package asks

import (
	"context"
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"

	"git.novox.be/novox/mesh-sdk/go/asker"
	"git.novox.be/novox/mesh-sdk/go/asks"
)

// The operator's own Telegram account in the lab, and somebody else's.
const (
	operatorAccount = 42
	strangerAccount = 99
	groupChat       = -1001
)

// TestTheOperatorsAnswerEndToEnd is the operator's acceptance of novox/hq ADR 0259, run before anybody uses it:
//
//	"I get a Telegram message from the mesh with what is asked, why, by whom, and Approve/Decline buttons;
//	tapping Approve makes the mesh do exactly that one thing once; Decline or no answer does nothing;
//	nobody else (no agent, no other Telegram user, no replay of an old message) can produce an approval;
//	and I can see in the record who approved what."
//
// What is real: the bus, of the release the mesh runs, with the accounts the controller at its commit composes
// for one machine and raised by that controller's own code (its fixture TestTheAsksLabBus); the mesh's runtime
// (mesh-tools node-tools) serving the router (messenger) and the Telegram channel (telegram), each on its own
// credential, as `runs-as` places them; the router's and the channel's code at their commits; the SDK's asker.
//
// What is the lab's: Telegram itself (a fake Bot API, the operator's phone), the desk (the desktop kind at the
// bus, which shows the link's code), the controller's conditions verb (a list the lab keeps), and the asker
// (the module `lab-asker`, the SDK's client in this process). The controller as an asker — that it acts on a
// warrant once, through the verb the action names, and records it — is its own repository's test
// (asker_test.go); the live acceptance after rollout runs it for real.
func TestTheOperatorsAnswerEndToEnd(t *testing.T) {
	repos := clonesFor(t)
	dir := os.Getenv("MESH_LAB_ASKS_KEEP")
	if dir == "" {
		dir = t.TempDir()
	} else if err := os.MkdirAll(dir, 0o700); err != nil {
		t.Fatal(err)
	}
	l := &lab{t: t, repos: repos, dir: dir}
	token := "123456789:" + strings.Repeat("A", 35)
	l.tg = newFakeTelegram(t, token)

	// The bus, as the controller composes and raises it.
	l.compose("")
	l.startBus()
	l.compose(l.url)
	l.playController()

	// The programs, at their commits. The channel is built to call the lab's phone in place of Telegram.
	runtimeBin := l.build(filepath.Join(repos.tools, "node-tools"), "./cmd/node-tools", "node-tools", "")
	routerBin := l.build(filepath.Join(repos.catalogue, "modules", "messenger"), "./cmd/messenger", "messenger", "")
	channelBin := l.build(filepath.Join(repos.catalogue, "modules", "telegram"), "./cmd/telegram", "telegram",
		"-X main.API="+l.tg.URL())

	routerState := filepath.Join(dir, "messenger")
	if err := os.MkdirAll(routerState, 0o700); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(routerState, "settings.json"), []byte(`{"time-zone": "UTC"}`), 0o600); err != nil {
		t.Fatal(err)
	}
	tokenFile := filepath.Join(dir, "telegram", "telegram-token")
	if err := os.MkdirAll(filepath.Dir(tokenFile), 0o700); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(tokenFile, []byte(token+"\n"), 0o600); err != nil {
		t.Fatal(err)
	}

	ctx, stop := context.WithCancel(context.Background())
	t.Cleanup(stop)
	l.playDesk(ctx)
	l.runtime("messenger", runtimeBin, routerBin, map[string]string{
		"MESH_MESSENGER_SETTINGS": filepath.Join(routerState, "settings.json"), "MESH_MESSENGER_STATE": routerState})
	l.runtime("telegram", runtimeBin, channelBin, map[string]string{"MESH_TELEGRAM_TOKEN_FILE": tokenFile})
	l.waitSaid("messenger", "taking the asks submitted", time.Minute)
	l.waitSaid("telegram", "taking the router's messages for this kind", time.Minute)
	a := newLabAsker(t, l)

