# frozen_string_literal: true

class BadgeGranter
  class GrantError < StandardError
  end

  def self.disable_queue
    @queue_disabled = true
  end

  def self.enable_queue
    @queue_disabled = false
  end

  def initialize(badge, user, opts = {})
    @badge, @user, @opts = badge, user, opts
    @granted_by = opts[:granted_by] || Discourse.system_user
    @post_id = opts[:post_id]
  end

  def self.grant(badge, user, opts = {})
    BadgeGranter.new(badge, user, opts).grant
  end

  def self.enqueue_mass_grant_for_users(
    badge,
    emails: [],
    usernames: [],
    ensure_users_have_badge_once: true
  )
    emails = emails.map(&:downcase)
    usernames = usernames.map(&:downcase)
    usernames_map_to_ids = {}
    emails_map_to_ids = {}
    if usernames.size > 0
      usernames_map_to_ids = User.where(username_lower: usernames).pluck(:username_lower, :id).to_h
    end
    if emails.size > 0
      emails_map_to_ids = User.with_email(emails).pluck("LOWER(user_emails.email)", :id).to_h
    end

    count_per_user = {}
    unmatched = Set.new
    (usernames + emails).each do |entry|
      id = usernames_map_to_ids[entry] || emails_map_to_ids[entry]
      if id.blank?
        unmatched << entry
        next
      end

      if ensure_users_have_badge_once
        count_per_user[id] = 1
      else
        count_per_user[id] ||= 0
        count_per_user[id] += 1
      end
    end

    existing_owners_ids = []
    if ensure_users_have_badge_once
      existing_owners_ids = UserBadge.where(badge: badge).distinct.pluck(:user_id)
    end
    count_per_user.each do |user_id, count|
      next if ensure_users_have_badge_once && existing_owners_ids.include?(user_id)

      Jobs.enqueue(:mass_award_badge, user: user_id, badge: badge.id, count: count)
    end

    {
      unmatched_entries: unmatched.to_a,
      matched_users_count: count_per_user.size,
      unmatched_entries_count: unmatched.size,
    }
  end

  def self.mass_grant(badge, user, count:)
    return if !badge.enabled?

    raise ArgumentError.new("count can't be less than 1") if count < 1

    UserBadge.transaction do
      DB.exec(
        <<~SQL * count,
        INSERT INTO user_badges
        (granted_at, created_at, granted_by_id, user_id, badge_id, seq)
        VALUES
        (
          :now,
          :now,
          :system,
          :user_id,
          :badge_id,
          COALESCE((
            SELECT MAX(seq) + 1
            FROM user_badges
            WHERE badge_id = :badge_id AND user_id = :user_id
          ), 0)
        );
      SQL
        now: Time.zone.now,
        system: Discourse.system_user.id,
        user_id: user.id,
        badge_id: badge.id,
      )
      notification = send_notification(user.id, user.username, user.locale, badge)

      DB.exec(<<~SQL, notification_id: notification.id, user_id: user.id, badge_id: badge.id)
        UPDATE user_badges
        SET notification_id = :notification_id
        WHERE notification_id IS NULL AND user_id = :user_id AND badge_id = :badge_id
      SQL

      UserBadge.update_featured_ranks!(user.id)
    end
  end

  def grant
    return if @granted_by && !Guardian.new(@granted_by).can_grant_badges?(@user)
    return unless @badge.present? && @badge.enabled?
    return if @user.blank?

    find_by = { badge_id: @badge.id, user_id: @user.id }

    find_by[:post_id] = @post_id if @badge.multiple_grant?

    user_badge = UserBadge.find_by(find_by)

    if user_badge.nil? || (@badge.multiple_grant? && @post_id.nil?)
      UserBadge.transaction do
        seq = 0
        if @badge.multiple_grant?
          seq = UserBadge.where(badge: @badge, user: @user).maximum(:seq)
          seq = (seq || -1) + 1
        end

        user_badge =
          UserBadge.create!(
            badge: @badge,
            user: @user,
            granted_by: @granted_by,
            granted_at: @opts[:created_at] || Time.now,
            post_id: @post_id,
            seq: seq,
          )

        return unless SiteSetting.enable_badges

        if @granted_by != Discourse.system_user
          StaffActionLogger.new(@granted_by).log_badge_grant(user_badge)
        end

        skip_new_user_tips = @user.user_option.skip_new_user_tips
        unless self.class.suppress_notification?(@badge, user_badge.granted_at, skip_new_user_tips)
          notification =
            self.class.send_notification(@user.id, @user.username, @user.effective_locale, @badge)
          user_badge.update!(notification_id: notification.id)
        end
      end
    end

    user_badge
  end

  def self.revoke(user_badge, options = {})
    UserBadge.transaction do
      user_badge.destroy!
      if options[:revoked_by]
        StaffActionLogger.new(options[:revoked_by]).log_badge_revoke(user_badge)
      end

