package api

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

	"github.com/ponzischeme89/memby/server/internal/config"
	"github.com/ponzischeme89/memby/server/internal/emby"
)

// embyAccessLevel stands in for an Emby whose answer about a person's access level is
// under the test's control. userPolicy is the policy the authentication response carries
// ("" for a server that sends none, which is what sends the gate to ask again), and
// lookupPolicy is what a direct read of the account then answers ("" to fail that read).
func embyAccessLevel(t *testing.T, userPolicy, lookupPolicy string) *Server {
	t.Helper()
	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		switch {
		case r.URL.Path == "/Users/AuthenticateByName":
			policy := ""
			if userPolicy != "" {
				policy = `,"Policy":` + userPolicy
			}
			w.Header().Set("Content-Type", "application/json")
			_, _ = io.WriteString(w, `{
				"User":{"Id":"emby-user","Name":"Viewer"`+policy+`},
				"AccessToken":"temporary-emby-token",
				"ServerId":"emby-server"
			}`)
		case r.URL.Path == "/Users/emby-user":
			if lookupPolicy == "" {
				http.Error(w, "no", http.StatusInternalServerError)
				return
			}
			w.Header().Set("Content-Type", "application/json")
			_, _ = io.WriteString(w,
				`{"Id":"emby-user","Name":"Viewer","Policy":`+lookupPolicy+`}`)
		case r.URL.Path == "/Sessions/Logout":
			w.WriteHeader(http.StatusNoContent)
		case r.URL.Path == "/Devices":
			if r.Method == http.MethodGet {
				_, _ = io.WriteString(w, `{"Items":[]}`)
				return
			}
			w.WriteHeader(http.StatusNoContent)
		default:
			http.NotFound(w, r)
		}
	}))
	t.Cleanup(upstream.Close)

	return &Server{
		cfg: config.Config{
			AdminToken:          "secret",
			ReleasePublishToken: "release-secret",
			SyncUserID:          "service-user", SyncAPIKey: "service-token",
		},
		emby: emby.New(upstream.URL, upstream.URL, "MbyATV", "MbyGateway", 2*time.Second),
		log:  slog.New(slog.NewTextHandler(io.Discard, nil)),
	}
}

func signIn(s *Server, next string) *httptest.ResponseRecorder {
	form := url.Values{
		"username": {"Viewer"}, "password": {"correct horse"}, "next": {next},
	}
	req := httptest.NewRequest(http.MethodPost, "/install/login",
		strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	rec := httptest.NewRecorder()
	s.handleInstallLogin(rec, req)
	return rec
}

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

// The console administers the server, so knowing a household password is not the
// qualification for reaching it. Emby's own user policy is the authority on who may, and
// it is the one an operator already manages.
func TestAdminSignInRequiresAnEmbyAdministrator(t *testing.T) {
	s := embyAccessLevel(t, `{"IsAdministrator":false}`, "")

	rec := signIn(s, "/admin/")

	if rec.Code != http.StatusForbidden {
		t.Fatalf("non-administrator sign-in = %d, want 403", rec.Code)
	}
	if sessionCookie(rec) != nil {
		t.Fatal("a refused admin sign-in issued a session anyway")
	}
	// The wording must not separate "wrong password" from "right password, wrong person":
	// somebody who may not administer the server has no business learning either.
	if !strings.Contains(rec.Body.String(), "Sign-in failed.") {
		t.Fatalf("refusal discloses more than a failed sign-in: %s", rec.Body.String())
	}
}

// The installer is the other half of the same gate and is public by design: a viewer
// putting Memby on a new television signs in there and must still be able to.
func TestNonAdministratorMayStillUseTheInstaller(t *testing.T) {
	s := embyAccessLevel(t, `{"IsAdministrator":false}`, "")

	rec := signIn(s, "/install")

	if rec.Code != http.StatusSeeOther {
		t.Fatalf("installer sign-in = %d, want 303", rec.Code)
	}
	cookie := sessionCookie(rec)
	if cookie == nil {
		t.Fatal("installer sign-in issued no session")
	}
	req := httptest.NewRequest(http.MethodGet, "/install", nil)
	req.AddCookie(cookie)
	if !s.validInstallerSession(req) {
		t.Fatal("a viewer's installer session was not accepted by the installer")
	}
	if s.validAdminSession(req) {
		t.Fatal("a viewer's installer session was accepted as an admin session")
	}
}

