package localauth

import (
	"encoding/json"
	"io"
	"log/slog"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"time"

	"github.com/sentry/sentry/api/authz"
)

func newTestHandler(t *testing.T, fs *fakeStore) (*Handler, *http.ServeMux) {
	t.Helper()
	authorizer := NewAuthorizer(fs)
	h := NewHandler(slog.New(slog.NewTextHandler(io.Discard, nil)), fs, authorizer, time.Hour, CookieConfig{})
	mux := http.NewServeMux()
	h.RegisterRoutes(mux)
	return h, mux
}

func doRequest(t *testing.T, mux *http.ServeMux, method, path, body string, cookie *http.Cookie) *httptest.ResponseRecorder {
	t.Helper()
	var r io.Reader
	if body != "" {
		r = strings.NewReader(body)
	}
	req := httptest.NewRequest(method, path, r)
	if cookie != nil {
		req.AddCookie(cookie)
	}
	rec := httptest.NewRecorder()
	mux.ServeHTTP(rec, req)
	return rec
}

func mustCreateUser(t *testing.T, fs *fakeStore, username, password string, role authz.Role) *User {
	t.Helper()
	hash, err := HashPassword(password)
	if err != nil {
		t.Fatalf("hashing password: %v", err)
	}
	u, err := fs.CreateUser(t.Context(), username, hash, role)
	if err != nil {
		t.Fatalf("creating user: %v", err)
	}
	return u
}

func sessionCookieFrom(rec *httptest.ResponseRecorder) *http.Cookie {
	for _, c := range rec.Result().Cookies() {
		if c.Name == sessionCookieName {
			return c
		}
	}
	return nil
}

func TestLoginSuccess(t *testing.T) {
	fs := newFakeStore()
	mustCreateUser(t, fs, "alice", "hunter22", authz.RoleEditor)
	_, mux := newTestHandler(t, fs)

	rec := doRequest(t, mux, http.MethodPost, "/auth/login", `{"username":"alice","password":"hunter22"}`, nil)
	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d, want 200; body=%s", rec.Code, rec.Body.String())
	}
	cookie := sessionCookieFrom(rec)
	if cookie == nil || cookie.Value == "" {
		t.Fatalf("expected a session cookie to be set, got none")
	}
	if !cookie.HttpOnly {
		t.Errorf("session cookie must be HttpOnly")
	}

	var resp sessionResponse
	if err := json.Unmarshal(rec.Body.Bytes(), &resp); err != nil {
		t.Fatalf("decoding response: %v", err)
	}
	if resp.Token == "" {
		t.Errorf("expected the response body to also carry the raw token for non-browser callers")
	}
	if resp.Role != "editor" {
		t.Errorf("role = %q, want editor", resp.Role)
	}
}

func TestLoginWrongPassword(t *testing.T) {
	fs := newFakeStore()
	mustCreateUser(t, fs, "alice", "hunter22", authz.RoleEditor)
	_, mux := newTestHandler(t, fs)

	rec := doRequest(t, mux, http.MethodPost, "/auth/login", `{"username":"alice","password":"wrong"}`, nil)
	if rec.Code != http.StatusUnauthorized {
		t.Fatalf("status = %d, want 401", rec.Code)
	}
}

func TestLoginUnknownUserSameErrorAsWrongPassword(t *testing.T) {
	fs := newFakeStore()
	mustCreateUser(t, fs, "alice", "hunter22", authz.RoleEditor)
	_, mux := newTestHandler(t, fs)

	unknown := doRequest(t, mux, http.MethodPost, "/auth/login", `{"username":"bob","password":"whatever"}`, nil)
	wrongPass := doRequest(t, mux, http.MethodPost, "/auth/login", `{"username":"alice","password":"wrong"}`, nil)

