monitor

type Agents interface {
	ListAgents(ctx context.Context, who keys.Who) ([]agents.Agent, error)
	GetAgent(ctx context.Context, who keys.Who, id string) (*agents.Agent, error)
}

type Alert struct {
	ID, Key, Kind, Subject, Severity, Detail, Href string
	FirstSeen, LastSeen                            time.Time
	Resolved                                       time.Time // zero while open
	NotifiedSeverity                               string    // "" = not reported yet
	Notified                                       time.Time
}

type Changes struct {
	Opened, Raised, Lowered, Resolved []Alert
}

type DigestOptions struct {
	Server      string              // host name in the subject
	RepeatEvery time.Duration       // reminder for an alert still open
	Link        func(string) string // UI path → absolute link; nil = none
	Channels    []string            // queue one message per channel
}

type Engine interface {
	Certificates(ctx context.Context, who keys.Who, f ca.CertificateFilter) (*ca.CertificatePage, error)
	Certificate(ctx context.Context, who keys.Who, id string) (*ca.CertificateInfo, error)
	CAs(ctx context.Context, who keys.Who) ([]ca.CAInfo, error)
}

type Evaluator struct {
	Engine Engine
	Agents Agents // nil = no agent rules
	Seal   func() keys.Status
	Rules  Rules
	Who    keys.Who // a system principal that may read the whole tenant
}

type Finding struct {
	Key, Kind, Subject, Severity, Detail, Href string
}

type Rules struct {
	// End-entity certificates: warning and critical before they expire.
	ExpiryWarn, ExpiryCrit time.Duration
	// CA certificates.
	CAWarn, CACrit time.Duration
	// A sealed server: warning after SealedAfter; critical once a CRL's
	// next update is closer than CRLHorizon (a sealed server can't sign).
	SealedAfter, CRLHorizon time.Duration
	// Agents: warning and critical after this long without a report.
	AgentSilentWarn, AgentSilentCrit time.Duration
	// An active agent's own certificate: critical below this.
	AgentCertificate time.Duration
	// ExpiredFor: an expired, not superseded certificate stays an alert this
	// long after its end, then the alert is closed.
	ExpiredFor time.Duration
	// RepeatEvery: a reminder for an open alert (step 23).
	RepeatEvery time.Duration
}

type Store struct {
	DB     *sql.DB // system.db, the write connection
	Tenant string
	Rand   io.Reader // nil = crypto/rand (IDs)
}