// Copyright 2026 Alibaba Group
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

//go:build darwin

package keychain

import (
	"bytes"
	"encoding/base64"
	"errors"
	"os"
	"path/filepath"
	"strings"
	"testing"

	keyringpkg "github.com/zalando/go-keyring"
)

func TestDefaultKeychainPathFromSecurityOutput(t *testing.T) {
	got := defaultKeychainPathFromSecurityOutput([]byte("\"/Users/me/Library/Keychains/login.keychain-db\"\n"))
	if got != "/Users/me/Library/Keychains/login.keychain-db" {
		t.Fatalf("path = %q", got)
	}
}

func TestCheckDefaultKeychainAvailableReportsMissingPath(t *testing.T) {
	missingPath := filepath.Join(t.TempDir(), "missing.keychain-db")
	prev := readDefaultKeychain
	readDefaultKeychain = func() ([]byte, error) {
		return []byte("\"" + missingPath + "\"\n"), nil
	}
	t.Cleanup(func() {
		readDefaultKeychain = prev
	})

	err := checkDefaultKeychainAvailable()
	if !IsUnavailable(err) {
		t.Fatalf("error = %v, want unavailable", err)
	}
	if !strings.Contains(err.Error(), missingPath) {
		t.Fatalf("error = %v, want missing keychain path", err)
	}
}

func TestGetMissingAccountDoesNotReadMacOSDEK(t *testing.T) {
	t.Setenv(DisableKeychainEnv, "")

	keychainPath := filepath.Join(t.TempDir(), "login.keychain-db")
	if err := os.WriteFile(keychainPath, nil, 0600); err != nil {
		t.Fatalf("WriteFile(default keychain) error = %v", err)
	}

	prevReadDefault := readDefaultKeychain
	prevGet := keyringGet
	prevSet := keyringSet
	readDefaultKeychain = func() ([]byte, error) {
		return []byte("\"" + keychainPath + "\"\n"), nil
	}
	keyringGet = func(service, account string) (string, error) {
		t.Fatalf("keyring.Get(%q, %q) called for missing account", service, account)
		return "", nil
	}
	keyringSet = func(service, account, value string) error {
		t.Fatalf("keyring.Set(%q, %q) called for missing account", service, account)
		return nil
	}
	t.Cleanup(func() {
		readDefaultKeychain = prevReadDefault
		keyringGet = prevGet
		keyringSet = prevSet
	})

	got, err := Get("test-missing-account", "auth-token")
	if err != nil {
		t.Fatalf("Get() error = %v, want nil", err)
	}
	if got != "" {
		t.Fatalf("Get() = %q, want empty string", got)
	}
}

func TestGetWithMissingMacOSDEKDoesNotCreateDEK(t *testing.T) {
	t.Setenv(DisableKeychainEnv, "")

	keychainPath := filepath.Join(t.TempDir(), "login.keychain-db")
	if err := os.WriteFile(keychainPath, nil, 0600); err != nil {
		t.Fatalf("WriteFile(default keychain) error = %v", err)
	}

	prevReadDefault := readDefaultKeychain
	prevGet := keyringGet
	prevSet := keyringSet
	readDefaultKeychain = func() ([]byte, error) {
		return []byte("\"" + keychainPath + "\"\n"), nil
	}
	keyringGet = func(service, account string) (string, error) {
		if account != "dek" {
			t.Fatalf("keyring.Get account = %q, want dek", account)
		}
		return "", keyringpkg.ErrNotFound
	}
	setCalls := 0
	keyringSet = func(service, account, value string) error {
		setCalls++
		return errors.New("keyring.Set should not be called by Get")
	}
	t.Cleanup(func() {
		readDefaultKeychain = prevReadDefault
		keyringGet = prevGet
		keyringSet = prevSet
	})

	service := "test-missing-dek"
	account := "auth-token"
	dir := StorageDir(service)
	if err := os.MkdirAll(dir, 0700); err != nil {
		t.Fatalf("MkdirAll() error = %v", err)
	}
	if err := os.WriteFile(filepath.Join(dir, safeFileName(account)), []byte("ciphertext"), 0600); err != nil {
		t.Fatalf("WriteFile(ciphertext) error = %v", err)
	}

