;;; Commentary:
;; Tests date, time, and datetime creation,
;; (output) formatting, and arithmetic.
;;; Code:

(define-module (test datetime)
  :use-module (srfi srfi-64)
  :use-module (srfi srfi-88)
  :use-module ((datetime)
               :select (date+ date-
                              time+
                              time-
                              year
                              month
                              day
                              date
                              time
                              datetime
                              datetime+
                              datetime<=?
                              datetime-difference
                              datetime-
                              leap-year?
                              string->date
                              string->time
                              string->datetime
                              parse-month
                              days-in-interval))
  :use-module ((ice-9 format) :select (format))
  :use-module ((hnh util) :select (let*))
  :use-module ((ice-9 i18n) :select (make-locale))
  :use-module ((guile) :select (LC_TIME)))

(test-equal
  "empty time"
  (time)
  #00:00:00)

(test-assert
  "Synatx date"
  #2020-01-01)

(test-assert
  "Test year type"
  (integer? (year (date year: 2020))))

(test-assert
  "Test mmnth type"
  (integer? (month (date month: 1))))

(test-assert
  "Test day type"
  (integer? (day (date day: 1))))

(test-equal
  "Manual print (any)"
  "2020-10-10"
  (let ((d #2020-10-10))
    (format #f "~a-~a-~a" (year d) (month d) (day d))))

(test-equal
  "Manual print (number)"
  "2020-10-10"
  (let ((d #2020-10-10))
    (format #f "~d-~d-~d" (year d) (month d) (day d))))

(test-equal
  "Date print"
  "#2020-01-01"
  (format
    #f
    "~a"
    #2020-01-01))

(test-equal
  "Syntax date="
  (date year: 2020 month: 1 day: 1)
  #2020-01-01)

(test-equal
  "Syntax time="
  (time hour: 13 minute: 37 second: 0)
  #13:37:00)

(test-equal
  "Syntax Datetime="
  (datetime year: 2020 month: 1 day: 1
            hour: 13 minute: 37 second: 0)
  #2020-01-01T13:37:00)

(test-equal
  #2020-02-28
  (date- #2020-03-05
         (date day: 6)))

(test-equal
  #2020-02-29
  (date- #2020-03-05
         (date day: 5)))

(test-equal
  #2020-03-01
  (date- #2020-03-05
         (date day: 4)))

(test-equal
  "date+ day"
  #2020-10-10
  (date+ #2020-10-01
         (date day: 9)))

(test-equal
  "date+ month"
  #2020-10-10
  (date+ #2020-01-10
         (date month: 9)))

(test-equal
  "date+ day/month"
  #2020-10-10
  (date+ #2020-01-01
         (date day: 9 month: 9)))

(test-assert
  "date+ first literal"
  (date+ #2020-01-01
         (date day: 0)))

(test-assert
  "date+ second literal"
  (date+ #0001-01-01
         #0001-00-00))

(test-assert
  "date+ both literal"
  (date+ #2020-01-01
         #0000-00-00))

(test-equal
  "date+ year overflow"
  #2019-01-01
  (date+ #2018-12-31
         (date day: 1)))

(test-equal
  "date- year overflow"
  #2018-12-31
  (date- #2019-01-01
         (date day: 1)))

(test-equal
  "date- large"
  #0001-01-01
  (date- #2020-01-01
         #2019-00-00))

(test-equal
  "date- equal"
  (date year: -1 month: 11 day: 31)
  (date- #2020-01-01
         #2020-01-01))

(test-equal
  #2020-01-01T10:00:00
  (datetime
    date:
    #2020-01-01
    time:
    #10:00:00))

(test-equal
  #2020-01-01T10:00:00
  (datetime+
    (datetime
      date:
      #2020-01-01)
    (datetime
      time:
      #10:00:00)))

(test-equal
  #2020-10-09T14:00:00
  (datetime-
    #2020-10-10T00:00:00
    (datetime
      time:
      #10:00:00)))

(test-equal
  #2020-09-24T14:00:00
  (datetime-
    #2020-10-10T00:00:00
    #0000-00-15T10:00:00))

(test-equal
  #2020-03-10
  (date+ #2020-03-01
         (date day: 4)
         (date day: 5)))

(let* ((diff overflow
             (time- #10:20:30
                    #10:20:30)))
  (test-equal
    "time- self"
    #00:00:00
    diff)
  (test-equal "time- self overflow" 0 overflow))

