package server

import (
	"io"
	"net/http"
	"net/http/cookiejar"
	"net/url"
	"regexp"
	"strings"
	"testing"

	"cc.tiredsysadmin.keeporg/internal/kdbx"
)

// browser is a cookie-keeping client, so the web tests behave like a real
// browser including the session cookie and the CSRF token in each form.
type browser struct {
	t    *testing.T
	h    *harness
	http *http.Client
}

func newBrowser(t *testing.T, h *harness) *browser {
	jar, err := cookiejar.New(nil)
	if err != nil {
		t.Fatal(err)
	}
	c := *h.http.Client()
	c.Jar = jar
	return &browser{t: t, h: h, http: &c}
}

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

func (b *browser) post(path string, form url.Values) (int, string) {
	b.t.Helper()
	resp, err := b.http.PostForm(b.h.http.URL+path, form)
	if err != nil {
		b.t.Fatal(err)
	}
	defer resp.Body.Close()
	body, _ := io.ReadAll(resp.Body)
	return resp.StatusCode, string(body)
}

func (b *browser) cookie() string {
	u, _ := url.Parse(b.h.http.URL)
	for _, c := range b.http.Jar.Cookies(u) {
		if c.Name == webCookie {
			return c.Value
		}
	}
	return ""
}

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

func (b *browser) csrf(page string) string {
	b.t.Helper()
	m := csrfPattern.FindStringSubmatch(page)
	if m == nil {
		b.t.Fatalf("no CSRF token in the page:\n%s", page)
	}
	return m[1]
}

// signIn takes the browser through the sign-in form.
func (b *browser) signIn() string {
	b.t.Helper()
	status, page := b.post("/web/signin", url.Values{
		"username": {"admin"}, "password": {adminPassword}})
	if status != http.StatusOK || !strings.Contains(page, "Your vaults") {
		b.t.Fatalf("sign in: %d\n%s", status, page)
	}
	return b.csrf(page)
}

func TestWebRootOffersSignIn(t *testing.T) {
	b := newBrowser(t, newHarness(t))
	status, page := b.get("/")
	if status != http.StatusOK || !strings.Contains(page, "Sign in") {
		t.Fatalf("root = %d\n%s", status, page)
	}
	if b.cookie() != "" {
		t.Fatal("a session cookie was set before signing in")
	}
}

func TestWebSignInRejectsWrongPassword(t *testing.T) {
	b := newBrowser(t, newHarness(t))
	status, page := b.post("/web/signin", url.Values{
		"username": {"admin"}, "password": {"nope"}})
	if status != http.StatusOK || !strings.Contains(page, "wrong password") {
		t.Fatalf("status %d\n%s", status, page)
	}
	if b.cookie() != "" {
		t.Fatal("a session cookie was set after a failed sign-in")
	}
}

func TestWebSessionCookieIsHardened(t *testing.T) {
	h := newHarness(t)
	b := newBrowser(t, h)
	resp, err := b.http.PostForm(h.http.URL+"/web/signin", url.Values{
		"username": {"admin"}, "password": {adminPassword}})
	if err != nil {
		t.Fatal(err)
	}
	defer resp.Body.Close()
	// The harness serves over http, so Secure is correctly off; the rest
	// must be set.
	var found bool
	for _, c := range resp.Request.Response.Cookies() {
		if c.Name != webCookie {
			continue
		}
		found = true
		if !c.HttpOnly || c.SameSite != http.SameSiteStrictMode || c.Path != "/" {
			t.Fatalf("cookie = %+v", c)
		}
	}
	if !found {
		t.Fatal("no session cookie was issued")
	}
}

// A server reached over https must mark its cookie Secure, which is also
// why the harness above is configured with an http external URL.
func TestWebCookieIsSecureBehindHTTPS(t *testing.T) {
	h := newHarness(t)
	h.srv.cfg.ExternalURL = "https://keeporg.example.com"
	resp, err := h.http.Client().PostForm(h.http.URL+"/web/signin", url.Values{
		"username": {"admin"}, "password": {adminPassword}})
	if err != nil {
		t.Fatal(err)
	}
	defer resp.Body.Close()
	for _, c := range resp.Request.Response.Cookies() {
		if c.Name == webCookie && !c.Secure {
			t.Fatal("the cookie is not marked Secure although the server is https")
		}
	}
}

func TestWebCreatesAVaultThatOpensWithItsPassword(t *testing.T) {
	h := newHarness(t)
	b := newBrowser(t, h)
	csrf := b.signIn()

	status, page := b.post("/web/vaults", url.Values{
		"csrf": {csrf}, "name": {"Web Vault"}, "group": {"everyone"},
		"strategy": {"merge"},
		"password": {vaultPassword}, "password2": {vaultPassword},
	})
	if status != http.StatusOK {
		t.Fatalf("create = %d\n%s", status, page)
	}
	if !strings.Contains(page, "Created Web Vault") {
		t.Fatalf("no confirmation:\n%s", page)
	}
	if !strings.Contains(page, "Web Vault.kdbx") {
		t.Fatal("the new vault is not listed")
	}