	if unknown.Code != http.StatusUnauthorized || wrongPass.Code != http.StatusUnauthorized {
		t.Fatalf("both must be 401, got unknown=%d wrongPass=%d", unknown.Code, wrongPass.Code)
	}
	if unknown.Body.String() != wrongPass.Body.String() {
		t.Errorf("responses must be identical (no username enumeration): unknown=%q wrongPass=%q", unknown.Body.String(), wrongPass.Body.String())
	}
}

func TestSessionRequiresAuth(t *testing.T) {
	fs := newFakeStore()
	_, mux := newTestHandler(t, fs)

	rec := doRequest(t, mux, http.MethodGet, "/auth/session", "", nil)
	if rec.Code != http.StatusUnauthorized {
		t.Fatalf("status = %d, want 401 with no session cookie", rec.Code)
	}
}

func TestLoginThenSessionRoundTrip(t *testing.T) {
	fs := newFakeStore()
	mustCreateUser(t, fs, "alice", "hunter22", authz.RoleEditor)
	_, mux := newTestHandler(t, fs)

	login := doRequest(t, mux, http.MethodPost, "/auth/login", `{"username":"alice","password":"hunter22"}`, nil)
	cookie := sessionCookieFrom(login)

	sess := doRequest(t, mux, http.MethodGet, "/auth/session", "", cookie)
	if sess.Code != http.StatusOK {
		t.Fatalf("status = %d, want 200; body=%s", sess.Code, sess.Body.String())
	}
	var resp sessionResponse
	if err := json.Unmarshal(sess.Body.Bytes(), &resp); err != nil {
		t.Fatalf("decoding response: %v", err)
	}
	if resp.Username != "alice" {
		t.Errorf("username = %q, want alice", resp.Username)
	}
}

func TestLogoutInvalidatesSession(t *testing.T) {
	fs := newFakeStore()
	mustCreateUser(t, fs, "alice", "hunter22", authz.RoleEditor)
	_, mux := newTestHandler(t, fs)

	login := doRequest(t, mux, http.MethodPost, "/auth/login", `{"username":"alice","password":"hunter22"}`, nil)
	cookie := sessionCookieFrom(login)

	logout := doRequest(t, mux, http.MethodPost, "/auth/logout", "", cookie)
	if logout.Code != http.StatusNoContent {
		t.Fatalf("logout status = %d, want 204", logout.Code)
	}

	sess := doRequest(t, mux, http.MethodGet, "/auth/session", "", cookie)
	if sess.Code != http.StatusUnauthorized {
		t.Fatalf("status after logout = %d, want 401 (session must be revoked)", sess.Code)
	}
}

func TestNonOwnerCannotManageUsers(t *testing.T) {
	fs := newFakeStore()
	mustCreateUser(t, fs, "alice", "hunter22", authz.RoleEditor)
	_, mux := newTestHandler(t, fs)

	login := doRequest(t, mux, http.MethodPost, "/auth/login", `{"username":"alice","password":"hunter22"}`, nil)
	cookie := sessionCookieFrom(login)

	rec := doRequest(t, mux, http.MethodGet, "/auth/users", "", cookie)
	if rec.Code != http.StatusForbidden {
		t.Fatalf("status = %d, want 403 for a non-owner listing users", rec.Code)
	}
}

func TestOwnerCanCreateAndDeleteUsers(t *testing.T) {
	fs := newFakeStore()
	mustCreateUser(t, fs, "admin", "adminpass1", authz.RoleOwner)
	_, mux := newTestHandler(t, fs)

	login := doRequest(t, mux, http.MethodPost, "/auth/login", `{"username":"admin","password":"adminpass1"}`, nil)
	cookie := sessionCookieFrom(login)

	create := doRequest(t, mux, http.MethodPost, "/auth/users", `{"username":"bob","password":"bobspassword","role":"viewer"}`, cookie)
	if create.Code != http.StatusCreated {
		t.Fatalf("create status = %d, want 201; body=%s", create.Code, create.Body.String())
	}
	var created userResponse
	if err := json.Unmarshal(create.Body.Bytes(), &created); err != nil {
		t.Fatalf("decoding response: %v", err)
	}
	if created.Role != "viewer" {
		t.Errorf("role = %q, want viewer", created.Role)
	}
	if created.CreatedAt.IsZero() {
		t.Errorf("created_at was not populated in the create response")
	}

