src

commit cc703aded3f352760a56c4b79e5600614fe9ffaa
parent b28407f5c22220027e4d81e85991cc4ebc979ae2
Author: dwrz <dwrz@dwrz.net>
Date:   Sun, 25 Feb 2024 18:10:12 +0000

Add sun cmd

Diffstat:
A
cmd/sun/main.go
 | 
60
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 60 insertions(+), 0 deletions(-)
diff --git a/cmd/sun/main.go b/cmd/sun/main.go
@@ -0,0 +1,60 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"time"
+
+	"github.com/nathan-osman/go-sunrise"
+
+	"code.dwrz.net/src/pkg/geo"
+)
+
+var (
+	name        = flag.String("n", "", "location name")
+	coordinates = flag.String("c", "", "coordinates")
+	date        = flag.String("d", "", "date in YYYY-MM-DD format")
+	tz          = flag.String("z", "", "timezone")
+)
+
+func main() {
+	flag.Parse()
+	if *coordinates == "" {
+		log.Fatalf("missing coordinates")
+	}
+
+	c, err := geo.ParseCoordinates(*coordinates)
+	if err != nil {
+		log.Fatalf("failed to parse coordinates: %v", err)
+	}
+
+	var now = time.Now()
+	if *date != "" {
+		var err error
+		now, err = time.Parse(time.DateOnly, *date)
+		if err != nil {
+			log.Fatalf("failed to parse date: %v", err)
+		}
+	}
+
+	var loc *time.Location = time.UTC
+	if *tz != "" {
+		var err error
+		loc, err = time.LoadLocation(*tz)
+		if err != nil {
+			log.Fatalf("failed to parse timezone: %v", err)
+		}
+	}
+
+	// https://en.wikipedia.org/wiki/Sunrise_equation
+	rise, set := sunrise.SunriseSunset(
+		c.Latitude, c.Longitude,
+		now.Year(), now.Month(), now.Day(),
+	)
+
+	fmt.Println(
+		rise.In(loc).Format(time.RFC3339),
+		set.In(loc).Format(time.RFC3339),
+	)
+}