module Calendar = Hito_web.Calendar

let invalid_month f =
  try
    ignore (f ());
    false
  with Invalid_argument _ -> true

let suite =
  [
    ( "calendar",
      [
        ( "recognizes Gregorian leap years",
          `Quick,
          fun () ->
            Alcotest.(check bool)
              "1900 is not leap" false (Calendar.is_leap 1900);
            Alcotest.(check bool) "2000 is leap" true (Calendar.is_leap 2000);
            Alcotest.(check bool) "2024 is leap" true (Calendar.is_leap 2024) );
        ( "counts every month",
          `Quick,
          fun () ->
            let expected = [ 31; 29; 31; 30; 31; 30; 31; 31; 30; 31; 30; 31 ] in
            List.iteri
              (fun index days ->
                Alcotest.(check int)
                  (Printf.sprintf "month %d" (index + 1))
                  days
                  (Calendar.days_in_month ~year:2024 ~month:(index + 1)))
              expected );
        ( "rejects an invalid month",
          `Quick,
          fun () ->
            Alcotest.(check bool)
              "month 13" true
              (invalid_month (fun () ->
                   Calendar.days_in_month ~year:2024 ~month:13)) );
        ( "converts Gregorian dates to UTC seconds",
          `Quick,
          fun () ->
            Alcotest.(check int)
              "Unix epoch" 0
              (Calendar.unix_seconds_of_date ~year:1970 ~month:1 ~day:1);
            Alcotest.(check int)
              "day after epoch" 86_400
              (Calendar.unix_seconds_of_date ~year:1970 ~month:1 ~day:2) );
        ( "returns Monday-first weekdays",
          `Quick,
          fun () ->
            Alcotest.(check int)
              "1970-01-01 was Thursday" 3
              (Calendar.monday_first_weekday ~year:1970 ~month:1 ~day:1);
            Alcotest.(check int)
              "2024-01-01 was Monday" 0
              (Calendar.monday_first_weekday ~year:2024 ~month:1 ~day:1) );
      ] );
  ]