# frozen_string_literal: true

class UserNotifications < ActionMailer::Base
  include UserNotificationsHelper
  include ApplicationHelper
  helper :application, :email
  default charset: 'UTF-8'
  layout 'email_template'

  include Email::BuildEmailHelper

  def signup(user, opts = {})
    build_user_email_token_by_template(
      "user_notifications.signup",
      user,
      opts[:email_token]
    )
  end

  def activation_reminder(user, opts = {})
    build_user_email_token_by_template(
      "user_notifications.activation_reminder",
      user,
      opts[:email_token]
    )
  end

  def signup_after_approval(user, opts = {})
    locale = user_locale(user)
    tips = I18n.t('system_messages.usage_tips.text_body_template',
                  base_url: Discourse.base_url,
                  locale: locale)

    build_email(user.email,
                template: 'user_notifications.signup_after_approval',
                locale: locale,
                new_user_tips: tips)
  end

  def post_approved(user, opts = {})
    post_url = opts.dig(:notification_data_hash, :post_url)

    return if post_url.nil?

    locale = user_locale(user)
    build_email(user.email,
      template: 'user_notifications.post_approved',
      locale: locale,
      base_url: Discourse.base_url,
      post_url: post_url
    )
  end

  def signup_after_reject(user, opts = {})
    locale = user_locale(user)
    build_email(user.email,
                template: 'user_notifications.signup_after_reject',
                locale: locale,
                reject_reason: opts[:reject_reason])
  end

  def suspicious_login(user, opts = {})
    ipinfo = DiscourseIpInfo.get(opts[:client_ip])
    location = ipinfo[:location]
    browser = BrowserDetection.browser(opts[:user_agent])
    device = BrowserDetection.device(opts[:user_agent])
    os = BrowserDetection.os(opts[:user_agent])

    build_email(
      user.email,
      template: "user_notifications.suspicious_login",
      locale: user_locale(user),
      client_ip: opts[:client_ip],
      location: location.present? ? location : I18n.t('staff_action_logs.unknown'),
      browser: I18n.t("user_auth_tokens.browser.#{browser}"),
      device: I18n.t("user_auth_tokens.device.#{device}"),
      os: I18n.t("user_auth_tokens.os.#{os}")
    )
  end

  def notify_old_email(user, opts = {})
    build_email(user.email,
                template: "user_notifications.notify_old_email",
                locale: user_locale(user),
                new_email: opts[:new_email])
  end

  def notify_old_email_add(user, opts = {})
    build_email(user.email,
                template: "user_notifications.notify_old_email_add",
                locale: user_locale(user),
                new_email: opts[:new_email])
  end

  def confirm_old_email(user, opts = {})
    build_user_email_token_by_template(
      "user_notifications.confirm_old_email",
      user,
      opts[:email_token]
    )
  end

  def confirm_old_email_add(user, opts = {})
    build_user_email_token_by_template(
      "user_notifications.confirm_old_email_add",
      user,
      opts[:email_token]
    )
  end

  def confirm_new_email(user, opts = {})
    build_user_email_token_by_template(
      opts[:requested_by_admin] ? "user_notifications.confirm_new_email_via_admin" : "user_notifications.confirm_new_email",
      user,
      opts[:email_token]
    )
  end

  def forgot_password(user, opts = {})
    build_user_email_token_by_template(
      user.has_password? ? "user_notifications.forgot_password" : "user_notifications.set_password",
      user,
      opts[:email_token]
    )
  end

  def email_login(user, opts = {})
    build_user_email_token_by_template(
      "user_notifications.email_login",
      user,
      opts[:email_token]
    )
  end

  def admin_login(user, opts = {})
    build_user_email_token_by_template(
      "user_notifications.admin_login",
      user,
      opts[:email_token]
    )
  end

  def account_created(user, opts = {})
    build_user_email_token_by_template(
      "user_notifications.account_created",
      user,
      opts[:email_token]
    )
  end

  def account_silenced(user, opts = nil)
    opts ||= {}

    return unless user_history = opts[:user_history]