	// --- 1. The operator links their account: /start on the phone, the code from the desk.
	t.Run("the operator links their account with the code shown on the desk", func(t *testing.T) {
		since := time.Now()
		l.tg.typed(operatorAccount, operatorAccount, "private", "/start")
		code := l.codeOnTheDesk(90 * time.Second)
		l.tg.typed(operatorAccount, operatorAccount, "private", code[:3]+" "+code[3:])
		l.tg.waitFor("the link said done", operatorAccount, since, 90*time.Second, func(m tgMessage) bool {
			return strings.Contains(m.Text, "Linked")
		})
	})
	if t.Failed() {
		return
	}

	// --- 2. Within the hour after a link, an approval is refused; the button is not spent.
	var first asks.Ask
	var firstMessage tgMessage
	t.Run("an approval in the hour after linking is refused and nothing is done", func(t *testing.T) {
		since := time.Now()
		first = a.ask("a1", "Flip the lab's switch?", time.Hour)
		firstMessage = l.tg.waitFor("the first question with its buttons", operatorAccount, since, 90*time.Second,
			func(m tgMessage) bool { return !m.Edited && button(m, "Approve") != "" && button(m, "Decline") != "" })
		for _, says := range []string{"Flip the lab's switch?", "approve or decline", "lab-asker",
			"the switch is flipped, once", "nothing is flipped"} {
			if !strings.Contains(firstMessage.Text, says) {
				t.Errorf("the question does not say %q (what is asked, why, by whom, what each answer does, what "+
					"no answer does): %q", says, firstMessage.Text)
			}
		}
		tapped := time.Now()
		l.tg.tapped(operatorAccount, operatorAccount, "private", firstMessage.ID, button(firstMessage, "Approve"))
		l.tg.waitFor("the refusal of an approval inside the hour", operatorAccount, tapped, 90*time.Second,
			func(m tgMessage) bool {
				return strings.Contains(m.Text, "That answer was not taken") && strings.Contains(m.Text, "linked at")
			})
		if !a.noWordOn("a1", 2*time.Second) || len(a.performed()) != 0 {
			t.Fatalf("an approval inside the hour was a warrant: %v", a.performed())
		}
	})

	// The hour passes: the lab ages the link in the router's own record (the hour itself is the router's
	// unit test: an approve at 59 minutes refused, at 60 taken).
	t.Run("the hour after the link passes", func(t *testing.T) {
		e, kv := l.routerRecord("messenger_identities", fmt.Sprintf("telegram.%d", operatorAccount))
		var id map[string]any
		if err := json.Unmarshal(e.Value(), &id); err != nil {
			t.Fatal(err)
		}
		past := time.Now().Add(-61 * time.Minute).UTC()
		id["linked"], id["approve-from"] = past.Format(time.RFC3339Nano), past.Add(time.Hour).Format(time.RFC3339Nano)
		raw, _ := json.Marshal(id)
		if _, err := kv.Update(context.Background(), e.Key(), raw, e.Revision()); err != nil {
			t.Fatal(err)
		}
	})

