package web

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"net/http/cookiejar"
	"net/http/httptest"
	"net/url"
	"os"
	"path/filepath"
	"regexp"
	"strings"
	"sync"
	"testing"
	"time"

	"github.com/coder/websocket"
	embeddedpostgres "github.com/fergusstrange/embedded-postgres"
	"github.com/jackc/pgx/v5"

	"git.t5de.dev/t5de/t5de-hub/internal/imvu"
	"git.t5de.dev/t5de/t5de-hub/internal/realtime"
	"git.t5de.dev/t5de/t5de-hub/internal/store"
	"git.t5de.dev/t5de/t5de-hub/internal/token"
)

// The tests run the whole hub against a real Postgres (embedded, downloaded once) and a fake IMVU API.

var dbURL string

func TestMain(m *testing.M) {
	// CI gives a Postgres of its own (embedded Postgres won't run as root, as CI jobs do).
	if url := os.Getenv("T5DE_TEST_DB"); url != "" {
		dbURL = url
		os.Exit(m.Run())
	}
	dir, _ := os.MkdirTemp("", "t5de-hub-test")
	cache := os.Getenv("T5DE_PG_CACHE")
	if cache == "" {
		home, _ := os.UserCacheDir()
		cache = filepath.Join(home, "t5de-hub-test-postgres")
	}
	const port = 54339
	pg := embeddedpostgres.NewDatabase(embeddedpostgres.DefaultConfig().Port(port).
		DataPath(filepath.Join(dir, "data")).RuntimePath(filepath.Join(dir, "rt")).CachePath(cache).
		Logger(io.Discard).StartTimeout(2 * time.Minute))
	if err := pg.Start(); err != nil {
		fmt.Println("starting Postgres:", err)
		os.Exit(1)
	}
	dbURL = fmt.Sprintf("postgres://postgres:postgres@localhost:%d/postgres?sslmode=disable", port)
	code := m.Run()
	pg.Stop()
	os.RemoveAll(dir)
	os.Exit(code)
}

// fakeIMVU is IMVU's public user API, with accounts the test controls.
type fakeIMVU struct {
	mu    sync.Mutex
	users map[int64]*imvu.User
}

func (f *fakeIMVU) set(u imvu.User) {
	f.mu.Lock()
	defer f.mu.Unlock()
	f.users[u.ID] = &u
}

func (f *fakeIMVU) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	f.mu.Lock()
	defer f.mu.Unlock()
	var found *imvu.User
	for _, u := range f.users {
		if r.URL.Path == fmt.Sprintf("/user/user-%d", u.ID) || r.URL.Path == "/user" && strings.EqualFold(r.URL.Query().Get("username"), u.Username) {
			found = u
		}
	}
	den := map[string]any{}
	if found != nil {
		den[fmt.Sprintf("https://api.imvu.com/user/user-%d", found.ID)] = map[string]any{"data": map[string]any{
			"legacy_cid": found.ID, "username": found.Username, "tagline": found.Tagline,
			"is_ageverified": found.AgeVerified, "is_ap": found.AccessPass}}
	}
	json.NewEncoder(w).Encode(map[string]any{"status": "success", "id": r.URL.String(), "denormalized": den})
}

type hub struct {
	t      *testing.T
	server *Server
	http   *httptest.Server
	imvu   *fakeIMVU
}

// newHub runs a hub on a fresh database.
func newHub(t *testing.T) *hub {
	ctx := context.Background()
	admin, err := pgx.Connect(ctx, dbURL)
	if err != nil {
		t.Fatal(err)
	}
	db := "t" + strings.ToLower(token.Random(6))
	db = regexp.MustCompile(`[^a-z0-9]`).ReplaceAllString(db, "x")
	if _, err := admin.Exec(ctx, "create database "+db); err != nil {
		t.Fatal(err)
	}
	admin.Close(ctx)
	u, _ := url.Parse(dbURL)
	u.Path = "/" + db
	st, err := store.Open(ctx, u.String())
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(st.Close)
	fake := &fakeIMVU{users: map[int64]*imvu.User{}}
	imvuServer := httptest.NewServer(fake)
	t.Cleanup(imvuServer.Close)
	keys, err := token.LoadOrCreate(filepath.Join(t.TempDir(), "key"), "http://hub.test")
	if err != nil {
		t.Fatal(err)
	}
	s := &Server{Store: st, IMVU: &imvu.Client{Base: imvuServer.URL, HTTP: imvuServer.Client()}, Keys: keys,
		Log: log.New(io.Discard, "", 0)}
	s.Realtime = realtime.New(Owners{Store: st}, s.Log)
	handler, err := s.Handler()
	if err != nil {
		t.Fatal(err)
	}
	srv := httptest.NewServer(handler)
	t.Cleanup(srv.Close)
	s.PublicURL = srv.URL
	return &hub{t: t, server: s, http: srv, imvu: fake}
}

