var Expr = require('./expr');
var ListHolder = require('./list-holder');

/**
 * The equivalent of a SQL operation between exprs.
 *
 * @param {Array#Expr} exprs Array with the exprs
 * @param {Type} type The type of the operation
 */
var Klass = new Class();
module.exports = Klass;

var Type = {
	 EQUAL  : 0
	,LIKE   : 1
	,AND    : 2
	,OR     : 3
	,REGEXP : 4
	,LOWER  : 5
	,UPPER  : 6
	,LE     : 7
	,UE     : 8
	,PLUS   : 9
	,MINUS  : 10
	,MULT   : 11
	,DIV    : 12
	,NE     : 13
	,MOD    : 14
};

var Operators = [
	 '='
	,'LIKE'
	,'AND'
	,'OR'
	,'REGEXP'
	,'<'
	,'>'
	,'<='
	,'>='
	,'+'
	,'-'
	,'*'
	,'/'
	,'<>'
	,'MOD'
];

Klass.extend({
	Type: Type
	,Operators: Operators
});

Klass.implement({
	Extends: Expr
	,Implements: ListHolder
	,Tag: 'sql-operation'
	,Properties: {
		type: {
			enumType: Type
			,value: -1
		},
		target: {
			type: String
			,value: null
		},
		exprs: {
			type: Array
			,set(x) {
				this.list = x;
			}
			,get() {
				return this.list;
			}
		}
	}

	,render(params) {
		var operator = ' '+ Operators[this.type] +' ';
		return '('
			+ this.renderListWs(this.list, params, operator)
			+ ')';
	}
});