1 files changed, 78 insertions, 0 deletions
diff --git a/pkg/ical/service.go b/pkg/ical/service.go
new file mode 100644
index 0000000..2b89fe7
--- /dev/null
+++ b/pkg/ical/service.go
@@ -0,0 +1,78 @@
+package ical
+
+import (
+	"errors"
+	"strings"
+	"time"
+
+	"github.com/LMBishop/confplanner/pkg/database/sqlc"
+	"github.com/LMBishop/confplanner/pkg/favourites"
+	"github.com/LMBishop/confplanner/pkg/schedule"
+	"github.com/microcosm-cc/bluemonday"
+)
+
+type Service interface {
+	GenerateIcalForCalendar(calendar sqlc.Calendar) (string, error)
+}
+
+var (
+	ErrImproperType = errors.New("improper type")
+	ErrNotFound     = errors.New("not found")
+)
+
+type service struct {
+	favouritesService favourites.Service
+	scheduleService   schedule.Service
+}
+
+func NewService(
+	favouritesService favourites.Service,
+	scheduleService schedule.Service,
+) Service {
+	return &service{
+		favouritesService: favouritesService,
+		scheduleService:   scheduleService,
+	}
+}
+
+func (s *service) GenerateIcalForCalendar(calendar sqlc.Calendar) (string, error) {
+	favourites, err := s.favouritesService.GetFavouritesForUser(calendar.UserID)
+	if err != nil {
+		return "", err
+	}
+
+	sched, _, err := s.scheduleService.GetSchedule()
+	if err != nil {
+		return "", err
+	}
+
+	events := make([]schedule.Event, 0)
+	for _, favourite := range *favourites {
+		event := s.scheduleService.GetEventByID(favourite.EventID.Int32)
+		events = append(events, *event)
+	}
+
+	now := time.Now()
+
+	// https://www.rfc-editor.org/rfc/rfc5545.html
+
+	ret := "BEGIN:VCALENDAR\n"
+	ret += "VERSION:2.0\n"
+	ret += "METHOD:PUBLISH\n"
+	ret += "X-WR-CALNAME:confplanner calendar\n"
+	for _, event := range events {
+		utcStart := event.Start.UTC()
+		utcEnd := event.End.UTC()
+
+		ret += "BEGIN:VEVENT\n"
+		ret += "SUMMARY:" + event.Title + "\n"
+		ret += "DTSTART;TZID=" + sched.Conference.TimeZoneName + ":" + utcStart.Format("20060102T150405Z") + "\n"
+		ret += "DTEND;TZID=" + sched.Conference.TimeZoneName + ":" + utcEnd.Format("20060102T150405Z") + "\n"
+		ret += "LOCATION:" + event.Room + "\n"
+		ret += "DESCRIPTION;ENCODING=QUOTED-PRINTABLE:" + bluemonday.StrictPolicy().Sanitize(strings.Replace(event.Abstract, "\n", "\\n", -1)) + "\\nLast Synchronised: " + now.Format(time.DateTime) + "\n"
+		ret += "END:VEVENT\n"
+	}
+	ret += "END:VCALENDAR\n"
+
+	return ret, nil
+}