// browser is a person on the website.
type browser struct {
	h      *hub
	client *http.Client
	csrf   string
}

func (h *hub) browser() *browser {
	jar, _ := cookiejar.New(nil)
	return &browser{h: h, client: &http.Client{Jar: jar}}
}

var csrfPattern = regexp.MustCompile(`name="csrf" value="([^"]+)"`)

func (b *browser) get(path string) (int, string) {
	b.h.t.Helper()
	resp, err := b.client.Get(b.h.http.URL + path)
	if err != nil {
		b.h.t.Fatal(err)
	}
	defer resp.Body.Close()
	body, _ := io.ReadAll(resp.Body)
	if m := csrfPattern.FindSubmatch(body); m != nil {
		b.csrf = string(m[1])
	}
	return resp.StatusCode, string(body)
}

func (b *browser) post(path string, form url.Values) (int, string) {
	b.h.t.Helper()
	if form == nil {
		form = url.Values{}
	}
	if b.csrf != "" && form.Get("csrf") == "" {
		form.Set("csrf", b.csrf)
	}
	req, _ := http.NewRequest("POST", b.h.http.URL+path, strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	req.Header.Set("Sec-Fetch-Site", "same-origin")
	resp, err := b.client.Do(req)
	if err != nil {
		b.h.t.Fatal(err)
	}
	defer resp.Body.Close()
	body, _ := io.ReadAll(resp.Body)
	if m := csrfPattern.FindSubmatch(body); m != nil {
		b.csrf = string(m[1])
	}
	return resp.StatusCode, string(body)
}

func (b *browser) signup(username string) {
	b.h.t.Helper()
	status, body := b.post("/signup", url.Values{"username": {username}, "password": {"a long password"}, "password2": {"a long password"}})
	if status != 200 || !strings.Contains(body, "Signed in as "+username) {
		b.h.t.Fatalf("signup %s: %d %s", username, status, body)
	}
}

var codePattern = regexp.MustCompile(`t5de-[A-Z0-9]{4}-[A-Z0-9]{4}`)

// link links an IMVU account through the website, putting the code in its fake tagline.
func (b *browser) link(u imvu.User) string {
	b.h.t.Helper()
	b.h.imvu.set(u)
	_, body := b.post("/account/link", url.Values{"username": {u.Username}})
	code := codePattern.FindString(body)
	if code == "" {
		b.h.t.Fatalf("no code: %s", body)
	}
	u.Tagline = "hello " + strings.ToLower(code)
	b.h.imvu.set(u)
	_, body = b.post(fmt.Sprintf("/account/link/%d/check", u.ID), nil)
	return body
}

func TestSignupSigninAndCSRF(t *testing.T) {
	h := newHub(t)
	a := h.browser()
	a.signup("alice")
	// The first account is the admin.
	if _, body := a.get("/account"); !strings.Contains(body, ">admin<") {
		t.Fatal("first account isn't admin")
	}
	b := h.browser()
	b.signup("bob")
	if status, _ := b.get("/console"); status != http.StatusForbidden {
		t.Fatalf("bob sees the console: %d", status)
	}
	// Taken usernames (any case), bad passwords.
	c := h.browser()
	if status, body := c.post("/signup", url.Values{"username": {"ALICE"}, "password": {"a long password"}, "password2": {"a long password"}}); status != 400 || !strings.Contains(body, "taken") {
		t.Fatalf("%d %s", status, body)
	}
	if status, _ := c.post("/signup", url.Values{"username": {"carol"}, "password": {"short"}, "password2": {"short"}}); status != 400 {
		t.Fatalf("short password: %d", status)
	}
	// Signing in, with the right and wrong password.
	if status, body := c.post("/signin", url.Values{"username": {"bob"}, "password": {"wrong"}}); status != 400 || !strings.Contains(body, "Wrong") {
		t.Fatalf("%d %s", status, body)
	}
	if _, body := c.post("/signin", url.Values{"username": {"Bob"}, "password": {"a long password"}}); !strings.Contains(body, "Signed in as bob") {
		t.Fatal("sign-in failed")
	}
	// A form without the session's CSRF token is refused.
	if status, _ := c.post("/account/link", url.Values{"username": {"x"}, "csrf": {"forged"}}); status != http.StatusForbidden {
		t.Fatalf("forged CSRF: %d", status)
	}
}