    if user.silenced_forever?
      build_email(
        user.email,
        template: "user_notifications.account_silenced_forever",
        locale: user_locale(user),
        reason: user_history.details
      )
    else
      silenced_till = user.silenced_till.in_time_zone(user.user_option.timezone)
      build_email(
        user.email,
        template: "user_notifications.account_silenced",
        locale: user_locale(user),
        reason: user_history.details,
        silenced_till: I18n.l(silenced_till, format: :long)
      )
    end
  end

  def account_suspended(user, opts = nil)
    opts ||= {}

    return unless user_history = opts[:user_history]

    if user.suspended_forever?
      build_email(
        user.email,
        template: "user_notifications.account_suspended_forever",
        locale: user_locale(user),
        reason: user_history.details
      )
    else
      suspended_till = user.suspended_till.in_time_zone(user.user_option.timezone)
      build_email(
        user.email,
        template: "user_notifications.account_suspended",
        locale: user_locale(user),
        reason: user_history.details,
        suspended_till: I18n.l(suspended_till, format: :long)
      )
    end
  end

  def account_exists(user, opts = {})
    build_email(
      user.email,
      template: 'user_notifications.account_exists',
      locale: user_locale(user),
      email: user.email
    )
  end

  def account_second_factor_disabled(user, opts = {})
    build_email(
      user.email,
      template: 'user_notifications.account_second_factor_disabled',
      locale: user_locale(user),
      email: user.email
    )
  end

  def digest(user, opts = {})
    build_summary_for(user)
    min_date = opts[:since] || user.last_emailed_at || user.last_seen_at || 1.month.ago

    # Fetch some topics and posts to show
    digest_opts = { limit: SiteSetting.digest_topics + SiteSetting.digest_other_topics, top_order: true }
    topics_for_digest = Topic.for_digest(user, min_date, digest_opts).to_a
    if topics_for_digest.empty? && !user.user_option.try(:include_tl0_in_digests)
      # Find some topics from new users that are at least 24 hours old
      topics_for_digest = Topic.for_digest(user, min_date, digest_opts.merge(include_tl0: true)).where('topics.created_at < ?', 24.hours.ago).to_a
    end

    @popular_topics = topics_for_digest[0, SiteSetting.digest_topics]

    if @popular_topics.present?
      @other_new_for_you = topics_for_digest.size > SiteSetting.digest_topics ? topics_for_digest[SiteSetting.digest_topics..-1] : []

      @popular_posts = if SiteSetting.digest_posts > 0
        Post.order("posts.score DESC")
          .for_mailing_list(user, min_date)
          .where('posts.post_type = ?', Post.types[:regular])
          .where('posts.deleted_at IS NULL AND posts.hidden = false AND posts.user_deleted = false')
          .where("posts.post_number > ? AND posts.score > ?", 1, ScoreCalculator.default_score_weights[:like_score] * 5.0)
          .where('posts.created_at < ?', (SiteSetting.editing_grace_period || 0).seconds.ago)
          .limit(SiteSetting.digest_posts)
      else
        []
      end

      @excerpts = {}

      @popular_topics.map do |t|
        @excerpts[t.first_post.id] = email_excerpt(t.first_post.cooked, t.first_post) if t.first_post.present?
      end

      # Try to find 3 interesting stats for the top of the digest
      new_topics_count = Topic.for_digest(user, min_date).count

      if new_topics_count == 0
        # We used topics from new users instead, so count should match
        new_topics_count = topics_for_digest.size
      end
      @counts = [{ label_key: 'user_notifications.digest.new_topics',
                   value: new_topics_count,
                   href: "#{Discourse.base_url}/new" }]

      # totalling unread notifications (which are low-priority only) and unread
      # PMs and bookmark reminder notifications, so the total is both unread low
      # and high priority PMs
      value = user.unread_notifications + user.unread_high_priority_notifications
      @counts << { label_key: 'user_notifications.digest.unread_notifications', value: value, href: "#{Discourse.base_url}/my/notifications" } if value > 0

      if @counts.size < 3
        value = user.unread_notifications_of_type(Notification.types[:liked])
        @counts << { label_key: 'user_notifications.digest.liked_received', value: value, href: "#{Discourse.base_url}/my/notifications" } if value > 0
      end

      if @counts.size < 3 && user.user_option.digest_after_minutes.to_i >= 1440
        value = summary_new_users_count(min_date)
        @counts << { label_key: 'user_notifications.digest.new_users', value: value, href: "#{Discourse.base_url}/about" } if value > 0
      end

