add week command

main.go

@@ -9,7 +9,8 @@ func commandsUsage() string {
 	return fmt.Sprintf(
 		`commands:
   path        %v
-`, commandPathDescription)
+  week        %v
+`, commandPathDescription, commandWeekDescription)
 }
 
 func main() {
@@ -17,6 +18,8 @@ func main() {
 		switch os.Args[1] {
 		case "path":
 			commandPath(os.Args[1:])
+		case "week":
+			commandWeek(os.Args[1:])
 		default:
 			fmt.Printf("unknow command `%v`\n\n", os.Args[1])
 			fmt.Printf("%v", commandsUsage())

week.go

@@ -0,0 +1,36 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+	"time"
+)
+
+var commandWeekDescription = "get week in this year and week begin and end offset by this week"
+
+func commandWeek(args []string) {
+	var err error
+	offset := 0
+	if len(args) == 2 {
+		offset, err = strconv.Atoi(args[1])
+		if err != nil {
+			fmt.Printf("expect `%v` to be a integer\n", args[1])
+			os.Exit(1)
+		}
+	} else if len(args) > 2 {
+		fmt.Printf("only accept 1 argument, got %v\n", len(args)-1)
+		os.Exit(1)
+	}
+	offsetTime := time.Hour * time.Duration(offset) * 7 * 24
+	targetTime := time.Now().Add(offsetTime)
+	_, week := targetTime.ISOWeek()
+	weekday := int(targetTime.Weekday())
+	// make Sunday = 7
+	if weekday == 0 {
+		weekday = 7
+	}
+	weekBegin := targetTime.Add(time.Hour * 24 * time.Duration(weekday-1) * -1)
+	weekEnd := targetTime.Add(time.Hour * 24 * time.Duration(7-weekday))
+	fmt.Printf("week-%v-%v-%v\n", week, weekBegin.Format("0102"), weekEnd.Format("0102"))
+}