	list := doRequest(t, mux, http.MethodGet, "/auth/users", "", cookie)
	var users []userResponse
	if err := json.Unmarshal(list.Body.Bytes(), &users); err != nil {
		t.Fatalf("decoding response: %v", err)
	}
	if len(users) != 2 {
		t.Fatalf("len(users) = %d, want 2 (admin + bob)", len(users))
	}

	del := doRequest(t, mux, http.MethodDelete, "/auth/users/"+created.ID, "", cookie)
	if del.Code != http.StatusNoContent {
		t.Fatalf("delete status = %d, want 204", del.Code)
	}
}

func TestCreateUserRejectsShortPassword(t *testing.T) {
	fs := newFakeStore()
	mustCreateUser(t, fs, "admin", "adminpass1", authz.RoleOwner)
	_, mux := newTestHandler(t, fs)

	login := doRequest(t, mux, http.MethodPost, "/auth/login", `{"username":"admin","password":"adminpass1"}`, nil)
	cookie := sessionCookieFrom(login)

	rec := doRequest(t, mux, http.MethodPost, "/auth/users", `{"username":"bob","password":"short"}`, cookie)
	if rec.Code != http.StatusBadRequest {
		t.Fatalf("status = %d, want 400 for a too-short password", rec.Code)
	}
}

func TestResetPasswordRevokesExistingSessions(t *testing.T) {
	fs := newFakeStore()
	mustCreateUser(t, fs, "admin", "adminpass1", authz.RoleOwner)
	bob := mustCreateUser(t, fs, "bob", "bobspassword", authz.RoleViewer)
	_, mux := newTestHandler(t, fs)

	adminLogin := doRequest(t, mux, http.MethodPost, "/auth/login", `{"username":"admin","password":"adminpass1"}`, nil)
	adminCookie := sessionCookieFrom(adminLogin)
	bobLogin := doRequest(t, mux, http.MethodPost, "/auth/login", `{"username":"bob","password":"bobspassword"}`, nil)
	bobCookie := sessionCookieFrom(bobLogin)

	reset := doRequest(t, mux, http.MethodPost, "/auth/users/"+bob.ID+"/reset-password", "", adminCookie)
	if reset.Code != http.StatusOK {
		t.Fatalf("reset status = %d, want 200; body=%s", reset.Code, reset.Body.String())
	}
	var resp resetPasswordResponse
	if err := json.Unmarshal(reset.Body.Bytes(), &resp); err != nil {
		t.Fatalf("decoding response: %v", err)
	}
	if resp.Password == "" {
		t.Fatalf("expected a generated password in the response when none was supplied")
	}

	stale := doRequest(t, mux, http.MethodGet, "/auth/session", "", bobCookie)
	if stale.Code != http.StatusUnauthorized {
		t.Fatalf("bob's pre-reset session status = %d, want 401 (reset must revoke existing sessions)", stale.Code)
	}
}

func TestResetPasswordAcceptsCallerSuppliedPassword(t *testing.T) {
	fs := newFakeStore()
	mustCreateUser(t, fs, "admin", "adminpass1", authz.RoleOwner)
	bob := mustCreateUser(t, fs, "bob", "bobspassword", authz.RoleViewer)
	_, mux := newTestHandler(t, fs)

	adminLogin := doRequest(t, mux, http.MethodPost, "/auth/login", `{"username":"admin","password":"adminpass1"}`, nil)
	adminCookie := sessionCookieFrom(adminLogin)

