namespace FileShare_EFCore.Database
{
    /// <summary>
    /// 支持的数据库提供程序类型。
    /// </summary>
    public enum DatabaseProvider
    {
        /// <summary>SQLite（本地文件数据库，无需安装，跨平台）</summary>
        SQLite,

        /// <summary>MySQL / MariaDB</summary>
        MySQL,

        /// <summary>PostgreSQL</summary>
        PostgreSQL,

        /// <summary>SQL Server</summary>
        SqlServer
    }

    /// <summary>
    /// 数据库连接配置 —— 在 appsettings.json 中配置。
    /// </summary>
    public class DatabaseConfiguration
    {
        /// <summary>数据库提供程序</summary>
        public DatabaseProvider Provider { get; set; } = DatabaseProvider.SQLite;

        /// <summary>连接字符串</summary>
        public string ConnectionString { get; set; } = "Data Source=app.db";

        /// <summary>是否在启动时自动执行迁移</summary>
        public bool AutoMigrate { get; set; } = true;

        /// <summary>
        /// 是否在迁移前删除并重建当前连接指向的数据库。
        /// 仅用于切换数据库类型或本地开发重建库；生产环境默认必须保持 false。
        /// </summary>
        public bool RecreateDatabase { get; set; } = false;

        /// <summary>是否启用详细日志（会打印 SQL 语句）</summary>
        public bool EnableDetailedLog { get; set; } = false;

        /// <summary>连接超时（秒）</summary>
        public int Timeout { get; set; } = 30;

        // ---- 快捷构建方法 ----

        /// <summary>SQLite 本地数据库</summary>
        public static DatabaseConfiguration ForSQLite(string dataSource = "app.db")
        {
            return new DatabaseConfiguration
            {
                Provider = DatabaseProvider.SQLite,
                ConnectionString = $"Data Source={dataSource}",
                AutoMigrate = true,
            };
        }

        /// <summary>MySQL 数据库</summary>
        public static DatabaseConfiguration ForMySQL(string server, string database, string user, string password, uint port = 3306)
        {
            return new DatabaseConfiguration
            {
                Provider = DatabaseProvider.MySQL,
                ConnectionString = $"Server={server};Port={port};Database={database};User={user};Password={password};",
            };
        }

        /// <summary>PostgreSQL 数据库</summary>
        public static DatabaseConfiguration ForPostgreSQL(string host, string database, string username, string password, int port = 5432)
        {
            return new DatabaseConfiguration
            {
                Provider = DatabaseProvider.PostgreSQL,
                ConnectionString = $"Host={host};Port={port};Database={database};Username={username};Password={password};",
            };
        }

        /// <summary>SQL Server 数据库</summary>
        public static DatabaseConfiguration ForSqlServer(string server, string database, string? user = null, string? password = null)
        {
            var connStr = string.IsNullOrEmpty(user)
                ? $"Server={server};Database={database};Trusted_Connection=True;TrustServerCertificate=True;"
                : $"Server={server};Database={database};User Id={user};Password={password};TrustServerCertificate=True;";
            return new DatabaseConfiguration
            {
                Provider = DatabaseProvider.SqlServer,
                ConnectionString = connStr,
            };
        }
    }
}