import AttributeReferenceValue = require("../values/AttributeReferenceValue");
import assert = require("assert");
import Expression = require("./Expression");
import Scope = require("../Scope");
import Stack = require("../Stack");
import _ = require("../utilities");

function isFalse(value:any):boolean { return value === false }
function isTrue(value:any):boolean { return value === true }

class BooleanLogicExpression extends Expression {

  private static operators = {
    "||": "any",
    "&&": "all"
  };

  constructor(public operator:string, public expressions:Expression[]) {
    super();
  }

  evaluateToIntermediate(scope:Scope, stack:Stack):any {
    var operator = BooleanLogicExpression.operators[this.operator];

    var values:any[] = _.map(
      this.expressions,
      (expression) => { return expression.evaluate(scope, stack) }
    )

    if (operator == "any") {
      if (_.all(values, isFalse)) { return false }

      values = _.reject(values, isFalse)

      if (values.length === 0) { return true }
      else if (values.length === 1) { return values[0] }
      else if (_.any(values, isTrue)) { return true }

    } else if (operator == "all") {
      if (_.all(values, isTrue)) { return true }

      values = _.reject(values, isTrue)

      if (values.length === 0) { return true }
      else if (values.length === 1) { return values[0] }
      else if (_.any(values, isFalse)) { return false }

    } else {
      assert(false)
    }

    return [operator].concat(values)
  }

}

export = BooleanLogicExpression