package models

// PosHealth is what a till reports about itself every 30 seconds.
//
// This is a liveness signal, not a record. It lives in Redis under a TTL and is
// never written to Postgres: a terminal that dies simply stops refreshing and
// disappears from the board on its own, with no reaper job and no row left
// claiming "online" three days after the shop closed.
//
// The fields exist to answer questions a person actually asks when a shop
// phones in: is the till on, is it reaching us, is it selling anything, and is
// the hardware in the way.
type PosHealth struct {
	// Identity. Terminalid is the short code printed on invoices — the thing a
	// support call starts with.
	Terminalid string `json:"terminal_id"`
	Locationid string `json:"location_id"`
	Storename  string `json:"store_name"`
	Appversion string `json:"app_version"`

	// "online" while the till is refreshing this. The broker's Last Will
	// overwrites it with "offline" if the terminal loses power mid-shift, which
	// is the only way to tell *closed for the night* from *unplugged*.
	Status string `json:"status"`

	// Queue depth — the number that matters most. A shop quietly accumulating
	// unsynced takings looks completely normal from the shop floor, and this is
	// the only thing that makes it visible before someone reconciles a till and
	// finds a day missing.
	Pendingbills         int    `json:"pending_bills"`
	Pendingregistrations int    `json:"pending_registrations"`
	Oldestpendingat      string `json:"oldest_pending_at"`

	// Today's trading. A till that is connected but has rung nothing in three
	// hours usually means a jammed printer or an absent cashier, and neither
	// shows up in a plain online/offline board.
	Todaybills  int     `json:"today_bills"`
	Todayamount float64 `json:"today_amount"`
	Lastbillat  string  `json:"last_bill_at"`

	// Device state, for pre-emptive support.
	//
	// Pointers so that *not reported* is distinguishable from *reported as
	// zero*. Not every build collects these — battery and free storage need
	// platform packages a desktop till has no use for — and writing an
	// uncollected reading as 0 would show a board full of terminals on a flat
	// battery with an unreachable printer. A nil field is skipped entirely.
	Batterylevel     *int    `json:"battery_level,omitempty"`
	Batterycharging  *bool   `json:"battery_charging,omitempty"`
	Storagefreemb    *int    `json:"storage_free_mb,omitempty"`
	Printerreachable *bool   `json:"printer_reachable,omitempty"`
	Drawerstatus     *string `json:"drawer_status,omitempty"`

	// Stamped by the till. The consumer also stamps its own arrival time, and
	// the two disagreeing is itself a signal — a till whose clock is wrong
	// writes bills under the wrong business date.
	Reportedat string `json:"reported_at"`
}