	_, err := Get(service, account)
	if !IsDEKMissing(err) {
		t.Fatalf("Get() error = %v, want dek missing", err)
	}
	if setCalls != 0 {
		t.Fatalf("keyring.Set calls = %d, want 0", setCalls)
	}
}

// TestDisableKeychainFallback verifies that setting DWS_DISABLE_KEYCHAIN
// routes the DEK to a local file (same scheme as Linux) and the full
// Set/Get/Remove cycle works without touching the system Keychain.
// This is the support path for sandboxed runtimes such as Codex App.
func TestDisableKeychainFallback(t *testing.T) {
	tmp := t.TempDir()
	t.Setenv(StorageDirEnv, tmp)
	t.Setenv(DisableKeychainEnv, "1")

	service := "test-disable-keychain"
	account := "auth-token"
	payload := `{"access_token":"abc","refresh_token":"def"}`

	if err := Set(service, account, payload); err != nil {
		t.Fatalf("Set() error = %v", err)
	}

	// File DEK must materialize on disk.
	dekPath := filepath.Join(tmp, service, "dek")
	info, err := os.Stat(dekPath)
	if err != nil {
		t.Fatalf("file DEK not created at %s: %v", dekPath, err)
	}
	if mode := info.Mode().Perm(); mode != 0600 {
		t.Fatalf("DEK file perm = %o, want 0600", mode)
	}

	got, err := Get(service, account)
	if err != nil {
		t.Fatalf("Get() error = %v", err)
	}
	if got != payload {
		t.Fatalf("Get() = %q, want %q", got, payload)
	}

	// A second Get must reuse the same DEK (no regeneration).
	dek1, err := os.ReadFile(dekPath)
	if err != nil {
		t.Fatalf("ReadFile(dek) error = %v", err)
	}
	if _, err := Get(service, account); err != nil {
		t.Fatalf("second Get() error = %v", err)
	}
	dek2, err := os.ReadFile(dekPath)
	if err != nil {
		t.Fatalf("ReadFile(dek) second error = %v", err)
	}
	if string(dek1) != string(dek2) {
		t.Fatal("DEK rotated between calls; want stable")
	}

	if err := Remove(service, account); err != nil {
		t.Fatalf("Remove() error = %v", err)
	}
	if Exists(service, account) {
		t.Fatal("Exists() = true after Remove(), want false")
	}
}

// TestDisableKeychainOverwrite verifies the fallback path supports
// overwriting an existing token entry.
func TestDisableKeychainOverwrite(t *testing.T) {
	tmp := t.TempDir()
	t.Setenv(StorageDirEnv, tmp)
	t.Setenv(DisableKeychainEnv, "1")

	service := "test-disable-keychain-overwrite"
	account := "auth-token"

	if err := Set(service, account, "initial"); err != nil {
		t.Fatalf("Set() initial error = %v", err)
	}
	if err := Set(service, account, "overwritten"); err != nil {
		t.Fatalf("Set() overwrite error = %v", err)
	}

	got, err := Get(service, account)
	if err != nil {
		t.Fatalf("Get() error = %v", err)
	}
	if got != "overwritten" {
		t.Fatalf("Get() = %q, want %q", got, "overwritten")
	}
}

func stubMacOSSystemDEK(t *testing.T, systemDEK []byte, getErr error) *int {
	t.Helper()

	defaultKeychainPath := filepath.Join(t.TempDir(), "login.keychain-db")
	if err := os.WriteFile(defaultKeychainPath, nil, 0600); err != nil {
		t.Fatalf("WriteFile(default keychain) error = %v", err)
	}