func TestLinkingByTagline(t *testing.T) {
	h := newHub(t)
	a := h.browser()
	a.signup("alice")
	// Without the code in the tagline, nothing is linked.
	h.imvu.set(imvu.User{ID: 42, Username: "AliceAv"})
	a.post("/account/link", url.Values{"username": {"aliceav"}})
	if _, body := a.post("/account/link/42/check", nil); !strings.Contains(body, "doesn&#39;t have the code") {
		t.Fatalf("linked without the code: %s", body)
	}
	body := a.link(imvu.User{ID: 42, Username: "AliceAv", AgeVerified: true})
	if !strings.Contains(body, "Linked AliceAv") || !strings.Contains(body, "age verified") {
		t.Fatalf("%s", body)
	}
	if _, body := a.post("/account/link", url.Values{"username": {"nobody"}}); !strings.Contains(body, "IMVU has no account") {
		t.Fatalf("%s", body)
	}

	// Bob proves the same account is his (it was sold, say): it moves to him, with a new pairwise ID.
	before, _ := h.server.Store.LinkByIMVUID(context.Background(), 42)
	b := h.browser()
	b.signup("bob")
	b.link(imvu.User{ID: 42, Username: "AliceAv"})
	after, _ := h.server.Store.LinkByIMVUID(context.Background(), 42)
	if after.PersonID == before.PersonID || after.PairwiseID == before.PairwiseID {
		t.Fatalf("not moved: %+v -> %+v", before, after)
	}
	if _, body := a.get("/account"); strings.Contains(body, "AliceAv") {
		t.Fatal("alice still has the account")
	}

	// The link cap: bob may link only one more after a moderator lowers it.
	bob, _ := h.server.Store.PersonByUsername(context.Background(), "bob")
	a.get("/console/people/" + fmt.Sprint(bob.ID))
	if status, _ := a.post(fmt.Sprintf("/console/people/%d/cap", bob.ID), url.Values{"cap": {"1"}}); status != 200 {
		t.Fatalf("setting the cap: %d", status)
	}
	if body := b.link(imvu.User{ID: 43, Username: "BobAlt"}); !strings.Contains(body, "link up to 1") {
		t.Fatalf("over the cap: %s", body)
	}
}

func TestProxySignInAndPresence(t *testing.T) {
	h := newHub(t)
	a := h.browser()
	a.signup("alice")
	a.link(imvu.User{ID: 42, Username: "AliceAv"})

	// The proxy asks for a code, alice enters it, the proxy gets tokens.
	resp, err := http.Post(h.http.URL+"/api/v1/device/code", "", nil)
	if err != nil {
		t.Fatal(err)
	}
	var device struct{ DeviceCode, UserCode string }
	var raw map[string]any
	json.NewDecoder(resp.Body).Decode(&raw)
	resp.Body.Close()
	device.DeviceCode, device.UserCode = raw["device_code"].(string), raw["user_code"].(string)
	poll := func() map[string]any {
		resp, err := http.PostForm(h.http.URL+"/api/v1/device/token", url.Values{"device_code": {device.DeviceCode}})
		if err != nil {
			t.Fatal(err)
		}
		defer resp.Body.Close()
		var out map[string]any
		json.NewDecoder(resp.Body).Decode(&out)
		return out
	}
	if out := poll(); out["error"] != "authorization_pending" {
		t.Fatalf("%v", out)
	}
	a.get("/device")
	if _, body := a.post("/device", url.Values{"code": {strings.ToLower(strings.ReplaceAll(device.UserCode, "-", ""))}}); !strings.Contains(body, "T5DE is signed in") {
		t.Fatalf("%s", body)
	}
	tokens := poll()
	access, _ := tokens["access_token"].(string)
	if access == "" || tokens["refresh_token"] == "" {
		t.Fatalf("%v", tokens)
	}
	if out := poll(); out["error"] != "expired_token" {
		t.Fatalf("a code worked twice: %v", out)
	}

