require "secure_random"
require "../model"

class Guff::SessionModel < Guff::Model
  SQL = TemplateCache.new({
    add: "
      INSERT INTO sessions(session_id) VALUES (:session_id)
    ",

    delete: "
      DELETE FROM sessions WHERE session_id = :session_id
    ",

    get: "
      SELECT data

        FROM sessions

       WHERE session_id = :session_id
         AND strftime('%s', datetime(updated_at, :age)) >=
             strftime('%s', 'now')

    ",

    set: "
      UPDATE sessions

         SET data = :data,
             updated_at = CURRENT_TIMESTAMP

       WHERE session_id = :session_id
         AND strftime('%s', datetime(updated_at, :age)) >=
             strftime('%s', 'now')

    ",

    scrub: "
      DELETE FROM sessions
       WHERE strftime('%s', datetime(updated_at, :age)) <
             strftime('%s', 'now')
    ",
  })

  # maximum session age
  AGE = "24 hours"

  def initialize(models : Models)
    super(models, SQL)

    # TODO: make this configurable
    @age = AGE
  end

  def add : String
    # create sid
    r = SecureRandom.hex(16)

    # add session
    query(:add, {
       "session_id": r
    }, nil)

    # return sid
    r
  end

  def get(session_id : String) : String?
    one(:get, {
      "session_id": session_id,
      "age":        @age,
    }, nil)
  end

  def set(session_id : String, data : String)
    query(:set, {
      "session_id": session_id,
      "age":        @age,
      "data":       data,
    }, nil)
  end

  def delete(session_id : String)
    query(:delete, {
      "session_id": sesion_id,
    }, nil)
  end

  private def scrub
    query(:scrub, {
      "age": @age,
    }, nil)
  end
end