import { TableColumnOptions } from '../options/TableColumnOptions';

/**
 * Table's columns in the database represented in this class.
 */
export class TableColumn {
	readonly '@instanceof' = Symbol.for('TableColumn');

	// -------------------------------------------------------------------------
	// Public Properties
	// -------------------------------------------------------------------------

	/**
	 * Column name.
	 */
	name: string;

	/**
	 * Column type.
	 */
	type: string;

	/**
	 * Column's default value.
	 */
	default?: any;

	/**
	 * ON UPDATE trigger. Works only for MySQL.
	 */
	onUpdate?: string;

	/**
	 * Indicates if column is NULL, or is NOT NULL in the database.
	 */
	isNullable: boolean = false;

	/**
	 * Indicates if column is auto-generated sequence.
	 */
	isGenerated: boolean = false;

	/**
	 * Specifies generation strategy if this column will use auto increment.
	 * `rowid` option supported only in CockroachDB.
	 */
	generationStrategy?: 'uuid' | 'increment' | 'rowid' | 'identity';

	/**
	 * Indicates if column is a primary key.
	 */
	isPrimary: boolean = false;

	/**
	 * Indicates if column has unique value.
	 */
	isUnique: boolean = false;

	/**
	 * Indicates if column stores array.
	 */
	isArray: boolean = false;

	/**
	 * Column's comment.
	 */
	comment?: string;

	/**
	 * Column type's length. Used only on some column types.
	 * For example type = "string" and length = "100" means that ORM will create a column with type varchar(100).
	 */
	length: string = '';

	/**
	 * Column type's display width. Used only on some column types in MySQL.
	 * For example, INT(4) specifies an INT with a display width of four digits.
	 */
	width?: number;

	/**
	 * Defines column character set.
	 */
	charset?: string;

	/**
	 * Defines column collation.
	 */
	collation?: string;

	/**
	 * The precision for a decimal (exact numeric) column (applies only for decimal column), which is the maximum
	 * number of digits that are stored for the values.
	 */
	precision?: number | null;

	/**
	 * The scale for a decimal (exact numeric) column (applies only for decimal column), which represents the number
	 * of digits to the right of the decimal point and must not be greater than precision.
	 */
	scale?: number;

	/**
	 * Puts ZEROFILL attribute on to numeric column. Works only for MySQL.
	 * If you specify ZEROFILL for a numeric column, MySQL automatically adds the UNSIGNED attribute to the column
	 */
	zerofill: boolean = false;

	/**
	 * Puts UNSIGNED attribute on to numeric column. Works only for MySQL.
	 */
	unsigned: boolean = false;

	/**
	 * Array of possible enumerated values.
	 */
	enum?: string[];

	/**
	 * Exact name of enum
	 */
	enumName?: string;

	/**
	 * Name of the primary key constraint for primary column.
	 */
	primaryKeyConstraintName?: string;

	/**
	 * Generated column expression.
	 */
	asExpression?: string;

	/**
	 * Generated column type.
	 */
	generatedType?: 'VIRTUAL' | 'STORED';

	/**
	 * Identity column type. Supports only in Postgres 10+.
	 */
	generatedIdentity?: 'ALWAYS' | 'BY DEFAULT';

	/**
	 * Spatial Feature Type (Geometry, Point, Polygon, etc.)
	 */
	spatialFeatureType?: string;

	/**
	 * SRID (Spatial Reference ID (EPSG code))
	 */
	srid?: number;

	// -------------------------------------------------------------------------
	// Constructor
	// -------------------------------------------------------------------------

	constructor(options?: TableColumnOptions) {
		if (options) {
			this.name = options.name;
			this.type = options.type || '';
			this.length = options.length || '';
			this.width = options.width;
			this.charset = options.charset;
			this.collation = options.collation;
			this.precision = options.precision;
			this.scale = options.scale;
			this.zerofill = options.zerofill || false;
			this.unsigned = this.zerofill ? true : options.unsigned || false;
			this.default = options.default;
			this.onUpdate = options.onUpdate;
			this.isNullable = options.isNullable || false;
			this.isGenerated = options.isGenerated || false;
			this.generationStrategy = options.generationStrategy;
			this.generatedIdentity = options.generatedIdentity;
			this.isPrimary = options.isPrimary || false;
			this.isUnique = options.isUnique || false;
			this.isArray = options.isArray || false;
			this.comment = options.comment;
			this.enum = options.enum;
			this.enumName = options.enumName;
			this.primaryKeyConstraintName = options.primaryKeyConstraintName;
			this.asExpression = options.asExpression;
			this.generatedType = options.generatedType;
			this.spatialFeatureType = options.spatialFeatureType;
			this.srid = options.srid;
		}
	}

	// -------------------------------------------------------------------------
	// Public Methods
	// -------------------------------------------------------------------------

	/**
	 * Clones this column to a new column with exact same properties as this column has.
	 */
	clone(): TableColumn {
		return new TableColumn(<TableColumnOptions>{
			name: this.name,
			type: this.type,
			length: this.length,
			width: this.width,
			charset: this.charset,
			collation: this.collation,
			precision: this.precision,
			scale: this.scale,
			zerofill: this.zerofill,
			unsigned: this.unsigned,
			enum: this.enum,
			enumName: this.enumName,
			primaryKeyConstraintName: this.primaryKeyConstraintName,
			asExpression: this.asExpression,
			generatedType: this.generatedType,
			default: this.default,
			onUpdate: this.onUpdate,
			isNullable: this.isNullable,
			isGenerated: this.isGenerated,
			generationStrategy: this.generationStrategy,
			generatedIdentity: this.generatedIdentity,
			isPrimary: this.isPrimary,
			isUnique: this.isUnique,
			isArray: this.isArray,
			comment: this.comment,
			spatialFeatureType: this.spatialFeatureType,
			srid: this.srid,
		});
	}
}