package report

import "log"

// Customer-claim arc (v0.122.0, F-4) — the ACK-side of the claim-code delivery. The hub serves
// the ACTIVE code's bcrypt hash + monotonic generation on every report ACK of a managed
// customer; this reconciler caches it into settings.json IDEMPOTENTLY BY GENERATION (the
// offsite-descriptor guard shape: an unchanged generation never rewrites, a hub outage never
// clears — set/refresh only, exactly like the escrow confirmer's one-way rules). The gate itself
// (internal/web) reads the cached state; nothing here decides gating.

// ClaimStatus mirrors the hub ACK's `claim` object (nil when the hub has no claim row / old hub).
type ClaimStatus struct {
	CodeHash   string `json:"code_hash"`
	Generation int    `json:"generation"`
	IssuedAt   string `json:"issued_at"` // RFC3339
}

// ClaimSettings is the settings surface the sync needs (satisfied by *settings.Settings).
type ClaimSettings interface {
	GetClaimCode() (hash string, generation int, issuedAt string)
	SetClaimCode(hash string, generation int, issuedAt string) error
}

// ClaimSync applies one ACK's claim status to the settings cache.
type ClaimSync struct {
	Settings ClaimSettings
	Logger   *log.Logger
}

func (c *ClaimSync) logf(f string, a ...any) {
	if c.Logger != nil {
		c.Logger.Printf(f, a...)
	}
}

// Reconcile caches a newer-generation code state; same-or-older generations and nil/empty
// statuses are no-ops (a rotation is the ONLY thing that moves the cache — no write-back, no
// clearing on hub silence).
func (c *ClaimSync) Reconcile(cs *ClaimStatus) {
	if cs == nil || cs.CodeHash == "" || cs.Generation <= 0 {
		return
	}
	_, curGen, _ := c.Settings.GetClaimCode()
	if cs.Generation <= curGen {
		return // idempotent: this generation (or a newer one) is already cached
	}
	if err := c.Settings.SetClaimCode(cs.CodeHash, cs.Generation, cs.IssuedAt); err != nil {
		c.logf("[ERROR] [claim-sync] caching hub claim code (gen %d) failed (retries next ACK): %v", cs.Generation, err)
		return
	}
	c.logf("[INFO] [claim-sync] hub claim code cached (generation %d) — hash first 8: %.8s…", cs.Generation, cs.CodeHash)
}