package api

import (
	"context"
	"database/sql"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"

	"gitea.dooplex.hu/admin/felhom-hub/internal/intent"
	"gitea.dooplex.hu/admin/felhom-hub/internal/mailhold"
	"gitea.dooplex.hu/admin/felhom-hub/internal/notify"
	"gitea.dooplex.hu/admin/felhom-hub/internal/store"
)

// R-1154 (v0.159.0) — a reinstall while the customer's OLD host record still exists. The reuse path NEVER
// re-issues the claim code or the off-site login (operator session-only powers — `05` §17.5; the passphrase must
// not reach them) and makes the reinstall LOUD: an operator-only warning mailed to the operator. reenroll.go
// carries the rule; `05` §8 the design.

const r1154Host = "c1-abc123"

type r1154Fixture struct {
	h       *Handler
	st      *store.Store
	db      *sql.DB
	mail    *nullMailer
	offsite int // off-site re-issuer calls
	gen0    int // the claim generation before the enroll
}

// newR1154 builds a CLAIMED customer c1 with an existing host record that has reported, the hub threshold at 45 m
// (the production value), a claim engine, a counting off-site re-issuer, and a dispatcher behind a MAIL-HOLD
// marker (so the operator mail path is observable in notification_log as "held" with no network).
func newR1154(t *testing.T) *r1154Fixture {
	t.Helper()
	h, st, path := newTestHandler(t)
	f := &r1154Fixture{h: h, st: st}
	cc := &store.CustomerConfig{CustomerID: "c1", APIKey: "ckey", RetrievalPassword: "pass-phrase",
		Email: "owner@example.hu", Domain: "example.hu", ConfigJSON: "{}"}
	if err := st.SaveCustomerConfig(cc); err != nil {
		t.Fatal(err)
	}
	f.mail = withClaimEngine(t, h, st)
	if _, err := h.claimEngine.EnsureIssued(cc); err != nil {
		t.Fatalf("EnsureIssued: %v", err)
	}
	if _, err := st.MarkClaimed("c1"); err != nil {
		t.Fatalf("MarkClaimed: %v", err)
	}
	h.SetOffsiteReissuer(func(_ context.Context, id string) error {
		if id == "c1" {
			f.offsite++
		}
		return nil
	})
	h.SetStaleThreshold(45 * time.Minute)
	holdDir := t.TempDir()
	if err := os.WriteFile(filepath.Join(holdDir, mailhold.FileName), nil, 0o600); err != nil {
		t.Fatal(err)
	}
	d := notify.NewDispatcher(st, "test-key-not-used", "from@felhom.eu", "operator@felhom.eu", true, log.New(io.Discard, "", 0))
	d.SetMailHold(mailhold.New(holdDir, log.New(io.Discard, "", 0)))
	h.SetDispatcher(d)
	if err := st.UpsertHost(&store.Host{HostID: r1154Host, CustomerID: "c1", APIKey: "old-host-key-0123456789"}); err != nil {
		t.Fatal(err)
	}
	if err := st.SaveHostReport(r1154Host, "c1", []byte(`{"host_id":"`+r1154Host+`"}`), store.HostReportDenorm{}); err != nil {
		t.Fatal(err)
	}
	db, err := sql.Open("sqlite", path)
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { db.Close() })
	f.db = db
	f.mail.sends = 0
	f.gen0 = f.generation(t)
	return f
}

func (f *r1154Fixture) exec(t *testing.T, q string, args ...any) {
	t.Helper()
	if _, err := f.db.Exec(q, args...); err != nil {
		t.Fatalf("%s: %v", q, err)
	}
}

func (f *r1154Fixture) hostReportedAgo(t *testing.T, d time.Duration) {
	f.exec(t, `UPDATE hosts SET last_report_at = datetime('now', ?) WHERE host_id = ?`, fmt.Sprintf("-%d seconds", int(d.Seconds())), r1154Host)
}

