package api

import (
	"encoding/json"
	"net/http"
	"strings"
	"testing"
)

// Registration is by invitation, and almost everything worth testing here is a
// property of that choice: what the code decides versus what the request
// decides, and who is allowed to mint one.

// Real user ids are uuids and the id-addressed routes check the shape before
// spending a database round trip. A fixture using "u5" would 404 on the guard
// rather than on the rule under test - which is a test that passes for the
// wrong reason, and would keep passing if tenant scoping were removed.
const (
	acmeStaffID = "11111111-1111-4111-8111-111111111111"
	acmeOwnerID = "22222222-2222-4222-8222-222222222222"
	acmeOtherID = "33333333-3333-4333-8333-333333333333"
)

func seedMember(fs *fakeStore, id, email, name, role string) {
	fs.addUser(email, "correct horse battery", UserRecord{
		ID: id, ClientID: "client-acme", ClientName: "Acme Retail",
		FullName: name, Role: role, Active: true,
	})
}

func invite(t *testing.T, s *Server, token string, body map[string]any) Invitation {
	t.Helper()
	rec := do(t, s, "POST", "/api/team/invitations", token, body)
	if rec.Code != http.StatusCreated {
		t.Fatalf("invite: got %d, body %s", rec.Code, rec.Body.String())
	}
	var inv Invitation
	if err := json.Unmarshal(rec.Body.Bytes(), &inv); err != nil {
		t.Fatal(err)
	}
	return inv
}

func TestAnInvitationBecomesAnAccountAndASession(t *testing.T) {
	s, fs := newServer(t)
	seedUser(fs)
	sess := login(t, s, "manager@acme.com", "correct horse battery")

	inv := invite(t, s, sess.Token, map[string]any{
		"email": "Nikhil@Acme.com", "full_name": "Nikhil", "role": "staff"})
	if inv.Code == "" {
		t.Fatal("the response that mints a code must carry it - it is not recoverable later")
	}
	// Normalised on the way in, so the address somebody types at sign-in is the
	// one that was invited whatever case they used.
	if inv.Email != "nikhil@acme.com" {
		t.Errorf("email should be normalised, got %q", inv.Email)
	}

	rec := do(t, s, "POST", "/api/auth/register", "", map[string]any{
		"code": inv.Code, "password": "a-good-long-password", "device": "Pixel 8"})
	if rec.Code != http.StatusCreated {
		t.Fatalf("register: got %d, body %s", rec.Code, rec.Body.String())
	}
	var out Session
	if err := json.Unmarshal(rec.Body.Bytes(), &out); err != nil {
		t.Fatal(err)
	}
	// A session, not just a 201. Sending somebody who has just chosen a
	// password to a sign-in form to type it again is the sort of thing that
	// gets blamed on the password.
	if out.Token == "" || out.RefreshToken == "" {
		t.Fatal("registration should sign the new member in")
	}
	if out.User.Email != "nikhil@acme.com" || out.User.Role != "staff" {
		t.Errorf("wrong account: %+v", out.User)
	}
	if out.User.ClientID != "client-acme" {
		t.Errorf("joined the wrong company: %q", out.User.ClientID)
	}
	if strings.Contains(rec.Body.String(), "$2a$") {
		t.Error("password hash leaked into the registration response")
	}

	// And the account works.
	again := login(t, s, "nikhil@acme.com", "a-good-long-password")
	if again.User.ID != out.User.ID {
		t.Error("registered account cannot sign in as itself")
	}
}

// The single most important test in this file. A code is forwarded, pasted into
// a chat, screenshotted; if the body could name the address or the role, one
// staff invitation would be an owner account for anybody who saw it.
func TestTheCodeDecidesTheAddressAndTheRoleNotTheRequest(t *testing.T) {
	s, fs := newServer(t)
	seedUser(fs)
	sess := login(t, s, "manager@acme.com", "correct horse battery")
	inv := invite(t, s, sess.Token, map[string]any{
		"email": "nikhil@acme.com", "role": "staff"})

