feat:#34 refactored function to intended service, fixed docker files

services/data-manager/service/fetch/v2/fetcher.go

@@ -0,0 +1,181 @@
+//Calendar implementation for the HTWK Leipzig timetable. Evaluation and display of the individual dates in iCal format.
+//Copyright (C) 2024 HTWKalender support@htwkalender.de
+
+//This program is free software: you can redistribute it and/or modify
+//it under the terms of the GNU Affero General Public License as published by
+//the Free Software Foundation, either version 3 of the License, or
+//(at your option) any later version.
+
+//This program is distributed in the hope that it will be useful,
+//but WITHOUT ANY WARRANTY; without even the implied warranty of
+//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//GNU Affero General Public License for more details.
+
+//You should have received a copy of the GNU Affero General Public License
+//along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package v2
+
+import (
+	"fmt"
+	"github.com/google/uuid"
+	"github.com/pocketbase/pocketbase"
+	"golang.org/x/net/html"
+	"htwkalender/model"
+	"htwkalender/service/db"
+	"htwkalender/service/fetch"
+	v1 "htwkalender/service/fetch/v1"
+	"htwkalender/service/functions"
+	localTime "htwkalender/service/functions/time"
+	"log/slog"
+	"strings"
+)
+
+func ParseEventsFromRemote(app *pocketbase.PocketBase) (model.Events, error) {
+	savedRecords, err := FetchAllEventsAndSave(app, localTime.RealClock{})
+	if err != nil {
+		return nil, err
+	}
+	return savedRecords, nil
+}
+
+func FetchAllEventsAndSave(app *pocketbase.PocketBase, clock localTime.Clock) ([]model.Event, error) {
+	var savedRecords []model.Event
+	var err error = nil
+
+	var stubUrl = [2]string{
+		"https://stundenplan.htwk-leipzig.de/",
+		"/Berichte/Text-Listen;Veranstaltungsarten;name;" +
+			"Vp%0A" +
+			"Vw%0A" +
+			"V%0A" +
+			"Sp%0A" +
+			"Sw%0A" +
+			"S%0A" +
+			"Pp%0A" +
+			"Pw%0A" +
+			"P%0A" +
+			"ZV%0A" +
+			"Tut%0A" +
+			"Sperr%0A" +
+			"pf%0A" +
+			"wpf%0A" +
+			"fak%0A" +
+			"Pruefung%0A" +
+			"gebucht%0A" +
+			"Vertretung%0A" +
+			"Fremdveranst.%0A" +
+			"Buchen%0A" +
+			"%0A?&template=sws_modul&weeks=1-65&combined=yes",
+	}
+
+	// Fetch and save events for all semesters
+	for _, semester := range functions.CalculateSemesterList(clock) {
+		events, fetchErr := fetchAndSaveAllEventsForSemester(app, semester, stubUrl)
+		if fetchErr != nil {
+			return nil, fmt.Errorf("failed to fetch and save events for "+semester+": %w", err)
+		}
+		savedRecords = append(savedRecords, events...)
+	}
+
+	return savedRecords, err
+}
+
+func fetchAndSaveAllEventsForSemester(
+	app *pocketbase.PocketBase,
+	semester string,
+	stubUrl [2]string,
+) ([]model.Event, error) {
+	var savedRecords []model.Event
+	url := stubUrl[0] + semester + stubUrl[1]
+	events, err := parseEventForOneSemester(url)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse events for "+semester+": %w", err)
+	}
+	err = db.DeleteAllEventsBySemesterWithoutCourse(app, "Sport", semester)
+	if err != nil {
+		return nil, fmt.Errorf("failed to delete all events for "+semester+": %w", err)
+	}
+	savedEvents, dbError := db.SaveEvents(events, app)
+	if dbError != nil {
+		return nil, fmt.Errorf("failed to save events for "+semester+": %w", dbError)
+	}
+	savedRecords = append(savedRecords, savedEvents...)
+	return savedRecords, err
+}
+
+func parseEventForOneSemester(url string) ([]model.Event, error) {
+	// Fetch Webpage from URL
+	webpage, err := fetch.GetHTML(url)
+	if err != nil {
+		return nil, err
+	}
+
+	// Parse HTML to Node Tree
+	var doc *html.Node
+	doc, err = parseHTML(webpage)
+	if err != nil {
+		return nil, err
+	}
+
+	// Get all event tables and all day labels
+	eventTables := getEventTables(doc)
+	allDayLabels := getAllDayLabels(doc)
+	eventsWithCombinedWeeks := toEvents(eventTables, allDayLabels)
+
+	splitEventsByWeekVal := splitEventsByWeek(eventsWithCombinedWeeks)
+	events := splitEventsBySingleWeek(splitEventsByWeekVal)
+
+	if events == nil {
+		return nil, err
+	}
+
+	table := findFirstTable(doc)
+
+	if table == nil {
+		return nil, fmt.Errorf("failed to find first table")
+	}
+
+	semesterString := findFirstSpanWithClass(table, "header-0-2-0").FirstChild.Data
+	semester, year := extractSemesterAndYear(semesterString)
+	events = convertWeeksToDates(events, semester, year)
+	events, err = v1.SplitEventType(events)
+	if err != nil {
+		slog.Error("Error occurred while splitting event types: ", "error", err)
+		return nil, err
+	}
+	events = switchNameAndNotesForExam(events)
+	events = generateUUIDs(events)
+
+	return events, nil
+}
+
+// switch name and notes for Pruefung events when Note is not empty and Name starts with "Prüfungen" and contains email
+func switchNameAndNotesForExam(events []model.Event) []model.Event {
+	for i, event := range events {
+		if event.EventType == "Pruefung" {
+			if event.Notes != "" && strings.HasPrefix(event.Name, "Prüfungen") && strings.Contains(event.Name, "@") {
+				events[i].Name = event.Notes
+				events[i].Notes = event.Name
+			}
+		}
+	}
+	return events
+}
+
+func parseHTML(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
+}