func (f *r1154Fixture) controllerReportedAgo(t *testing.T, d time.Duration) {
	t.Helper()
	if err := f.st.SaveReport("c1", []byte(`{"customer_id":"c1"}`)); err != nil {
		t.Fatal(err)
	}
	f.exec(t, `UPDATE reports SET received_at = datetime('now', ?) WHERE customer_id = 'c1'`, fmt.Sprintf("-%d seconds", int(d.Seconds())))
}

func (f *r1154Fixture) generation(t *testing.T) int {
	t.Helper()
	cs, err := f.st.GetClaim("c1")
	if err != nil || cs == nil {
		t.Fatalf("GetClaim: %+v %v", cs, err)
	}
	return cs.Generation
}

// enroll runs the installer's call and checks the reuse contract that holds on EVERY branch: 200, the same host id
// and key, one record — and NOTHING re-issued (no claim rotation, no claim mail, no off-site re-issue).
func (f *r1154Fixture) enroll(t *testing.T) {
	t.Helper()
	rr := doEnroll(f.h, "c1", "pass-phrase")
	if rr.Code != http.StatusOK {
		t.Fatalf("enroll = %d, want 200 (reuse), body=%s", rr.Code, rr.Body.String())
	}
	var got enrollResp
	if err := json.Unmarshal(rr.Body.Bytes(), &got); err != nil {
		t.Fatal(err)
	}
	if got.HostID != r1154Host || got.APIKey != "old-host-key-0123456789" {
		t.Fatalf("reuse returned another credential: %s", got.HostID)
	}
	if n := countHostsForCustomer(t, f.st, "c1"); n != 1 {
		t.Fatalf("host rows = %d, want 1 (the record is reused, never duplicated)", n)
	}
	if gen := f.generation(t); gen != f.gen0 || f.mail.sends != 0 || f.offsite != 0 {
		t.Fatalf("the reuse path re-issued: claim generation %d→%d, claim mails %d, off-site re-issues %d — a passphrase must not reach these",
			f.gen0, gen, f.mail.sends, f.offsite)
	}
}

func (f *r1154Fixture) eventAt(t *testing.T, et string) time.Time {
	t.Helper()
	at, err := f.st.LastEventAt("c1", et)
	if err != nil {
		t.Fatal(err)
	}
	return at
}

// operatorMailed waits (the dispatch is asynchronous) for an operator-channel notification row of eventType.
func (f *r1154Fixture) operatorMailed(t *testing.T, eventType string) bool {
	t.Helper()
	deadline := time.Now().Add(3 * time.Second)
	for time.Now().Before(deadline) {
		logs, err := f.st.GetRecentNotifications("c1", 50)
		if err != nil {
			t.Fatal(err)
		}
		for _, l := range logs {
			if l.EventType == eventType && l.Channel == "operator" {
				return true
			}
		}
		time.Sleep(20 * time.Millisecond)
	}
	return false
}

func (f *r1154Fixture) eventMessage(t *testing.T, et string) string {
	t.Helper()
	var msg, sev string
	if err := f.db.QueryRow(`SELECT message, severity FROM events WHERE customer_id='c1' AND event_type=? ORDER BY id DESC LIMIT 1`, et).Scan(&msg, &sev); err != nil {
		t.Fatalf("event %s: %v", et, err)
	}
	return sev + "|" + msg
}

