Extend the stats module to track per-user counts in addition to the
existing per-command totals. CommandHook now receives the originating
*models.Update so the hook can attribute invocations to a user; only
the stats module consumes this hook today.
Schema (sort keys under pk="stats"):
count:<cmd> existing, per-command total
user:<id> new, per-user total with cached username
pair:<cmd>:<id> new, per (command, user) pair
Subcommands (all public):
/stats top commands (unchanged)
/stats users top users overall
/stats user <name> top commands for that user
/stats cmd <name> top users of that command
When the sender has no Telegram username the per-user/pair writes are
skipped — the global per-command counter still increments. View helpers
fan out KV reads in parallel to stay inside the webhook deadline. The
existing read-modify-write race is unchanged; closing it would need
atomic UpdateItem ADD on the KV interface.
Sequential List + N GetItem made /stats latency scale with the number
of tracked commands. On a cold Lambda container with ~25 commands the
cumulative DynamoDB round-trips can exceed the 10s webhook handler
deadline; the trailing chathelper.Reply -> b.SendMessage then fails on
a cancelled ctx and the dispatcher only logs the error, leaving the
user with no reply at all.
Fan the per-key GetJSONs out into goroutines joined by sync.WaitGroup.
Wall-clock latency collapses to ~1 round-trip while preserving the
per-key error isolation (a single GetJSON failure still drops only its
own row). Storage interface unchanged; no race regression vs. the prior
per-item write pattern.
- Remove ReservedConcurrentExecutions: 1 (account lacks unreserved
concurrency headroom; deploy rolled back). Accept best-effort
counter semantics as documented.
- Add /stats to aws/telegram-commands.json so it appears in the
Telegram client's / autocomplete after the next deploy.
Implement a new stats module for the Telegram bot that tracks per-command usage with persistent KV storage. The module provides a /stats command displaying usage sorted by popularity with a 4096-byte Telegram message cap. Includes CommandHook integration for post-dispatch tracking via background goroutine (2s bounded context), proper test coverage, and registry initialization. Updated server config with stats factory and reserved concurrent execution control to prevent TOCTOU issues.
tiennm99