      # If the user's title is the same as the badge name OR the custom badge name, remove their title.
      custom_badge_name =
        TranslationOverride.find_by(translation_key: user_badge.badge.translation_key)&.value
      user_title_is_badge_name = user_badge.user.title == user_badge.badge.name
      user_title_is_custom_badge_name =
        custom_badge_name.present? && user_badge.user.title == custom_badge_name

      if user_title_is_badge_name || user_title_is_custom_badge_name
        if options[:revoked_by]
          StaffActionLogger.new(options[:revoked_by]).log_title_revoke(
            user_badge.user,
            revoke_reason: "user title was same as revoked badge name or custom badge name",
            previous_value: user_badge.user.title,
          )
        end
        user_badge.user.title = nil
        user_badge.user.save!
      end
    end
  end

  def self.revoke_all(badge)
    custom_badge_names =
      TranslationOverride.where(translation_key: badge.translation_key).pluck(:value)

    users =
      User.joins(:user_badges).where(user_badges: { badge_id: badge.id }).where(title: badge.name)
    users =
      users.or(
        User.joins(:user_badges).where(title: custom_badge_names),
      ) unless custom_badge_names.empty?
    users.update_all(title: nil)

    UserBadge.where(badge: badge).delete_all
  end

  def self.queue_badge_grant(type, opt)
    return if !SiteSetting.enable_badges || @queue_disabled
    payload = nil

    case type
    when Badge::Trigger::PostRevision
      post = opt[:post]
      payload = { type: "PostRevision", post_ids: [post.id] }
    when Badge::Trigger::UserChange
      user = opt[:user]
      payload = { type: "UserChange", user_ids: [user.id] }
    when Badge::Trigger::TrustLevelChange
      user = opt[:user]
      payload = { type: "TrustLevelChange", user_ids: [user.id] }
    when Badge::Trigger::PostAction
      action = opt[:post_action]
      payload = { type: "PostAction", post_ids: [action.post_id, action.related_post_id].compact! }
    end

    Discourse.redis.lpush queue_key, payload.to_json if payload
  end

  def self.clear_queue!
    Discourse.redis.del queue_key
  end

  def self.process_queue!
    limit = 1000
    items = []
    while limit > 0 && item = Discourse.redis.lpop(queue_key)
      items << JSON.parse(item)
      limit -= 1
    end

    items = items.group_by { |i| i["type"] }

    items.each do |type, list|
      post_ids = list.flat_map { |i| i["post_ids"] }.compact.uniq
      user_ids = list.flat_map { |i| i["user_ids"] }.compact.uniq

      next if post_ids.blank? && user_ids.blank?

      find_by_type(type).each { |badge| backfill(badge, post_ids: post_ids, user_ids: user_ids) }
    end
  end

  def self.find_by_type(type)
    Badge.where(trigger: "Badge::Trigger::#{type}".constantize)
  end

  def self.queue_key
    "badge_queue"
  end

  # Options:
  #   :target_posts - whether the badge targets posts
  #   :trigger - the Badge::Trigger id
  def self.contract_checks!(sql, opts = {})
    return if sql.blank?

    if Badge::Trigger.uses_post_ids?(opts[:trigger])
      unless sql.match(/:post_ids/)
        raise(
          "Contract violation:\nQuery triggers on posts, but does not reference the ':post_ids' array",
        )
      end
      if sql.match(/:user_ids/)
        raise "Contract violation:\nQuery triggers on posts, but references the ':user_ids' array"
      end
    end

    if Badge::Trigger.uses_user_ids?(opts[:trigger])
      unless sql.match(/:user_ids/)
        raise "Contract violation:\nQuery triggers on users, but does not reference the ':user_ids' array"
      end
      if sql.match(/:post_ids/)
        raise "Contract violation:\nQuery triggers on users, but references the ':post_ids' array"
      end
    end

    if opts[:trigger] && !Badge::Trigger.is_none?(opts[:trigger])
      unless sql.match(/:backfill/)
        raise "Contract violation:\nQuery is triggered, but does not reference the ':backfill' parameter.\n(Hint: if :backfill is TRUE, you should ignore the :post_ids/:user_ids)"
      end
    end

