Announce the controller's states, keep every module's word, and grant a read only where its owner announced the state readable; the copied list of the controller's mirrors goes (issue 1790, D1-D4, ADR 0495, ADR 0513 §3)

internal/inventory/busrecords.go

@@ -3,6 +3,7 @@ package inventory
 import (
 	"context"
 	"fmt"
+	"git.novox.be/novox/mesh-sdk/go/announce"
 	"slices"
 	"strings"
 
@@ -16,6 +17,10 @@ import (
 // apart for the reason that package keeps its own types: a permission must be a function of what a
 // module declared, and a query that decided anything would be a second place authority came from.
 
+// Announcements reads the last announcement of each module (novox/hq ADR 0495, issue 1790), set by the controller that
+// reaches the bus; nil, nothing is read and every read is granted from `reads`.
+var Announcements func(ctx context.Context) (map[string]announce.States, error)
+
 // BusRecords is every fact the composer needs about who may reach the bus.
 //
 // **A module's authority comes from the manifest, not from the assignment.** The assignment says
@@ -110,6 +115,29 @@ func (i *Inventory) BusRecords(ctx context.Context) (broker.Records, error) {
 		}
 	}
 
+	// **Who may read a state is what its owner announced** (novox/hq ADR 0495 clause 3, issue 1790): a read the owner's
+	// announcement does not make readable is granted nothing, and said; an owner that announced nothing yet is read as
+	// before. Announcements that cannot be read are said, and every read is granted as before: the bus's users are
+	// composed either way.
+	if Announcements != nil {
+		announced, err := Announcements(ctx)
+		if err != nil {
+			fmt.Printf("the states the modules announced cannot be read, so every read is granted from `reads` as before: %v\n", err)
+		} else {
+			out.Announced = announced
+			for node, ds := range out.Assigned {
+				for k := range ds {
+					granted, refused := broker.ReadsAnnounced(ds[k].Reads, announced)
+					ds[k].Reads, ds[k].ReadsRefused = granted, refused
+					for _, r := range refused {
+						fmt.Printf("%s on %s reads %s, which its owner does not announce readable: not granted\n",
+							ds[k].Module, node, r)
+					}
+				}
+			}
+		}
+	}
+
 	enrolling, err := i.NodesWithALiveToken(ctx)
 	if err != nil {
 		return broker.Records{}, err