// The old box silent on both streams past the threshold → nothing re-issued, the operator WARNED by mail with the
// instruction.
//
// COMPANION RED-PROOF (observed 2026-10-19): with the pre-fix reuse path restored (the existing host returned at
// once, noteReenrollOverExistingHost not called) this fails with
//
//	r1154_reenroll_test.go: no host_reinstall_over_old_host event — the reinstall is silent again
//
// and with the first draft's automatic re-issue (reissueOnReenroll called on this branch) it fails with
//
//	r1154_reenroll_test.go: the reuse path re-issued: claim generation 1→2, claim mails 1, off-site re-issues 1 — a passphrase must not reach these
//
// Restored.
func TestR1154_StaleOldHostWarnsTheOperatorAndReissuesNothing(t *testing.T) {
	f := newR1154(t)
	f.hostReportedAgo(t, 2*time.Hour)
	f.controllerReportedAgo(t, 2*time.Hour)
	f.enroll(t)
	if f.eventAt(t, eventHostReinstallOverOldHost).IsZero() {
		t.Fatal("no host_reinstall_over_old_host event — the reinstall is silent again")
	}
	got := f.eventMessage(t, eventHostReinstallOverOldHost)
	for _, want := range []string{"warning|", "A reinstall of c1", r1154Host, "nothing was re-issued", "delete the old host", "re-issue the claim code and the off-site login from the customer page"} {
		if !strings.Contains(got, want) {
			t.Errorf("warning text lacks %q: %s", want, got)
		}
	}
	if !f.operatorMailed(t, eventHostReinstallOverOldHost) {
		t.Error("the operator mail path was not reached (no operator notification row)")
	}
}

// Switched off on purpose minutes ago (both report clocks still fresh) → the same warning: the box said it was
// going down. Deliberate-off only changes which message the operator reads — it unlocks nothing.
//
// COMPANION RED-PROOF (observed 2026-10-19): with the deliberate-off branch removed this fails with
//
//	r1154_reenroll_test.go: deliberately off: no host_reinstall_over_old_host event
//
// Restored.
func TestR1154_DeliberatelyOffOldHostWarnsAndReissuesNothing(t *testing.T) {
	f := newR1154(t)
	f.hostReportedAgo(t, 3*time.Minute)
	f.controllerReportedAgo(t, 3*time.Minute)
	off := time.Now().UTC().Add(-5 * time.Minute).Truncate(time.Second)
	if _, err := f.st.SetHostDeliberateOff(r1154Host, &off); err != nil {
		t.Fatal(err)
	}
	f.enroll(t)
	if f.eventAt(t, eventHostReinstallOverOldHost).IsZero() {
		t.Fatal("deliberately off: no host_reinstall_over_old_host event")
	}
	if !strings.Contains(f.eventMessage(t, eventHostReinstallOverOldHost), "switched the box off") {
		t.Errorf("the warning does not say why: %s", f.eventMessage(t, eventHostReinstallOverOldHost))
	}
}

// A LIVE box enrolling again (an installer --resume after its agent started, a repair re-run) is recorded as info,
// NOT mailed, and nothing is re-issued. Three ways to be live, each alone, plus connected-while-off.
//
// COMPANION RED-PROOF (observed 2026-10-19): with classifyReenroll replaced by an unconditional "gone" this fails
// with
//
//	r1154_reenroll_test.go: host report fresh: a live box raised the reinstall warning
//
// (and the same for the other three cases). Restored.
func TestR1154_LiveHostIsRecordedNotWarned(t *testing.T) {
	cases := []struct {
		name  string
		setup func(t *testing.T, f *r1154Fixture)
	}{
		{"host report fresh", func(t *testing.T, f *r1154Fixture) {
			f.hostReportedAgo(t, 2*time.Minute)
			f.controllerReportedAgo(t, 2*time.Hour)
		}},
		{"controller report fresh, agent silent", func(t *testing.T, f *r1154Fixture) {
			f.hostReportedAgo(t, 2*time.Hour)
			f.controllerReportedAgo(t, 5*time.Minute)
		}},
		{"controller connected, both reports old", func(t *testing.T, f *r1154Fixture) {
			f.hostReportedAgo(t, 2*time.Hour)
			f.controllerReportedAgo(t, 2*time.Hour)
			hub := intent.New()
			f.h.SetIntentHub(hub)
			hub.MarkWaitStart("c1")
		}},
		{"controller connected, deliberately off", func(t *testing.T, f *r1154Fixture) {
			f.hostReportedAgo(t, 2*time.Minute)
			f.controllerReportedAgo(t, 2*time.Minute)
			off := time.Now().UTC().Add(-time.Minute).Truncate(time.Second)
			f.st.SetHostDeliberateOff(r1154Host, &off)
			hub := intent.New()
			f.h.SetIntentHub(hub)
			hub.MarkWaitStart("c1")
		}},
	}
	for _, c := range cases {
		t.Run(c.name, func(t *testing.T) {
			f := newR1154(t)
			c.setup(t, f)
			f.enroll(t)
			if !f.eventAt(t, eventHostReinstallOverOldHost).IsZero() {
				t.Fatalf("%s: a live box raised the reinstall warning", c.name)
			}
			if f.eventAt(t, eventHostReenrollWhileLive).IsZero() {
				t.Errorf("%s: the live re-enroll was not recorded (host_reenroll_while_live)", c.name)
			}
			if !strings.HasPrefix(f.eventMessage(t, eventHostReenrollWhileLive), "info|") {
				t.Errorf("%s: the live record must be info (recorded, never mailed): %s", c.name, f.eventMessage(t, eventHostReenrollWhileLive))
			}
		})
	}
}

