1 files changed, 45 insertions, 0 deletions
diff --git a/hommaexceli_py/parser.py b/hommaexceli_py/parser.py
new file mode 100644
index 0000000..b4abb46
--- /dev/null
+++ b/hommaexceli_py/parser.py
@@ -0,0 +1,45 @@
+import datetime
+import logging
+import re
+from sheets_client import SheetsRow
+
+INTERVAL_ABBREVS = {
+    "pv": datetime.timedelta(days=1),
+    "vk": datetime.timedelta(days=7),
+    "kk": datetime.timedelta(days=30),
+    "v": datetime.timedelta(days=365),
+}
+
+
+def _calculate_interval(interval_str: str):
+    match = re.search(r"(\d+)(\w+)", interval_str)
+    number = int(match[1])
+    abbrev = match[2]
+
+    try:
+        interval = INTERVAL_ABBREVS[abbrev]
+    except KeyError:
+        raise Exception(f'"{interval_str}" is an invalid interval string!')
+
+    total_interval = datetime.timedelta(seconds=interval.total_seconds() * number)
+    return total_interval
+
+
+def _timestamp_to_date(timestamp: str):
+    return datetime.datetime.strptime(timestamp, "%Y-%m-%d")
+
+
+def _date_to_timestamp(date):
+    return datetime.datetime.strftime(date, "%Y-%m-%d")
+
+
+def _process_row(row: SheetsRow):
+    interval = _calculate_interval(row.interval)
+    last_done_date = _timestamp_to_date(row.last_done)
+    next_date = last_done_date + interval
+    next_date_str = _date_to_timestamp(next_date)
+    return (row.last_done, row.interval, next_date_str, row.name)
+
+
+def process_rows(rows: list[SheetsRow]):
+    return map(_process_row, rows)