	prevReadDefault := readDefaultKeychain
	prevGet := keyringGet
	prevSet := keyringSet
	readDefaultKeychain = func() ([]byte, error) {
		return []byte("\"" + defaultKeychainPath + "\"\n"), nil
	}
	keyringGet = func(service, account string) (string, error) {
		if account != "dek" {
			return "", errors.New("unexpected keyring account")
		}
		if getErr != nil {
			return "", getErr
		}
		return base64.StdEncoding.EncodeToString(systemDEK), nil
	}
	setCalls := 0
	keyringSet = func(service, account, value string) error {
		setCalls++
		return errors.New("unexpected keyring.Set")
	}
	t.Cleanup(func() {
		readDefaultKeychain = prevReadDefault
		keyringGet = prevGet
		keyringSet = prevSet
	})
	return &setCalls
}

func TestSystemKeychainModePreservesFileDEKCredentials(t *testing.T) {
	t.Setenv(StorageDirEnv, t.TempDir())
	systemDEK := bytes.Repeat([]byte{0x22}, dekBytes)
	setCalls := stubMacOSSystemDEK(t, systemDEK, nil)

	service := "test-dek-mode-switch"
	account := "auth-token"

	t.Setenv(DisableKeychainEnv, "1")
	if err := Set(service, account, "file-dek-token"); err != nil {
		t.Fatalf("Set() in file-DEK mode error = %v", err)
	}

	t.Setenv(DisableKeychainEnv, "")
	got, err := Get(service, account)
	if err != nil {
		t.Fatalf("Get() after switching to system Keychain mode error = %v", err)
	}
	if got != "file-dek-token" {
		t.Fatalf("Get() after switching modes = %q, want file-dek-token", got)
	}
	if err := Set(service, account, "updated-token"); err != nil {
		t.Fatalf("Set() after switching to system Keychain mode error = %v", err)
	}
	profileAccount := account + ":corp"
	if err := Set(service, profileAccount, "profile-token"); err != nil {
		t.Fatalf("Set() new profile account in system Keychain mode error = %v", err)
	}

	t.Setenv(DisableKeychainEnv, "1")
	got, err = Get(service, account)
	if err != nil {
		t.Fatalf("Get() after switching back to file-DEK mode error = %v", err)
	}
	if got != "updated-token" {
		t.Fatalf("Get() after switching back = %q, want updated-token", got)
	}
	got, err = Get(service, profileAccount)
	if err != nil {
		t.Fatalf("Get() new profile account in file-DEK mode error = %v", err)
	}
	if got != "profile-token" {
		t.Fatalf("Get() new profile account = %q, want profile-token", got)
	}
	if *setCalls != 0 {
		t.Fatalf("keyring.Set calls = %d, want 0", *setCalls)
	}
}

func TestSystemKeychainModeFallsBackWhenSystemDEKIsMissing(t *testing.T) {
	t.Setenv(StorageDirEnv, t.TempDir())
	setCalls := stubMacOSSystemDEK(t, nil, keyringpkg.ErrNotFound)

	service := "test-missing-system-dek-fallback"
	account := "auth-token"
	t.Setenv(DisableKeychainEnv, "1")
	if err := Set(service, account, "file-dek-token"); err != nil {
		t.Fatalf("Set() in file-DEK mode error = %v", err)
	}

	t.Setenv(DisableKeychainEnv, "")
	got, err := Get(service, account)
	if err != nil {
		t.Fatalf("Get() with missing system DEK error = %v", err)
	}
	if got != "file-dek-token" {
		t.Fatalf("Get() with missing system DEK = %q, want file-dek-token", got)
	}
	if *setCalls != 0 {
		t.Fatalf("keyring.Set calls = %d, want 0", *setCalls)
	}
}

func TestFileDEKModeDoesNotOverwriteSystemKeychainCredentials(t *testing.T) {
	root := t.TempDir()
	t.Setenv(StorageDirEnv, root)
	systemDEK := bytes.Repeat([]byte{0x22}, dekBytes)
	stubMacOSSystemDEK(t, systemDEK, nil)

	service := "test-system-ciphertext-preserved"
	account := "auth-token"
	t.Setenv(DisableKeychainEnv, "")
	if err := Set(service, account, "system-token"); err != nil {
		t.Fatalf("Set() in system Keychain mode error = %v", err)
	}
	if _, err := os.Stat(filepath.Join(StorageDir(service), "dek")); !os.IsNotExist(err) {
		t.Fatalf("system Keychain Set created file DEK; stat error = %v", err)
	}

