package backup

import (
	"context"
	"os"
	"path/filepath"
	"testing"

	"gitea.dooplex.hu/admin/felhom-controller/internal/appbackup"
)

// R-203 Part 2 — "ok" must mean the mandatory data is in the snapshot.
//
// The defect these pin is NOT that the gap went undetected. It WAS detected, and warned about, in
// Hungarian, naming the app and the folders — that warning is what stopped the drill. The defect is
// that the run reported `ok` beside it, and a warning standing beside a success is read as a success.

func mandatoryUserdata(rel string) ClassifiedBind {
	return ClassifiedBind{ComposeBind: appbackup.ComposeBind{Root: appbackup.RootUserdata, RelPath: rel}, Class: appbackup.ClassMandatory}
}

// Scenario C — a MANDATORY declared path absent on disk is a STRUCTURAL gap, not just prose.
//
// RED-PROOF: stop recording capGaps into res.mandatoryGaps (or drop the third return) and the verdict
// has nothing to act on — the run reports `ok` over a mandatory gap, which is production behaviour up
// to v0.196.0.
func TestOffboxCaptureSet_MandatoryGapIsStructural(t *testing.T) {
	drive := t.TempDir()
	m, _, prov := classifiedOffboxManager(t, drive)
	prov.hdd["calibre-web"] = drive
	prov.binds["calibre-web"] = []ClassifiedBind{mandatoryUserdata("media/books")}
	prov.has["calibre-web"] = true

	// The declared directory does not exist on disk — exactly the shape the drill hit.
	extra, warns, gaps := m.offboxCaptureSet("calibre-web")
	if len(gaps) != 1 || gaps[0] != "media/books" {
		t.Fatalf("a missing MANDATORY path must be reported as a structural gap, got %v", gaps)
	}
	if len(warns) == 0 {
		t.Error("the customer-facing Hungarian warning must SURVIVE this change — it is what caught the defect")
	}
	if len(extra) != 0 {
		t.Errorf("a missing path must not be handed to restic, got %v", extra)
	}

	// Create it: no gap, no warning, and the path IS captured.
	nsRoot := appbackup.NamespaceRootFor(drive, m.systemDataPath)
	if err := os.MkdirAll(filepath.Join(appbackup.UserdataDir(nsRoot), "media", "books"), 0o755); err != nil {
		t.Fatal(err)
	}
	extra2, warns2, gaps2 := m.offboxCaptureSet("calibre-web")
	if len(gaps2) != 0 || len(warns2) != 0 {
		t.Fatalf("a PRESENT mandatory path must be silent, got gaps %v warns %v", gaps2, warns2)
	}
	if len(extra2) != 1 {
		t.Fatalf("a present mandatory path must be handed to restic, got %v", extra2)
	}
}

// Scenario D — an OPTIONAL declared path absent on disk changes nothing.
//
// RED-PROOF: remove the `p.Class == ClassMandatory` check in the stat-filter → an optional gap starts
// being reported, and together with the verdict would flip every app with an unused optional folder
// to not-ok, which is how a status stops being read.
//
// STATED BECAUSE IT CHANGES WHAT THIS PROVES: TierOffsite's tierKeeps() already admits ClassMandatory
// only, so an optional path cannot reach the stat-filter today. The class check is therefore a NO-OP
// and NO customer-visible warning disappears with it. It is written for parity with Tier 2 and so the
// verdict can never be flipped by an optional folder if that tier filter ever widens.
func TestOffboxCaptureSet_OptionalGapIsSilent(t *testing.T) {
	drive := t.TempDir()
	m, _, prov := classifiedOffboxManager(t, drive)
	prov.hdd["komga"] = drive
	prov.binds["komga"] = []ClassifiedBind{optionalUserdata("media/comics")}
	prov.has["komga"] = true

	extra, warns, gaps := m.offboxCaptureSet("komga")
	if len(gaps) != 0 {
		t.Fatalf("an absent OPTIONAL path must be silent, got gaps %v", gaps)
	}
	if len(warns) != 0 {
		t.Fatalf("an absent OPTIONAL path must raise no customer warning, got %v", warns)
	}
	if len(extra) != 0 {
		t.Fatalf("an absent path must not be captured, got %v", extra)
	}
}

// A mandatory path that IS present alongside an absent optional one: still silent, still captured.
func TestOffboxCaptureSet_MixedClassesOnlyMandatoryCounts(t *testing.T) {
	drive := t.TempDir()
	m, _, prov := classifiedOffboxManager(t, drive)
	prov.hdd["mixed"] = drive
	prov.binds["mixed"] = []ClassifiedBind{mandatoryUserdata("docs"), optionalUserdata("cache")}
	prov.has["mixed"] = true

	nsRoot := appbackup.NamespaceRootFor(drive, m.systemDataPath)
	if err := os.MkdirAll(filepath.Join(appbackup.UserdataDir(nsRoot), "docs"), 0o755); err != nil {
		t.Fatal(err)
	}
	extra, warns, gaps := m.offboxCaptureSet("mixed")
	if len(gaps) != 0 || len(warns) != 0 {
		t.Fatalf("a present mandatory + absent optional must be silent, got gaps %v warns %v", gaps, warns)
	}
	if len(extra) != 1 {
		t.Fatalf("the mandatory path must be captured, got %v", extra)
	}
}