func TestAdministratorSignInMintsAnAdminSession(t *testing.T) {
	s := embyAccessLevel(t, `{"IsAdministrator":true}`, "")

	rec := signIn(s, "/admin/overview")

	if rec.Code != http.StatusSeeOther || rec.Header().Get("Location") != "/admin/overview" {
		t.Fatalf("admin sign-in = %d %q", rec.Code, rec.Header().Get("Location"))
	}
	cookie := sessionCookie(rec)
	if cookie == nil {
		t.Fatal("admin sign-in issued no session")
	}
	if cookie.MaxAge != int(adminSessionTTL/time.Second) {
		t.Fatalf("admin cookie MaxAge = %d, want %d",
			cookie.MaxAge, int(adminSessionTTL/time.Second))
	}
	req := httptest.NewRequest(http.MethodGet, "/admin/api/status", nil)
	req.AddCookie(cookie)
	if !s.validAdminSession(req) {
		t.Fatal("an administrator's session was not accepted by the console")
	}
	_, username, ok := s.browserSession(req, adminSessionPurpose)
	if !ok || username != "Viewer" {
		t.Fatalf("admin session identity = %q, valid %t; want Viewer", username, ok)
	}
}

// An Emby that returns no policy at all is a question, not a refusal — reading its silence
// as "not an administrator" would lock an operator out of their own console.
func TestAdminSignInAsksEmbyWhenTheAuthResponseCarriesNoPolicy(t *testing.T) {
	s := embyAccessLevel(t, "", `{"IsAdministrator":true}`)

	rec := signIn(s, "/admin/")

	if rec.Code != http.StatusSeeOther {
		t.Fatalf("sign-in = %d, want the policy to be read directly and accepted", rec.Code)
	}
	cookie := sessionCookie(rec)
	if cookie == nil {
		t.Fatal("no session issued after the access level was read directly")
	}
	req := httptest.NewRequest(http.MethodGet, "/admin/api/status", nil)
	req.AddCookie(cookie)
	if !s.validAdminSession(req) {
		t.Fatal("the session issued was not an admin session")
	}
}

// The user switcher names whoever is signed in, so an admin session must carry the
// verified Emby account name. A fresh sign-in does; a session predating the identity in
// the cookie is still valid but anonymous, and the console handler prompts those to sign
// in again rather than falling back to "Administrator" for ever.
func TestAdminSessionCarriesTheVerifiedName(t *testing.T) {
	s := embyAccessLevel(t, `{"IsAdministrator":true}`, "")

	cookie := sessionCookie(signIn(s, "/admin/"))
	if cookie == nil {
		t.Fatal("admin sign-in issued no session")
	}
	named := httptest.NewRequest(http.MethodGet, "/admin/", nil)
	named.AddCookie(cookie)
	if !s.adminSessionNamed(named) {
		t.Fatal("a fresh admin session is missing the verified name")
	}

	anon, err := s.newBrowserSessionFor(adminSessionPurpose, adminSessionTTL, "")
	if err != nil {
		t.Fatalf("anonymous session: %v", err)
	}
	req := httptest.NewRequest(http.MethodGet, "/admin/", nil)
	req.AddCookie(&http.Cookie{Name: installerCookieName, Value: anon})
	if !s.validAdminSession(req) {
		t.Fatal("an anonymous admin session should still be valid")
	}
	if s.adminSessionNamed(req) {
		t.Fatal("an anonymous admin session should not report a name")
	}
}

// And an Emby that will not answer either way must not be guessed at in the permissive
// direction: no answer means no session.
func TestAdminSignInIsRefusedWhenTheAccessLevelCannotBeRead(t *testing.T) {
	s := embyAccessLevel(t, "", "")

	rec := signIn(s, "/admin/")

	if rec.Code != http.StatusBadGateway {
		t.Fatalf("unreadable access level = %d, want 502", rec.Code)
	}
	if sessionCookie(rec) != nil {
		t.Fatal("a session was issued without knowing the access level")
	}
}