From 0f984696c7cb2306661ad974d64e96bafa204c0c Mon Sep 17 00:00:00 2001
From: Ronja <ronja@boehringer-mueller.de>
Date: Sun, 1 Nov 2020 16:44:40 +0100
Subject: [PATCH] time module

---
 Luxe/math/time.wren | 325 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 325 insertions(+)
 create mode 100644 Luxe/math/time.wren

diff --git a/Luxe/math/time.wren b/Luxe/math/time.wren
new file mode 100644
index 0000000..4cdd353
--- /dev/null
+++ b/Luxe/math/time.wren
@@ -0,0 +1,325 @@
+import "luxe: io" for IO
+
+//modulo utility function in here to make this pretty self contained for now
+var mod = Fn.new{|dividend, divisor|
+  return (dividend%divisor + divisor) % divisor
+}
+
+//time based on epoch time - assumes time is after 1.1.1970 and doesnt do leap seconds
+class DateTime{
+  static seconds_per_minute{60}
+  static seconds_per_hour{3600}
+  static seconds_per_day{86400}
+  static minutes_per_hour{60}
+  static hours_per_day{24}
+  static epoch{1970}
+
+  toString{
+    var month_names = ["jan", "feb", "mar", "apr", "may", "jun", "jul", "aug", "sep", "oct", "nov", "dec"]
+    var week_names = ["mon", "tue", "wed", "thu", "fri", "sat", "sun"]
+    var ends = ["th", "st", "nd", "rd", "th", "th", "th", "th", "th", "th"]
+    return "%(week_names[day_of_week]), %(days+1)%(ends[(days+1)%10]) of %(month_names[months]) %(years) "+
+        "%(hours):%(minutes):%(seconds)"
+  }
+
+  total_seconds{_time}
+  total_minutes{(_time / DateTime.seconds_per_minute).truncate}
+  total_hours{(_time / DateTime.seconds_per_hour).truncate}
+  total_days{(_time / DateTime.seconds_per_day).truncate}
+  total_years{years}
+
+  seconds{total_seconds % DateTime.seconds_per_minute}
+  minutes{(total_minutes % DateTime.minutes_per_hour).truncate}
+  hours{(total_hours % DateTime.hours_per_day).truncate}
+  days{
+    var months = [31, DateTime.is_leap_year(years)?29:28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
+    var month = 0
+    var days = day_in_year
+    while(days >= months[month]){
+      days = days - months[month]
+      month = month + 1
+    }
+    return days
+  }
+  day_in_year{
+    var days = total_days
+    var year = DateTime.epoch
+    //while the day is in a later year
+    while(days >= 365){
+      if(DateTime.is_leap_year(year)){
+        if(days == 365) return days
+        days = days - 366
+      } else {
+        days = days - 365
+      }
+      year = year + 1
+    }
+    return days
+  }
+  //day of the week from monday=0 to sunday=6
+  day_of_week{
+    return (total_days + 3) % 7 //+3 is because 1.1.1970 was a thursday
+  }
+  week_in_year{
+    //what
+    return ((day_in_year-day_of_week-1)/7).truncate+1
+  }
+  months{
+    var months = [31, DateTime.is_leap_year(years)?29:28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
+    var month = 0
+    var days = day_in_year
+    while(days >= months[month]){
+      days = days - months[month]
+      month = month + 1
+    }
+    return month
+  }
+  years{
+    return DateTime.epoch + ((total_days - leap_days_since_epoch_start) / 365).truncate
+  }
+  leap_days_since_epoch_start{
+    var days = total_days
+    var year = DateTime.epoch
+    var leaps = 0
+    //while the day is in a later year or later than january 29/march 1
+    while(days > 58){
+      if(DateTime.is_leap_year(year)){
+        leaps = leaps + 1
+        days = days - 366
+      } else {
+        days = days - 365
+      }
+      year = year + 1
+    }
+    return leaps
+  }
+
+  is_leap_year{is_leap_year(years)}
+
+  static is_leap_year(year){
+    return year % 4 == 0 && (year % 100 != 0 || year % 400 == 0)
+  }
+
+  construct new(epoch){
+    _time = epoch
+  }
+
+  construct now(){
+    _time = IO.time_since_epoch_utc()
+  }
+
+  construct clone(instance){
+    _time = instance.total_seconds
+  }
+
+  //overloads
+  static from_time(years) {from_time(years, 0, 0, 0, 0, 0)}
+  static from_time(years, months) {from_time(years, months, 0, 0, 0, 0)}
+  static from_time(years, months, days) {from_time(years, months, days, 0, 0, 0)}
+  static from_time(years, months, days, hours) {from_time(years, months, days, hours, 0, 0)}
+  static from_time(years, months, days, hours, minutes) {from_time(years, months, days, hours, minutes, 0)}
+
+  construct from_time(years, months, days, hours, minutes, seconds){
+    if(years < DateTime.epoch) {
+      System.print("[warn] dates before %(DateTime.epoch) aren't possible yet :(")
+      return
+    }
+    for(i in DateTime.epoch...years){
+      days = days + (DateTime.is_leap_year(i)?366:365)
+    }
+    var month_days = [31, DateTime.is_leap_year(years)?29:28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
+    for(i in 0...months){
+      days = days + month_days[i]
+    }
