requires: {#Magnitude}.
provides: {#Time. #Date. #Duration. #Month}.

"Date and Time protocols, included from ANSI Smalltalk packages for Squeak."

lobby addSlot: #Time valued: Namespace clone.

Time addSlot: #Time valued: Magnitude derive.
Time Time addSlot: #seconds.

"Time represents an amount of time within a 24-hour period, stored as seconds."

t@(Time Time traits) newForSeconds: n
[| newT |
  newT: t clone.
  newT seconds: n.
  newT
].

t@(Time Time traits) newForHours: h minutes: m seconds: s
[| newT |
  newT: t clone.
  newT seconds: h * 3600 + (m * 60) + s.
  newT
].

t@(Time Time traits) hours
"Answer the number of hours the receiver represents."
[
  t seconds // 3600 \\ 24
].

t@(Time Time traits) minutes
"Answer the number of minutes the receiver represents."
[
  t seconds \\ 3600 // 60
].

t@(Time Time traits) seconds
"Answer the number of seconds the receiver represents."
[
  t seconds \\ 60
].

t1@(Time Time traits) + t2@(Time Time traits)
[
  t1 newForSeconds: t1 seconds + t2 seconds
].

t1@(Time Time traits) - t2@(Time Time traits)
[
  t1 newForSeconds: t1 seconds - t2 seconds
].

t1@(Time Time traits) < t2@(Time Time traits)
[
  t1 seconds < t2 seconds
].

t1@(Time Time traits) = t2@(Time Time traits)
[
  t1 seconds = t2 seconds
].

t@(Time Time traits) hash
[
  t seconds hash
].

Time addSlot: #Date valued: Magnitude derive.
Time Date addSlot: #julianDayNumber.

Time addSlot: #DaysInMonth.
Time addSlot: #FirstDayOfMonth.
Time addSlot: #MonthNames.
Time addSlot: #SecondsInDay.
Time addSlot: #WeekDayNames.

Time addSlot: #Month valued: Cloneable derive.
Time Month addSlot: #name valued: ''.
Time Month addSlot: #firstDayWithinYear valued: 0.
Time Month addSlot: #length valued: 0.

m@(Time Month traits) newNamed: name startingAt: start length: length
[| newM |
  newM: m clone.
  newM name: name.
  newM firstDayWithinYear: start.
  newM length: length.
  newM
].

m@(Time Month traits) newNamed: name from: start to: end
[
  m newNamed: name startingAt: start length: end - start + 1
].

Time addSlot: #months valued: Namespace clone.
Time months addSlot: #January valued:
  (Month newNamed: 'January' startingAt: 1 length: 31).
Time months addSlot: #January valued:
  (Month newNamed: 'February' startingAt: 32 length: 28).
Time months addSlot: #March valued:
  (Month newNamed: 'March' startingAt: 60 length: 31).
Time months addSlot: #April valued:
  (Month newNamed: 'April' startingAt: 91 length: 30).
Time months addSlot: #May valued:
  (Month newNamed: 'May' startingAt: 121 length: 31).
Time months addSlot: #June valued:
  (Month newNamed: 'June' startingAt: 152 length: 30).
Time months addSlot: #July valued:
  (Month newNamed: 'July' startingAt: 182 length: 31).
Time months addSlot: #August valued:
  (Month newNamed: 'August' startingAt: 213 length: 31).
Time months addSlot: #September valued:
  (Month newNamed: 'September' startingAt: 244 length: 30).
Time months addSlot: #October valued:
  (Month newNamed: 'October' startingAt: 274 length: 31).
Time months addSlot: #November valued:
  (Month newNamed: 'November' startingAt: 305 length: 30).
Time months addSlot: #December valued:
  (Month newNamed: 'December' startingAt: 335 length: 31).

Time addSlot: #JulianMonths valued: (Set newSize: 12).
Time months slotValuesDo: [| :each | Time JulianMonths add: each].

