// Copyright (c) 2026 Zeni Kim <zenik@smarteching.com>
// Use of this source code is governed by MIT-style
// license that can be found in the LICENSE file.

package core

import (
	"encoding/hex"
	"net/http"
	"net/http/httptest"
	"os"
	"strings"
	"testing"
)

// testCookieSecret is a 32 byte (AES-256) key expressed as a hex string, suitable
// for the COOKIE_SECRET env var used by SetCookie/ClearCookie.
const testCookieSecret = "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"

// enableTemplateCookieEnv enables the template engine (required for cookie handling)
// and sets a deterministic cookie secret, restoring both env vars on cleanup.
func enableTemplateCookieEnv(t *testing.T) {
	t.Helper()
	prevTemplate := os.Getenv("TEMPLATE_ENABLE")
	prevSecret := os.Getenv("COOKIE_SECRET")
	prevSecure := os.Getenv("COOKIE_SECURE")
	os.Setenv("TEMPLATE_ENABLE", "true")
	os.Setenv("COOKIE_SECRET", testCookieSecret)
	os.Setenv("COOKIE_SECURE", "false")
	t.Cleanup(func() {
		os.Setenv("TEMPLATE_ENABLE", prevTemplate)
		os.Setenv("COOKIE_SECRET", prevSecret)
		os.Setenv("COOKIE_SECURE", prevSecure)
	})
}

func decodeSecret(t *testing.T) []byte {
	t.Helper()
	key, err := hex.DecodeString(testCookieSecret)
	if err != nil {
		t.Fatalf("failed decoding test cookie secret: %v", err)
	}
	return key
}

func TestCookieWrite(t *testing.T) {
	w := httptest.NewRecorder()
	cookie := http.Cookie{Name: "goffee", Value: "hello", Path: "/"}
	if err := CookieWrite(w, cookie); err != nil {
		t.Fatalf("failed testing cookie write: %v", err)
	}
	rsp := w.Result()
	cookies := rsp.Cookies()
	if len(cookies) != 1 {
		t.Fatalf("expected 1 cookie, got %d", len(cookies))
	}
	if cookies[0].Name != "goffee" {
		t.Errorf("expected cookie name 'goffee', got %q", cookies[0].Name)
	}
}

func TestCookieWriteTooLong(t *testing.T) {
	w := httptest.NewRecorder()
	// A value large enough that the base64-encoded cookie string exceeds 4096 bytes.
	cookie := http.Cookie{Name: "goffee", Value: strings.Repeat("a", 5000), Path: "/"}
	err := CookieWrite(w, cookie)
	if err == nil {
		t.Errorf("expected ErrValueTooLong, got nil")
	}
}

func TestCookieRead(t *testing.T) {
	// Build a request carrying a base64-encoded cookie value.
	w := httptest.NewRecorder()
	cookie := http.Cookie{Name: "goffee", Value: "hello-world", Path: "/"}
	if err := CookieWrite(w, cookie); err != nil {
		t.Fatalf("failed writing cookie: %v", err)
	}
	r := httptest.NewRequest(GET, LOCALHOST, nil)
	for _, c := range w.Result().Cookies() {
		r.AddCookie(c)
	}
	val, err := CookieRead(r, "goffee")
	if err != nil {
		t.Fatalf("failed testing cookie read: %v", err)
	}
	if val != "hello-world" {
		t.Errorf("expected 'hello-world', got %q", val)
	}
}

func TestCookieReadMissing(t *testing.T) {
	r := httptest.NewRequest(GET, LOCALHOST, nil)
	_, err := CookieRead(r, "goffee")
	if err == nil {
		t.Errorf("expected error reading missing cookie")
	}
}

func TestCookieReadInvalidBase64(t *testing.T) {
	r := httptest.NewRequest(GET, LOCALHOST, nil)
	r.AddCookie(&http.Cookie{Name: "goffee", Value: "!!!not-base64!!!"})
	_, err := CookieRead(r, "goffee")
	if err == nil {
		t.Errorf("expected error reading invalid base64 cookie")
	}
}

func TestCookieWriteReadEncrypted(t *testing.T) {
	key := decodeSecret(t)
	w := httptest.NewRecorder()
	cookie := http.Cookie{Name: "goffee", Value: "secret-value", Path: "/"}
	if err := CookieWriteEncrypted(w, cookie, key); err != nil {
		t.Fatalf("failed writing encrypted cookie: %v", err)
	}

	r := httptest.NewRequest(GET, LOCALHOST, nil)
	for _, c := range w.Result().Cookies() {
		r.AddCookie(c)
	}
	val, err := CookieReadEncrypted(r, "goffee", key)
	if err != nil {
		t.Fatalf("failed reading encrypted cookie: %v", err)
	}
	if val != "secret-value" {
		t.Errorf("expected 'secret-value', got %q", val)
	}
}

func TestCookieReadEncryptedWrongKey(t *testing.T) {
	key := decodeSecret(t)
	w := httptest.NewRecorder()
	cookie := http.Cookie{Name: "goffee", Value: "secret-value", Path: "/"}
	if err := CookieWriteEncrypted(w, cookie, key); err != nil {
		t.Fatalf("failed writing encrypted cookie: %v", err)
	}

