1 files changed, 46 insertions, 0 deletions

diff --git a/tools/tai64dec/tai64dec/__main__.py b/tools/tai64dec/tai64dec/__main__.py
new file mode 100644
index 00000000..a8854523
--- /dev/null
+++ b/tools/tai64dec/tai64dec/__main__.py
@@ -0,0 +1,46 @@
+import sys, os
+
+import argparse
+
+from leapseconddata import LeapSecondData
+from math import ldexp
+from pathlib import Path
+from datetime import datetime, timezone
+import secrets
+
+
+class BooleanAction(argparse.Action):
+    def __init__(self, option_strings, dest, nargs=None, **kwargs):
+        super(BooleanAction, self).__init__(option_strings, dest, nargs=0, **kwargs)
+
+    def __call__(self, parser, namespace, values, option_string=None):
+        setattr(namespace, self.dest, False if option_string.startswith('--no') else True)
+
+
+def main():
+    parser = argparse.ArgumentParser(prog='tai64dec', formatter_class=argparse.ArgumentDefaultsHelpFormatter)
+    parser.add_argument('--random', '--no-random', action=BooleanAction, default=False)
+    parser.add_argument('--ns', '--no-ns', action=BooleanAction, default=True)
+    args = parser.parse_args()
+
+
+    leapsecond_data = LeapSecondData.from_file(Path(os.getenv('LEAPSECONDS_FILE')))
+
+    now = datetime.now(tz=timezone.utc)
+
+    tai_dt = leapsecond_data.to_tai(now)
+    seconds = int(tai_dt.timestamp())
+    seconds += int(ldexp(1, 62))
+    out = seconds
+
+    if args.ns:
+        nanoseconds = int((tai_dt.timestamp() - seconds) / 1e-9)
+        out = out << 32 | nanoseconds
+
+    if args.random:
+        out = out << 24 | int.from_bytes(secrets.token_bytes(3), byteorder='little', signed=False)
+
+    print('{:d}'.format(out), file=sys.stdout)
+
+if __name__ == '__main__':
+    sys.exit(main())