      @last_seen_at = short_date(user.last_seen_at || user.created_at)

      @preheader_text = I18n.t('user_notifications.digest.preheader', last_seen_at: @last_seen_at)

      opts = {
        from_alias: I18n.t('user_notifications.digest.from', site_name: Email.site_title),
        subject: I18n.t('user_notifications.digest.subject_template', email_prefix: @email_prefix, date: short_date(Time.now)),
        add_unsubscribe_link: true,
        unsubscribe_url: "#{Discourse.base_url}/email/unsubscribe/#{@unsubscribe_key}",
      }

      build_email(user.email, opts)
    end
  end

  def user_replied(user, opts)
    opts[:allow_reply_by_email] = true
    opts[:use_site_subject] = true
    opts[:show_category_in_subject] = true
    opts[:show_tags_in_subject] = true
    notification_email(user, opts)
  end

  def user_quoted(user, opts)
    opts[:allow_reply_by_email] = true
    opts[:use_site_subject] = true
    opts[:show_category_in_subject] = true
    opts[:show_tags_in_subject] = true
    notification_email(user, opts)
  end

  def user_linked(user, opts)
    opts[:allow_reply_by_email] = true
    opts[:use_site_subject] = true
    opts[:show_category_in_subject] = true
    opts[:show_tags_in_subject] = true
    notification_email(user, opts)
  end

  def user_mentioned(user, opts)
    opts[:allow_reply_by_email] = true
    opts[:use_site_subject] = true
    opts[:show_category_in_subject] = true
    opts[:show_tags_in_subject] = true
    notification_email(user, opts)
  end

  def group_mentioned(user, opts)
    opts[:allow_reply_by_email] = true
    opts[:use_site_subject] = true
    opts[:show_category_in_subject] = true
    opts[:show_tags_in_subject] = true
    notification_email(user, opts)
  end

  def user_posted(user, opts)
    opts[:allow_reply_by_email] = true
    opts[:use_site_subject] = true
    opts[:add_re_to_subject] = true
    opts[:show_category_in_subject] = true
    opts[:show_tags_in_subject] = true
    notification_email(user, opts)
  end

  def user_private_message(user, opts)
    opts[:allow_reply_by_email] = true
    opts[:use_site_subject] = true
    opts[:add_re_to_subject] = true
    opts[:show_category_in_subject] = false
    opts[:show_tags_in_subject] = false
    opts[:show_group_in_subject] = true if SiteSetting.group_in_subject

    # We use the 'user_posted' event when you are emailed a post in a PM.
    opts[:notification_type] = 'posted'

    notification_email(user, opts)
  end

  def user_invited_to_private_message(user, opts)
    opts[:allow_reply_by_email] = false
    opts[:use_invite_template] = true
    notification_email(user, opts)
  end

  def user_invited_to_topic(user, opts)
    opts[:allow_reply_by_email] = false
    opts[:use_invite_template] = true
    opts[:show_category_in_subject] = true
    opts[:show_tags_in_subject] = true
    notification_email(user, opts)
  end

  def user_watching_first_post(user, opts)
    user_posted(user, opts)
  end

  def mailing_list_notify(user, post)
    opts = {
      post: post,
      allow_reply_by_email: true,
      use_site_subject: true,
      add_re_to_subject: true,
      show_category_in_subject: true,
      show_tags_in_subject: true,
      notification_type: "posted",
      notification_data_hash: {
        original_username: post.user.username,
        topic_title: post.topic.title,
      },
    }
    notification_email(user, opts)
  end

  protected

  def user_locale(user)
    user.effective_locale
  end

  def email_post_markdown(post, add_posted_by = false)
    result = +"#{post.raw}\n\n"
    if add_posted_by
      result << "#{I18n.t('user_notifications.posted_by', username: post.username, post_date: post.created_at.strftime("%m/%d/%Y"))}\n\n"
    end
    result
  end

  def self.get_context_posts(post, topic_user, user)
    if (user.user_option.email_previous_replies == UserOption.previous_replies_type[:never]) ||
       SiteSetting.private_email?
      return []
    end

    allowed_post_types = [Post.types[:regular]]
    allowed_post_types << Post.types[:whisper] if topic_user.try(:user).try(:staff?)