	// --- 3. Approve: the warrant, for this ask alone, performed once.
	t.Run("approve does exactly the one thing, once, and says who approved", func(t *testing.T) {
		tapped := time.Now()
		l.tg.tapped(operatorAccount, operatorAccount, "private", firstMessage.ID, button(firstMessage, "Approve"))
		w := a.warrantFor("a1", 30*time.Second)
		if w.Outcome != asks.OutcomeChosen || w.Option != "approve" || w.Level != asks.Approve {
			t.Fatalf("the warrant: %+v", w)
		}
		if w.By == nil || w.By.Kind != "telegram" || w.By.Identity != fmt.Sprint(operatorAccount) ||
			w.By.Verified != "user id verified" || w.Channel != "telegram" || strings.Join(w.Proofs, ",") != "P1" {
			t.Errorf("the warrant does not say who approved, how and where: %+v by %+v", w, w.By)
		}
		if w.AskDigest != first.Digest() {
			t.Errorf("the warrant names the digest %s, not the ask's %s", w.AskDigest, first.Digest())
		}
		if got := a.performed(); len(got) != 1 || got[0]["arg.switch"] != "approve" {
			t.Fatalf("performed %v, want the one bound act once", got)
		}
		// At the tap, the phone says it was recorded, and never before the warrant was (issue 372).
		ack := l.tg.waitForToast("the approval confirmed", tapped, 30*time.Second, func(s string) bool {
			return strings.HasPrefix(s, "You chose Approve: recorded")
		})
		if ack.At.Before(w.At) {
			t.Errorf("the phone said recorded at %s, before the warrant at %s", ack.At, w.At)
		}
		// Every copy says how it ended — as its title, read at a glance — its buttons gone.
		edited := l.tg.waitFor("the question edited to its outcome", operatorAccount, tapped, 90*time.Second,
			func(m tgMessage) bool { return m.Edited && m.ID == firstMessage.ID && len(m.Buttons) == 0 })
		if !strings.HasPrefix(edited.Text, "You chose Approve at ") || !strings.Contains(firstLine(edited.Text), " on Telegram · ") {
			t.Errorf("the question does not open with how it ended: %q", firstLine(edited.Text))
		}
		// And the router's record holds who approved what.
		e, _ := l.routerRecord("messenger_asks", "lab-asker.a1")
		var rec struct {
			State   string        `json:"state"`
			Warrant *asks.Warrant `json:"warrant"`
		}
		_ = json.Unmarshal(e.Value(), &rec)
		if rec.State != "chosen" || rec.Warrant == nil || rec.Warrant.By == nil || rec.Warrant.By.Identity != fmt.Sprint(operatorAccount) {
			t.Errorf("the router's record: %s", e.Value())
		}
		t.Logf("the record reads: %s", w.Says())
	})

	// --- 4. A replayed tap, and a redelivered warrant, do nothing more.
	t.Run("a replayed tap and a redelivered warrant do nothing more", func(t *testing.T) {
		tapped := time.Now()
		l.tg.tapped(operatorAccount, operatorAccount, "private", firstMessage.ID, button(firstMessage, "Approve"))
		// The same answer tapped again is what was recorded: the phone says so, and nothing more is done (issue 372:
		// a refusal here read as the approval failing).
		l.tg.waitForToast("the replayed tap said as already recorded", tapped, 30*time.Second, func(s string) bool {
			return strings.HasPrefix(s, "You already chose Approve at ") && strings.HasSuffix(s, ": recorded.")
		})
		time.Sleep(2 * time.Second)
		if n := a.wordsOn("a1"); n != 1 {
			t.Errorf("the router said %d words on one ask", n)
		}
		w := a.warrantFor("a1", time.Second)
		if h := a.take(w); h != asker.Done {
			t.Errorf("a warrant heard again was %s", h)
		}
		if got := a.performed(); len(got) != 1 {
			t.Fatalf("performed %v after a replay", got)
		}
	})

