package app

import (
	"os"
	"path/filepath"
	"strings"
	"testing"
)

func TestWriteFileWithBackup(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "user.txt")
	original := []byte("# 账号\r\nfoo----bar----cookie\r\n")
	updated := []byte("# 账号\r\n")

	if err := os.WriteFile(path, original, 0640); err != nil {
		t.Fatalf("写入原始账号文件失败: %v", err)
	}

	backupPath, err := writeFileWithBackup(path, updated)
	if err != nil {
		t.Fatalf("writeFileWithBackup 返回错误: %v", err)
	}
	if backupPath == "" {
		t.Fatal("backupPath 为空")
	}

	got, err := os.ReadFile(path)
	if err != nil {
		t.Fatalf("读取更新后账号文件失败: %v", err)
	}
	if string(got) != string(updated) {
		t.Fatalf("更新后账号文件内容 = %q, want %q", got, updated)
	}

	backup, err := os.ReadFile(backupPath)
	if err != nil {
		t.Fatalf("读取备份文件失败: %v", err)
	}
	if string(backup) != string(original) {
		t.Fatalf("备份文件内容 = %q, want %q", backup, original)
	}

	entries, err := os.ReadDir(dir)
	if err != nil {
		t.Fatalf("读取临时目录失败: %v", err)
	}
	for _, entry := range entries {
		if strings.HasSuffix(entry.Name(), ".tmp") {
			t.Fatalf("发现残留临时文件: %s", entry.Name())
		}
	}
}