package backup

import (
	"encoding/json"
	"io"
	"log"
	"os"
	"path/filepath"
	"strings"
	"testing"

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

// R-204 item 4 / R-193 — a REBUILT box declares that it needs an off-site credential, instead of
// reporting an absence the hub cannot interpret.
//
// THE POINT OF THESE TESTS is the conjunction. An absent off-site object has FOUR meanings (never
// configured / mid-restart / a transient read failure / rebuilt-and-stranded). The declaration has
// one, and it is only sound because BOTH halves are required: a fresh data area AND a hub-held
// recovery package. Scenario B is the one that matters most — drop the escrow half and every
// un-configured box in the fleet starts asking for a credential.

// bareManager builds a Manager with NO off-site target and NO repository password — the shape of a
// freshly rebuilt box before anything is configured.
func bareManager(t *testing.T) (*Manager, *settings.Settings) {
	t.Helper()
	lg := log.New(io.Discard, "", 0)
	dataDir := t.TempDir()
	sett, err := settings.Load(filepath.Join(dataDir, "settings.json"), lg)
	if err != nil {
		t.Fatal(err)
	}
	cfg := &config.Config{}
	cfg.Paths.DataDir = dataDir
	cfg.Paths.SystemDataPath = filepath.Join(dataDir, "sys")
	return NewManager(cfg, sett, lg), sett
}

// SCENARIO A — a rebuilt box (fresh data area + a hub-held escrow) DECLARES the state.
//
// RED-PROOF: remove the `GetHubEscrowIdentityPresent()` condition from needsOffsiteCredential —
// Scenario A still passes (it has an escrow), and SCENARIO B FAILS, which is the point: the plausible
// wrong fix is to declare on freshness alone, and that would make every un-configured box in the
// fleet ask for a credential.
func TestOffsiteDeclare_RebuiltBoxDeclaresNeedsCredential(t *testing.T) {
	m, sett := bareManager(t)
	if err := sett.SetHubEscrowIdentityPresent(true); err != nil {
		t.Fatal(err)
	}

	st := m.OffboxReportStatus()
	if st == nil {
		t.Fatal("a rebuilt box reported NO off-site object — the hub cannot distinguish it from a box that never had off-site backups (this is the defect)")
	}
	if st.State != OffsiteStateNeedsCredential {
		t.Fatalf("declared state = %q, want %q", st.State, OffsiteStateNeedsCredential)
	}
	// Enabled MUST be false and the sizes zero — that is what makes the declaration inert to the
	// hub's existing fill and staleness checkers (and to a pre-upgrade hub).
	if st.Enabled {
		t.Error("a declaration must not claim the tier is enabled — the hub's staleness check keys on it")
	}
	if st.QuotaGB != 0 || st.RepoSizeBytes != 0 || st.SnapshotCount != 0 {
		t.Errorf("a declaration must carry zero sizes (fill band keys on them): %+v", st)
	}
	// And it must be on the off-site object, not a new top-level field.
	b, err := json.Marshal(st)
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(string(b), `"state":"needs_credential"`) {
		t.Fatalf("declared state absent from the marshalled off-site object: %s", b)
	}
	if !strings.Contains(string(b), `"enabled":false`) {
		t.Fatalf("marshalled object must carry enabled:false: %s", b)
	}
}

// SCENARIO B — a box that never had off-site backups says NOTHING. This is the guard on the
// conjunction; without it the feature churns credentials fleet-wide.
func TestOffsiteDeclare_NeverHadOffsiteSaysNothing(t *testing.T) {
	m, _ := bareManager(t) // fresh data area, but NO hub-held escrow

	if st := m.OffboxReportStatus(); st != nil {
		t.Fatalf("a box that never had off-site backups DECLARED a need: %+v — every un-configured box in the fleet would now ask for a credential", st)
	}
}

// The other half of the conjunction: a box that still holds its repository password is NOT stranded,
// even though the hub holds an escrow for it. That is simply a healthy box between configurations.
func TestOffsiteDeclare_BoxThatStillHoldsItsRepoPasswordDoesNotDeclare(t *testing.T) {
	m, sett := bareManager(t)
	if err := sett.SetHubEscrowIdentityPresent(true); err != nil {
		t.Fatal(err)
	}
	// Place a repository password exactly where the manager looks for it.
	if err := os.MkdirAll(m.offboxDir(), 0o700); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(m.offboxPwPath(), []byte("a-repository-password"), 0o600); err != nil {
		t.Fatal(err)
	}

	if st := m.OffboxReportStatus(); st != nil {
		t.Fatalf("a box holding its repository password declared a need: %+v", st)
	}
}

// A DISABLED target is the customer's own choice, not a rebuild — it must not declare either.
func TestOffsiteDeclare_DisabledTargetIsNotStranded(t *testing.T) {
	m, sett := bareManager(t)
	if err := sett.SetHubEscrowIdentityPresent(true); err != nil {
		t.Fatal(err)
	}
	if err := sett.SetOffboxTarget(&settings.OffboxTarget{
		Enabled: false, Host: "nas.local", Port: 22, User: "felhom", RepoPath: "/srv/repo",
	}); err != nil {
		t.Fatal(err)
	}

	if st := m.OffboxReportStatus(); st != nil {
		t.Fatalf("a deliberately DISABLED target declared a need: %+v", st)
	}
}

// A CONFIGURED box's report object must be byte-identical to v0.198.0's — no `state` key at all.
// This is what lets a pre-upgrade hub and every existing checker read the fleet unchanged.
func TestOffsiteDeclare_ConfiguredBoxJSONIsUnchanged(t *testing.T) {
	m, sett := bareManager(t)
	if err := sett.SetOffboxTarget(&settings.OffboxTarget{
		Enabled: true, Host: "nas.local", Port: 22, User: "felhom", RepoPath: "/srv/repo",
		Schedule: "daily", EscrowState: "escrowed", LastStatus: "ok",
	}); err != nil {
		t.Fatal(err)
	}

	st := m.OffboxReportStatus()
	if st == nil {
		t.Fatal("a configured box must still report an off-site object")
	}
	if st.State != "" {
		t.Errorf("a configured box must declare NO state, got %q", st.State)
	}
	b, err := json.Marshal(st)
	if err != nil {
		t.Fatal(err)
	}
	if strings.Contains(string(b), `"state"`) {
		t.Fatalf("a healthy report's JSON gained a `state` key — it must stay byte-compatible: %s", b)
	}
	if !strings.Contains(string(b), `"enabled":true`) {
		t.Fatalf("a configured box must report enabled:true: %s", b)
	}
}