+    _time = days * DateTime.seconds_per_day + hours * DateTime.seconds_per_hour + minutes * DateTime.seconds_per_minute + seconds
+  }
+
+  add_seconds(second_diff){
+    _time = _time + second_diff
+  }
+
+  add_minutes(minute_diff){
+    _time = _time + minute_diff * DateTime.seconds_per_minute
+  }
+
+  add_hours(hour_diff){
+    _time = _time + hour_diff * DateTime.seconds_per_hour
+  }
+
+  add_days(day_diff){
+    _time = _time + day_diff * DateTime.seconds_per_day
+  }
+
+  add_weeks(week_diff){
+    _time = _time + week_diff * DateTime.seconds_per_day * 7
+  }
+
+  add_months(month_diff){
+    var month_days = [31, null, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
+    var day_difference = 0
+    var month = months
+    var year = years
+    var sign = month_diff.sign
+    var original_days = days
+    //execute once if counting down to use the next months days, not this months days
+    if(sign < 0){
+      month = month + sign
+      if(month < 0){
+        month = month + 12
+        year = year - 1
+      }
+      if(month >= 12){
+        month = month - 12
+        year = year + 1
+      }
+    }
+    //collect days we have to move the time
+    for(i in 0...month_diff){
+      var days = month_days[month]
+      if(days){
+        day_difference = day_difference + days * sign
+      } else {
+        day_difference = day_difference + (DateTime.is_leap_year(year)?29:28) * sign
+      }
+      month = month + sign
+      if(month < 0){
+        month = month + 12
+        year = year - 1
+      }
+      if(month >= 12){
+        month = month - 12
+        year = year + 1
+      }
+    }
+    add_days(day_difference)
+    //if the days shifted we can assume we jumped, for example from a 31st of jan to a 2nd of march since the feb is short
+    //so we just go back until we arrive in the previous month
+    var new_days = days
+    if(new_days != original_days){
+      add_days(-new_days-1)
+    }
+  }
+
+  add_years(year_diff){
+    var before_leap = day_in_year <= 59
+    var day_difference = 0
+    var year = years
+    var sign = year_diff.sign
+    if(sign > 0 != before_leap){
+      year = year + sign
+    }
+    for(i in 0...year_diff){
+      day_difference = day_difference + sign * (DateTime.is_leap_year(year)?366:365)
+      year = year + sign
+    }
+    add_days(day_difference)
+  }
+
+  add(span){
+    _time = _time + span.total_seconds
+  }
+
+  set(time){
+    _time = time
+  }
+
+  update(){
+    _time = IO.time_since_epoch_utc()
+  }
+
+  static difference(time_1, time_2){
+    return TimeSpan.new((time_1.total_seconds - time_2.total_seconds).abs)
+  }
+
+  +(val){
+    if(val is TimeSpan){
+      return DateTime.new(_time + val.total_seconds)
+    }
+    Fiber.abort("Can't add DateTime and %(val.type.name)")
+  }
+
+  -(val){
+    if(val is DateTime){
+      return DateTime.difference(this, val)
+    }
+    if(val is TimeSpan){
+      return DateTime.new(_time - val.total_seconds)
+    }
+    Fiber.abort("Can't subtract %(val.type.name) from TimeSpan")
+  }
+}
+
+class TimeSpan{
+  static zero{TimeSpan.new(0)}
+
+  toString{"%(days) days, %(hours) hours, %(minutes) minutes, and %(seconds) seconds"}
+
+  total_seconds{_time}
+  total_minutes{(_time / DateTime.seconds_per_minute).truncate}
+  total_hours{(_time / DateTime.seconds_per_hour).truncate}
+  total_days{(_time / DateTime.seconds_per_day).truncate}
+
+  seconds{total_seconds % DateTime.seconds_per_minute}
+  minutes{total_minutes % DateTime.minutes_per_hour}
+  hours{total_hours % DateTime.hours_per_day}
+  days{total_days}
+  //months and years are not possible because we don't know which months/years we're talking about
+
+  construct new(time){
+    _time = time
+  }
+
+  construct from_seconds(seconds){
+    _time = seconds
+  }
+
+  construct from_minutes(minutes){
+    _time = minutes * DateTime.seconds_per_minute
+  }
+
+  construct from_hours(hours){
+    _time = hours * DateTime.seconds_per_hour
+  }
+
+  construct from_days(days){
+    _time = days * DateTime.seconds_per_day
+  }
+
+  add_seconds(seconds){
+    _time = _time + seconds
+  }
+
+  add_minutes(minutes){
+    _time = _time + minutes * DateTime.seconds_per_minute
+  }
+
+  add_hours(hours){
+    _time = _time + hours * DateTime.seconds_per_hour
+  }
+
+  add_days(days){
+    _time = _time + days * DateTime.seconds_per_day
+  }
+
+  add(span){
+    _time = _time + span.total_seconds
+  }
+
+  set(time){
+    _time = time
+  }
+
+  +(val){
+    if(val is TimeSpan){
+      return TimeSpan.new(_time + val.total_seconds)
+    }
+    Fiber.abort("Can't add TimeSpan and %(val.type.name)")
+  }
+
+  -(val){
+    if(val is TimeSpan){
+      return TimeSpan.new(_time - val.total_seconds)
+    }
+    Fiber.abort("Can't add TimeSpan and %(val.type.name)")
+  }
+}
\ No newline at end of file