1 files changed, 61 insertions, 0 deletions
diff --git a/plugins/caldav/caldav.go b/plugins/caldav/caldav.go
new file mode 100644
index 0000000..1c043e9
--- /dev/null
+++ b/plugins/caldav/caldav.go
@@ -0,0 +1,61 @@
+package koushincaldav
+
+import (
+	"fmt"
+	"net/http"
+	"net/url"
+
+	"git.sr.ht/~emersion/koushin"
+	"github.com/emersion/go-webdav/caldav"
+)
+
+var errNoCalendar = fmt.Errorf("caldav: no calendar found")
+
+type authRoundTripper struct {
+	upstream http.RoundTripper
+	session  *koushin.Session
+}
+
+func (rt *authRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
+	rt.session.SetHTTPBasicAuth(req)
+	return rt.upstream.RoundTrip(req)
+}
+
+func newClient(u *url.URL, session *koushin.Session) (*caldav.Client, error) {
+	rt := authRoundTripper{
+		upstream: http.DefaultTransport,
+		session:  session,
+	}
+	c, err := caldav.NewClient(&http.Client{Transport: &rt}, u.String())
+	if err != nil {
+		return nil, fmt.Errorf("failed to create CalDAV client: %v", err)
+	}
+
+	return c, nil
+}
+
+func getCalendar(u *url.URL, session *koushin.Session) (*caldav.Client, *caldav.Calendar, error) {
+	c, err := newClient(u, session)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	principal, err := c.FindCurrentUserPrincipal()
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to query CalDAV principal: %v", err)
+	}
+
+	calendarHomeSet, err := c.FindCalendarHomeSet(principal)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to query CalDAV calendar home set: %v", err)
+	}
+
+	calendars, err := c.FindCalendars(calendarHomeSet)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to find calendars: %v", err)
+	}
+	if len(calendars) == 0 {
+		return nil, nil, errNoCalendar
+	}
+	return c, &calendars[0], nil
+}