	// Unknown fields are refused outright, which is the strongest form of this:
	// a client cannot even ask.
	rec := do(t, s, "POST", "/api/auth/register", "", map[string]any{
		"code": inv.Code, "password": "a-good-long-password",
		"email": "attacker@example.com", "role": "owner"})
	if rec.Code != http.StatusBadRequest {
		t.Fatalf("a body naming an address or a role must be refused, got %d: %s",
			rec.Code, rec.Body.String())
	}

	// And redeemed properly, the account is still staff at the invited address.
	rec = do(t, s, "POST", "/api/auth/register", "", map[string]any{
		"code": inv.Code, "password": "a-good-long-password"})
	var out Session
	_ = json.Unmarshal(rec.Body.Bytes(), &out)
	if out.User.Email != "nikhil@acme.com" || out.User.Role != "staff" {
		t.Fatalf("the invitation did not decide the account: %+v", out.User)
	}
}

func TestAnInvitationIsSingleUse(t *testing.T) {
	s, fs := newServer(t)
	seedUser(fs)
	sess := login(t, s, "manager@acme.com", "correct horse battery")
	inv := invite(t, s, sess.Token, map[string]any{"email": "one@acme.com"})

	first := do(t, s, "POST", "/api/auth/register", "", map[string]any{
		"code": inv.Code, "password": "a-good-long-password"})
	if first.Code != http.StatusCreated {
		t.Fatalf("first redemption: %d %s", first.Code, first.Body.String())
	}
	second := do(t, s, "POST", "/api/auth/register", "", map[string]any{
		"code": inv.Code, "password": "another-long-password"})
	if second.Code == http.StatusCreated {
		t.Fatal("a spent invitation created a second account")
	}
}

func TestARevokedInvitationCannotBeRedeemed(t *testing.T) {
	s, fs := newServer(t)
	seedUser(fs)
	sess := login(t, s, "manager@acme.com", "correct horse battery")
	inv := invite(t, s, sess.Token, map[string]any{"email": "gone@acme.com"})

	if rec := do(t, s, "DELETE", "/api/team/invitations/"+inv.ID, sess.Token, nil); rec.Code != http.StatusNoContent {
		t.Fatalf("revoke: %d %s", rec.Code, rec.Body.String())
	}
	rec := do(t, s, "POST", "/api/auth/register", "", map[string]any{
		"code": inv.Code, "password": "a-good-long-password"})
	if rec.Code == http.StatusCreated {
		t.Fatal("a withdrawn invitation still worked")
	}
}

// Unknown, expired, spent and revoked are one answer. The difference only ever
// helps somebody guessing, and the holder's next step is identical in all four.
func TestAnInvalidCodeSaysNothingAboutWhy(t *testing.T) {
	s, fs := newServer(t)
	seedUser(fs)
	sess := login(t, s, "manager@acme.com", "correct horse battery")
	inv := invite(t, s, sess.Token, map[string]any{"email": "used@acme.com"})
	_ = do(t, s, "POST", "/api/auth/register", "", map[string]any{
		"code": inv.Code, "password": "a-good-long-password"})

	spent := do(t, s, "POST", "/api/auth/register", "", map[string]any{
		"code": inv.Code, "password": "a-good-long-password"})
	invented := do(t, s, "POST", "/api/auth/register", "", map[string]any{
		"code": "AAAAAA-BBBBBB-CCCCCC-DDDDDD", "password": "a-good-long-password"})

	if spent.Code != invented.Code || spent.Body.String() != invented.Body.String() {
		t.Fatalf("a spent code is distinguishable from an invented one:\n%d %s\n%d %s",
			spent.Code, spent.Body.String(), invented.Code, invented.Body.String())
	}
}

func TestStaffCannotInviteAndAManagerCannotMintAnOwner(t *testing.T) {
	s, fs := newServer(t)
	seedMember(fs, acmeStaffID, "sam@acme.com", "Sam", "staff")
	seedUser(fs)

	staff := login(t, s, "sam@acme.com", "correct horse battery")
	if rec := do(t, s, "POST", "/api/team/invitations", staff.Token,
		map[string]any{"email": "x@acme.com"}); rec.Code != http.StatusForbidden {
		t.Errorf("staff should not be able to invite, got %d", rec.Code)
	}