    # TODO these three conditions have a lot of false negatives
    if opts[:target_posts]
      unless sql.match(/post_id/)
        raise "Contract violation:\nQuery targets posts, but does not return a 'post_id' column"
      end
    end

    unless sql.match(/user_id/)
      raise "Contract violation:\nQuery does not return a 'user_id' column"
    end
    unless sql.match(/granted_at/)
      raise "Contract violation:\nQuery does not return a 'granted_at' column"
    end
    if sql.match(/;\s*\z/)
      raise "Contract violation:\nQuery ends with a semicolon. Remove the semicolon; your sql will be used in a subquery."
    end
  end

  # Options:
  #   :target_posts - whether the badge targets posts
  #   :trigger - the Badge::Trigger id
  #   :explain - return the EXPLAIN query
  def self.preview(sql, opts = {})
    params = { user_ids: [], post_ids: [], backfill: true }

    BadgeGranter.contract_checks!(sql, opts)

    # hack to allow for params, otherwise sanitizer will trigger sprintf
    count_sql = <<~SQL
      SELECT COUNT(*) count
                 FROM (
                        #{sql}
                      ) q
                WHERE :backfill = :backfill
    SQL
    grant_count = DB.query_single(count_sql, params).first.to_i

    grants_sql =
      if opts[:target_posts]
        <<~SQL
        SELECT u.id, u.username, q.post_id, t.title, q.granted_at
          FROM (
                 #{sql}
               ) q
          JOIN users u on u.id = q.user_id
     LEFT JOIN badge_posts p on p.id = q.post_id
     LEFT JOIN topics t on t.id = p.topic_id
         WHERE :backfill = :backfill
         LIMIT 10
      SQL
      else
        <<~SQL
        SELECT u.id, u.username, q.granted_at
         FROM (
                #{sql}
              ) q
         JOIN users u on u.id = q.user_id
        WHERE :backfill = :backfill
        LIMIT 10
      SQL
      end

    query_plan = nil
    # HACK: active record sanitization too flexible, force it to go down the sanitization path that cares not for % stuff
    # note mini_sql uses AR sanitizer at the moment (review if changed)
    query_plan = DB.query_hash("EXPLAIN #{sql} /*:backfill*/", params) if opts[:explain]

    sample = DB.query(grants_sql, params)

    sample.each do |result|
      unless User.exists?(id: result.id)
        raise "Query returned a non-existent user ID:\n#{result.id}"
      end
      unless result.granted_at
        raise "Query did not return a badge grant time\n(Try using 'current_timestamp granted_at')"
      end
      if opts[:target_posts]
        raise "Query did not return a post ID" unless result.post_id
        if Post.exists?(result.post_id).blank?
          raise "Query returned a non-existent post ID:\n#{result.post_id}"
        end
      end
    end

    { grant_count: grant_count, sample: sample, query_plan: query_plan }
  rescue => e
    { errors: e.message }
  end

  MAX_ITEMS_FOR_DELTA ||= 200
  def self.backfill(badge, opts = nil)
    return unless SiteSetting.enable_badges
    return unless badge.enabled
    return if badge.query.blank?

    post_ids = user_ids = nil
    post_ids = opts[:post_ids] if opts
    user_ids = opts[:user_ids] if opts

    # safeguard fall back to full backfill if more than 200
    if (post_ids && post_ids.size > MAX_ITEMS_FOR_DELTA) ||
         (user_ids && user_ids.size > MAX_ITEMS_FOR_DELTA)
      post_ids = nil
      user_ids = nil
    end

    post_ids = nil if post_ids.blank?
    user_ids = nil if user_ids.blank?