	// --- 5. Somebody else's account, and a group, cannot answer; Decline does nothing.
	t.Run("another account and a group cannot answer, and decline does nothing", func(t *testing.T) {
		since := time.Now()
		a.ask("a2", "Flip it once more?", time.Hour)
		m := l.tg.waitFor("the second question", operatorAccount, since, 90*time.Second,
			func(m tgMessage) bool { return !m.Edited && button(m, "Approve") != "" })
		// The buttons' data reached a stranger (a forwarded question), who taps in their own chat with the bot:
		// the channel never showed that message there, so the tap goes nowhere, and the stranger is told
		// nothing. (A stranger's answer that does reach the router is refused there and told to the operator by
		// name: the router's own test.)
		l.tg.tapped(strangerAccount, strangerAccount, "private", m.ID, button(m, "Approve"))
		// The operator taps a message whose words are not the ones the channel put there.
		l.tg.tappedOn(operatorAccount, operatorAccount, "private", m.ID, button(m, "Approve"), "Flip ALL the switches?")
		// The operator taps in a group the bot is in: not their own chat, dropped by the channel.
		l.tg.tapped(operatorAccount, groupChat, "supergroup", m.ID, button(m, "Approve"))
		if !a.noWordOn("a2", 3*time.Second) {
			t.Fatal("a tap from another account, on changed words, or from a group, was a warrant")
		}
		if got := l.tg.since(strangerAccount, since); len(got) != 0 {
			t.Errorf("the bot answered the stranger: %+v", got)
		}
		if got := l.tg.since(groupChat, since); len(got) != 0 {
			t.Errorf("the bot answered in a group: %+v", got)
		}
		l.tg.tapped(operatorAccount, operatorAccount, "private", m.ID, button(m, "Decline"))
		w := a.warrantFor("a2", 30*time.Second)
		if w.Option != "decline" || w.Level != asks.Acknowledge {
			t.Errorf("decline's warrant: %+v", w)
		}
		if got := a.performed(); len(got) != 1 {
			t.Fatalf("decline performed something: %v", got)
		}
	})

	// --- 6. No agent can produce an approval: the bus refuses every forgery, as the controller composed it.
	t.Run("no agent, channel or module but the router can say a warrant, and none asks in another's name", func(t *testing.T) {
		warrant, _ := json.Marshal(asks.Warrant{Ask: "a9", Asker: "lab-asker", Outcome: asks.OutcomeChosen,
			Option: "approve", Level: asks.Approve, AskDigest: first.Digest(),
			By: &asks.Person{Who: asks.Operator, Kind: "telegram", Identity: "42", Verified: "user id verified"}})
		decided := asks.DecidedSubject("lab-asker")
		// The control: what is granted is not refused, so a refusal below is the bus's word and not the lab's.
		// The channel's control is a true standing, now: a false one would hold the router's messages.
		standing, _ := json.Marshal(asks.Standing{Ready: true, EditsSilently: true, At: time.Now().UTC()})
		for _, try := range []struct {
			user, subject string
			body          []byte
		}{
			{machine + ".lab-asker", "mesh.seat.operator-channel.accept.cancel.lab-asker", []byte(`{"id":"none"}`)},
			{machine + ".telegram", asks.IntakeSubject(asks.StandingWhat, "telegram"), standing},
		} {
			if l.refusedToPublish(try.user, try.subject, try.body) {
				t.Fatalf("the control failed: %s was refused %s, which the controller grants it", try.user, try.subject)
			}
		}
		for _, user := range []string{
			machine + ".node-tools",    // the machine's runtime: every agent's tool calls go through one
			machine + ".lab-asker",     // the asker itself
			machine + ".lab-bystander", // any other module
			machine + ".telegram",      // the channel
			"node." + machine,          // the machine's node-engine
			"controller",               // the controller asks; it does not decide
		} {
			if !l.refusedToPublish(user, decided, warrant) {
				t.Errorf("%s may say a warrant on %s", user, decided)
			}
		}
		for _, try := range []struct{ user, subject, what string }{
			{machine + ".lab-asker", asks.AskSubject("mesh-controller"), "an ask in another asker's name"},
			{machine + ".lab-bystander", asks.AskSubject("lab-bystander"), "an ask from a module that may not ask"},
			{machine + ".node-tools", asks.AskSubject("mesh-controller"), "an agent asking as the controller through the runtime"},
			{machine + ".node-tools", asks.IntakeSubject(asks.Chosen, "telegram"), "an agent saying a Telegram tap"},
			{machine + ".lab-asker", asks.IntakeSubject(asks.Chosen, "telegram"), "an asker saying a Telegram tap"},
			{machine + ".node-tools", "$KV.messenger_identities.telegram.666", "an agent linking an account of its own"},
			{machine + ".lab-asker", "$KV.messenger_asks.lab-asker.a1", "an asker rewriting the router's record"},
			{machine + ".telegram", asks.ProofSubject(asks.CodeProof, "desktop"), "a channel speaking for another kind"},
		} {
			if !l.refusedToPublish(try.user, try.subject, []byte(`{}`)) {
				t.Errorf("%s: %s may publish %s", try.what, try.user, try.subject)
			}
		}
		time.Sleep(time.Second)
		if n := a.wordsOn("a9"); n != 0 || len(a.performed()) != 1 {
			t.Fatalf("a forged warrant reached the asker: %d words, performed %v", n, a.performed())
		}
	})