	reset := doRequest(t, mux, http.MethodPost, "/auth/users/"+bob.ID+"/reset-password", `{"password":"bobs-new-password"}`, adminCookie)
	if reset.Code != http.StatusOK {
		t.Fatalf("reset status = %d, want 200; body=%s", reset.Code, reset.Body.String())
	}
	var resp resetPasswordResponse
	if err := json.Unmarshal(reset.Body.Bytes(), &resp); err != nil {
		t.Fatalf("decoding response: %v", err)
	}
	if resp.Password != "" {
		t.Errorf("expected no password echoed back when the caller supplied one, got %q", resp.Password)
	}

	login := doRequest(t, mux, http.MethodPost, "/auth/login", `{"username":"bob","password":"bobs-new-password"}`, nil)
	if login.Code != http.StatusOK {
		t.Fatalf("login with caller-supplied password: status = %d, want 200", login.Code)
	}
}

func TestOwnerCanReassignRole(t *testing.T) {
	fs := newFakeStore()
	mustCreateUser(t, fs, "admin", "adminpass1", authz.RoleOwner)
	bob := mustCreateUser(t, fs, "bob", "bobspassword", authz.RoleViewer)
	_, mux := newTestHandler(t, fs)

	adminLogin := doRequest(t, mux, http.MethodPost, "/auth/login", `{"username":"admin","password":"adminpass1"}`, nil)
	adminCookie := sessionCookieFrom(adminLogin)
	bobLogin := doRequest(t, mux, http.MethodPost, "/auth/login", `{"username":"bob","password":"bobspassword"}`, nil)
	bobCookie := sessionCookieFrom(bobLogin)

	set := doRequest(t, mux, http.MethodPut, "/auth/users/"+bob.ID+"/role", `{"role":"admin"}`, adminCookie)
	if set.Code != http.StatusOK {
		t.Fatalf("set role status = %d, want 200; body=%s", set.Code, set.Body.String())
	}
	var updated userResponse
	if err := json.Unmarshal(set.Body.Bytes(), &updated); err != nil {
		t.Fatalf("decoding response: %v", err)
	}
	if updated.Role != "admin" {
		t.Errorf("role = %q, want admin", updated.Role)
	}

	stale := doRequest(t, mux, http.MethodGet, "/auth/session", "", bobCookie)
	if stale.Code != http.StatusUnauthorized {
		t.Fatalf("bob's pre-reassignment session status = %d, want 401 (role change must revoke existing sessions)", stale.Code)
	}
}

// TestOwnerCanReassignEveryRoleTransition exercises every ordered pair
// of the four roles (viewer/editor/admin/owner), including a role's
// no-op transition to itself -- "an owner can reassign a role" must
// hold universally, not just for the one viewer->admin pair
// TestOwnerCanReassignRole already covers, and in particular must not
// silently special-case promotion to/from owner.
func TestOwnerCanReassignEveryRoleTransition(t *testing.T) {
	allRoles := []authz.Role{authz.RoleViewer, authz.RoleEditor, authz.RoleAdmin, authz.RoleOwner}

	for _, from := range allRoles {
		for _, to := range allRoles {
			t.Run(string(from)+"_to_"+string(to), func(t *testing.T) {
				fs := newFakeStore()
				mustCreateUser(t, fs, "admin", "adminpass1", authz.RoleOwner)
				target := mustCreateUser(t, fs, "target", "targetspassword", from)
				_, mux := newTestHandler(t, fs)

				adminLogin := doRequest(t, mux, http.MethodPost, "/auth/login", `{"username":"admin","password":"adminpass1"}`, nil)
				adminCookie := sessionCookieFrom(adminLogin)

				set := doRequest(t, mux, http.MethodPut, "/auth/users/"+target.ID+"/role", `{"role":"`+string(to)+`"}`, adminCookie)
				if set.Code != http.StatusOK {
					t.Fatalf("set role %s -> %s: status = %d, want 200; body=%s", from, to, set.Code, set.Body.String())
				}
				var updated userResponse
				if err := json.Unmarshal(set.Body.Bytes(), &updated); err != nil {
					t.Fatalf("decoding response: %v", err)
				}
				if updated.Role != string(to) {
					t.Fatalf("role in response = %q, want %q", updated.Role, to)
				}