	// A manager promoting somebody past themselves is an escalation, and it is
	// the shape of this endpoint that would matter if a manager account were
	// ever taken over.
	mgr := login(t, s, "manager@acme.com", "correct horse battery")
	if rec := do(t, s, "POST", "/api/team/invitations", mgr.Token,
		map[string]any{"email": "boss@acme.com", "role": "owner"}); rec.Code != http.StatusForbidden {
		t.Errorf("a manager minted an owner invitation, got %d", rec.Code)
	}
}

// 'admin' is a platform administrator, which is defined by having no company at
// all. An invitation always carries one, so the role could never work - what it
// could do is create the tenant-scoped row with role='admin' that adminOnly
// exists to reject.
func TestAnInvitationCannotMintAPlatformAdmin(t *testing.T) {
	s, fs := newServer(t)
	seedUser(fs)
	sess := login(t, s, "manager@acme.com", "correct horse battery")

	rec := do(t, s, "POST", "/api/team/invitations", sess.Token,
		map[string]any{"email": "root@acme.com", "role": "admin"})
	if rec.Code != http.StatusBadRequest {
		t.Fatalf("admin should not be an invitable role, got %d: %s",
			rec.Code, rec.Body.String())
	}
}

func TestAnInvitationIsScopedToTheInvitersCompany(t *testing.T) {
	s, fs := newServer(t)
	seedUser(fs)
	fs.addUser("other@beta.com", "correct horse battery", UserRecord{
		ID: "u2", ClientID: "client-beta", ClientName: "Beta Ltd",
		FullName: "Bo", Role: "manager", Active: true,
	})
	acme := login(t, s, "manager@acme.com", "correct horse battery")
	beta := login(t, s, "other@beta.com", "correct horse battery")

	inv := invite(t, s, acme.Token, map[string]any{"email": "new@acme.com"})

	// Beta cannot see it...
	rec := do(t, s, "GET", "/api/team/invitations", beta.Token, nil)
	if strings.Contains(rec.Body.String(), "new@acme.com") {
		t.Fatalf("another tenant can see Acme's invitations: %s", rec.Body.String())
	}
	// ...nor withdraw it.
	if rec := do(t, s, "DELETE", "/api/team/invitations/"+inv.ID, beta.Token, nil); rec.Code == http.StatusNoContent {
		t.Fatal("another tenant withdrew Acme's invitation")
	}
}

// The preview is unauthenticated by necessity - the holder has no account yet -
// so what it discloses is the whole question.
func TestThePreviewShowsWhatToJoinAndNothingElse(t *testing.T) {
	s, fs := newServer(t)
	seedUser(fs)
	sess := login(t, s, "manager@acme.com", "correct horse battery")
	inv := invite(t, s, sess.Token, map[string]any{
		"email": "nikhil@acme.com", "full_name": "Nikhil", "role": "manager"})

	rec := do(t, s, "GET", "/api/auth/invitation?code="+inv.Code, "", nil)
	if rec.Code != http.StatusOK {
		t.Fatalf("preview: %d %s", rec.Code, rec.Body.String())
	}
	var prev InvitationPreview
	if err := json.Unmarshal(rec.Body.Bytes(), &prev); err != nil {
		t.Fatal(err)
	}
	if prev.Role != "manager" || prev.Email != "nikhil@acme.com" {
		t.Errorf("preview should say what is being joined: %+v", prev)
	}
	// It must not become a way to read a company's staff list or anything else
	// about it beyond the one line the code already asserts.
	if strings.Contains(rec.Body.String(), "manager@acme.com") {
		t.Error("the preview disclosed the inviter's address")
	}

	if rec := do(t, s, "GET", "/api/auth/invitation?code=NOPE", "", nil); rec.Code != http.StatusNotFound {
		t.Errorf("an invented code should 404, got %d", rec.Code)
	}
}

