{-# LANGUAGE OverloadedStrings #-}

module Notification
  ( todayAndNextWeek
  ) where

import qualified Data.Text as T

import SendMail (sendMail)
import Time (formatCurrentLocale)

import Model.Date (getCurrentDate, getNextWeek)
import Model.Birthdate (Birthdate, filterBirthdayAt, filterBirthdayBetween)
import Model.Mail (mailSubject, mailBody)
import Model.Config

todayAndNextWeek :: [Birthdate] -> Config -> IO ()
todayAndNextWeek birthdates config = do
  currentDate <- getCurrentDate
  birthdaysToday <- filterBirthdaysToday birthdates
  birthdaysNextWeek <- filterBirthdaysNextWeek birthdates config
  if length birthdaysToday > 0 || length birthdaysNextWeek > 0
    then
      sendMail
        (mailTo config)
        (mailFrom config)
        (mailSubject birthdaysToday birthdaysNextWeek)
        (mailBody currentDate birthdaysToday birthdaysNextWeek)
    else
      return ()

filterBirthdaysToday :: [Birthdate] -> IO [Birthdate]
filterBirthdaysToday birthdates = do
  currentDate <- getCurrentDate
  return (filterBirthdayAt currentDate birthdates)

filterBirthdaysNextWeek :: [Birthdate] -> Config -> IO [Birthdate]
filterBirthdaysNextWeek birthdates config = do
  currentDayOfWeek <- formatCurrentLocale "%A"
  if T.toLower currentDayOfWeek == T.toLower (dayForNextWeekNotification config)
    then do
      (begin, end) <- getNextWeek
      return (filterBirthdayBetween begin end birthdates)
    else
      return []