				// Confirm it actually took, not just that the handler said
				// so -- log back in as target and check the session's role.
				login := doRequest(t, mux, http.MethodPost, "/auth/login", `{"username":"target","password":"targetspassword"}`, nil)
				if login.Code != http.StatusOK {
					t.Fatalf("login as target after reassignment: status = %d", login.Code)
				}
				var loginResp sessionResponse
				if err := json.Unmarshal(login.Body.Bytes(), &loginResp); err != nil {
					t.Fatalf("decoding login response: %v", err)
				}
				if loginResp.Role != string(to) {
					t.Fatalf("role after fresh login = %q, want %q", loginResp.Role, to)
				}
			})
		}
	}
}

// TestOwnerCanReassignOwnRole confirms self-reassignment isn't
// special-cased away -- consistent with handleDeleteUser's documented
// "single-operator deployment knows what it's doing" trust posture, an
// owner can demote (or re-promote) themselves same as anyone else.
func TestOwnerCanReassignOwnRole(t *testing.T) {
	fs := newFakeStore()
	admin := mustCreateUser(t, fs, "admin", "adminpass1", authz.RoleOwner)
	_, mux := newTestHandler(t, fs)

	login := doRequest(t, mux, http.MethodPost, "/auth/login", `{"username":"admin","password":"adminpass1"}`, nil)
	cookie := sessionCookieFrom(login)

	set := doRequest(t, mux, http.MethodPut, "/auth/users/"+admin.ID+"/role", `{"role":"viewer"}`, cookie)
	if set.Code != http.StatusOK {
		t.Fatalf("self role change status = %d, want 200; body=%s", set.Code, set.Body.String())
	}
	var updated userResponse
	if err := json.Unmarshal(set.Body.Bytes(), &updated); err != nil {
		t.Fatalf("decoding response: %v", err)
	}
	if updated.Role != "viewer" {
		t.Errorf("role = %q, want viewer", updated.Role)
	}

	// The role change revokes sessions same as any other target -- the
	// admin's own now-stale cookie must stop working too.
	stale := doRequest(t, mux, http.MethodGet, "/auth/session", "", cookie)
	if stale.Code != http.StatusUnauthorized {
		t.Fatalf("own session after self-reassignment status = %d, want 401", stale.Code)
	}
}

func TestSetRoleRejectsInvalidRole(t *testing.T) {
	fs := newFakeStore()
	mustCreateUser(t, fs, "admin", "adminpass1", authz.RoleOwner)
	bob := mustCreateUser(t, fs, "bob", "bobspassword", authz.RoleViewer)
	_, mux := newTestHandler(t, fs)

	adminLogin := doRequest(t, mux, http.MethodPost, "/auth/login", `{"username":"admin","password":"adminpass1"}`, nil)
	adminCookie := sessionCookieFrom(adminLogin)

	rec := doRequest(t, mux, http.MethodPut, "/auth/users/"+bob.ID+"/role", `{"role":"superuser"}`, adminCookie)
	if rec.Code != http.StatusBadRequest {
		t.Fatalf("status = %d, want 400 for an invalid role", rec.Code)
	}
}

func TestNonOwnerCannotReassignRole(t *testing.T) {
	fs := newFakeStore()
	mustCreateUser(t, fs, "alice", "hunter22", authz.RoleEditor)
	bob := mustCreateUser(t, fs, "bob", "bobspassword", authz.RoleViewer)
	_, mux := newTestHandler(t, fs)

	login := doRequest(t, mux, http.MethodPost, "/auth/login", `{"username":"alice","password":"hunter22"}`, nil)
	cookie := sessionCookieFrom(login)

	rec := doRequest(t, mux, http.MethodPut, "/auth/users/"+bob.ID+"/role", `{"role":"admin"}`, cookie)
	if rec.Code != http.StatusForbidden {
		t.Fatalf("status = %d, want 403 for a non-owner reassigning a role", rec.Code)
	}
}