import { type T, Model } from '..';
type NullableKeys<T> = ({
    [K in keyof T]: null extends T[K] ? K : never;
}[keyof T]) & {};
declare class ModelMeta<M extends Model> {
    private model;
    constructor(model: M);
    /**
     * Get the table name of the current model.
     *
     * @returns {string} The table name.
     */
    table(): string;
    /**
     * Get a column key from the model schema.
     *
     * @param {T.ColumnKeys<M>} column - The column key.
     * @returns {T.ColumnKeys<M>} The validated column key.
     */
    column(column: T.ColumnKeys<M>): T.ColumnKeys<M>;
    /**
     * Build a fully qualified column reference with an optional alias.
     *
     * @param {T.ColumnKeys<M>} column - The column key.
     * @param {{ alias?: string | null }} [options] - Optional alias for the table.
     * @returns {`${string}.${T.ColumnKeys<M>}`} The column reference.
     */
    columnReference(column: T.ColumnKeys<M>, { alias, raw }?: {
        alias?: string | null;
        raw?: boolean | null;
    }): `${string}.${T.ColumnKeys<M>}`;
    /**
     * Alias for {@link columnReference}.
     *
     * @param {T.ColumnKeys<M>} column - The column key.
     * @param {{ alias?: string | null }} [options] - Optional alias for the table.
     * @returns {`${string}.${T.ColumnKeys<M>}`} The column reference.
     */
    columnRef(column: T.ColumnKeys<M>, { alias, raw }?: {
        alias?: string | null;
        raw?: boolean | null;
    }): `${string}.${T.ColumnKeys<M>}`;
    /**
     * Get all column keys defined in the model schema.
     *
     * @returns {T.ColumnKeys<M>[]} An array of column keys.
     */
    columns(): T.ColumnKeys<M>[];
    /**
     * Check if a given column exists in the model schema.
     *
     * @param {string} name - The column name to check.
     * @returns {boolean} True if the column exists, false otherwise.
     */
    hasColumn(name: string): boolean;
    /**
     * Get the primary key column of the model.
     *
     * @returns {string | undefined} The primary key column, or undefined if not found.
     */
    primaryKey(): string | undefined;
    /**
     * Get all index names defined in the model schema.
     *
     * @returns {string[]} An array of index names.
     */
    indexes(): string[];
    /**
     * Get all nullables columns in the model schema.
     *
     * @returns {string[]} An array of nullables column keys.
     */
    nullables(): NullableKeys<T.Columns<M>>[];
    /**
     * Get the default values for all columns in the schema.
     *
     * @returns {T.SchemaModel<M> | null} An object of default values, or null if none are defined.
     */
    defaults(): T.Columns<M> | null;
    /**
     * Get the inferred JavaScript type of a column (based on constructor mapping).
     *
     * @param {T.ColumnKeys<M>} column - The column key.
     * @returns {("number" | "string" | "boolean" | "date" | undefined)} The column type, or undefined if not found.
     */
    columnTypeOf(column: T.ColumnKeys<M>): string | undefined;
    /**
     * Get the database type of a column (e.g. varchar, int, etc.).
     *
     * @param {T.ColumnKeys<M>} column - The column key.
     * @returns {string | undefined} The column type, or undefined if not found.
     */
    columnType(column: T.ColumnKeys<M>): string | undefined;
    /**
     * Get an enum column as a key-value map.
     *
     * @template C
     * @param {C} column - The column key.
     * @returns {Record<T.Result<M>[C], T.Result<M>[C]> | null} A record mapping each enum value to itself, or null if not defined.
     */
    enum<C extends T.ColumnEnumKeys<M>>(column: C): Record<T.Result<M>[C], T.Result<M>[C]> | null;
    /**
     * Get all enum values for a given column.
     *
     * @template C
     * @param {C} column - The column key.
     * @returns {T.Result<M>[C][]}
     */
    enums<C extends T.ColumnEnumKeys<M>>(column: C): T.Result<M>[C][];
}
/**
 * The 'Meta' used to get the metadata of a Model works only when a schema is added to the Model.
 *
 * @example
 *  import { Meta, Model , Blueprint , type T } from 'tspace-mysql';
 *  import { Column } from './Decorator';
 *
 *  const schema = {
 *   id        : Blueprint.int().notNull().primary().autoIncrement(),
 *   uuid      : Blueprint.varchar(50).null(),
 *   email     : Blueprint.varchar(255).notNull().index('users.email@index'),
 *   name      : Blueprint.varchar(255).null(),
 *   username  : Blueprint.varchar(255).notNull(),
 *   password  : Blueprint.varchar(255).notNull(),
 *   status    : Blueprint.tinyInt().notNull().default(0),
 *   role      : Blueprint.enum('admin','user').default('user'),
 *   createdAt : Blueprint.timestamp().null(),
 *   updatedAt : Blueprint.timestamp().null()
 *  }
 *
 *  type TS = T.Schema<typeof schema>
 *
 *  class User extends Model<TS>  {
 *    constructor() {
 *       super()
 *       this.useSchema(schema)
 *    }
 *  }
 *
 *  const meta          = Meta(User)
 *  // --- get metadata of User ---
 *  const table         = meta.table() // 'users'
 *  const column        = meta.column('id') // id
 *  const columnRef     = meta.columnRef('id') // `users`.`id`
 *  const columnTypeOf  = meta.columnTypeOf('id') // number
 *  const columnType    = meta.columnType('id') // Int
 *  const columns       = meta.columns() // ['id','uuid',...'updatedAt']
 *  const hasColumn     = meta.hasColumn('id') // false
 *  const primaryKey    = meta.primaryKey() // 'id'
 *  const indexes       = meta.indexes() // ['users.email@index']
 *  const nullables     = meta.nullables() // ['uuid','name','createdAt','updatedAt']
 *  const defaults      = meta.defaults() // { id : null, ..., status : 0, role: 'user', ..updatedAt : null  }
 *  const enums         = meta.enums('role') // [ 'admin', 'user' ]
 *  const enumsObj      = meta.enum('role', { asObject: true }) // { admin: 'admin', user: 'user' }
 *
 */
declare const Meta: <M extends Model>(model: new () => M) => ModelMeta<M>;
export { Meta };
export default Meta;