cardav working (tm)

internal/extra/color.go

@@ -6,7 +6,9 @@ import (
 	"fmt"
 	"context"
 	"io"
+	"log"
 	"net/http"
+
 	"nxcaldav/internal/backend"
 	"regexp"
 	"time"
@@ -99,8 +101,87 @@ func AddColorToCalendarPropfind(r *http.Request, ctx context.Context, handler ht
 		return resp
 	})
 
-	// Headers are already set in h.ResponseWriter.Header() by caldav.Handler
-	// But Content-Length might have changed
+	w.Header().Set("Content-Length", fmt.Sprintf("%d", len(body)))
+	w.WriteHeader(rw.status)
+	w.Write(body)
+}
+
+func HandleDiscoveryPropfind(r *http.Request, ctx context.Context, handler http.Handler, w http.ResponseWriter, be *backend.DBBackend) {
+	reqBody, _ := io.ReadAll(r.Body)
+	r.Body = io.NopCloser(bytes.NewBuffer(reqBody))
+
+	buf := &bytes.Buffer{}
+	rw := &responseWriter{w, buf, http.StatusOK}
+	handler.ServeHTTP(rw, r.WithContext(ctx))
+
+	body := buf.Bytes()
+
+	// 1. Unconditionally add namespaces to root tag
+	reMultistatus := regexp.MustCompile(`(<[a-zA-Z0-9]*:?multistatus)`)
+	body = reMultistatus.ReplaceAll(body, []byte(`$1 xmlns:C="urn:ietf:params:xml:ns:caldav" xmlns:card="urn:ietf:params:xml:ns:carddav"`))
+
+	// 2. Response processing
+	reResponse := regexp.MustCompile(`(?s)<[a-zA-Z0-9]*:?response.*?>.*?</[a-zA-Z0-9]*:?response>`)
+	reHref := regexp.MustCompile(`<[a-zA-Z0-9]*:?href.*?>(.*?)</[a-zA-Z0-9]*:?href>`)
+	rePropstat := regexp.MustCompile(`(?s)<[a-zA-Z0-9]*:?propstat.*?>.*?</[a-zA-Z0-9]*:?propstat>`)
+	reStatusOk := regexp.MustCompile(`(?s)<[a-zA-Z0-9]*:?status.*?>HTTP/1.1 200 OK</[a-zA-Z0-9]*:?status>`)
+	reProp := regexp.MustCompile(`(?s)<[a-zA-Z0-9]*:?prop.*?>.*?</[a-zA-Z0-9]*:?prop>`)
+	rePropClose := regexp.MustCompile(`</[a-zA-Z0-9]*:?prop>`)
+
+	body = reResponse.ReplaceAllFunc(body, func(resp []byte) []byte {
+		hrefMatch := reHref.FindSubmatch(resp)
+		if len(hrefMatch) < 2 {
+			return resp
+		}
+
+		calHome, _ := be.CalendarHomeSetPath(ctx)
+		cardHome, _ := be.AddressBookHomeSetPath(ctx)
+
+		// Strip these tags ONLY from non-200 propstats
+		resp = rePropstat.ReplaceAllFunc(resp, func(ps []byte) []byte {
+			if !reStatusOk.Match(ps) {
+				reTags := regexp.MustCompile(`(?s)<[a-zA-Z0-9:]*(calendar-home-set|addressbook-home-set).*?/>|<[a-zA-Z0-9:]*(calendar-home-set|addressbook-home-set).*?>.*?</[a-zA-Z0-9:]*(calendar-home-set|addressbook-home-set)>`)
+				return reTags.ReplaceAll(ps, []byte(""))
+			}
+			return ps
+		})
+
+		props := ""
+		if calHome != "" && !strings.Contains(string(resp), "calendar-home-set") {
+			props += fmt.Sprintf("<C:calendar-home-set><href xmlns=\"DAV:\">%s</href></C:calendar-home-set>", calHome)
+		}
+		if cardHome != "" && !strings.Contains(string(resp), "addressbook-home-set") {
+			props += fmt.Sprintf("<card:addressbook-home-set><href xmlns=\"DAV:\">%s</href></card:addressbook-home-set>", cardHome)
+		}
+
+		if props == "" {
+			return resp
+		}
+
+		has200 := false
+		resp = rePropstat.ReplaceAllFunc(resp, func(ps []byte) []byte {
+			if reStatusOk.Match(ps) {
+				has200 = true
+				return reProp.ReplaceAllFunc(ps, func(prop []byte) []byte {
+					return rePropClose.ReplaceAllFunc(prop, func(closeTag []byte) []byte {
+						return append([]byte(props), closeTag...)
+					})
+				})
+			}
+			return ps
+		})
+
+		if !has200 {
+			newPropstat := fmt.Sprintf("<propstat xmlns=\"DAV:\"><prop>%s</prop><status>HTTP/1.1 200 OK</status></propstat>", props)
+			reResponseClose := regexp.MustCompile(`</[a-zA-Z0-9]*:?response>`)
+			resp = reResponseClose.ReplaceAllFunc(resp, func(closeTag []byte) []byte {
+				return append([]byte(newPropstat), closeTag...)
+			})
+		}
+
+		return resp
+	})
+
 	w.Header().Set("Content-Length", fmt.Sprintf("%d", len(body)))
 	w.WriteHeader(rw.status)
 	w.Write(body)