(let* ((diff overflow
             (time- #10:00:00
                    #10:00:01)))
  (test-equal
    "time- overflow 1s"
    #23:59:59
    diff)
  (test-equal
    "time- overflow 1s overflow"
    1
    overflow))

(let* ((diff overflow
             (time- #10:00:00
                    (time hour: (+ 48 4)))))
  (test-equal
    "time- overflow multiple"
    #06:00:00
    diff)
  (test-equal
    "time- overflow multiple overflow"
    2
    overflow))

(test-equal
  "datetime-difference self"
  #0000-00-00T00:00:00
  (datetime-difference
    (datetime
      date:
      #2020-01-01)
    (datetime
      date:
      #2020-01-01)))

;; NOTE
;; at the time of writing this returns #2020-02-00
;; The general question is, how is the last in a month handled?
(test-equal
  #2020-01-31
  (date+ #2019-12-31
         (date month: 1)))

(test-assert (leap-year? 2020))

(test-equal
  "Add to Leap day"
  #2020-02-29
  (date+ #2020-02-28
         (date day: 1)))

(test-equal
  "Parse ISO"
  #2021-12-30T13:53:33
  (string->datetime
    "2021-12-30T13:53:33"
    "~Y-~m-~dT~H:~M:~S"))

(test-equal
  "Parse ical date-time"
  #2021-12-30T13:53:33
  (string->datetime
    "20211230T135333"
    "~Y~m~dT~H~M~S"))

(test-equal
  "Parse single hour (padded)"
  (time hour: 5)
  (string->time "05" "~H"))

(test-equal
  "Parse single hour (non-padded)"
  (time hour: 5)
  (string->time "5" "~H"))

(test-equal
  "Parse month (swedish)"
  (date month: 5)
  (string->date
    "Maj"
    "~b"
    (make-locale LC_TIME "sv_SE.UTF-8")))

(test-equal
  "Parse month (english)"
  (date month: 5)
  (string->date
    "May"
    "~b"
    (make-locale LC_TIME "en_US.UTF-8")))

(test-equal
  "AM/PM AM"
  (time hour: 10)
  (string->time "10 AM" "~H ~p"))

(test-equal
  "AM/PM PM"
  (time hour: 22)
  (string->time "10 PM" "~H ~p"))

(test-equal
  "AM/PM AM 12"
  (time hour: 0)
  (string->time "12 AM" "~H ~p"))

(test-equal
  "AM/PM PM 12"
  (time hour: 12)
  (string->time "12 PM" "~H ~p"))

(test-equal
  "AM/PM PM (prefix)"
  (time hour: 22)
  (string->time "PM 10" "~p ~H"))

(test-equal
  "Parse complicated 1"
  #2021-12-30T10:56:00
  (string->datetime
    "Dec. 30, 2021, 10:56"
    "~b. ~d, ~Y, ~H:~M"
    (make-locale LC_TIME "en_US.UTF-8")))

(test-equal
  "Parse complicated 2"
  #2021-12-30T10:56:00
  (string->datetime
    "Dec. 30, 2021, 10:56 a.m."
    "~b. ~d, ~Y, ~H:~M"
    (make-locale LC_TIME "en_US.UTF-8")))

(test-equal
  "Parse complicated 3"
  #2021-12-30T22:56:00
  (string->datetime
    "Dec. 30, 2021, 10:56 p.m."
    "~b. ~d, ~Y, ~H:~M ~p"
    (make-locale LC_TIME "en_US.UTF-8")))

(test-equal
  "Parse date single digit day"
  (date day: 6)
  (string->date "6" "~d"))

(test-equal
  "Parse date single digit day, trailing comma"
  (date day: 6)
  (string->date "6," "~d,"))

(test-equal
  "Parse date single digit day, trailing comma + space"
  (date day: 6)
  (string->date "6, " "~d, "))

(define en_US
  (make-locale LC_TIME "en_US.UTF-8"))

(define sv_SE
  (make-locale LC_TIME "sv_SE.UTF-8"))

(test-equal 1 (parse-month "jan" en_US))

(test-equal 1 (parse-month "jan" sv_SE))

(test-equal 12 (parse-month "dec" en_US))

(test-equal -1 (parse-month "inv" en_US))

(test-equal 5 (parse-month "mAJ" sv_SE))

(test-equal
  "Days in regular year"
  365
  (days-in-interval
    #2021-01-01
    #2021-12-31))

(test-equal
  "Days in leap year"
  366
  (days-in-interval
    #2020-01-01
    #2020-12-31))