feat(rules): dry-run counts what a rule matches

Two numbers per rule: what it matches across all mail, and what it
would tag on the next sync. The first is what decides whether a rule
is still earning its place.

1 files changed, 27 insertions, 0 deletions

diff --git a/mailctl.py b/mailctl.py
index ea31286..550e56c 100755
--- a/mailctl.py
+++ b/mailctl.py
@@ -509,6 +509,27 @@ def cmd_rules_show(args):
     sys.exit(1)
 
 
+def cmd_rules_dry_run(args):
+    """What each rule matches right now. Two numbers, because they answer
+    different questions: the corpus count says whether a rule is still doing
+    anything and whether it would bury real correspondence, the pending count
+    says what the next sync would tag."""
+    store = mailrules.load()
+    rules = [r for r in store.rules if not args.id or r.id == args.id]
+    if not rules:
+        print(f"No rule with id '{args.id}'", file=sys.stderr)
+        sys.exit(1)
+
+    print(f"{'rule':<28}  {'corpus':>8}  {'pending':>8}")
+    for rule in rules:
+        corpus = run_notmuch(["count", mailrules.scoped_query(rule, None)])
+        pending = run_notmuch(["count",
+                               mailrules.scoped_query(rule, "tag:new")])
+        state = "" if rule.enabled else "  (disabled)"
+        print(f"{rule.id:<28.28}  {corpus.strip():>8}  "
+              f"{pending.strip():>8}{state}")
+
+
 def build_parser():
     p = argparse.ArgumentParser(
         prog="mailctl",
@@ -600,6 +621,12 @@ def build_parser():
     rp.add_argument("id")
     rp.set_defaults(func=cmd_rules_show)
 
+    rp = rules_sub.add_parser("dry-run",
+                              help="count what each rule matches, changing "
+                                   "nothing")
+    rp.add_argument("id", nargs="?", help="one rule, default is all")
+    rp.set_defaults(func=cmd_rules_dry_run)
+
     return p