	// The vault the form created is a real KDBX file with that password.
	tok, _, _ := h.login("admin", adminPassword, "")
	var id string
	_, list := h.call("GET", "/api/v1/databases", tok, nil)
	for _, row := range list["databases"].([]any) {
		m := row.(map[string]any)
		if m["name"] == "Web Vault" {
			id = m["id"].(string)
			if m["merge_strategy"] != "merge" {
				t.Fatalf("strategy = %v", m["merge_strategy"])
			}
		}
	}
	if id == "" {
		t.Fatal("the vault is missing from the API listing")
	}
	db, err := kdbx.Open(h.pull(tok, id), vaultPassword)
	if err != nil {
		t.Fatalf("the vault created from the web does not open: %v", err)
	}
	if db.Name() != "Web Vault" {
		t.Fatalf("vault name = %q", db.Name())
	}
	// The API must never hand the wrapped key back out.
	if strings.Contains(strings.ToLower(string(h.stateBytes())), vaultPassword) {
		t.Fatal("the vault password is in the state file in the clear")
	}
	for _, row := range list["databases"].([]any) {
		if _, leaked := row.(map[string]any)["wrapped_key"]; leaked {
			t.Fatal("the API returned the wrapped vault key")
		}
	}
}

func TestWebRefusesAFormWithoutItsToken(t *testing.T) {
	b := newBrowser(t, newHarness(t))
	b.signIn()
	status, _ := b.post("/web/vaults", url.Values{
		"name": {"No Token"}, "group": {"everyone"},
		"password": {vaultPassword}, "password2": {vaultPassword},
	})
	if status != http.StatusForbidden {
		t.Fatalf("a form without a CSRF token returned %d", status)
	}
	status, _ = b.post("/web/vaults", url.Values{
		"csrf": {"not-the-token"}, "name": {"Wrong Token"}, "group": {"everyone"},
		"password": {vaultPassword}, "password2": {vaultPassword},
	})
	if status != http.StatusForbidden {
		t.Fatalf("a form with the wrong CSRF token returned %d", status)
	}
}

func TestWebRejectsMismatchedAndShortVaultPasswords(t *testing.T) {
	b := newBrowser(t, newHarness(t))
	csrf := b.signIn()
	_, page := b.post("/web/vaults", url.Values{
		"csrf": {csrf}, "name": {"V"}, "group": {"everyone"},
		"password": {vaultPassword}, "password2": {"something-else"},
	})
	if !strings.Contains(page, "do not match") {
		t.Fatalf("mismatch not reported:\n%s", page)
	}
	_, page = b.post("/web/vaults", url.Values{
		"csrf": {csrf}, "name": {"V"}, "group": {"everyone"},
		"password": {"short"}, "password2": {"short"},
	})
	if !strings.Contains(page, "at least 12") {
		t.Fatalf("a short vault password was not reported:\n%s", page)
	}
}

func TestWebOnlyOffersGroupsYouAdminister(t *testing.T) {
	h := newHarness(t)
	admin, _, _ := h.login("admin", adminPassword, "")
	// A member who administers nothing sees no create form at all.
	status, inv := h.call("POST", "/api/v1/invites", admin,
		map[string]any{"group_id": "everyone", "role": "member", "ttl_hours": 1, "max_uses": 1})
	if status != http.StatusCreated {
		t.Fatalf("invite: %d %v", status, inv)
	}
	form := url.Values{"username": {"member"}, "password": {"member-password"},
		"password2": {"member-password"}}
	resp, err := h.http.Client().PostForm(h.http.URL+"/invite/"+inv["token"].(string), form)
	if err != nil {
		t.Fatal(err)
	}
	resp.Body.Close()

	b := newBrowser(t, h)
	status, page := b.post("/web/signin", url.Values{
		"username": {"member"}, "password": {"member-password"}})
	if status != http.StatusOK {
		t.Fatalf("member sign in: %d", status)
	}
	if strings.Contains(page, "Create vault") {
		t.Fatal("a member who administers no group was offered the create form")
	}
	if !strings.Contains(page, "do not administer a group") {
		t.Fatalf("no explanation shown:\n%s", page)
	}
}

func TestWebSignOutEndsTheSession(t *testing.T) {
	b := newBrowser(t, newHarness(t))
	csrf := b.signIn()
	if b.cookie() == "" {
		t.Fatal("no cookie after signing in")
	}
	if status, _ := b.post("/web/signout", url.Values{"csrf": {csrf}}); status != http.StatusOK {
		t.Fatalf("sign out = %d", status)
	}
	status, page := b.get("/web/vaults")
	if status != http.StatusOK || !strings.Contains(page, "Sign in") {
		t.Fatalf("after sign out: %d\n%s", status, page)
	}
}