// Edges the code shows. A host record that never reported (an operator /admin/hosts mint) with no controller
// report → the warning; not wired (no threshold) → no event at all, nothing re-issued; and the MINT path (the old
// host deleted by the operator) still re-issues exactly as before — the operator's delete is the gate.
//
// COMPANION RED-PROOF (observed 2026-10-19): with the call removed from the reuse path „never reported" fails with
// „never reported: no host_reinstall_over_old_host event"; with an unconditional "gone", „threshold not wired"
// fails with „not wired: an event was written". Restored.
func TestR1154_NeverReportedUnwiredAndMintEdges(t *testing.T) {
	t.Run("never reported", func(t *testing.T) {
		f := newR1154(t)
		f.exec(t, `UPDATE hosts SET last_report_at = NULL WHERE host_id = ?`, r1154Host)
		f.enroll(t)
		if f.eventAt(t, eventHostReinstallOverOldHost).IsZero() {
			t.Fatal("never reported: no host_reinstall_over_old_host event")
		}
	})
	t.Run("threshold not wired", func(t *testing.T) {
		f := newR1154(t)
		f.h.SetStaleThreshold(0)
		f.hostReportedAgo(t, 2*time.Hour)
		f.controllerReportedAgo(t, 2*time.Hour)
		f.enroll(t)
		if !f.eventAt(t, eventHostReinstallOverOldHost).IsZero() || !f.eventAt(t, eventHostReenrollWhileLive).IsZero() {
			t.Fatal("not wired: an event was written")
		}
	})
	t.Run("old host deleted: the mint path re-issues", func(t *testing.T) {
		f := newR1154(t)
		if err := f.st.DeleteHost(r1154Host, false); err != nil {
			t.Fatalf("DeleteHost: %v", err)
		}
		if rr := doEnroll(f.h, "c1", "pass-phrase"); rr.Code != http.StatusCreated {
			t.Fatalf("enroll after delete = %d, want 201 (mint)", rr.Code)
		}
		if gen := f.generation(t); gen != f.gen0+1 || f.mail.sends != 1 || f.offsite != 1 {
			t.Fatalf("mint after the operator's delete must re-issue: claim generation %d→%d, claim mails %d, off-site re-issues %d",
				f.gen0, gen, f.mail.sends, f.offsite)
		}
	})
}

// Both R-1154 event types: operator-only, and hub-origin only (no box can POST them).
func TestR1154_EventsAreOperatorOnlyAndHubOrigin(t *testing.T) {
	for _, et := range []string{eventHostReinstallOverOldHost, eventHostReenrollWhileLive} {
		if !notify.IsOperatorOnly(et) {
			t.Errorf("%s is not operator-only", et)
		}
		if allowedEventTypes[et] {
			t.Errorf("%s is in allowedEventTypes — a box could POST it", et)
		}
	}
}