    context_posts = Post.where(topic_id: post.topic_id)
      .where("post_number < ?", post.post_number)
      .where(user_deleted: false)
      .where(hidden: false)
      .where(post_type: allowed_post_types)
      .order('created_at desc')
      .limit(SiteSetting.email_posts_context)

    if topic_user && topic_user.last_emailed_post_number && user.user_option.email_previous_replies == UserOption.previous_replies_type[:unless_emailed]
      context_posts = context_posts.where("post_number > ?", topic_user.last_emailed_post_number)
    end

    context_posts
  end

  def notification_email(user, opts)
    notification_type = opts[:notification_type]
    notification_data = opts[:notification_data_hash]
    post = opts[:post]

    unless String === notification_type
      if Numeric === notification_type
        notification_type = Notification.types[notification_type]
      end
      notification_type = notification_type.to_s
    end

    user_name = notification_data[:original_username]

    if post && SiteSetting.enable_names && SiteSetting.display_name_on_email_from
      name = User.where(id: notification_data[:original_user_id] || post.user_id).pluck_first(:name)
      user_name = name unless name.blank?
    end

    allow_reply_by_email = opts[:allow_reply_by_email] unless user.suspended?
    original_username = notification_data[:original_username] || notification_data[:display_username]

    if user.staged && post
      original_subject = IncomingEmail.joins(:post)
        .where("posts.topic_id = ? AND posts.post_number = 1", post.topic_id)
        .pluck(:subject)
        .first
    end

    if original_subject
      topic_title = original_subject
      opts[:use_site_subject] = false
      opts[:add_re_to_subject] = true
      use_topic_title_subject = true
    else
      topic_title = notification_data[:topic_title]
      use_topic_title_subject = false
    end

    email_options = {
      title: topic_title,
      post: post,
      username: original_username,
      from_alias: I18n.t('email_from', user_name: user_name, site_name: Email.site_title),
      allow_reply_by_email: allow_reply_by_email,
      use_site_subject: opts[:use_site_subject],
      add_re_to_subject: opts[:add_re_to_subject],
      show_category_in_subject: opts[:show_category_in_subject],
      show_tags_in_subject: opts[:show_tags_in_subject],
      show_group_in_subject: opts[:show_group_in_subject],
      notification_type: notification_type,
      use_invite_template: opts[:use_invite_template],
      use_topic_title_subject: use_topic_title_subject,
      user: user
    }

    if group_id = notification_data[:group_id]
      email_options[:group_name] = Group.find_by(id: group_id)&.name
    end

    send_notification_email(email_options)
  end

  def send_notification_email(opts)
    post = opts[:post]
    title = opts[:title]

    allow_reply_by_email = opts[:allow_reply_by_email]
    use_site_subject = opts[:use_site_subject]
    add_re_to_subject = opts[:add_re_to_subject] && post.post_number > 1
    use_topic_title_subject = opts[:use_topic_title_subject]
    username = opts[:username]
    from_alias = opts[:from_alias]
    notification_type = opts[:notification_type]
    user = opts[:user]
    group_name = opts[:group_name]
    locale = user_locale(user)

    template = +"user_notifications.user_#{notification_type}"
    if post.topic.private_message?
      template << "_pm"

      if group_name
        template << "_group"
      elsif user.staged
        template << "_staged"
      end
    end

    # category name
    category = Topic.find_by(id: post.topic_id)&.category
    if opts[:show_category_in_subject] && post.topic_id && category && !category.uncategorized?
      show_category_in_subject = category.name

