From 9de30d0cbf8bc9a3aadd81f703d7cc7f055f952f Mon Sep 17 00:00:00 2001
From: Valentin Ochs <a@0au.de>
Date: Fri, 17 Jul 2020 21:38:56 +0200
Subject: [PATCH] Initial commit

---
 .gitignore        |   2 +
 auth.yaml.example |  10 ++++
 sync.py           | 119 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 131 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 auth.yaml.example
 create mode 100644 sync.py

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..594229f
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+auth.yaml
+data.yaml
diff --git a/auth.yaml.example b/auth.yaml.example
new file mode 100644
index 0000000..a5e4dea
--- /dev/null
+++ b/auth.yaml.example
@@ -0,0 +1,10 @@
+logins:
+  test_login:
+    password: hoarse_battery_steeple
+    url: https://example.com/remote.php/dav
+    user: root
+cals:
+- login: test_login
+  url: https://example.com/remote.php/dav/calendars/root/cal_1
+- login: test_login
+  url: https://example.com/remote.php/dav/calendars/root/cal_2
diff --git a/sync.py b/sync.py
new file mode 100644
index 0000000..9c00818
--- /dev/null
+++ b/sync.py
@@ -0,0 +1,119 @@
+import yaml
+import caldav
+import sys
+
+with open('auth.yaml') as f:
+    auth = yaml.full_load(f)
+try:
+    with open('data.yaml') as f:
+        known = yaml.full_load(f)
+except:
+    known = {}
+
+logins = {}
+for login, content in auth['logins'].items():
+    logins[login] = caldav.DAVClient(url=content['url'], username=content['user'], password=content['password'])
+
+cals = []
+for cal in auth['cals']:
+    cals.append(caldav.Calendar(client = logins[cal['login']], url = cal['url']))
+
+new = {}
+changed = {}
+deleted = {}
+
+def cal_contains_uid(cal, uid):
+    try:
+        event = cal.event_by_uid(uid)
+        return True
+    except caldav.lib.error.NotFoundError:
+        return False
+
+for cal in cals:
+    for event in cal.events():
+        uid = event.vobject_instance.vevent.uid.value
+        data = event.data
+        entry = (cal.canonical_url, data)
+
+        if uid not in known:
+            if uid not in new:
+                new[uid] = [entry]
+            else:
+                new[uid].append(entry)
+        else:
+            if data != known[uid]:
+                if uid not in changed:
+                    changed[uid] = [entry]
+                else:
+                    changed[uid].append(entry)
+for uid, data in known.items():
+    for cal in cals:
+        if not cal_contains_uid(cal, uid):
+            if uid not in deleted:
+                deleted[uid] = [cal.canonical_url]
+            else:
+                deleted[uid].append(cal.canonical_url)
+
+print("New:")
+print(new)
+print()
+print("Changed:")
+print(changed)
+print()
+print("Deleted:")
+print(deleted)
+print()
+
+for uid, arr in new.items():
+    if len(set([entry[1] for entry in arr])) != 1:
+        print("Multiple new entries with the same UID (%s) detected:" % (uid,), file=sys.stderr)
+        for ev in arr:
+            print("  %s: %s" % (ev[0], ev[1].vobject_instance.vevent.summary.value), file = sys.stderr)
+        print("", file=sys.stderr)
+        continue
+    
+    entry = arr[0]
+    known_cals = [ entry[0] for entry in arr ]
+    for cal in cals:
+        if cal.canonical_url not in known_cals:
+            cal.save_event(entry[1], no_overwrite=True)
+    known[uid] = entry[1]
+
+for uid, arr in changed.items():
+    if uid in deleted:
+        print("Changed entry with UID (%s) and was also deleted:" % (uid, ), file=sys.stderr)
+        print("Deletions in:", file=sys.stderr)
+        for cal in deleted[uid]:
+            print("  - %s" % (cal,), file=sys.stderr)
+        print("Changes in:", file=sys.stderr)
+        for entry in arr:
+            print("  - %s" % (entry[0],), file=sys.stderr)
+        print("", file=sys.stderr)
+        continue
+
+    if len(set([entry[1] for entry in arr])) != 1:
+        print("Multiple changed entries with the same UID (%s) detected:" % (uid,), file=sys.stderr)
+        for ev in arr:
+            print("  %s: %s" % (ev[0], ev[1].vobject_instance.vevent.summary.value), file = sys.stderr)
+        del deleted[uid]
+        continue
+    
+    entry = arr[0]
+    changed_cals = [ entry[0] for entry in arr ]
+    for cal in cals:
+        if cal.canonical_url not in changed_cals:
+            cal.save_event(entry[1], no_create=True)
+    known[uid] = entry[1]
+
+for uid in deleted:
+    for cal in cals:
+        try:
+            cal.event_by_uid(uid).delete()
+        except:
+            pass
+
+print(known)
+
+with open("data.yaml", "w") as f:
+    yaml.dump(known, f)
+