import {fromJSON as behaviorItemFromJSON} from './registry';

export class Condition {

  static type() {
    return 'condition';
  }

  constructor() {
    this.operator = '';
    this.operands = [];
  }

  check(...args) {
    return this.get(...args);
  }

  fromJSON(json) {
    this.operator = json.operator;
    this.operands = json.operands.map((operand) => {
      return behaviorItemFromJSON(operand);
    });
    return this;
  }

  get(context) {
    switch (this.operator) {
      case 'is':
        return this.operands[0].get(context) === this.operands[1].get(context);
      case 'isnt':
        return this.operands[0].get(context) !== this.operands[1].get(context);
      case '>':
        return this.operands[0].get(context) > this.operands[1].get(context);
      case '>=':
        return this.operands[0].get(context) >= this.operands[1].get(context);
      case '<':
        return this.operands[0].get(context) < this.operands[1].get(context);
      case '<=':
        return this.operands[0].get(context) <= this.operands[1].get(context);

      case 'or':
        if (0 === this.operands.length) {
          return true;
        }
        for (const operand of this.operands) {
          if (!!operand.get(context)) {
            return true;
          }
        }
        return false;

      case 'and':
        if (0 === this.operands.length) {
          return true;
        }
        for (const operand of this.operands) {
          if (!operand.get(context)) {
            return false;
          }
        }
        return true;

    }
  }

  operandCount() {
    return this.operands.length;
  }

  operand(index) {
    return this.operands[index];
  }

  operands() {
    return this.operands;
  }

  operator() {
    return this.operator;
  }

  setOperand(index, operand) {
    this.operands[index] = operand;
  }

  setOperator(operator) {
    this.operator = operator;
  }

  toJSON() {
    return {
      type: 'condition',
      operator: this.operator,
      operands: this.operands.map((operand) => operand.toJSON()),
    };
  }
}