class UserMailer < ActionMailer::Base
  helper :application,  # for textilizable
         :custom_fields # for show_value

  # 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 => :welcome)

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

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

  def issue_added(user, issue)
    @issue = issue

    open_project_headers 'Project'        => @issue.project.identifier,
                         'Issue-Id'       => @issue.id,
                         'Issue-Author'   => @issue.author.login,
                         'Type'           => 'Issue'
    open_project_headers 'Issue-Assignee' => @issue.assigned_to.login if @issue.assigned_to

    message_id @issue

    with_locale_for(user) do
      subject = "[#{@issue.project.name} - #{@issue.tracker.name} ##{@issue.id}] (#{@issue.status.name}) #{@issue.subject}"
      mail :to => user.mail, :subject => subject
    end
  end

  def issue_updated(user, journal)
    @journal = journal
    @issue   = journal.journaled.reload

    open_project_headers 'Project'        => @issue.project.identifier,
                         'Issue-Id'       => @issue.id,
                         'Issue-Author'   => @issue.author.login,
                         'Type'           => 'Issue'
    open_project_headers 'Issue-Assignee' => @issue.assigned_to.login if @issue.assigned_to

    message_id @journal
    references @issue

    with_locale_for(user) do
      subject =  "[#{@issue.project.name} - #{@issue.tracker.name} ##{@issue.id}] "
      subject << "(#{@issue.status.name}) " if @journal.details['status_id']
      subject << @issue.subject

      mail :to => user.mail, :subject => subject
    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 news_added(user, news)
    @news = news

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

    message_id @news

    with_locale_for(user) do
      subject = "#{t(:label_news)}: #{@news.title}"
      subject = "[#{@news.project.name}] #{subject}" if @news.project
      mail :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)
    @comment = comment
    @news    = @comment.commented

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

    message_id @comment
    references @news

    with_locale_for(user) do
      subject = "#{t(:label_news)}: #{@news.title}"
      subject = "Re: [#{@news.project.name}] #{subject}" if @news.project
      mail :to => user.mail, :subject => subject
    end
  end

  def wiki_content_added(user, wiki_content)
    @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

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

  def wiki_content_updated(user, wiki_content)
    @wiki_content  = wiki_content
    @wiki_diff_url = url_for(:controller => :wiki,
                             :action     => :diff,
                             :project_id => wiki_content.project,
                             :id         => wiki_content.page.title,
                             :version    => wiki_content.version)

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

    message_id @wiki_content

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

  def message_posted(user, message)
    @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
    references @message.parent if @message.parent

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

  def document_added(user, document)
    @document = document

    open_project_headers 'Project' => @document.project.identifier,
                         'Type'    => 'Document'

    with_locale_for(user) do
      subject = "[#{@document.project.name}] #{t(:label_document_new)}: #{@document.title}"
      mail :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     => User::STATUS_REGISTERED,
                              :sort       => 'created_on: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 attachments_added(user, attachments)
    @attachments = attachments

    container = attachments.first.container

    open_project_headers 'Type'    => 'Attachment'
    open_project_headers 'Project' => container.project.identifier if container.project

    case container.class.name
    when 'Project'
      @added_to     = "#{t(:label_project)}: #{container}"
      @added_to_url = url_for(:controller => 'files', :action => 'index', :project_id => container)
    when 'Version'
      @added_to     = "#{t(:label_version)}: #{container.name}"
      @added_to_url = url_for(:controller => 'files', :action => 'index', :project_id => container.project)
    when 'Document'
      @added_to     = "#{t(:label_document)}: #{container.title}"
      @added_to_url = url_for(:controller => 'documents', :action => 'show', :id => container.id)
    end

    with_locale_for(user) do
      subject = t(:label_attachment_new)
      subject = "[#{container.project.name}] #{subject}" if container.project
      mail :to => user.mail, :subject => subject
    end
  end

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

    @assigned_issues_url = url_for(:controller     => :issues,
                                   :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/desactivates 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)
    # id + timestamp should reduce the odds of a collision
    # as far as we don't send multiple emails for the same object
    timestamp = object.send(object.respond_to?(:created_on) ? :created_on : :updated_on)
    hash = "openproject.#{object.class.name.demodulize.underscore}-#{object.id}.#{timestamp.strftime("%Y%m%d%H%M%S")}"
    host = Setting.mail_from.to_s.gsub(%r{^.*@}, '')
    host = "#{::Socket.gethostname}.openproject" if host.empty?
    "#{hash}@#{host}"
  end

private

  def self.host
    if Redmine::Utils.relative_url_root.blank?
      Setting.host_name
    else
      Setting.host_name.to_s.gsub(%r{\/.*$}, '')
    end
  end

  def self.protocol
    Setting.protocol
  end

  def self.default_url_options
    super.merge :host => host, :protocol => protocol
  end

  def mail(headers = {})
    super(headers) do |format|
      format.text
      format.html unless Setting.plain_text_mail?
    end
  end

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

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

  def with_locale_for(user, &block)
    locale = user.language.presence || Setting.default_language.presence || I18n.default_locale
    I18n.with_locale(locale, &block)
  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

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

  def 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 RemoveSelfNotificationsInterceptor
  def delivering_email(mail)
    current_user = User.current
    if current_user.pref[:no_self_notified].present?
      mail.to = mail.to.reject {|address| address == current_user.mail} if mail.to.present?
    end
  end
end

class DoNotSendMailsWithoutReceiverInterceptor
  def delivering_email(mail)
    mail.perform_deliveries = false if mail.to.blank?
  end
end

# register interceptors

UserMailer.register_interceptor(DefaultHeadersInterceptor.new)
UserMailer.register_interceptor(RemoveSelfNotificationsInterceptor.new)
# following needs to be the last interceptor
UserMailer.register_interceptor(DoNotSendMailsWithoutReceiverInterceptor.new)

# helper object for `rake redmine:send_reminders`

class DueIssuesReminder
  def initialize(days = nil, project_id = nil, tracker_id = nil, user_ids = [])
    @days     = days ? days.to_i : 7
    @project  = Project.find_by_id(project_id)
    @tracker  = Tracker.find_by_id(tracker_id)
    @user_ids = user_ids
  end

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

    issues_by_assignee = Issue.find(:all, :include => [:status, :assigned_to, :project, :tracker],
                                          :conditions => s.conditions
                                   ).group_by(&:assigned_to)
    issues_by_assignee.each do |assignee, issues|
      UserMailer.reminder_mail(assignee, issues, @days).deliver if assignee && assignee.active?
    end
  end
end