	// The refresh token rotates: the old one stops working.
	refresh := func(tok string) map[string]any {
		resp, err := http.PostForm(h.http.URL+"/api/v1/token/refresh", url.Values{"refresh_token": {tok}})
		if err != nil {
			t.Fatal(err)
		}
		defer resp.Body.Close()
		var out map[string]any
		json.NewDecoder(resp.Body).Decode(&out)
		return out
	}
	next := refresh(tokens["refresh_token"].(string))
	if next["access_token"] == nil || refresh(tokens["refresh_token"].(string))["error"] != "invalid_grant" {
		t.Fatalf("rotation: %v", next)
	}

	// The live connection: an account that isn't alice's is refused; hers shows as online (to moderators, and to
	// everyone once she opts in) with her community outfit.
	ctx := context.Background()
	ws, _, err := websocket.Dial(ctx, strings.Replace(h.http.URL, "http", "ws", 1)+"/api/v1/realtime",
		&websocket.DialOptions{HTTPHeader: http.Header{"Authorization": {"Bearer " + access}}})
	if err != nil {
		t.Fatal(err)
	}
	defer ws.CloseNow()
	read := func() map[string]any {
		_, data, err := ws.Read(ctx)
		if err != nil {
			t.Fatal(err)
		}
		var m map[string]any
		json.Unmarshal(data, &m)
		return m
	}
	if m := read(); m["type"] != "welcome" {
		t.Fatalf("%v", m)
	}
	ws.Write(ctx, websocket.MessageText, []byte(`{"type":"session","imvu_id":99}`))
	if m := read(); m["message"] != "not_linked" {
		t.Fatalf("%v", m)
	}
	ws.Write(ctx, websocket.MessageText, []byte(`{"type":"session","imvu_id":42}`))
	ws.Write(ctx, websocket.MessageText, []byte(`{"type":"outfit","items":[{"id":"blue-coat","name":"Blue Coat"}]}`))
	waitFor(t, func() bool { o := h.server.Realtime.Online(); return len(o) == 1 && len(o[0].Outfit) == 1 })

	visitor := h.browser()
	if _, body := visitor.get("/online"); strings.Contains(body, "AliceAv") {
		t.Fatal("online shown without opting in")
	}
	if _, body := a.get("/console"); !strings.Contains(body, "AliceAv") || !strings.Contains(body, "Blue Coat") {
		t.Fatal("the console doesn't show her")
	}
	a.post("/account/links/42/settings", url.Values{"presence": {"on"}, "badge": {"on"}})
	if _, body := visitor.get("/online"); !strings.Contains(body, "AliceAv") || !strings.Contains(body, "Blue Coat") {
		t.Fatal("online not shown after opting in")
	}

	// A ban ends the connection and the sign-in.
	bob := h.browser()
	bob.signup("bob")
	alice, _ := h.server.Store.PersonByUsername(ctx, "alice")
	h.server.Store.SetRole(ctx, alice.ID, "user")
	bobP, _ := h.server.Store.PersonByUsername(ctx, "bob")
	h.server.Store.SetRole(ctx, bobP.ID, "admin")
	bob.get("/account")
	if status, _ := bob.post(fmt.Sprintf("/console/people/%d/ban", alice.ID), url.Values{"reason": {"testing"}}); status != 200 {
		t.Fatalf("ban: %d", status)
	}
	waitFor(t, func() bool { return len(h.server.Realtime.Online()) == 0 })
	if out := refresh(next["refresh_token"].(string)); out["access_token"] != nil {
		t.Fatal("a banned person's proxy can still sign in")
	}
}

func waitFor(t *testing.T, ok func() bool) {
	t.Helper()
	for i := 0; i < 200; i++ {
		if ok() {
			return
		}
		time.Sleep(10 * time.Millisecond)
	}
	t.Fatal("timed out")
}