package monitor

import (
	"strings"
	"testing"
	"time"
)

// R-434 — the snapshot-drop alarm must not promise a recovery that cannot be performed.
//
// WHAT WENT WRONG. hub v0.111.0 shipped, on 2026-09-01, an alarm reading "The daily Storage Box
// snapshots are read-only and still hold the older copy, so this is recoverable file-by-file; it is
// NOT confirmed data loss." Measured the same day (R-433): NO snapshot is reachable from a
// sub-account by any name — 777,600 exact names in the vendor format over nine days, zero hits, with
// a passing control. The promise named a route nobody can walk, in the one message an operator acts
// on while their customer's off-site history is disappearing.
//
// WHY THE FIX IS A DELETION AND NOT A REPLACEMENT. A sentence asserting neither loss nor recovery is
// true under every possible answer to the outstanding provider question, so it never needs a second
// rewrite. That is why this test pins the ABSENCE of a promise as hard as it pins the new words:
// the next person who "improves" this message by putting a route back into it must fail here.
//
// THESE TESTS DRIVE THE REAL PATH — saveOffsiteReport -> oc.Check() -> the notify callback — so they
// assert the CONSEQUENCE (the sentence an operator receives), not the mechanism. Asserting the
// mechanism one layer below where the damage happens is R-224, entry 9 of the doctrine table.
//
// ASCII-ONLY FRAGMENTS. The message contains an em dash. A fragment carrying one has returned 0 for
// strings that WERE there in this project before, so every fragment below is plain ASCII.

// the promise that must never come back, in the shapes it could plausibly return as
var r434ForbiddenFragments = []string{
	"recoverable file-by-file",
	"recoverable file by file",
	"so this is recoverable",
}

// the withdrawal that replaced it
var r434RequiredFragments = []string{
	"The route back out of them is not yet established",
	"neither confirmed data loss nor confirmed recovery",
	"Get in touch before restoring anything",
	"still hold the older copy", // clause (a) STANDS and must not be lost with the promise
}

// r434Message drives the production path once and returns the message the operator would receive.
func r434Message(t *testing.T) string {
	t.Helper()
	st := newDiskStore(t)
	var msgs []string
	saveOffsiteReport(t, st, "victim", dropJSON(69, true, "", "ok"))
	oc := NewOffsiteChecker(st, 48*time.Hour, func(_, et, _, msg, _, _ string) {
		if et == "offsite_snapshots_dropped" {
			msgs = append(msgs, msg)
		}
	}, quietLog())

	saveOffsiteReport(t, st, "victim", dropJSON(4, true, "", "ok"))
	oc.Check()

	if len(msgs) != 1 {
		t.Fatalf("setup: want exactly 1 offsite_snapshots_dropped message, got %d", len(msgs))
	}
	return msgs[0]
}

// TestR434_AlarmMakesNoRecoveryPromise — the fix, both directions, with both controls.
//
// RED-PROOF (run 2026-09-01, recorded in REPORT.md): restoring the v0.111.0 sentence in
// emitSnapshotDrop makes this FAIL on the forbidden fragment "recoverable file-by-file" AND on all
// three required fragments, with the offending sentence printed in the failure message.
func TestR434_AlarmMakesNoRecoveryPromise(t *testing.T) {
	msg := r434Message(t)

	// POSITIVE CONTROL — a fragment present in EVERY version of this alarm. If this is missing the
	// test is reading the wrong string and every other assertion below is worthless.
	if !strings.Contains(msg, "off-site backup count fell from") {
		t.Fatalf("positive control failed: not the snapshot-drop message at all: %q", msg)
	}
	// NEGATIVE CONTROL — proves Contains can actually report absence here.
	if strings.Contains(msg, "zzz-no-such-fragment-r434") {
		t.Fatalf("negative control failed: matched a fragment that cannot exist: %q", msg)
	}

	for _, bad := range r434ForbiddenFragments {
		if strings.Contains(msg, bad) {
			t.Errorf("alarm promises a recovery that cannot be performed (R-433): found %q in %q", bad, msg)
		}
	}
	for _, want := range r434RequiredFragments {
		if !strings.Contains(msg, want) {
			t.Errorf("alarm is missing the withdrawal wording: want %q in %q", want, msg)
		}
	}
}

// TestR434_AlarmStillDoesNotClaimDataLoss — the OTHER direction, and the reason the fix is a
// withdrawal rather than a reversal.
//
// After R-433 the temptation is to swing to "your backups are gone". That is still usually FALSE:
// the snapshots exist and hold the older copy; what is unproven is our route to them. An alarm that
// over-claims loss sends an operator into a destructive recovery they did not need — which is the
// failure the v0.111.0 comment was written to prevent, and it must survive its own correction.
func TestR434_AlarmStillDoesNotClaimDataLoss(t *testing.T) {
	msg := r434Message(t)

	for _, bad := range []string{
		"data is lost", "backups are gone", "data has been lost", "permanently lost", "unrecoverable",
	} {
		if strings.Contains(msg, bad) {
			t.Errorf("alarm over-claims loss: found %q in %q", bad, msg)
		}
	}
	// The one phrase that must appear NEGATED, never bare. A bare "confirmed data loss" would read
	// as a verdict; the shipped sentence only ever uses it inside "neither ... nor".
	if strings.Contains(msg, "confirmed data loss") &&
		!strings.Contains(msg, "neither confirmed data loss nor confirmed recovery") {
		t.Errorf("the phrase 'confirmed data loss' appears outside its negation: %q", msg)
	}
}

// TestR434_StoredEventCarriesTheSameSentence — the delivered message and the stored one are the same
// string today, and a future refactor that formats them separately must not let them drift: the
// operator reads the mail, but every later audit reads the stored row.
func TestR434_StoredEventCarriesTheSameSentence(t *testing.T) {
	st := newDiskStore(t)
	var delivered string
	saveOffsiteReport(t, st, "victim", dropJSON(69, true, "", "ok"))
	oc := NewOffsiteChecker(st, 48*time.Hour, func(_, et, _, msg, _, _ string) {
		if et == "offsite_snapshots_dropped" {
			delivered = msg
		}
	}, quietLog())
	saveOffsiteReport(t, st, "victim", dropJSON(4, true, "", "ok"))
	oc.Check()

	evs, err := st.GetRecentEvents("victim", 50)
	if err != nil {
		t.Fatalf("GetRecentEvents: %v", err)
	}
	var stored []string
	for _, e := range evs {
		if e.EventType == "offsite_snapshots_dropped" {
			stored = append(stored, e.Message)
		}
	}
	if len(stored) != 1 {
		t.Fatalf("want exactly 1 stored offsite_snapshots_dropped, got %d", len(stored))
	}
	if stored[0] != delivered {
		t.Errorf("stored and delivered messages have drifted:\n stored:   %q\n delivered: %q", stored[0], delivered)
	}
	if strings.Contains(stored[0], "recoverable file-by-file") {
		t.Errorf("the stored row still carries the withdrawn promise: %q", stored[0])
	}
}