// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
// SPDX-License-Identifier: PolyForm-Noncommercial-1.0.0

package session

import (
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"testing/synctest"
	"time"
)

func TestSetSaveLoadRoundTrip(t *testing.T) {
	store := New("secret-key", time.Hour, false)
	rec := httptest.NewRecorder()
	sess := &Session{data: map[string]string{}, store: store}
	sess.Set("user", "petr")
	store.Save(rec, sess)

	cookies := rec.Result().Cookies()
	if len(cookies) != 1 {
		t.Fatalf("cookies = %v", cookies)
	}
	if cookies[0].Name != CookieName || cookies[0].HttpOnly != true ||
		cookies[0].SameSite != http.SameSiteStrictMode {
		t.Fatalf("cookie attrs = %+v", cookies[0])
	}

	req := httptest.NewRequest(http.MethodGet, "/admin/", nil)
	req.AddCookie(cookies[0])
	loaded := store.Load(req)
	if loaded.Get("user") != "petr" {
		t.Fatalf("loaded = %v", loaded.data)
	}
}

func TestTamperedCookieRejected(t *testing.T) {
	store := New("secret-key", time.Hour, false)
	rec := httptest.NewRecorder()
	sess := &Session{data: map[string]string{}, store: store}
	sess.Set("user", "petr")
	store.Save(rec, sess)
	value := rec.Result().Cookies()[0].Value

	tampered := value[:len(value)-2] + "xx"
	req := httptest.NewRequest(http.MethodGet, "/", nil)
	req.AddCookie(&http.Cookie{Name: CookieName, Value: tampered})
	if got := store.Load(req).Get("user"); got != "" {
		t.Fatalf("tampered cookie accepted: %q", got)
	}
}

func TestForeignSignatureRejected(t *testing.T) {
	other := New("other-key", time.Hour, false)
	store := New("secret-key", time.Hour, false)
	rec := httptest.NewRecorder()
	sess := &Session{data: map[string]string{}, store: other}
	sess.Set("user", "petr")
	other.Save(rec, sess)

	req := httptest.NewRequest(http.MethodGet, "/", nil)
	req.AddCookie(rec.Result().Cookies()[0])
	if got := store.Load(req).Get("user"); got != "" {
		t.Fatalf("foreign cookie accepted: %q", got)
	}
}

// synctest advances the clock past the one-nanosecond lifetime, so the
// test needs no sleep and cannot be flaky on a loaded machine.
func TestExpiredSessionRejected(t *testing.T) {
	synctest.Test(t, func(t *testing.T) {
		store := New("secret-key", time.Nanosecond, false)
		rec := httptest.NewRecorder()
		sess := &Session{data: map[string]string{}, store: store}
		sess.Set("user", "petr")
		store.Save(rec, sess)
		time.Sleep(time.Second)

		req := httptest.NewRequest(http.MethodGet, "/", nil)
		req.AddCookie(rec.Result().Cookies()[0])
		if got := store.Load(req).Get("user"); got != "" {
			t.Fatalf("expired cookie accepted: %q", got)
		}
	})
}

func TestMissingCookieYieldsEmptySession(t *testing.T) {
	store := New("k", time.Hour, false)
	req := httptest.NewRequest(http.MethodGet, "/", nil)
	sess := store.Load(req)
	if sess.Get("user") != "" || sess.dirty {
		t.Fatalf("session = %v dirty=%v", sess.data, sess.dirty)
	}
}

func TestCleanSessionNotPersisted(t *testing.T) {
	store := New("k", time.Hour, false)
	rec := httptest.NewRecorder()
	store.Save(rec, &Session{data: map[string]string{}, store: store})
	if len(rec.Result().Cookies()) != 0 {
		t.Fatal("cookie set for clean session")
	}
}

func TestSetSameValueNotDirty(t *testing.T) {
	store := New("k", time.Hour, false)
	sess := &Session{data: map[string]string{"a": "1"}, store: store}
	sess.Set("a", "1")
	if sess.dirty {
		t.Fatal("dirty for unchanged value")
	}
}

func TestDeleteAndClear(t *testing.T) {
	store := New("k", time.Hour, false)
	sess := &Session{data: map[string]string{"a": "1", "b": "2"}, store: store}
	sess.Delete("a")
	if sess.Get("a") != "" || !sess.dirty {
		t.Fatal("delete failed")
	}
	sess.dirty = false
	sess.Delete("missing")
	if sess.dirty {
		t.Fatal("deleting missing key dirtied the session")
	}
	sess.Clear()
	if sess.Get("b") != "" || !sess.dirty {
		t.Fatal("clear failed")
	}
	sess.dirty = false
	sess.Clear()
	if sess.dirty {
		t.Fatal("clearing empty session dirtied it")
	}
}

func TestMiddlewareRoundTrip(t *testing.T) {
	store := New("k", time.Hour, false)
	handler := store.Middleware(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		sess := FromContext(r.Context())
		sess.Set("user", "petr")
		w.WriteHeader(http.StatusNoContent)
	}))

	rec := httptest.NewRecorder()
	handler.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/", nil))
	cookies := rec.Result().Cookies()
	if len(cookies) != 1 {
		t.Fatalf("cookies = %v", cookies)
	}

	handler2 := store.Middleware(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if got := FromContext(r.Context()).Get("user"); got != "petr" {
			t.Errorf("user = %q", got)
		}
	}))
	rec2 := httptest.NewRecorder()
	req2 := httptest.NewRequest(http.MethodGet, "/", nil)
	req2.AddCookie(cookies[0])
	handler2.ServeHTTP(rec2, req2)
}

func TestFromContextWithoutMiddleware(t *testing.T) {
	req := httptest.NewRequest(http.MethodGet, "/", nil)
	sess := FromContext(req.Context())
	sess.Set("x", "y")
	if sess.Get("x") != "y" {
		t.Fatal("detached session broken")
	}
}

func TestGarbageCookieIgnored(t *testing.T) {
	store := New("k", time.Hour, false)
	for _, value := range []string{"nodot", ".", "a.b", strings.Repeat("!", 50)} {
		req := httptest.NewRequest(http.MethodGet, "/", nil)
		req.AddCookie(&http.Cookie{Name: CookieName, Value: value})
		store.Load(req) // must not panic
	}
}