www: selectie van de week

cmd/dates2json/dates2json.go

@@ -0,0 +1,105 @@
+package main
+
+import (
+	e "codeberg.org/pebbe/errors"
+
+	"encoding/json"
+	"fmt"
+	"os"
+	"slices"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type Date struct {
+	Week  string `json:"week"`
+	First string `json:"first"`
+	Last  string `json:"last"`
+}
+
+var (
+	x = e.ExitErr
+
+	dates = make([]Date, 0)
+)
+
+func main() {
+
+	files, err := os.ReadDir("/net/corpora/nlnieuws/data")
+	x(err)
+
+	for _, file := range files {
+		filename := file.Name()
+		if strings.HasPrefix(filename, "DATA-") && strings.HasSuffix(filename, "-4.json") {
+			addWeek(filename[5:12])
+		}
+	}
+
+	slices.Reverse(dates)
+	b, err := json.Marshal(dates)
+	x(err)
+	fmt.Println(string(b))
+
+}
+
+func addWeek(s string) {
+
+	week, err := strconv.Atoi(s[5:])
+	x(err)
+	year, err := strconv.Atoi(s[:4])
+	x(err)
+
+	// 15 januari van het jaar
+	t := time.Date(year, 1, 15, 12, 0, 0, 0, time.UTC)
+
+	// eerste gok
+	t = t.AddDate(0, 0, 7*week-14)
+
+	// zoek juiste week
+	var y, w int
+	for {
+		y, _ = t.ISOWeek()
+		if y < year {
+			t = t.AddDate(0, 12, 0)
+			continue
+		}
+		if y > year {
+			t = t.AddDate(0, -12, 0)
+			continue
+		}
+		break
+	}
+	for {
+		y, w = t.ISOWeek()
+		if w < week {
+			t = t.AddDate(0, 0, 7)
+			continue
+		}
+		if w > week {
+			t = t.AddDate(0, 0, -7)
+		}
+		break
+	}
+	if y != year {
+		x(fmt.Errorf("ongeldige combinatie van week/jaar: %d/%d", week, year))
+	}
+
+	// zoek begin van de week
+	d := int(t.Weekday())
+	if d == 0 {
+		d = 7
+	}
+	tFirst := t.AddDate(0, 0, 1-d)
+	tLast := tFirst.AddDate(0, 0, 6)
+
+	dates = append(dates, Date{
+		Week:  s,
+		First: makeDate(tFirst),
+		Last:  makeDate(tLast),
+	})
+}
+
+func makeDate(d time.Time) string {
+	return fmt.Sprintf("%d-%02d-%02d", d.Year(), int(d.Month()), d.Day())
+}