Time addSlot: #Duration valued: Magnitude derive.
Duration addSlot: #seconds valued: 0.

d@(Time Duration traits) newForSeconds: n
[| newD |
  newD: d clone.
  newD seconds: n.
  newD
].

d@(Time Duration traits) days
"The number of whole days represented, possibly negative."
[
  d seconds abs // Time SecondsInDay * d seconds sign
].

d@(Time Duration traits) hours
"The number of whole hours represented, possibly negative, after whole days
are discounted."
[
  d seconds abs \\ Time SecondsInDay // Time SecondsInHour * d seconds sign
].

d@(Time Duration traits) minutes
"The number of whole minutes, possibly negative, after whole days and hours
are discounted."
[
  d seconds abs \\ Time SecondsInDay \\ Time SecondsInHour
    // Time SecondsInMinute * d seconds sign
].

d@(Time Duration traits) seconds
"The number of seconds, possibly negative, after whole days, hours, minutes
are discounted."
[
  d seconds abs \\ Time SecondsInDay \\ Time SecondsInHour
    \\ Time SecondsInMinute * d seconds sign
].

d@(Time Duration traits) * n@(Number traits)
[
  d newForSeconds: d seconds * n
].

d@(Time Duration traits) / n@(Number traits)
[
  d newForSeconds: d seconds / n
].

d1@(Time Duration traits) / d2@(Time Duration traits)
[
  d1 seconds / d2 seconds
].

d1@(Time Duration traits) + d2@(Time Duration traits)
[
  d newForSeconds: d1 seconds + d2 seconds
].

d1@(Time Duration traits) - d2@(Time Duration traits)
[
  d newForSeconds: d1 seconds - d2 seconds
].

d@(Time Duration traits) abs
[
  d newForSeconds: d seconds abs
].

d@(Time Duration traits) negated
[
  d newForSeconds: d seconds negated
].

d@(Time Duration traits) isZero
[
  d seconds isZero
].

d@(Time Duration traits) sign
[
  d seconds sign
].

d@(Time Duration traits) isPositive
[
  d seconds isPositive
].

d@(Time Duration traits) isNegative
[
  d seconds isNegative
].

d1@(Time Duration traits) < d2@(Time Duration traits)
[
  d1 seconds < d2 seconds
].

d1@(Time Duration traits) > d2@(Time Duration traits)
[
  d1 seconds > d2 seconds
].

d1@(Time Duration traits) = d2@(Time Duration traits)
[
  d1 seconds = d2 seconds
].

d@(Time Duration traits) hash
[
  d seconds hash
].

d@(Time Duration traits) printAbsOn: stream
"Prints out the format [-]D:HH:MM:SS[.S] ."
[| tempSecs |
  stream ; (d days abs printPaddedWith: $0 to: 1).
  stream nextPut: $:.
  stream ; (d hours abs printPaddedWith: $0 to: 2).
  stream nextPut: $:.
  stream ; (d minutes abs printPaddedWith: $0 to: 2).
  tempSecs: d seconds abs.
  tempSecs fractionPart = 0
    ifTrue: [tempSecs: (tempSecs as: Integer)].
  stream ; (tempSecs printPaddedWith: $0 to: 2).
  d
].

d@(Time Duration traits) printOn: stream
[
  d seconds isNegative ifTrue: [stream nextPut: $-].
  d printAbsOn: stream
].


Time addSlot: #SecondsInMinute valued: 60.
Time addSlot: #SecondsInHour valued: Time SecondsInMinute * 60.
Time addSlot: #SecondsInDay valued: Time SecondsInHour * 24.

Time addSlot: #Instant valued: Magnitude derive.
Time Instant addSlot: #localDate.
Time Instant addSlot: #localOffsetToUTC.
Time Instant addSlot: #localTime.
Time Instant addSlot: #localTimeZoneName.
Time Instant addSlot: #localTimeZoneAbbrev.

"Instant instances represent individual points in Coordinated Universal
Time (UTC) formerly called GMT at Greenwich, UK as represented in an
implementation defined local time, including consideration of time zones."

i@(Time Instant traits) dayOfMonth
"Answer an Integer between 1 and 31, inclusive, representing the day of the
month in the local time of the receiver, which includes the receiver."
[
  i localDate dayOfMonth
].

i@(Time Instant traits) dayOfWeek
"Answer an Integer between 1 and 7, inclusive, representing the day of the
week in the local time of the receiver, which includes the receiver. Sunday
is 1, Monday 2, and so on."
[| dayIndex |
  dayIndex: i localDate weekdayIndex + 1.
  dayIndex > 7 ifTrue: [dayIndex: 1].
  dayIndex
].

