From f71ec34f48e56d5212520e817d054ef3d3ed5a9b Mon Sep 17 00:00:00 2001
From: Andreas Schneider <aksdb@gmx.de>
Date: Sun, 1 Apr 2018 20:20:02 +0200
Subject: [PATCH] Implemented create and delete sync logic

---
 src/calanonsync/calanonsync.go | 71 ++++++++++++++++++++++++++++------
 src/calanonsync/caldav.go      |  4 +-
 2 files changed, 62 insertions(+), 13 deletions(-)

diff --git a/src/calanonsync/calanonsync.go b/src/calanonsync/calanonsync.go
index 460d2ea..4ac492f 100644
--- a/src/calanonsync/calanonsync.go
+++ b/src/calanonsync/calanonsync.go
@@ -1,7 +1,6 @@
 package main
 
 import (
-	"fmt"
 	"log"
 	"time"
 )
@@ -12,28 +11,78 @@ func main() {
 	e := NewEWSCalendar(s.EWS.URL, s.EWS.Username, s.EWS.Password)
 	id, err := e.getCalendarFolderID()
 	if err != nil {
-		log.Println(err)
-		return
+		log.Fatalln(err)
 	}
 
-	items, err := e.getCalendarItems(id, time.Now().AddDate(0, -1, 0), time.Now().AddDate(0, 2, 0))
+	items, err := e.getCalendarItems(id,
+		time.Now().AddDate(0, -1, 0), // One month past
+		time.Now().AddDate(0, 2, 0))  // Two months ahead
 	if err != nil {
-		log.Println(err)
-		return
+		log.Fatalln(err)
 	}
 
+	relevantEWSItems := make(map[string]CalendarItem)
+
 	for _, item := range items {
-		fmt.Printf("%#v\n", item)
+		// Ignore private items.
+		if item.Sensitivity != "Private" {
+			// None-private items though ... remember them by hash.
+			// The hash will equal the CalDAV UID (and its filename).
+			relevantEWSItems[item.Hash()] = item
+		}
 	}
 
 	c := NewCalDAV(s.CalDAV)
 	calDavItems, err := c.GetEvents()
 	if err != nil {
-		log.Println(err)
-		return
+		log.Fatalln(err)
 	}
+	// Build a map for easier lookup by UID
+	calDavItemMap := make(map[string]CalDAVItem)
 	for _, item := range calDavItems {
-		fmt.Printf("%s\n  UID: %s\n  Summary: %s\n  Start: %s\n  End: %s\n",
-			item.HRef, item.UID(), item.Summary(), item.Start(), item.End())
+		calDavItemMap[item.UID()] = item
+	}
+
+	// First step: find items that were changed or that were removed
+	// and update the CalDAV side accordingly.
+	for uid, calDavItem := range calDavItemMap {
+		if ewsItem, ok := relevantEWSItems[uid]; ok {
+			// Good, so we still know the item at least.
+			if !ewsItem.Start.Equal(calDavItem.Start()) ||
+				!ewsItem.End.Equal(calDavItem.End()) {
+
+				// So times have changed. Update.
+				// TODO
+			}
+		} else {
+			// Oops, seems the item vanished.
+			err := c.DeleteItem(calDavItem)
+			if err == nil {
+				log.Printf("Deleted item %s (%s)\n", calDavItem.UID(), calDavItem.Summary())
+			} else {
+				// Not fatal, but worth a note.
+				log.Println(err)
+			}
+		}
+	}
+
+	// Find items we don't know so far and create them.
+	for uid, ewsItem := range relevantEWSItems {
+		if _, ok := calDavItemMap[uid]; !ok {
+			title := s.Anonymize.Title
+			if title == "" {
+				// No anonymization? Fine.
+				title = ewsItem.Subject
+			}
+			ical := CreateICal(ewsItem.Hash(), title, ewsItem.Start, ewsItem.End)
+			calDavItem := CalDAVItem{HRef: uid + ".ics", ICal: ical}
+
+			err := c.UploadItem(calDavItem)
+			if err == nil {
+				log.Printf("Created item %s (%s)\n", uid, ewsItem.Subject)
+			} else {
+				log.Println(err)
+			}
+		}
 	}
 }
diff --git a/src/calanonsync/caldav.go b/src/calanonsync/caldav.go
index d9364ca..59b0bb2 100644
--- a/src/calanonsync/caldav.go
+++ b/src/calanonsync/caldav.go
@@ -174,7 +174,7 @@ func NewCalDAV(settings ServerSettings) *CalDAV {
 
 type CalDAVItem struct {
 	HRef string
-	ICal
+	*ICal
 }
 
 func (c *CalDAV) GetEvents() ([]CalDAVItem, error) {
@@ -199,7 +199,7 @@ func (c *CalDAV) GetEvents() ([]CalDAVItem, error) {
 
 	result := make([]CalDAVItem, 0, len(ms.Response))
 	for _, p := range ms.Response {
-		item := CalDAVItem{p.HRef, p.PropStat.Prop.CalendarData}
+		item := CalDAVItem{p.HRef, &p.PropStat.Prop.CalendarData}
 		result = append(result, item)
 	}