	// A different but valid AES key must fail decryption.
	wrongKey, _ := hex.DecodeString("ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff")
	r := httptest.NewRequest(GET, LOCALHOST, nil)
	for _, c := range w.Result().Cookies() {
		r.AddCookie(c)
	}
	if _, err := CookieReadEncrypted(r, "goffee", wrongKey); err == nil {
		t.Errorf("expected error decrypting with wrong key")
	}
}

func TestCookieReadEncryptedWrongName(t *testing.T) {
	key := decodeSecret(t)
	w := httptest.NewRecorder()
	cookie := http.Cookie{Name: "goffee", Value: "secret-value", Path: "/"}
	if err := CookieWriteEncrypted(w, cookie, key); err != nil {
		t.Fatalf("failed writing encrypted cookie: %v", err)
	}
	r := httptest.NewRequest(GET, LOCALHOST, nil)
	for _, c := range w.Result().Cookies() {
		r.AddCookie(c)
	}
	// Reading with a different name must fail the authenticated name check.
	if _, err := CookieReadEncrypted(r, "other", key); err == nil {
		t.Errorf("expected error decrypting with wrong cookie name")
	}
}

func TestSetCookie(t *testing.T) {
	enableTemplateCookieEnv(t)
	w := httptest.NewRecorder()
	if err := SetCookie(w, "user@example.com", "token-123"); err != nil {
		t.Fatalf("failed testing set cookie: %v", err)
	}
	cookies := w.Result().Cookies()
	if len(cookies) != 1 {
		t.Fatalf("expected 1 cookie, got %d", len(cookies))
	}
	if cookies[0].Name != "goffee" {
		t.Errorf("expected cookie name 'goffee', got %q", cookies[0].Name)
	}
	if !cookies[0].HttpOnly {
		t.Errorf("expected cookie to be HttpOnly")
	}
	if cookies[0].MaxAge <= 0 {
		t.Errorf("expected a positive MaxAge, got %d", cookies[0].MaxAge)
	}
}

func TestSetCookieUsesJWT_Lifetime(t *testing.T) {
	enableTemplateCookieEnv(t)
	prev := os.Getenv("JWT_LIFESPAN_MINUTES")
	os.Setenv("JWT_LIFESPAN_MINUTES", "5")
	t.Cleanup(func() { os.Setenv("JWT_LIFESPAN_MINUTES", prev) })

	w := httptest.NewRecorder()
	if err := SetCookie(w, "user@example.com", "token-123"); err != nil {
		t.Fatalf("failed testing set cookie: %v", err)
	}
	cookies := w.Result().Cookies()
	if cookies[0].MaxAge != 5*60 {
		t.Errorf("expected MaxAge of %d, got %d", 5*60, cookies[0].MaxAge)
	}
}

func TestSetCookieWithMaxAge(t *testing.T) {
	enableTemplateCookieEnv(t)
	w := httptest.NewRecorder()
	if err := SetCookieWithMaxAge(w, "user@example.com", "token-abc", 120); err != nil {
		t.Fatalf("failed testing set cookie with max age: %v", err)
	}
	cookies := w.Result().Cookies()
	if cookies[0].MaxAge != 120 {
		t.Errorf("expected MaxAge of 120, got %d", cookies[0].MaxAge)
	}
}

func TestSetCookieTemplatesDisabledPanics(t *testing.T) {
	prev := os.Getenv("TEMPLATE_ENABLE")
	os.Setenv("TEMPLATE_ENABLE", "false")
	t.Cleanup(func() { os.Setenv("TEMPLATE_ENABLE", prev) })

	defer func() {
		if r := recover(); r == nil {
			t.Errorf("expected panic when templates are disabled")
		}
	}()
	w := httptest.NewRecorder()
	_ = SetCookieWithMaxAge(w, "user@example.com", "token", 60)
}

func TestClearCookie(t *testing.T) {
	prevSecure := os.Getenv("COOKIE_SECURE")
	os.Setenv("COOKIE_SECURE", "false")
	t.Cleanup(func() { os.Setenv("COOKIE_SECURE", prevSecure) })

	w := httptest.NewRecorder()
	if err := ClearCookie(w); err != nil {
		t.Fatalf("failed testing clear cookie: %v", err)
	}
	cookies := w.Result().Cookies()
	if len(cookies) != 1 {
		t.Fatalf("expected 1 cookie, got %d", len(cookies))
	}
	c := cookies[0]
	if c.Name != "goffee" {
		t.Errorf("expected cookie name 'goffee', got %q", c.Name)
	}
	if c.Value != "" {
		t.Errorf("expected empty cookie value, got %q", c.Value)
	}
	if c.MaxAge != -1 {
		t.Errorf("expected MaxAge of -1 to delete the cookie, got %d", c.MaxAge)
	}
	if !c.HttpOnly {
		t.Errorf("expected cleared cookie to be HttpOnly")
	}
}

func TestGetCookieRoundTrip(t *testing.T) {
	enableTemplateCookieEnv(t)

	// Set a cookie and feed it back into a request, then decrypt it.
	w := httptest.NewRecorder()
	if err := SetCookie(w, "user@example.com", "token-xyz"); err != nil {
		t.Fatalf("failed setting cookie: %v", err)
	}
	r := httptest.NewRequest(GET, LOCALHOST, nil)
	for _, c := range w.Result().Cookies() {
		r.AddCookie(c)
	}

	user, err := GetCookie(r)
	if err != nil {
		t.Fatalf("failed testing get cookie: %v", err)
	}
	if user.Email != "user@example.com" {
		t.Errorf("expected email 'user@example.com', got %q", user.Email)
	}
	if user.Token != "token-xyz" {
		t.Errorf("expected token 'token-xyz', got %q", user.Token)
	}
}

func TestGetCookieTemplatesDisabledPanics(t *testing.T) {
	prev := os.Getenv("TEMPLATE_ENABLE")
	os.Setenv("TEMPLATE_ENABLE", "false")
	t.Cleanup(func() { os.Setenv("TEMPLATE_ENABLE", prev) })

	defer func() {
		if r := recover(); r == nil {
			t.Errorf("expected panic when templates are disabled")
		}
	}()
	r := httptest.NewRequest(GET, LOCALHOST, nil)
	_, _ = GetCookie(r)
}