project.identifier,
                         'Wiki-Page-Id' => @wiki_content.page.id,
                         'Type'         => 'Wiki'

    message_id @wiki_content, user

    with_locale_for(user) do
      subject = "[#{@wiki_content.project.name}] #{t(:mail_subject_wiki_content_added, id: @wiki_content.page.title)}"
      mail_for_author author, to: user.mail, subject: subject
    end
  end

  def wiki_content_updated(user, wiki_content, author)
    @wiki_content  = wiki_content
    @wiki_diff_url = url_for(controller: '/wiki',
                             action:     :diff,
                             project_id: wiki_content.project,
                             id:         wiki_content.page.title,
                             # using wiki_content.version + 1 because at this point the journal is not saved yet
                             version:    wiki_content.version + 1)

    open_project_headers 'Project'      => @wiki_content.project.identifier,
                         'Wiki-Page-Id' => @wiki_content.page.id,
                         'Type'         => 'Wiki'

    message_id @wiki_content, user

    with_locale_for(user) do
      subject = "[#{@wiki_content.project.name}] #{t(:mail_subject_wiki_content_updated, id: @wiki_content.page.title)}"
      mail_for_author author, to: user.mail, subject: subject
    end
  end

  def message_posted(user, message, author)
    @message     = message
    @message_url = topic_url(@message.root, r: @message.id, anchor: "message-#{@message.id}")

    open_project_headers 'Project'      => @message.project.identifier,
                         'Wiki-Page-Id' => @message.parent_id || @message.id,
                         'Type'         => 'Forum'

    message_id @message, user
    references @message.parent, user if @message.parent

    with_locale_for(user) do
      subject = "[#{@message.board.project.name} - #{@message.board.name} - msg#{@message.root.id}] #{@message.subject}"
      mail_for_author author, to: user.mail, subject: subject
    end
  end

  def account_activated(user)
    @user = user

    open_project_headers 'Type' => 'Account'

    with_locale_for(user) do
      subject = t(:mail_subject_register, value: Setting.app_title)
      mail to: user.mail, subject: subject
    end
  end

  def account_information(user, password)
    @user     = user
    @password = password

    open_project_headers 'Type' => 'Account'

    with_locale_for(user) do
      subject = t(:mail_subject_register, value: Setting.app_title)
      mail to: user.mail, subject: subject
    end
  end

  def account_activation_requested(admin, user)
    @user           = user
    @activation_url = url_for(controller: '/users',
                              action:     :index,
                              status:     'registered',
                              sort:       'created_at:desc')

    open_project_headers 'Type' => 'Account'

    with_locale_for(admin) do
      subject = t(:mail_subject_account_activation_request, value: Setting.app_title)
      mail to: admin.mail, subject: subject
    end
  end

  def reminder_mail(user, issues, days)
    @issues = issues
    @days   = days

    @assigned_issues_url = url_for(controller:     :work_packages,
                                   action:         :index,
                                   set_filter:     1,
                                   assigned_to_id: user.id,
                                   sort:           'due_date:asc')

    open_project_headers 'Type' => 'Issue'

    with_locale_for(user) do
      subject = t(:mail_subject_reminder, count: @issues.size, days: @days)
      mail to: user.mail, subject: subject
    end
  end

  # Activates/deactivates email deliveries during +block+
  def self.with_deliveries(temporary_state = true, &_block)
    old_state = ActionMailer::Base.perform_deliveries
    ActionMailer::Base.perform_deliveries = temporary_state
    yield
  ensure
    ActionMailer::Base.perform_deliveries = old_state
  end

  def self.generate_message_id(object, user)
    # id + timestamp should reduce the odds of a collision
    # as far as we don't send multiple emails for the same object
    journable = (object.is_a? Journal) ? object.journable : object

    timestamp = mail_timestamp(object)
    hash = 'openproject'\
           '.'\
           "#{journable.class.name.demodulize.underscore}"\
           '-'\
           "#{user.id}"\
           '-'\
           "#{journable.id}"\
           '.'\
           "#{timestamp.strftime('%Y%m%d%H%M%S')}"
    host = Setting.mail_from.to_s.gsub(%r{\A.*@}, '')
    host = "#{::Socket.gethostname}.openproject" if host.empty?
    "#{hash}@#{host}"
  end

  private

  def subject_for_work_package(work_package)
    subject =  "[#{work_package.project.name} - #{work_package.type.name} ##{work_package.id}] "
    subject << "(#{work_package.status.name}) " << work_package.subject
  end