      # subcategory case
      if !category.parent_category_id.nil?
        show_category_in_subject = "#{Category.where(id: category.parent_category_id).pluck_first(:name)}/#{show_category_in_subject}"
      end
    else
      show_category_in_subject = nil
    end

    # tag names
    if opts[:show_tags_in_subject] && post.topic_id

      tags = Tag.joins(:topic_tags)
        .where("topic_tags.topic_id = ?", post.topic_id)
        .limit(3)
        .pluck(:name)

      show_tags_in_subject = tags.any? ? tags.join(" ") : nil
    end

    group = post.topic.allowed_groups&.first

    if post.topic.private_message?
      subject_pm =
        if opts[:show_group_in_subject] && group.present?
          if group.full_name
            "[#{group.full_name}] "
          else
            "[#{group.name}] "
          end
        else
          I18n.t('subject_pm')
        end

      participants = self.class.participants(post, user)
    end

    if SiteSetting.private_email?
      title = I18n.t("system_messages.private_topic_title", id: post.topic_id)
    end

    context = +""
    tu = TopicUser.get(post.topic_id, user)
    context_posts = self.class.get_context_posts(post, tu, user)

    # make .present? cheaper
    context_posts = context_posts.to_a

    if context_posts.present?
      context << +"-- \n*#{I18n.t('user_notifications.previous_discussion')}*\n"
      context_posts.each do |cp|
        context << email_post_markdown(cp, true)
      end
    end

    translation_override_exists = TranslationOverride.where(
      locale: SiteSetting.default_locale,
      translation_key: "#{template}.text_body_template"
    ).exists?

    if opts[:use_invite_template]
      invite_template = +"user_notifications.invited"
      invite_template << "_group" if group_name

      invite_template <<
        if post.topic.private_message?
          "_to_private_message_body"
        else
          "_to_topic_body"
        end

      topic_excerpt = post.excerpt.tr("\n", " ") if post.is_first_post? && post.excerpt
      topic_url = post.topic&.url

      if SiteSetting.private_email?
        topic_excerpt = ""
        topic_url = ""
      end

      message = I18n.t(invite_template,
        username: username,
        group_name: group_name,
        topic_title: gsub_emoji_to_unicode(title),
        topic_excerpt: topic_excerpt,
        site_title: SiteSetting.title,
        site_description: SiteSetting.site_description,
        topic_url: topic_url
      )

      html = PrettyText.cook(message, sanitize: false).html_safe
    else
      reached_limit = SiteSetting.max_emails_per_day_per_user > 0
      reached_limit &&= (EmailLog.where(user_id: user.id)
                              .where('created_at > ?', 1.day.ago)
                              .count) >= (SiteSetting.max_emails_per_day_per_user - 1)

      in_reply_to_post = post.reply_to_post if user.user_option.email_in_reply_to
      if SiteSetting.private_email?
        message = I18n.t('system_messages.contents_hidden')
      else
        message = email_post_markdown(post) + (reached_limit ? "\n\n#{I18n.t "user_notifications.reached_limit", count: SiteSetting.max_emails_per_day_per_user}" : "")
      end

      first_footer_classes = "highlight"
      if (allow_reply_by_email && user.staged) || (user.suspended? || user.staged?)
        first_footer_classes = ""
      end

      unless translation_override_exists
        html = UserNotificationRenderer.render(
          template: 'email/notification',
          format: :html,
          locals: { context_posts: context_posts,
                    reached_limit: reached_limit,
                    post: post,
                    in_reply_to_post: in_reply_to_post,
                    classes: Rtl.new(user).css_class,
                    first_footer_classes: first_footer_classes,
                    reply_above_line: false
          }
        )
      end
    end

