using SqlSugar;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ORM
{
    public static class DatabaseConfig
    {
        /// <summary>
        /// 当前数据库类型
        /// </summary>
        public static DbType DbConnectionType { get; private set; }

        /// <summary>
        /// 数据库连接字符串
        /// </summary>
        public static string DbConnectionString { get; private set; }

        /// <summary>
        /// 默认 SQLite 文件路径（仅记录，不自动启用）
        /// </summary>
        public static string DefaultDbFilePath { get; private set; }

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

        public static int SnowFlakeDatacenterId { get; private set; }
        public static int SnowFlakeWorkId { get; private set; }

        static DatabaseConfig()
        {
            InitDefaultDbPath(); // 只生成路径，不指定 DB 类型/连接
        }

        /// <summary>
        /// 生成默认 DB 路径 EXE目录/SQLDB/Data.db
        /// </summary>
        private static void InitDefaultDbPath()
        {
            string baseDir = AppDomain.CurrentDomain.BaseDirectory;

            string folder = Path.Combine(baseDir, "SQLDB");
            if (!Directory.Exists(folder))
                Directory.CreateDirectory(folder);

            DefaultDbFilePath = Path.Combine(folder, "Data.db");
        }

        /// <summary>
        /// 手动设置数据库连接
        /// </summary>
        public static void SetConnection(string conn, DbType dbType)
        {
            if (string.IsNullOrWhiteSpace(conn))
                throw new Exception("数据库连接字符串为空");

            DbConnectionString = conn;
            DbConnectionType = dbType;
        }

        /// <summary>
        /// 如果未 SetConnection，默认使用 SQLite + 默认路径
        /// </summary>
        public static void EnsureConnection()
        {
            if (string.IsNullOrEmpty(DbConnectionString))
            {
                DbConnectionString = $"Data Source={DefaultDbFilePath};";
                DbConnectionType = DbType.Sqlite;
            }
        }

        /// <summary>
        /// 设置租户并计算雪花算法节点
        /// </summary>
        public static void SetTenant(int tenantId)
        {
            if (tenantId <= 10000)
                throw new Exception("数据租户Id值需大于10000");

            TenantId = tenantId;

            int snowId = (tenantId - 10000) % 1024;

            if (snowId is < 0 or > 1023)
                throw new Exception("雪花算法机器码值范围0至1023");

            SnowFlakeDatacenterId = snowId >> 5;
            SnowFlakeWorkId = snowId & 31;
        }
    }
}