  # like #mail, but contains special author based filters
  # currently only:
  #  - remove_self_notifications
  # might be refactored at a later time to be as generic as Interceptors
  def mail_for_author(author, headers = {}, &block)
    message = mail headers, &block

    self.class.remove_self_notifications(message, author)

    message
  end

  def self.remove_self_notifications(message, author)
    if author.pref && author.pref[:no_self_notified]
      message.to = message.to.reject { |address| address == author.mail } if message.to.present?
    end
  end

  def self.mail_timestamp(object)
    if object.respond_to? :created_at
      object.send(object.respond_to?(:created_at) ? :created_at : :updated_at)
    else
      object.send(object.respond_to?(:created_on) ? :created_on : :updated_on)
    end
  end

  def self.host
    if OpenProject::Configuration.rails_relative_url_root.blank?
      Setting.host_name
    else
      Setting.host_name.to_s.gsub(%r{\/.*\z}, '')
    end
  end

  def self.protocol
    Setting.protocol
  end

  def self.default_url_options
    options = super.merge host: host, protocol: protocol
    unless OpenProject::Configuration.rails_relative_url_root.blank?
      options[:script_name] = OpenProject::Configuration.rails_relative_url_root
    end

    options
  end

  def message_id(object, user)
    headers['Message-ID'] = "<#{self.class.generate_message_id(object, user)}>"
  end

  def references(object, user)
    headers['References'] = "<#{self.class.generate_message_id(object, user)}>"
  end

  def set_work_package_headers(work_package)
    open_project_headers 'Project'        => work_package.project.identifier,
                         'Issue-Id'       => work_package.id,
                         'Issue-Author'   => work_package.author.login,
                         'Type'           => 'WorkPackage'

    if work_package.assigned_to
      open_project_headers 'Issue-Assignee' => work_package.assigned_to.login
    end
  end

  # Prepends given fields with 'X-OpenProject-' to save some duplication
  def open_project_headers(hash)
    hash.each { |key, value| headers["X-OpenProject-#{key}"] = value.to_s }
  end
end

##
# Interceptors
#
# These are registered in config/initializers/register_mail_interceptors.rb
#
# Unfortunately, this results in changes on the interceptor classes during development mode
# not being reflected until a server restart.

class DefaultHeadersInterceptor
  def self.delivering_email(mail)
    mail.headers(default_headers)
  end

  def self.default_headers
    {
      'X-Mailer'           => 'OpenProject',
      'X-OpenProject-Host' => Setting.host_name,
      'X-OpenProject-Site' => Setting.app_title,
      'Precedence'         => 'bulk',
      'Auto-Submitted'     => 'auto-generated'
    }
  end
end

class DoNotSendMailsWithoutReceiverInterceptor
  def self.delivering_email(mail)
    receivers = [mail.to, mail.cc, mail.bcc]
    # the above fields might be empty arrays (if entries have been removed
    # by another interceptor) or nil, therefore checking for blank?
    mail.perform_deliveries = false if receivers.all?(&:blank?)
  end
end

# helper object for `rake redmine:send_reminders`

class DueIssuesReminder
  def initialize(days = nil, project_id = nil, type_id = nil, user_ids = [])
    @days     = days ? days.to_i : 7
    @project  = Project.find_by(id: project_id)
    @type  = ::Type.find_by(id: type_id)
    @user_ids = user_ids
  end

  def remind_users
    s = ARCondition.new ["#{Status.table_name}.is_closed = ? AND #{WorkPackage.table_name}.due_date <= ?", false, @days.days.from_now.to_date]
    s << "#{WorkPackage.table_name}.assigned_to_id IS NOT NULL"
    s << ["#{WorkPackage.table_name}.assigned_to_id IN (?)", @user_ids] if @user_ids.any?
    s << "#{Project.table_name}.status = #{Project::STATUS_ACTIVE}"
    s << "#{WorkPackage.table_name}.project_id = #{@project.id}" if @project
    s << "#{WorkPackage.table_name}.type_id = #{@type.id}" if @type

    issues_by_assignee = WorkPackage.includes(:status, :assigned_to, :project, :type)
                         .where(s.conditions)
                         .references(:projects)
                         .group_by(&:assigned_to)
    issues_by_assignee.each do |assignee, issues|
      UserMailer.reminder_mail(assignee, issues, @days).deliver_now if assignee && assignee.active?
    end
  end
end