    full_backfill = !user_ids && !post_ids

    post_clause = badge.target_posts ? "AND (q.post_id = ub.post_id OR NOT :multiple_grant)" : ""
    post_id_field = badge.target_posts ? "q.post_id" : "NULL"

    sql = <<~SQL
      DELETE FROM user_badges
        WHERE id IN (
          SELECT ub.id
          FROM user_badges ub
          LEFT JOIN (
            #{badge.query}
          ) q ON q.user_id = ub.user_id
          #{post_clause}
          WHERE ub.badge_id = :id AND q.user_id IS NULL
        )
    SQL

    if badge.auto_revoke && full_backfill
      DB.exec(
        sql,
        id: badge.id,
        post_ids: [-1],
        user_ids: [-2],
        backfill: true,
        multiple_grant: true, # cheat here, cause we only run on backfill and are deleting
      )
    end

    sql = <<~SQL
      WITH w as (
        INSERT INTO user_badges(badge_id, user_id, granted_at, granted_by_id, created_at, post_id)
        SELECT :id, q.user_id, q.granted_at, -1, current_timestamp, #{post_id_field}
          FROM (
                 #{badge.query}
               ) q
     LEFT JOIN user_badges ub ON ub.badge_id = :id AND ub.user_id = q.user_id
        #{post_clause}
        /*where*/
        ON CONFLICT DO NOTHING
        RETURNING id, user_id, granted_at
      )
      SELECT w.*, username, locale, (u.admin OR u.moderator) AS staff, uo.skip_new_user_tips
        FROM w
        JOIN users u on u.id = w.user_id
        JOIN user_options uo ON uo.user_id = w.user_id
    SQL

    builder = DB.build(sql)
    builder.where("ub.badge_id IS NULL AND q.user_id > 0")

    if (post_ids || user_ids) && !badge.query.include?(":backfill")
      Rails.logger.warn "Your triggered badge query for #{badge.name} does not include the :backfill param, skipping!"
      return
    end

    if post_ids && !badge.query.include?(":post_ids")
      Rails.logger.warn "Your triggered badge query for #{badge.name} does not include the :post_ids param, skipping!"
      return
    end

    if user_ids && !badge.query.include?(":user_ids")
      Rails.logger.warn "Your triggered badge query for #{badge.name} does not include the :user_ids param, skipping!"
      return
    end

    builder
      .query(
        id: badge.id,
        multiple_grant: badge.multiple_grant,
        backfill: full_backfill,
        post_ids: post_ids || [-2],
        user_ids: user_ids || [-2],
      )
      .each do |row|
        next if suppress_notification?(badge, row.granted_at, row.skip_new_user_tips)
        next if row.staff && badge.awarded_for_trust_level?

        notification = send_notification(row.user_id, row.username, row.locale, badge)
        UserBadge.trigger_user_badge_granted_event(badge.id, row.user_id)

        DB.exec(
          "UPDATE user_badges SET notification_id = :notification_id WHERE id = :id",
          notification_id: notification.id,
          id: row.id,
        )
      end

    badge.reset_grant_count!
  rescue => e
    raise GrantError, "Failed to backfill '#{badge.name}' badge: #{opts}. Reason: #{e.message}"
  end

  def self.revoke_ungranted_titles!
    DB.exec <<~SQL
      UPDATE users u
      SET title = ''
      FROM user_profiles up
      WHERE u.title IS NOT NULL
        AND u.title <> ''
        AND up.user_id = u.id
        AND up.granted_title_badge_id IS NOT NULL
        AND NOT EXISTS(
          SELECT 1
          FROM badges b
                 JOIN user_badges ub ON ub.user_id = u.id AND ub.badge_id = b.id
          WHERE b.id = up.granted_title_badge_id
            AND b.allow_title
            AND b.enabled
        )
    SQL

    DB.exec <<~SQL
      UPDATE user_profiles up
      SET granted_title_badge_id = NULL
      FROM users u
      WHERE up.user_id = u.id
        AND (u.title IS NULL OR u.title = '')
        AND up.granted_title_badge_id IS NOT NULL
    SQL
  end

  def self.notification_locale(locale)
    use_default_locale = !SiteSetting.allow_user_locale || locale.blank?
    use_default_locale ? SiteSetting.default_locale : locale
  end

  def self.send_notification(user_id, username, locale, badge)
    I18n.with_locale(notification_locale(locale)) do
      Notification.create!(
        user_id: user_id,
        notification_type: Notification.types[:granted_badge],
        data: {
          badge_id: badge.id,
          badge_name: badge.display_name,
          badge_slug: badge.slug,
          badge_title: badge.allow_title,
          username: username,
        }.to_json,
      )
    end
  end

  def self.suppress_notification?(badge, granted_at, skip_new_user_tips)
    is_old_bronze_badge = badge.badge_type_id == BadgeType::Bronze && granted_at < 2.days.ago
    skip_beginner_badge = skip_new_user_tips && badge.for_beginners?

    is_old_bronze_badge || skip_beginner_badge
  end
end