var Utils = require('../utils/Utils');

module.exports = Solver;

/**
 * Base class for constraint solvers.
 * @class Solver
 * @constructor
 */
function Solver(){

    /**
     * Current equations in the solver.
     *
     * @property equations
     * @type {Array}
     */
    this.equations = [];
};

Solver.prototype.solve = function(dt,world){
    throw new Error("Solver.solve should be implemented by subclasses!");
};

/**
 * Add an equation to be solved.
 *
 * @method addEquation
 * @param {Equation} eq
 */
Solver.prototype.addEquation = function(eq){
    this.equations.push(eq);
};

/**
 * Add equations. Same as .addEquation, but this time the argument is an array of Equations
 *
 * @method addEquations
 * @param {Array} eqs
 */
Solver.prototype.addEquations = function(eqs){
    Utils.appendArray(this.equations,eqs);
};

/**
 * Remove an equation.
 *
 * @method removeEquation
 * @param {Equation} eq
 */
Solver.prototype.removeEquation = function(eq){
    var i = this.equations.indexOf(eq);
    if(i!=-1)
        this.equations.splice(i,1);
};

/**
 * Remove all currently added equations.
 *
 * @method removeAllEquations
 */
Solver.prototype.removeAllEquations = function(){
    this.equations.length=0;
};