using Insight.Database;
using System.Data;

namespace Database.Core.DDL
{
	/// <summary>
	/// This is by purpose not async await
	/// It is intended that this is created with the correct Application User, which is why the schema name is omitted.
	/// </summary>
	public class SetupIdentitySystem : IDbConfigure<SetupIdentitySystem.Command>
	{
		public class Command { }

		readonly IDbConnection _db;
		IDbTransaction _transaction = null;
		string _schema;

		public SetupIdentitySystem(IDbConnection db)
		{
			_db = db;
		}

		/// <summary>
		/// Creates the system tables in the specified schema within a transaction.
		/// </summary>
		/// <param name="schema">The schema name where the tables will be created.</param>
		public void With(Command emptyByIntention)
		{
			using (_transaction = _db.OpenWithTransaction())
			{
				try
				{
					CreateUsersTable();
					CreateOrganizationsTable();
					CreateUserOrganizationsTable();
					SetupRLS();

					_transaction.Commit();
				}
				catch (Exception ex)
				{
					_transaction.Rollback();
					throw new InvalidOperationException("Failed to SetupIdentitySystem. Transaction is rolled back", ex);
				}
			}
		}
		private void ExecuteSql(string sql)
		{
			if (string.IsNullOrEmpty(sql))
				throw new ArgumentNullException(nameof(sql));

			_db.ExecuteSql(sql);
		}


		/// <summary>
		/// Creates the users table
		/// </summary>
		void CreateUsersTable()
		{
			var sql = @"
                CREATE TABLE IF NOT EXISTS users (
                    id SERIAL PRIMARY KEY,
                    email VARCHAR(256) NOT NULL UNIQUE,
                    password_hash VARCHAR(256) NOT NULL,
                    security_stamp VARCHAR(36) NOT NULL,
                    email_confirmed BOOLEAN NOT NULL DEFAULT FALSE,
                    access_failed_count INTEGER NOT NULL DEFAULT 0,
                    lockout_enabled BOOLEAN NOT NULL DEFAULT TRUE,
                    lockout_end TIMESTAMPTZ NULL,
                    is_active BOOLEAN NOT NULL DEFAULT TRUE,
                    created_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
                    last_login_at TIMESTAMPTZ NULL
                );";

			ExecuteSql(sql);

		}

		/// <summary>
		/// Creates the organizations table
		/// </summary>
		void CreateOrganizationsTable()
		{
			var sql = @"
                CREATE TABLE IF NOT EXISTS organizations (
                    id SERIAL PRIMARY KEY,
                    connection_string VARCHAR(500) NOT NULL,
                    is_active BOOLEAN NOT NULL DEFAULT TRUE,
                    created_by INTEGER NOT NULL REFERENCES users(id),
                    created_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP
                );";

			ExecuteSql(sql);

		}

		/// <summary>
		/// Creates the user_organizations table
		/// </summary>
		void CreateUserOrganizationsTable()
		{
			var sql = @"
                CREATE TABLE IF NOT EXISTS user_organizations (
                    user_id INTEGER NOT NULL REFERENCES users(id),
                    organization_id INTEGER NOT NULL REFERENCES organizations(id),
                    pin_code VARCHAR(10) NULL,
                    created_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
                    PRIMARY KEY (user_id, organization_id)
                );";

			ExecuteSql(sql);

		}

		/// <summary>
		/// Sets up Row Level Security (RLS) for the organizations and user_organizations tables.
		/// </summary>
		void SetupRLS()
		{
			var sql = new[]
				{
					"ALTER TABLE organizations ENABLE ROW LEVEL SECURITY;",
					"ALTER TABLE user_organizations ENABLE ROW LEVEL SECURITY;",
					"DROP POLICY IF EXISTS organization_access ON organizations;",
					@"CREATE POLICY organization_access ON organizations
                        USING (id IN (
                            SELECT organization_id 
                            FROM user_organizations 
                            WHERE user_id = current_setting('app.user_id', TRUE)::INTEGER
                        ));",
					"DROP POLICY IF EXISTS user_organization_access ON user_organizations;",
					@"CREATE POLICY user_organization_access ON user_organizations
                        USING (user_id = current_setting('app.user_id', TRUE)::INTEGER);"
				};

			foreach (var statement in sql)
			{
				ExecuteSql(statement);
			}
		}


	}
}