package pbsdr

import (
	"context"
	"encoding/json"
	"go/ast"
	"go/parser"
	"go/printer"
	"go/token"
	"io"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"gitea.dooplex.hu/admin/felhom-agent/internal/hub"
)

// R-221 — the escrow seed must be ASSERTED on every converged tick, not remembered.
//
// These tests drive the real Apply() with a real temp-dir agent.json and a call-recording runner.
// Calling seedEscrowStorageID directly would prove nothing: the defect IS the early return in
// Apply, and a test that steps around it cannot see it.

// convergedMarker writes a marker whose hash matches the block, i.e. puts the manager on exactly
// the idempotent path where the seed used to be skipped.
func convergedMarker(t *testing.T, m *Manager, block *hub.WirePBSDR, state string) {
	t.Helper()
	if err := m.writeState(m.markerPath(), marker{
		Hash: descriptorHash(block), State: state, AppliedAt: "2026-08-08T00:00:00Z",
	}); err != nil {
		t.Fatalf("write marker: %v", err)
	}
}

func escrowStorageID(t *testing.T, cfgPath string) string {
	t.Helper()
	raw, err := os.ReadFile(cfgPath)
	if err != nil {
		t.Fatalf("read config: %v", err)
	}
	var doc struct {
		Escrow struct {
			PBSStorageID string `json:"pbs_storage_id"`
		} `json:"escrow"`
	}
	if err := json.Unmarshal(raw, &doc); err != nil {
		t.Fatalf("parse config: %v", err)
	}
	return doc.Escrow.PBSStorageID
}

// drBlock mirrors the existing valid fixture (manager_test.go descriptor()) so that validate()
// passes and Apply actually reaches the marker check — the branch these tests are about.
func drBlock(storageID string) *hub.WirePBSDR {
	return &hub.WirePBSDR{
		Enabled: true, StorageID: storageID, PBSTunnelIP: "10.77.0.1",
		Datastore: "felhom-offsite", Namespace: "peti", TokenID: "felhom@pbs!peti",
		Fingerprint: testFP,
	}
}

// SCENARIO A — the seed is re-asserted on a converged box, and nothing else happens.
//
// THIS IS THE TEST THAT MATTERS. It must fail against the pre-R-221 tree; if it passes there, it is
// not testing the defect and that is the finding.
func TestSeedReasserted_OnConvergedTick_WithZeroProxmoxCalls(t *testing.T) {
	r := &fakeRunner{}
	st := &fakeStorage{found: true, active: []bool{true}}
	c := &fakeConsumer{}
	m, cfgPath := newTestManager(t, r, st, c)

	block := drBlock("felhom-pbs-dr")
	convergedMarker(t, m, block, "applied")

	// the shape a rebuild leaves behind: escrow section present, pbs_storage_id GONE
	if got := escrowStorageID(t, cfgPath); got != "" {
		t.Fatalf("precondition: config already carries a storage id %q", got)
	}

	m.Apply(context.Background(), true, block)

	if got := escrowStorageID(t, cfgPath); got != "felhom-pbs-dr" {
		t.Errorf("the converged tick did not re-assert the seed: escrow.pbs_storage_id = %q, want %q.\n"+
			"This is R-221: the marker survives a rebuild, the descriptor hash still matches, the early "+
			"return fires and the seed never runs into the config that no longer has it — so the customer "+
			"cannot run the escrow ceremony at all.", got, "felhom-pbs-dr")
	}

	// ...and the idempotent path is STILL idempotent. This assertion is not decorative: without it
	// a "fix" that simply deletes the early return would pass the line above.
	if calls := r.recorded(); len(calls) != 0 {
		t.Errorf("a converged tick must execute ZERO Proxmox commands; got %d: %+v", len(calls), calls)
	}
}

// SCENARIO B — an operator's own different value survives, and the warning names both.
func TestSeedReasserted_NeverClobbersAnOperatorValue(t *testing.T) {
	r := &fakeRunner{}
	m, cfgPath := newTestManager(t, r, &fakeStorage{found: true, active: []bool{true}}, &fakeConsumer{})

	if err := os.WriteFile(cfgPath, []byte(
		`{"log_level":"info","escrow":{"posture":"zero_knowledge","pbs_storage_id":"operator-chosen"},`+
			`"custom_unknown":{"keep":1}}`), 0o600); err != nil {
		t.Fatal(err)
	}
	block := drBlock("hub-chosen")
	convergedMarker(t, m, block, "applied")

	m.Apply(context.Background(), true, block)

	if got := escrowStorageID(t, cfgPath); got != "operator-chosen" {
		t.Errorf("a value a person put there was overwritten by the descriptor: got %q, want %q", got, "operator-chosen")
	}
	// unknown keys must still round-trip
	raw, _ := os.ReadFile(cfgPath)
	if !strings.Contains(string(raw), "custom_unknown") {
		t.Error("an unknown config key was dropped by the re-assert")
	}
}