	// --- 7. While an agent can become root where the router runs, nothing proven there approves.
	t.Run("while the controller cannot say root is free where the router runs, nothing approves", func(t *testing.T) {
		// An approval the operator already sees on the phone, then root stops being free.
		since := time.Now()
		a.ask("a5", "Flip it while root is checked?", time.Hour)
		m := l.tg.waitFor("the question asked while root was free", operatorAccount, since, 90*time.Second,
			func(m tgMessage) bool { return !m.Edited && button(m, "Approve") != "" })
		l.mu.Lock()
		l.notFree = map[string]string{machine: "an agent can become root without a person"}
		asked := l.rootAsked
		l.mu.Unlock()
		tapped := time.Now()
		l.tg.tapped(operatorAccount, operatorAccount, "private", m.ID, button(m, "Approve"))
		l.tg.waitFor("the refusal of an approval while root is not free", operatorAccount, tapped, 90*time.Second,
			func(m tgMessage) bool { return strings.Contains(m.Text, "That answer was not taken") })
		l.mu.Lock()
		askedAgain := l.rootAsked > asked
		l.mu.Unlock()
		if !askedAgain {
			t.Error("the router judged an approval without asking the controller whether root is free")
		}
		if !a.noWordOn("a5", 2*time.Second) {
			t.Fatal("an approval was a warrant while root was not free")
		}
		// A new ask that needs an approval is refused to its asker, in words: no channel can carry it now.
		a.ask("a3", "Flip it while root is not free?", time.Hour)
		w := a.warrantFor("a3", 30*time.Second)
		if w.Outcome != asks.OutcomeRefused || w.By != nil {
			t.Errorf("an approving ask while root is not free: %+v", w)
		}
		if got := a.performed(); len(got) != 1 {
			t.Fatalf("performed %v while root was not free", got)
		}
		l.mu.Lock()
		l.notFree = nil
		l.mu.Unlock()
		if err := a.client.Cancel("a5"); err != nil {
			t.Errorf("taking the ask back: %v", err)
		}
	})

	// --- 8. No answer does nothing: the ask expires.
	t.Run("an ask nobody answers expires and nothing is done", func(t *testing.T) {
		since := time.Now()
		a.ask("a4", "Flip it if you answer in time?", 20*time.Second)
		m := l.tg.waitFor("the fourth question", operatorAccount, since, 90*time.Second,
			func(m tgMessage) bool { return !m.Edited && button(m, "Approve") != "" })
		w := a.warrantFor("a4", 2*time.Minute)
		if w.Outcome != asks.OutcomeExpired || w.By != nil {
			t.Errorf("the end of an unanswered ask: %+v", w)
		}
		late := time.Now()
		l.tg.tapped(operatorAccount, operatorAccount, "private", m.ID, button(m, "Approve"))
		l.tg.waitFor("the refusal of a late tap", operatorAccount, late, 90*time.Second,
			func(m tgMessage) bool { return strings.Contains(m.Text, "That answer was not taken") })
		time.Sleep(2 * time.Second)
		if got := a.performed(); len(got) != 1 {
			t.Fatalf("an expired ask performed something: %v", got)
		}
	})

	t.Logf("performed, over the whole run: %v (one approval, one act)", a.performed())
}