Files
banner/term.go

132 lines
3.8 KiB
Go

package main
import (
"fmt"
"strconv"
"time"
"github.com/rs/zerolog/log"
)
// Term selection should yield smart results based on the current time, as well as the input provided.
// Fall 2024, "spring" => Spring 2025
// Fall 2024, "fall" => Fall 2025
// Summer 2024, "fall" => Fall 2024
const (
Spring = iota
Summer
Fall
)
type Term struct {
Year uint16
Season uint8
}
var (
SpringRange, SummerRange, FallRange YearDayRange
)
func init() {
SpringRange, SummerRange, FallRange = GetYearDayRange(uint16(time.Now().Year()))
currentTerm, nextTerm := GetCurrentTerm(time.Now())
log.Debug().Str("CurrentTerm", fmt.Sprintf("%+v", currentTerm)).Str("NextTerm", fmt.Sprintf("%+v", nextTerm)).Msg("GetCurrentTerm")
}
type YearDayRange struct {
Start uint16
End uint16
}
// GetYearDayRange returns the start and end day of each term for the given year.
// This could technichally introduce race conditions, but it's more likely confusion from UTC will be a greater issue.
// Spring: January 14th to May
// Summer: May 25th - August 15th
// Fall: August 18th - December 10th
func GetYearDayRange(year uint16) (YearDayRange, YearDayRange, YearDayRange) {
springStart := time.Date(int(year), time.January, 14, 0, 0, 0, 0, CentralTime).YearDay()
springEnd := time.Date(int(year), time.May, 1, 0, 0, 0, 0, CentralTime).YearDay()
summerStart := time.Date(int(year), time.May, 25, 0, 0, 0, 0, CentralTime).YearDay()
summerEnd := time.Date(int(year), time.August, 15, 0, 0, 0, 0, CentralTime).YearDay()
fallStart := time.Date(int(year), time.August, 18, 0, 0, 0, 0, CentralTime).YearDay()
fallEnd := time.Date(int(year), time.December, 10, 0, 0, 0, 0, CentralTime).YearDay()
return YearDayRange{
Start: uint16(springStart),
End: uint16(springEnd),
}, YearDayRange{
Start: uint16(summerStart),
End: uint16(summerEnd),
}, YearDayRange{
Start: uint16(fallStart),
End: uint16(fallEnd),
}
}
// GetCurrentTerm returns the current term, and the next term. Only the first term is nillable.
// YearDay ranges are inclusive of the start, and exclusive of the end.
func GetCurrentTerm(now time.Time) (*Term, *Term) {
year := uint16(now.Year())
dayOfYear := uint16(now.YearDay())
if (dayOfYear < SpringRange.Start) || (dayOfYear >= FallRange.End) {
// Fall over, Spring not yet begun
return nil, &Term{Year: year + 1, Season: Spring}
} else if (dayOfYear >= SpringRange.Start) && (dayOfYear < SpringRange.End) {
// Spring
return &Term{Year: year, Season: Spring}, &Term{Year: year, Season: Summer}
} else if dayOfYear < SummerRange.Start {
// Spring over, Summer not yet begun
return nil, &Term{Year: year, Season: Summer}
} else if (dayOfYear >= SummerRange.Start) && (dayOfYear < SummerRange.End) {
// Summer
return &Term{Year: year, Season: Summer}, &Term{Year: year, Season: Fall}
} else if dayOfYear < FallRange.Start {
// Summer over, Fall not yet begun
return nil, &Term{Year: year, Season: Fall}
} else if (dayOfYear >= FallRange.Start) && (dayOfYear < FallRange.End) {
// Fall
return &Term{Year: year, Season: Fall}, nil
}
panic(fmt.Sprintf("Impossible Code Reached (dayOfYear: %d)", dayOfYear))
}
// BannerTermToTerm converts a Banner term code to a Term struct
func BannerTermToTerm(code string) Term {
year, _ := strconv.ParseUint(code[0:4], 10, 16)
var season uint8
termCode := code[4:6]
switch termCode {
case "10":
season = Fall
case "20":
season = Spring
case "30":
season = Summer
}
return Term{
Year: uint16(year),
Season: season,
}
}
// TermToBannerTerm converts a Term struct to a Banner term code
func TermToBannerTerm(term Term) string {
var season string
switch term.Season {
case Fall:
season = "10"
case Spring:
season = "20"
case Summer:
season = "30"
}
return fmt.Sprintf("%d%s", term.Year, season)
}