// The verdict rule itself, over its inputs. The surrounding run needs a live restic, so the decision
// is asserted where it is made rather than through a fake repository.
func TestMandatoryGapsDecideTheVerdict(t *testing.T) {
	verdict := func(gaps map[string][]string) string {
		if len(gaps) > 0 {
			return "incomplete"
		}
		return "ok"
	}
	cases := []struct {
		name string
		gaps map[string][]string
		want string
	}{
		{"no gaps", nil, "ok"},
		{"empty map", map[string][]string{}, "ok"},
		{"one app one folder", map[string][]string{"calibre-web": {"media/books"}}, "incomplete"},
		{"two apps", map[string][]string{"a": {"x"}, "b": {"y"}}, "incomplete"},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			got := verdict(tc.gaps)
			if got != tc.want {
				t.Fatalf("gaps %v → %q, want %q", tc.gaps, got, tc.want)
			}
			// "incomplete" must be distinct from every value that already existed, so a checker or a
			// template matching on those cannot silently treat a coverage gap as one of them.
			if got == "ok" && tc.want == "incomplete" {
				t.Fatal("a coverage gap must never read as ok")
			}
		})
	}
}

// Scenario C, THROUGH THE RUN — the verdict itself, not just the capture set.
//
// The first version of this file tested offboxCaptureSet alone, and its "red-proof" PASSED: the
// mutation (dropping the gap recording) lives in runOffboxInternal, which that test never reaches.
// A mutation that the test cannot observe is not a red-proof, and the fix is the test, not the code.
//
// RED-PROOF (now real): make the gap recording unreachable (`if false && len(capGaps) > 0`) or
// restore `o.LastStatus = "ok"` unconditionally → this FAILS with the run reporting ok over a
// mandatory gap, which is production behaviour up to v0.196.0.
func TestOffboxRun_MandatoryGapMakesTheRunIncomplete(t *testing.T) {
	drive := t.TempDir()
	m, sett, prov := classifiedOffboxManager(t, drive)
	mkUnit(t, drive, "calibre-web")
	prov.hdd["calibre-web"] = drive
	prov.has["calibre-web"] = true
	// Declared MANDATORY and deliberately ABSENT on disk — the drill's shape.
	prov.binds["calibre-web"] = []ClassifiedBind{mandatoryUserdata("media/books")}
	_ = sett.SetAppOffbox("calibre-web", true)

	var gapNotified map[string][]string
	m.SetOffboxGapNotify(func(g map[string][]string) { gapNotified = g })

	cap := &backupCapture{}
	m.SetOffboxRunner(cap.runner())
	if err := m.RunOffboxBackup(context.Background()); err != nil {
		t.Fatalf("the run itself must SUCCEED — a coverage gap is not a failed run: %v", err)
	}

	got := sett.GetOffboxTarget()
	if got.LastStatus != "incomplete" {
		t.Fatalf("LastStatus = %q, want \"incomplete\" — a run that dropped a MANDATORY directory is "+
			"not a successful run, and reporting ok beside a warning is how this defect hid", got.LastStatus)
	}
	// What WAS captured is still recorded — half a backup is not no backup.
	if got.LastSuccess == "" {
		t.Error("LastSuccess must still record what was captured (§8.5) — suppressing it would be its own lie")
	}
	if cap.backups != 1 {
		t.Errorf("the unit must still be pushed, got %d backup calls", cap.backups)
	}
	// And the OPERATOR is told, not only the log.
	if len(gapNotified) != 1 || len(gapNotified["calibre-web"]) != 1 || gapNotified["calibre-web"][0] != "media/books" {
		t.Fatalf("the operator gap signal did not fire with the app and folder, got %v", gapNotified)
	}
}

// The companion: no gap → ok, and no operator signal. Without this, "incomplete" everywhere would
// also pass the test above.
func TestOffboxRun_NoGapStaysOk(t *testing.T) {
	drive := t.TempDir()
	m, sett, prov := classifiedOffboxManager(t, drive)
	mkUnit(t, drive, "calibre-web")
	nsRoot := appbackup.NamespaceRootFor(drive, m.systemDataPath)
	if err := os.MkdirAll(filepath.Join(appbackup.UserdataDir(nsRoot), "media", "books"), 0o755); err != nil {
		t.Fatal(err)
	}
	prov.hdd["calibre-web"] = drive
	prov.has["calibre-web"] = true
	prov.binds["calibre-web"] = []ClassifiedBind{mandatoryUserdata("media/books")}
	_ = sett.SetAppOffbox("calibre-web", true)

	fired := false
	m.SetOffboxGapNotify(func(map[string][]string) { fired = true })
	cap := &backupCapture{}
	m.SetOffboxRunner(cap.runner())
	if err := m.RunOffboxBackup(context.Background()); err != nil {
		t.Fatalf("run: %v", err)
	}
	if got := sett.GetOffboxTarget(); got.LastStatus != "ok" {
		t.Fatalf("LastStatus = %q, want ok — a complete run must not be downgraded", got.LastStatus)
	}
	if fired {
		t.Error("the operator gap signal must NOT fire when nothing was missed")
	}
}