func TestRegistrationEnforcesThePasswordFloor(t *testing.T) {
	s, fs := newServer(t)
	seedUser(fs)
	sess := login(t, s, "manager@acme.com", "correct horse battery")
	inv := invite(t, s, sess.Token, map[string]any{"email": "short@acme.com"})

	rec := do(t, s, "POST", "/api/auth/register", "", map[string]any{
		"code": inv.Code, "password": "short"})
	if rec.Code != http.StatusBadRequest {
		t.Fatalf("a short password was accepted, got %d", rec.Code)
	}
	// And the invitation is NOT spent by a rejected attempt - otherwise one
	// mistyped password would cost the person their invitation.
	ok := do(t, s, "POST", "/api/auth/register", "", map[string]any{
		"code": inv.Code, "password": "a-good-long-password"})
	if ok.Code != http.StatusCreated {
		t.Fatalf("a failed attempt burned the invitation: %d %s", ok.Code, ok.Body.String())
	}
}

// ------------------------------------------------------------------- team --

func TestDeactivatingSomebodySignsThemOutNow(t *testing.T) {
	s, fs := newServer(t)
	seedUser(fs)
	seedMember(fs, acmeStaffID, "leaver@acme.com", "Lee", "staff")
	mgr := login(t, s, "manager@acme.com", "correct horse battery")
	leaver := login(t, s, "leaver@acme.com", "correct horse battery")

	if rec := do(t, s, "GET", "/api/auth/me", leaver.Token, nil); rec.Code != http.StatusOK {
		t.Fatalf("the leaver should be signed in to begin with, got %d", rec.Code)
	}

	rec := do(t, s, "PATCH", "/api/team/"+acmeStaffID, mgr.Token, map[string]any{"active": false})
	if rec.Code != http.StatusOK {
		t.Fatalf("deactivate: %d %s", rec.Code, rec.Body.String())
	}
	// The whole point. An access token lives twelve hours, so without revoking
	// the session, "remove their access" would remove it sometime tomorrow -
	// which is not what anybody pressing that button believes they have done.
	if rec := do(t, s, "GET", "/api/auth/me", leaver.Token, nil); rec.Code != http.StatusUnauthorized {
		t.Fatalf("a deactivated account is still signed in, got %d", rec.Code)
	}
}

func TestTheLastOwnerCannotRemoveThemselves(t *testing.T) {
	s, fs := newServer(t)
	seedMember(fs, acmeOwnerID, "boss@acme.com", "Bea", "owner")
	sess := login(t, s, "boss@acme.com", "correct horse battery")

	for _, body := range []map[string]any{{"active": false}, {"role": "staff"}} {
		rec := do(t, s, "PATCH", "/api/team/"+acmeOwnerID, sess.Token, body)
		if rec.Code != http.StatusConflict {
			t.Fatalf("the only owner removed themselves with %v: %d %s",
				body, rec.Code, rec.Body.String())
		}
	}
}

func TestTeamIsScopedToTheCallersCompany(t *testing.T) {
	s, fs := newServer(t)
	seedUser(fs)
	fs.addUser("other@beta.com", "correct horse battery", UserRecord{
		ID: "u2", ClientID: "client-beta", ClientName: "Beta Ltd",
		FullName: "Bo", Role: "manager", Active: true,
	})
	seedMember(fs, acmeOtherID, "asha@acme.com", "Asha", "manager")
	beta := login(t, s, "other@beta.com", "correct horse battery")

	rec := do(t, s, "GET", "/api/team", beta.Token, nil)
	if strings.Contains(rec.Body.String(), "manager@acme.com") {
		t.Fatalf("another tenant's staff are visible: %s", rec.Body.String())
	}
	// And a uuid guessed from elsewhere changes nothing.
	// A real, well-formed id belonging to the OTHER tenant. The 404 must come
	// from the client scope in the UPDATE, not from the shape check above it.
	if rec := do(t, s, "PATCH", "/api/team/"+acmeOtherID, beta.Token,
		map[string]any{"role": "staff"}); rec.Code != http.StatusNotFound {
		t.Errorf("cross-tenant team edit was not refused, got %d", rec.Code)
	}
}