feat:#52 added new fetcher from new endpoint

backend/service/fetch/v2/fetcher.go

@@ -0,0 +1,95 @@
+package v2
+
+import (
+	"github.com/google/uuid"
+	"github.com/labstack/echo/v5"
+	"github.com/pocketbase/pocketbase"
+	"golang.org/x/net/html"
+	"htwkalender/model"
+	"htwkalender/service/db"
+	"htwkalender/service/fetch"
+	"strconv"
+	"strings"
+)
+
+func ParseEventsFromRemote(c echo.Context, app *pocketbase.PocketBase) error {
+
+	url := "https://stundenplan.htwk-leipzig.de/ws/Berichte/Text-Listen;Veranstaltungsarten;name;Vp%0AVw%0AV%0ASp%0ASw%0AS%0APp%0APw%0AP%0AZV%0ATut%0ASperr%0Apf%0Awpf%0Afak%0A%0A?&template=sws_modul&weeks=1-65&combined=yes"
+
+	// Fetch Webpage from URL
+	webpage, err := fetch.GetHTML(url)
+	if err != nil {
+		return err
+	}
+
+	// Parse HTML to Node Tree
+	doc, err2 := parseHTML(err, webpage)
+	if err2 != nil {
+		return err2
+	}
+
+	// Get all event tables and all day labels
+	eventTables := getEventTables(doc)
+	allDayLabels := getAllDayLabels(doc)
+
+	if eventTables == nil || allDayLabels == nil {
+		return err
+	}
+
+	eventsWithCombinedWeeks := toEvents(eventTables, allDayLabels)
+
+	if eventsWithCombinedWeeks == nil {
+		return err
+	}
+
+	splitEventsByWeekVal := splitEventsByWeek(eventsWithCombinedWeeks)
+	events := splitEventsBySingleWeek(splitEventsByWeekVal)
+
+	if events == nil {
+		return err
+	}
+
+	// Search Semester String in Page Head
+	table := findFirstTable(doc)
+	semesterString := findFirstSpanWithClass(table, "header-0-2-0").FirstChild.Data
+
+	semester, year := extractSemesterAndYear(semesterString)
+	events = convertWeeksToDates(events, semester, year)
+	events = generateUUIDs(events)
+	events = splitEventType(events)
+
+	var seminarGroup = model.SeminarGroup{
+		University: findFirstSpanWithClass(table, "header-1-0-0").FirstChild.Data,
+		Events:     events,
+	}
+
+	if seminarGroup.Events == nil && seminarGroup.University == "" {
+		return err
+	}
+
+	savedRecords, dbError := db.SaveEvents(events, app)
+
+	if dbError != nil {
+		return dbError
+	} else {
+		savedRecordsLength := strconv.FormatInt(int64(len(savedRecords)), 10)
+		return c.JSON(200, "Successfully saved "+savedRecordsLength+" events")
+	}
+}
+
+func parseHTML(err error, webpage string) (*html.Node, error) {
+	doc, err := html.Parse(strings.NewReader(webpage))
+	if err != nil {
+		return nil, err
+	}
+	return doc, nil
+}
+
+func generateUUIDs(events []model.Event) []model.Event {
+	for i, event := range events {
+		// generate a hash value from the event name, course and semester
+		hash := uuid.NewSHA1(uuid.NameSpaceOID, []byte(event.Name+event.Course))
+		events[i].UUID = hash.String()
+	}
+	return events
+}