feat: implement caldav search

vendor/github.com/dolanor/caldav-go/icalendar/components/calendar.go

@@ -0,0 +1,87 @@
+package components
+
+import (
+	"fmt"
+	"github.com/dolanor/caldav-go/icalendar/values"
+	"github.com/dolanor/caldav-go/utils"
+	"time"
+)
+
+type Calendar struct {
+
+	// specifies the identifier corresponding to the highest version number or the minimum and maximum
+	// range of the iCalendar specification that is required in order to interpret the iCalendar object.
+	Version string `ical:",2.0"`
+
+	// specifies the identifier for the product that created the iCalendar object
+	ProductId string `ical:"prodid,-//dolanor/caldav-go//NONSGML v1.0.0//EN"`
+
+	// specifies the text value that uniquely identifies the "VTIMEZONE" calendar component.
+	TimeZoneId string `ical:"tzid,omitempty"`
+
+	// defines the iCalendar object method associated with the calendar object.
+	Method values.Method `ical:",omitempty"`
+
+	// defines the calendar scale used for the calendar information specified in the iCalendar object.
+	CalScale values.CalScale `ical:",omitempty"`
+
+	// defines the different timezones used by the various components nested within
+	TimeZones []*TimeZone `ical:",omitempty"`
+
+	// unique events to be stored together in the icalendar file
+	Events []*Event `ical:",omitempty"`
+}
+
+func (c *Calendar) UseTimeZone(location *time.Location) *TimeZone {
+	tz := NewDynamicTimeZone(location)
+	c.TimeZones = append(c.TimeZones, tz)
+	c.TimeZoneId = tz.Id
+	return tz
+}
+
+func (c *Calendar) UsingTimeZone() bool {
+	return len(c.TimeZoneId) > 0
+}
+
+func (c *Calendar) UsingGlobalTimeZone() bool {
+	return c.UsingTimeZone() && c.TimeZoneId[0] == '/'
+}
+
+func (c *Calendar) ValidateICalValue() error {
+
+	for i, e := range c.Events {
+
+		if e == nil {
+			continue // skip nil events
+		}
+
+		if err := e.ValidateICalValue(); err != nil {
+			msg := fmt.Sprintf("event %d failed validation", i)
+			return utils.NewError(c.ValidateICalValue, msg, c, err)
+		}
+
+		if e.DateStart == nil && c.Method == "" {
+			msg := fmt.Sprintf("no value for method and no start date defined on event %d", i)
+			return utils.NewError(c.ValidateICalValue, msg, c, nil)
+		}
+
+	}
+
+	if c.UsingTimeZone() && !c.UsingGlobalTimeZone() {
+		for i, t := range c.TimeZones {
+			if t == nil || t.Id != c.TimeZoneId {
+				msg := fmt.Sprintf("timezone ID does not match timezone %d", i)
+				return utils.NewError(c.ValidateICalValue, msg, c, nil)
+			}
+		}
+	}
+
+	return nil
+
+}
+
+func NewCalendar(events ...*Event) *Calendar {
+	cal := new(Calendar)
+	cal.Events = events
+	return cal
+}