    email_opts = {
      topic_title: Emoji.gsub_emoji_to_unicode(title),
      topic_title_url_encoded: title ? UrlHelper.encode_component(title) : title,
      message: message,
      url: post.url(without_slug: SiteSetting.private_email?),
      post_id: post.id,
      topic_id: post.topic_id,
      context: context,
      username: username,
      group_name: group_name,
      add_unsubscribe_link: !user.staged,
      mailing_list_mode: user.user_option.mailing_list_mode,
      unsubscribe_url: post.unsubscribe_url(user),
      allow_reply_by_email: allow_reply_by_email,
      only_reply_by_email: allow_reply_by_email && user.staged,
      use_site_subject: use_site_subject,
      add_re_to_subject: add_re_to_subject,
      show_category_in_subject: show_category_in_subject,
      show_tags_in_subject: show_tags_in_subject,
      private_reply: post.topic.private_message?,
      subject_pm: subject_pm,
      participants: participants,
      include_respond_instructions: !(user.suspended? || user.staged?),
      template: template,
      use_topic_title_subject: use_topic_title_subject,
      site_description: SiteSetting.site_description,
      site_title: SiteSetting.title,
      site_title_url_encoded: UrlHelper.encode_component(SiteSetting.title),
      locale: locale
    }

    unless translation_override_exists
      email_opts[:html_override] = html
    end

    # If we have a display name, change the from address
    email_opts[:from_alias] = from_alias if from_alias.present?

    TopicUser.change(user.id, post.topic_id, last_emailed_post_number: post.post_number)

    build_email(user.email, email_opts)
  end

  def self.participants(post, recipient_user, reveal_staged_email: false)
    list = []

    allowed_groups = post.topic.allowed_groups.order("user_count DESC")

    allowed_groups.each do |g|
      list.push("[#{g.name_full_preferred} (#{g.user_count})](#{g.full_url})")
      break if list.size >= SiteSetting.max_participant_names
    end

    recent_posts_query = post.topic.posts
      .select("user_id, MAX(post_number) AS post_number")
      .where(post_type: Post.types[:regular], post_number: ..post.post_number)
      .where.not(user_id: recipient_user.id)
      .group(:user_id)
      .order("post_number DESC")
      .limit(SiteSetting.max_participant_names)
      .to_sql

    allowed_users = post.topic.allowed_users
      .joins("LEFT JOIN (#{recent_posts_query}) pu ON topic_allowed_users.user_id = pu.user_id")
      .order("post_number DESC NULLS LAST", :id)
      .where.not(id: recipient_user.id)
      .human_users

    allowed_users.each do |u|
      break if list.size >= SiteSetting.max_participant_names

      if reveal_staged_email && u.staged?
        list.push("#{u.email}")
      else
        list.push("[#{u.display_name}](#{u.full_url})")
      end
    end

    participants = list.join(I18n.t("word_connector.comma"))
    others_count = allowed_groups.size + allowed_users.size - list.size

    if others_count > 0
      I18n.t("user_notifications.more_pm_participants", participants: participants, count: others_count)
    else
      participants
    end
  end

  private

  def build_user_email_token_by_template(template, user, email_token)
    build_email(
      user.email,
      template: template,
      locale: user_locale(user),
      email_token: email_token
    )
  end

  def build_summary_for(user)
    @site_name       = SiteSetting.email_prefix.presence || SiteSetting.title # used by I18n
    @user            = user
    @date            = short_date(Time.now)
    @base_url        = Discourse.base_url
    @email_prefix    = SiteSetting.email_prefix.presence || SiteSetting.title
    @header_color    = ColorScheme.hex_for_name('header_primary')
    @header_bgcolor  = ColorScheme.hex_for_name('header_background')
    @anchor_color    = ColorScheme.hex_for_name('tertiary')
    @markdown_linker = MarkdownLinker.new(@base_url)
    @unsubscribe_key = UnsubscribeKey.create_key_for(@user, "digest")
    @disable_email_custom_styles = !SiteSetting.apply_custom_styles_to_digest
  end

  def self.summary_new_users_count_key(min_date_str)
    "summary-new-users:#{min_date_str}"
  end

  def summary_new_users_count(min_date)
    min_date_str = min_date.is_a?(String) ? min_date : min_date.strftime('%Y-%m-%d')
    key = self.class.summary_new_users_count_key(min_date_str)
    ((count = Discourse.redis.get(key)) && count.to_i) || begin
      count = User.real.where(active: true, staged: false).not_suspended.where("created_at > ?", min_date_str).count
      Discourse.redis.setex(key, 1.day, count)
      count
    end
  end
end