i@(Time Instant traits) dayOfWeekAbbreviation
[
  i dayOfWeekName copyFrom: 0 to: 2
].

i@(Time Instant traits) dayOfWeekName
"Answer the name of the day of the week in the local time."
[
  i localDate weekday as: String
].

i@(Time Instant traits) dayOfYear
"Answer an Integer between 1 and 366, inclusive, representing the day of
the year in the local time of the receiver, which includes the receiver."
[
  i localDate day
].

i@(Time Instant traits) hour
"Answer an Integer between 0 and 23, inclusive, representing the hour of the
day in the local time of the receiver. This may be in either the 12 or 24
hour clock."
[
  i localTime hours
].

i@(Time Instant traits) hour24
[
  i hour
].

i@(Time Instant traits) hour12
"Answer an Integer between 1 and 12, inclusive, representing the hour of the
day in the 12-hour clock of the local time of the receiver."
[| tempHour |
  tempHour: (self hour + 1) abs.
  tempHour > 12 ifTrue: [tempHour: tempHour - 12].
  tempHour
].

i@(Time Instant traits) minute
"Answer an Integer between 0 and 59, inclusive, representing the minute of
the hour in the local time of the receiver."
[
  i localTime minutes
].

i@(Time Instant traits) second
"Answer an Integer between 0 and 59, inclusive, representing the second of
the minute in the local time of the receiver, including the fractional part."
[
  i localTime seconds abs
].

i@(Time Instant traits) year
"Answer an Integer representing the year of the local time which includes
the receiver."
[
  i localDate year
].

i@(Time Instant traits) month
"Answer an Integer between 1 and 12, inclusive, representing the month of
the year in the local time of the receiver."
[
  i localDate monthIndex
].

i@(Time Instant traits) monthName
"Answer the name of the month of the year in the local time of the
receiver, which includes the receiver."
[
  i localDate monthName as: String
].

i@(Time Instant traits) monthAbbreviation
"Answer a <readableString> which is the abbreviated name of the month of the
year in the local time of the receiver, which includes the receiver."
[
  i monthName copyFrom: 0 to: 2
].

i@(Time Instant traits) offset
[
  i localOffsetToUTC
].

i@(Time Instant traits) offset: d@(Time Duration traits)
"Answer an Instant equivalent to the receiver, but with its local time
offset from UTC by the Duration."
[| newI |
  d abs < Time Day ifFalse: [i error: 'Invalid UTC-offset.'].
  newI: i clone.
  newI localOffsetToUTC: d.
  newI
].

i@(Time Instant traits) rationalise
"Adjust the receiver so localTime is less than a day and positive."
[| timeDays |
  i localTime isNegative ifTrue: [
    timeDays: i localTime days abs + 1.
    i localDate: (i localDate subtractDays: timeDays).
    i localTime: (Duration days: timeDays) + i localTime].
  "Insure time is less than a day."
  timeDays: i localTime days.
  timeDays > 0 ifTrue: [i localDate: (i localDate addDays: timeDays).
    i localTime: i localTime - (Duration days: timeDays)].
  i
].

i@(Time Instant traits) + d@(Time Duration traits)
[| newI |
  newI: i clone.
  newI localTime: i localTime + d.
  newI rationalise.
  newI
].

i@(Time Instant traits) - d@(Time Duration traits)
[
  i + d negated
].

i1@(Time Instant traits) - i2@(Time Instant traits)
[
  Duration newSeconds: i2 localDate - i1 localDate
    + (i2 localTime - i1 localTime)
].

Time addSlot: #DaylightEndDate.
Time addSlot: #DaylightOffset.
Time addSlot: #DaylightStartDate.
Time addSlot: #DaylightTimeZoneAbbrev.
Time addSlot: #DaylightTimeZoneName.
Time addSlot: #DaysInMonth.
Time addSlot: #DaysToMonth.
Time addSlot: #DefaultIsStandard.
Time addSlot: #Offset.
Time addSlot: #StandardOffset.
Time addSlot: #StandardTimeZoneAbbrev.
Time addSlot: #StandardTimeZoneName.
Time addSlot: #TimeZoneAbbrev.
Time addSlot: #TimeZoneName.

Time addSlot: #Duration valued: Magnitude derive.