using SqlSugar;
using System;

using System.IO;
using System.Security.Cryptography;

namespace ORM
{
    public class DatabaseConfig
    {
        /// <summary>
        /// 数据库连接类型
        /// </summary>
        public static DbType DbConnectionType { get; private set; }

        /// <summary>
        /// SQLite 数据库文件路径
        /// </summary>
        public static string DbConnectionString { get; private set; }

        /// <summary>
        /// 数据租户Id
        /// </summary>
        public static int TenantId { get; private set; }

        /// <summary>
        /// 雪花算法DatacenterId，值范围：0至31
        /// </summary>
        public static int SnowFlakeDatacenterId { get; private set; }

        /// <summary>
        /// 雪花算法WorkID，值范围：0至31
        /// </summary>
        public static int SnowFlakeWorkId { get; private set; }

        #region 不同数据库初始化方法
        public static void InitSqlite()
        {
            DbConnectionType = DbType.Sqlite;
            // 获取程序运行目录
            string baseDir = AppDomain.CurrentDomain.BaseDirectory;
            // 确保 SQLDB 文件夹存在
            string folder = Path.Combine(baseDir, "SQLDB");
            if (!Directory.Exists(folder))
                Directory.CreateDirectory(folder);

            // 拼接数据库文件路径
            string DBPath = Path.Combine(folder, "SQL.db");
            DbConnectionString = $"Data Source={DBPath};";
        }
        public static void InitMySql(string Server, int Port, string Database, string Uid,string Pwd)
        {
            DbConnectionType = DbType.MySql;
            DbConnectionString =
                $"Server={Server};Port={Port};Database={Database};Uid={Uid};Pwd={Pwd};";
        }
        public static void InitSqlServer(string server,int port,string database,string user,string password)
        {
            DbConnectionType = DbType.SqlServer;

            DbConnectionString =
                $"Data Source={server},{port};Initial Catalog={database};user={user};Password={password};";
        }
        public static void InitSqlServerLocalDb()
        {
            DbConnectionType = DbType.SqlServer;
            string baseDir = AppDomain.CurrentDomain.BaseDirectory;
            // 确保 SQLDB 文件夹存在
            string folder = Path.Combine(baseDir, "SQLDB");
            if (!Directory.Exists(folder))
                Directory.CreateDirectory(folder);

            // 拼接数据库文件路径
            string DBPath = Path.Combine(folder, "SQL.db");
            DbConnectionString =$@"Data Source=(localdb)\MSSQLLocalDB;Initial Catalog={DBPath};Integrated Security=True;";
        }
        #endregion
        /// <summary>
        /// 设置数据库连接字符串（可手动覆盖）
        /// </summary>
        public static void SetDbConnection(string strConnection)
        {
            if (string.IsNullOrEmpty(strConnection))
            {
                throw new Exception("数据库连接字符串为空");
            }
            DbConnectionString = strConnection;
        }

        /// <summary>
        /// 设置数据租户Id
        /// </summary>
        public static void SetTenant(int nTenantId)
        {
            if (nTenantId <= 10000)
            {
                throw new Exception("数据租户Id值需大于10000");
            }
            TenantId = nTenantId;
            SetSnowFlake((nTenantId - 10000) % 1024);
        }

        /// <summary>
        /// 将指定数字转换为雪花算法DatacenterId和WorkID
        /// </summary>
        private static void SetSnowFlake(int nSnowFlakeId)
        {
            if (nSnowFlakeId > 1023 || nSnowFlakeId < 0)
            {
                throw new Exception("雪花算法机器码值范围0至1023");
            }
            SnowFlakeDatacenterId = nSnowFlakeId >> 5;
            SnowFlakeWorkId = nSnowFlakeId & 31;
        }
        /// <summary>
        /// 检测数据库连接
        /// </summary>
        public static void CreateDatabaseAndCheckConnection(bool createDatabase = false, bool checkConnection = false)
        {
            //数据库不存在则创建数据库
            if (createDatabase)
            {
                SqlSugarContext.DbContext.DbMaintenance.CreateDatabase();
            }
            // 检查数据库连接
            if (checkConnection && !SqlSugarContext.DbContext.Ado.IsValidConnection())
            {
                throw new Exception("连接数据库失败");
            }
        }

        /// <summary>
        /// 归档过期数据库文件：将旧的 SQLite 文件重命名为 "SQL_归档_yyyyMMdd_HHmmss.db"，
        /// 后续 <see cref="CreateDatabaseAndCheckConnection"/> 会自动创建新的空数据库。
        /// <para>
        /// 必须在 <see cref="InitSqlite"/> 之后、<see cref="CreateDatabaseAndCheckConnection"/> 之前调用，
        /// 此时连接字符串已就绪但数据库文件尚未被打开。
        /// </para>
        /// </summary>
        /// <param name="retentionDays">数据库文件保留天数，默认 180 天（半年）</param>
        public static void TryArchiveOldDatabase(int retentionDays = 180)
        {
            try
            {
                // 从连接字符串中提取文件路径（格式：Data Source=xxx;）
                string dbPath = DbConnectionString
                    .Replace("Data Source=", "", StringComparison.OrdinalIgnoreCase)
                    .TrimEnd(';');

                if (!File.Exists(dbPath)) return;

                var cutoff = DateTime.Now.AddDays(-retentionDays);
                var fileInfo = new FileInfo(dbPath);

                if (fileInfo.LastWriteTime < cutoff)
                {
                    string archiveName = $"SQL_归档_{fileInfo.LastWriteTime:yyyyMMdd_HHmmss}.db";
                    string archivePath = Path.Combine(fileInfo.DirectoryName!, archiveName);

                    File.Move(dbPath, archivePath);
                    System.Diagnostics.Debug.WriteLine(
                        $"[数据库归档] {dbPath} → {archivePath}（文件最后修改于 {fileInfo.LastWriteTime:yyyy-MM-dd}，已超过 {retentionDays} 天）");
                }
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.WriteLine($"数据库归档失败（不影响软件正常使用）：{ex.Message}");
            }
        }
    }
}