package main

import (
	"errors"
	"strings"
	"testing"
)

// Every operation's event is sent once, after a restart too (to-be 55 §1, AC51): the message id is the record, the version
// and the event; the last version sent is kept; a module stopped between an operation and its event sends it at start,
// under the same id, and sends it once.
func TestEveryOperationsEventIsSentOnceAfterARestartToo(t *testing.T) {
	w, f := ledgerWorld(t)
	type send struct{ event, id string }
	var sends []send
	down := false
	w.k.EmitID = func(event string, body any, id string) error {
		if down {
			return errors.New("the bus is down")
		}
		sends = append(sends, send{event, id})
		return nil
	}
	r, err := w.k.ReserveNumber("author@g14", KindDecision, "a test record")
	if err != nil {
		t.Fatal(err)
	}
	key := Key{KindDecision, r.Number}
	if len(sends) != 1 || sends[0].event != EventReserved || sends[0].id != key.Kind+"."+strings.Repeat("0", 4-len(itoa(key.Number)))+itoa(key.Number)+".v1.reserved" {
		t.Fatalf("%+v", sends)
	}
	if k := w.k.sentUpTo(key); k != 1 {
		t.Fatalf("sent up to %d", k)
	}
	// Stopped between the operation and its event: the proposal is in the history, its event was not sent.
	down = true
	if _, err := w.k.Propose("author@g14", valid(r.Number)); err != nil {
		t.Fatal(err)
	}
	if w.k.sentUpTo(key) != 1 {
		t.Fatal("an event never sent was marked sent")
	}
	// A restart: a new knowledge base over the same ledger and states sends what the stop lost, once.
	down = false
	sends = nil
	again := &KB{Store: w.k.Store, States: w.k.States, EmitID: w.k.EmitID, Now: w.k.Now, Logf: w.k.Logf}
	n, err := again.ResendEvents(t.Context())
	if err != nil || n != 1 || len(sends) != 1 || sends[0].event != EventProposed || !strings.HasSuffix(sends[0].id, ".v2.proposed") {
		t.Fatalf("%v: %d, %+v", err, n, sends)
	}
	if n, _ := again.ResendEvents(t.Context()); n != 0 || len(sends) != 1 {
		t.Fatalf("a second start sent %d again", n)
	}
	_ = f
}

func itoa(n int) string { return Key{KindDecision, n}.String()[4:] }