package calendar

import (
	"ArinDash/config"
	"sort"
	"time"

	"github.com/arran4/golang-ical"
)

type configFile struct {
	Calendar calendarConfig
}

type calendarConfig struct {
	ICS  []ICS
	Icon string
}

type ICS struct {
	Icon string
	URL  string
}

type Event struct {
	UID         string
	Summary     string
	Description string
	Start       time.Time
	End         time.Time
	Location    string
	Icon        string
}

func FetchEvents() []Event {
	cfg := &configFile{}
	config.LoadConfig(cfg)

	events := make([]Event, 0)
	for _, ic := range cfg.Calendar.ICS {
		cal, err := ics.ParseCalendarFromUrl(ic.URL)
		if err != nil {
			panic(err)
		}
		for _, event := range cal.Events() {
			startAt, err := event.GetStartAt()
			if err != nil {
				startAt = time.Now()
			}
			endAt, err := event.GetEndAt()
			if err != nil {
				endAt = startAt
			}
			events = append(events, Event{
				UID:         getValue(event, ics.ComponentPropertyUniqueId),
				Icon:        ic.Icon,
				Summary:     getValue(event, ics.ComponentPropertySummary),
				Description: getValue(event, ics.ComponentPropertyDescription),
				Start:       startAt,
				End:         endAt,
				Location:    getValue(event, ics.ComponentPropertyLocation),
			})
		}
	}
	result := filter(events, func(i Event) bool {
		return i.End.After(time.Now())
	})
	sort.Slice(result, func(i, j int) bool {
		return result[i].Start.Before(result[j].Start)
	})
	return result
}

func getValue(event *ics.VEvent, property ics.ComponentProperty) string {
	ianaProperty := event.GetProperty(property)
	if ianaProperty == nil {
		return ""
	}
	return ianaProperty.Value
}

func filter[T any](ss []T, test func(T) bool) (ret []T) {
	for _, s := range ss {
		if test(s) {
			ret = append(ret, s)
		}
	}
	return
}