	targetPath := filepath.Join(StorageDir(service), safeFileName(account))
	before, err := os.ReadFile(targetPath)
	if err != nil {
		t.Fatalf("ReadFile(ciphertext) error = %v", err)
	}
	fileDEK := bytes.Repeat([]byte{0x11}, dekBytes)
	if err := os.WriteFile(filepath.Join(StorageDir(service), "dek"), fileDEK, 0600); err != nil {
		t.Fatalf("WriteFile(file DEK) error = %v", err)
	}

	t.Setenv(DisableKeychainEnv, "1")
	if err := Set(service, account, "file-token"); !IsCiphertextKeyMismatch(err) {
		t.Fatalf("Set() error = %v, want ciphertext key mismatch", err)
	}
	after, err := os.ReadFile(targetPath)
	if err != nil {
		t.Fatalf("ReadFile(ciphertext after rejected Set) error = %v", err)
	}
	if !bytes.Equal(after, before) {
		t.Fatal("rejected file-DEK Set overwrote system Keychain ciphertext")
	}

	t.Setenv(DisableKeychainEnv, "")
	got, err := Get(service, account)
	if err != nil {
		t.Fatalf("Get() in system Keychain mode error = %v", err)
	}
	if got != "system-token" {
		t.Fatalf("Get() after rejected overwrite = %q, want system-token", got)
	}

	profileAccount := account + ":corp"
	if err := Set(service, profileAccount, "system-profile-token"); err != nil {
		t.Fatalf("Set() new profile beside system-backed root error = %v", err)
	}
	got, err = Get(service, profileAccount)
	if err != nil || got != "system-profile-token" {
		t.Fatalf("Get() new system-backed profile = %q, %v", got, err)
	}

	t.Setenv(DisableKeychainEnv, "1")
	if _, err := Get(service, profileAccount); !IsCiphertextKeyMismatch(err) {
		t.Fatalf("file-DEK Get() of system-backed profile error = %v, want ciphertext key mismatch", err)
	}
}

func TestSetDoesNotOverwriteCiphertextWithUnknownDEK(t *testing.T) {
	root := t.TempDir()
	t.Setenv(StorageDirEnv, root)
	systemDEK := bytes.Repeat([]byte{0x22}, dekBytes)
	stubMacOSSystemDEK(t, systemDEK, nil)

	service := "test-unknown-ciphertext-key"
	account := "auth-token"
	dir := StorageDir(service)
	if err := os.MkdirAll(dir, 0700); err != nil {
		t.Fatalf("MkdirAll() error = %v", err)
	}
	fileDEK := bytes.Repeat([]byte{0x11}, dekBytes)
	if err := os.WriteFile(filepath.Join(dir, "dek"), fileDEK, 0600); err != nil {
		t.Fatalf("WriteFile(file DEK) error = %v", err)
	}
	unknownDEK := bytes.Repeat([]byte{0x33}, dekBytes)
	ciphertext, err := encryptData("unknown-token", unknownDEK)
	if err != nil {
		t.Fatalf("encryptData() error = %v", err)
	}
	targetPath := filepath.Join(dir, safeFileName(account))
	if err := os.WriteFile(targetPath, ciphertext, 0600); err != nil {
		t.Fatalf("WriteFile(ciphertext) error = %v", err)
	}

	for _, disableKeychain := range []string{"", "1"} {
		t.Setenv(DisableKeychainEnv, disableKeychain)
		if err := Set(service, account, "replacement"); !IsCiphertextKeyMismatch(err) {
			t.Fatalf("Set() with %s=%q error = %v, want ciphertext key mismatch", DisableKeychainEnv, disableKeychain, err)
		}
		after, err := os.ReadFile(targetPath)
		if err != nil {
			t.Fatalf("ReadFile(ciphertext after rejected Set) error = %v", err)
		}
		if !bytes.Equal(after, ciphertext) {
			t.Fatalf("rejected Set with %s=%q overwrote ciphertext", DisableKeychainEnv, disableKeychain)
		}
	}
}