# frozen_string_literal: true

module ImapGuard
  # Query is a neat DSL to help you generate IMAP search queries.
  # @note All methods return self so they can be chained.
  class Query < Array
    # Messages that have the +\Seen+ flag set.
    # @return [self]
    def seen
      self << "SEEN"
    end

    # Messages that do not have the +\Seen+ flag set.
    # @return [self]
    def unseen
      self << "UNSEEN"
    end

    # Messages that do not have the +\Answered+ flag set.
    # @return [self]
    def unanswered
      self << "UNANSWERED"
    end

    # Messages that do not have the +\Flagged+ flag set.
    # @return [self]
    def unflagged
      self << "UNFLAGGED"
    end

    # Messages with the +\Deleted+ flag set.
    # @return [self]
    def deleted
      self << "DELETED"
    end

    # Messages that match either search key.
    # @param search_key1 Optional search key to pass to +OR+
    # @param search_key2 Optional search key to pass to +OR+
    # @note Reverse polish notation is expected,
    #   i.e. OR <search-key1> <search-key2>
    # @example
    #   or.unanswered.unflagged     #=> ["OR", "UNANSWERED", "UNFLAGGED"]
    #   or(:unanswered, :unflagged) #=> ["OR", "UNANSWERED", "UNFLAGGED"]
    # @return [self]
    def or(search_key1 = nil, search_key2 = nil)
      self << "OR"

      if search_key1 && search_key2
        send(search_key1)
        send(search_key2)
      elsif search_key1 || search_key2
        raise ArgumentError, "You must give either zero or two arguments."
      end

      self
    end

    # Messages that do not match the specified search key.
    # @param search_key Optional search key to pass to +NOT+
    # @example
    #   not.deleted   #=> ["NOT", "DELETED"]
    #   not(:deleted) #=> ["NOT", "DELETED"]
    # @return [self]
    def not(search_key = nil)
      self << "NOT"
      send(search_key) if search_key
      self
    end

    # Messages that contain the specified string in the envelope
    # structure's SUBJECT field.
    # @return [self]
    def subject(string)
      self << "SUBJECT" << string
    end

    # Messages that contain the specified string in the envelope
    # structure's FROM field.
    # @return [self]
    def from(string)
      self << "FROM" << string
    end

    # Messages that contain the specified string in the envelope
    # structure's TO field.
    # @return [self]
    def to(string)
      self << "TO" << string
    end

    # Messages that contain the specified string in the envelope
    # structure's CC field.
    # @return [self]
    def cc(string)
      self << "CC" << string
    end

    # Messages whose internal date (disregarding time and timezone)
    # is earlier than the specified date.
    # @param date Depending of its type:
    #   - [String]: uses it as is
    #   - [Fixnum]: _n_ days before today
    #   - [Date]: uses this date
    # @return [self]
    def before(date)
      date = case date
             when String
               date
             when Integer
               (Date.today - date).strftime "%e-%b-%Y"
             when Date
               date.strftime "%e-%b-%Y"
             else
               raise ArgumentError, "#{date.inspect} is invalid."
             end

      self << "BEFORE" << date
    end
  end
end