;;; Commentary:
;; Tests timespan overlaps and month-streams.
;; Separate from tests/datetime.scm since
;; (datetime util) originally was its own module.
;;; Code:

(define-module (test datetime-util)
  :use-module (srfi srfi-64)
  :use-module (srfi srfi-88)
  :use-module ((datetime)
               :select (date time
                             datetime
                             month-stream
                             in-date-range?
                             timespan-overlaps?))
  :use-module ((srfi srfi-41)
               :select (stream->list stream-take)))

(test-assert
  "jan->dec"
  (stream->list
    (stream-take
      11
      (month-stream
        #2020-01-01))))

(test-assert
  "dec->jan"
  (stream->list
    (stream-take
      2
      (month-stream
        #2020-12-01))))

(test-assert
  "dec->feb"
  (stream->list
    (stream-take
      3
      (month-stream
        #2020-12-01))))

(test-assert
  "20 months"
  (stream->list
    (stream-take
      20
      (month-stream
        #2020-01-01))))

(test-equal
  "Correct months"
  (list #2020-02-01
        #2020-03-01
        #2020-04-01
        #2020-05-01
        #2020-06-01
        #2020-07-01
        #2020-08-01
        #2020-09-01
        #2020-10-01
        #2020-11-01
        #2020-12-01
        #2021-01-01)
  (stream->list
    (stream-take
      12
      (month-stream
        #2020-02-01))))

(test-assert
  "in-date-range?"
  (not ((in-date-range?
          #2020-01-01
          #2020-02-29)
        #2018-02-02)))

(test-assert
  "A"
  (timespan-overlaps?
    #2020-01-01
    #2020-01-10
    #2020-01-05
    #2020-01-15))

(test-assert
  "A, shared start"
  (timespan-overlaps?
    #2020-01-01
    #2020-01-10
    #2020-01-01
    #2020-01-15))

(test-assert
  "A, tangential"
  (not (timespan-overlaps?
         #2020-01-01T00:00:00
         #2020-01-10T00:00:00
         #2020-01-10T00:00:00
         #2020-01-30T00:00:00)))

(test-assert
  "s1 instant"
  (timespan-overlaps?
    #2020-01-15T10:00:00
    #2020-01-15T10:00:00
    #2020-01-10T00:00:00
    #2020-01-30T00:00:00))

(test-assert
  "s2 instant"
  (timespan-overlaps?
    #2020-01-10T00:00:00
    #2020-01-30T00:00:00
    #2020-01-15T10:00:00
    #2020-01-15T10:00:00))

(test-assert
  "s1 instant, shared start with s2"
  (timespan-overlaps?
    #2020-01-15T10:00:00
    #2020-01-15T10:00:00
    #2020-01-15T10:00:00
    #2020-01-30T00:00:00))

(test-assert
  "s1 instant, shared end with s2"
  (not (timespan-overlaps?
         #2020-01-15T10:00:00
         #2020-01-15T10:00:00
         #2020-01-10T00:00:00
         #2020-01-15T10:00:00)))

(test-assert
  "s2 instant, shared start with s1"
  (timespan-overlaps?
    #2020-01-15T10:00:00
    #2020-01-30T00:00:00
    #2020-01-15T10:00:00
    #2020-01-15T10:00:00))

(test-assert
  "s2 instant, shared end with s1"
  (not (timespan-overlaps?
         #2020-01-10T00:00:00
         #2020-01-15T10:00:00
         #2020-01-15T10:00:00
         #2020-01-15T10:00:00)))

(test-assert
  "both instant"
  (not (timespan-overlaps?
         #2020-01-15T10:00:00
         #2020-01-15T10:00:00
         #2020-01-15T10:00:00
         #2020-01-15T10:00:00)))

(test-assert
  "tangential whole day"
  (not (timespan-overlaps?
         #2020-01-01
         #2020-01-02
         #2020-01-02
         #2020-01-03)))

(test-assert
  "B"
  (timespan-overlaps?
    #2020-01-05
    #2020-01-15
    #2020-01-01
    #2020-01-10))

(test-assert
  "E"
  (timespan-overlaps?
    #2020-01-01
    #2020-01-10
    #2020-01-01
    #2020-01-10))