// SCENARIO C — the ceremony preflight's live read sees the re-asserted value with NO restart.
//
// The preflight itself lives in internal/localapi and reads the file through config.Load; what this
// asserts is the half that belongs to this package: after a converged tick, THE FILE ON DISK carries
// the id, so any live re-read is green. The daemon is never restarted in this test because it is
// never started — which is the point.
func TestSeedReasserted_IsVisibleOnDiskImmediately(t *testing.T) {
	r := &fakeRunner{}
	m, cfgPath := newTestManager(t, r, &fakeStorage{found: true, active: []bool{true}}, &fakeConsumer{})
	block := drBlock("felhom-pbs-dr")
	convergedMarker(t, m, block, "applied")

	// preflight's predicate BEFORE: storageID == "" → the row is NOT OK
	if escrowStorageID(t, cfgPath) != "" {
		t.Fatal("precondition")
	}
	m.Apply(context.Background(), true, block)
	// preflight's predicate AFTER, from the same file the ceremony subprocess loads
	if id := escrowStorageID(t, cfgPath); id == "" {
		t.Error("the preflight row would still be NOT OK after a converged tick")
	}
}

// A seed failure must NEVER un-converge the box: no marker rewrite, no state change, and the status
// still reports the marker's converged state — with the failure surfaced as a message.
func TestSeedReassertFailure_DoesNotUnconverge(t *testing.T) {
	r := &fakeRunner{}
	m, cfgPath := newTestManager(t, r, &fakeStorage{found: true, active: []bool{true}}, &fakeConsumer{})
	block := drBlock("felhom-pbs-dr")
	convergedMarker(t, m, block, "applied")
	markerBefore, err := os.ReadFile(m.markerPath())
	if err != nil {
		t.Fatal(err)
	}

	// make the seed fail in a way it cannot recover from: unparseable config
	if err := os.WriteFile(cfgPath, []byte(`{ this is not json`), 0o600); err != nil {
		t.Fatal(err)
	}

	m.Apply(context.Background(), true, block)

	after, err := os.ReadFile(m.markerPath())
	if err != nil {
		t.Fatalf("the marker was removed by a seed failure: %v", err)
	}
	if string(after) != string(markerBefore) {
		t.Error("a seed failure rewrote the convergence marker — it must not touch state")
	}
	if calls := r.recorded(); len(calls) != 0 {
		t.Errorf("a seed failure must not trigger Proxmox work; got %+v", calls)
	}
	st := m.Status()
	if st == nil || st.State != "applied" {
		t.Errorf("a seed failure must leave the box converged; status = %+v", st)
	}
	if st != nil && !strings.Contains(st.Message, "seed failed") {
		t.Errorf("a seed failure must be surfaced on the status, got message %q", st.Message)
	}
}

// SEAM WIRING — production must construct the manager with the live config path, or the whole seed
// leg is inert. Three shipped defects in this project were fully green while their seam was never
// wired, so this walks main.go's AST for the actual call rather than grepping: a commented-out call
// satisfies strings.Contains, and an AST walk cannot see a comment.
func TestProductionWiring_NewManagerGetsTheLiveConfigPath(t *testing.T) {
	path := filepath.Join("..", "..", "cmd", "felhom-agent", "main.go")
	fset := token.NewFileSet()
	f, err := parser.ParseFile(fset, path, nil, 0) // comments not even collected
	if err != nil {
		t.Fatalf("parse main.go: %v", err)
	}
	found := false
	ast.Inspect(f, func(n ast.Node) bool {
		call, ok := n.(*ast.CallExpr)
		if !ok {
			return true
		}
		sel, ok := call.Fun.(*ast.SelectorExpr)
		if !ok || sel.Sel.Name != "NewManager" {
			return true
		}
		if pkg, ok := sel.X.(*ast.Ident); !ok || pkg.Name != "pbsdr" {
			return true
		}
		// signature: (runner, px, hubc, stateDir, secretDir, configPath, logger)
		if len(call.Args) < 6 {
			t.Errorf("pbsdr.NewManager called with %d args, expected >= 6", len(call.Args))
			return false
		}
		var buf strings.Builder
		if err := printNode(&buf, fset, call.Args[5]); err != nil {
			t.Fatalf("print arg: %v", err)
		}
		got := buf.String()
		if !strings.Contains(got, "SourcePath") {
			t.Errorf("pbsdr.NewManager's configPath argument is %q, which is not the live config path.\n"+
				"With an empty or wrong path seedEscrowStorageID returns nil immediately and the entire "+
				"R-221 fix is inert while every test above still passes.", got)
		}
		found = true
		return false
	})
	if !found {
		t.Error("no pbsdr.NewManager call found in main.go — the manager is not constructed in production")
	}
}

func printNode(w io.Writer, fset *token.FileSet, n ast.Node) error {
	return printer.Fprint(w, fset, n)
}