feat: new batt schedule command for fully automatic calibration

[brookqin]

hi @charlie0129,

I'm working on schedule command, will add scheduled calibration functionality to batt, allowing users to set up and manage calibration schedules using cron expressions.

Scheduled calibration feature:

• Added a new /calibration/schedule endpoint to accept a cron expression or null to enable or disable scheduling.
• Added the CLI command batt schedule.
• Before executing a scheduled task, a notification is sent and the daemon waits for 5 minutes. If no explicit postpone/skip command is received, the calibration process begins.
• If the power is not connected, the scheduled task will not start until plugged in.
• During calibration, users can control the status via the calibrate command.

CLI examples:

batt schedule '0 10 * * 0'   # every Sunday at 10:00 (quote * so the shell doesn't expand it)
batt schedule disable        # remove the schedule and stop future runs
batt schedule postpone 90m   # push the next run back by 90 minutes (defaults to 1h if omitted)
batt schedule skip           # skip only the upcoming run and keep the schedule

[Copilot]

Pull request overview

This PR adds scheduled automatic calibration functionality to batt, allowing users to configure recurring calibration runs using cron expressions. The feature includes a 5-minute lead notification period before execution and supports postpone/skip operations.

Key changes:

• New Scheduler component with cron-based scheduling and precheck retry logic
• REST API endpoints (/schedule, /schedule/postpone, /schedule/skip) for schedule management
• CLI command batt schedule with subcommands for setting, disabling, postponing, and skipping schedules

Reviewed changes

Copilot reviewed 14 out of 15 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
pkg/daemon/scheduler.go	Core scheduler implementation with cron parsing, timer management, and control message handling
pkg/daemon/scheduler_test.go	Unit tests for scheduler functionality including postpone, skip, and precheck failure scenarios
pkg/daemon/daemon.go	Scheduler initialization with task and precheck callbacks; adds schedule-related event publishing
pkg/daemon/calibration.go	Schedule persistence logic and helper functions for schedule, postpone, and skip operations
pkg/daemon/handlers.go	HTTP handlers for schedule management endpoints with validation
pkg/config/config.go	Config interface additions for cron expression getter/setter
pkg/config/file.go	File-based config implementation for persisting cron expressions
pkg/client/apis.go	Client API methods for schedule operations
cmd/batt/schedule.go	CLI command implementation for schedule management
cmd/batt/main.go	Registration of schedule command
README.md	Documentation for scheduled calibration feature
go.mod, go.sum	Added robfig/cron/v3 dependency
pkg/calibration/types.go	New action types and ScheduledAt field for status

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[Copilot]

Pull request overview

Copilot reviewed 14 out of 15 changed files in this pull request and generated 9 comments.

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[brookqin]

@charlie0129 pls take a look.

I am still testing.
The core logic is mainly in the scheduler.go, which automatically calls calibration-related api through Timer.

[charlie0129]

@brookqin Thanks! I will review and test it in this week when I am free.

[charlie0129]

Maybe add some examples on cron expressions?

For example:

batt schedule 'minute hour day month weekday'
batt schedule '0 10 * * 0' (At 10:00 on Sunday)
batt schedule '0 10 1 * *' (At 10:00 on the first day of every month)
batt schedule '0 10 1 */2 *' (At 10:00 on the first day of every two months)

[brookqin]

ok

[charlie0129]

By the way, do you know what timezone is the cron using? UTC or local timezone?

[brookqin]

By the way, do you know what timezone is the cron using? UTC or local timezone?

time.Now() should be UTC.

Scheduler may have a bug, every time computer goes to sleep, timer trigger will be delayed.

time: NewTimer firing later if computer sleeps, how to use wall clock?
time: add ExternalNow, etc for external time and timers

seems have to use a loop with a short timer.

[charlie0129]

Scheduler may have a bug, every time computer goes to sleep, timer trigger will be delayed.

You mean if a timer is supposed to fire in 5 minutes, but if the computer goes to sleep now, the timer will fire 5 minutes after waking up?

I think I experienced the opposite. If the computer goes to sleep, the timer will fire at the correct time. If the computer slept for longer than 5 minutes, it fires immediately after waking up. Correct me if I am wrong.

[charlie0129]

I think the cron should use user's local time. Using UTC will cause confusion for users. Adding TZ=xx CRON_TZ=xx to user's cron expression should be enough.

[brookqin]

I think the cron should use user's local time. Using UTC will cause confusion for users. Adding TZ=xx CRON_TZ=xx to user's cron expression should be enough.

you are right, I will fix this.

time="2025-12-01T19:29:25+08:00" level=debug msg="upcoming scheduled task at 2025-11-30 10:00:00"
time="2025-12-01T19:29:25+08:00" level=debug msg="running scheduled task at 2025-11-30 10:00:00"

My mac sleep whole day last sunday, seems there are issues with both time zone and timer.

[charlie0129]

Maybe the implementation of robfig/cron will be prolonged by sleep?

I remember that time.After will not be affected by sleep.

I will check how robfig/cron handles this.