MessageStats.js

export default class MessageStats {
  constructor (message = null) {
    // Constraints
    this.constraints = {
      byteCount1: "",
      byteCount2: "",
      minPlateNumberByteCount: "",
      maxPlateNumberByteCount: ""
    };

    // Stats
    this.totalChars;
    this.messageChars;
    this.specialChars;
    this.totalValidChars;
    this.invalidChars;

    // Alt Plate
    this.altPlate = false;

    // Message
    if(message) {
      this.message = message;
      this.calculateStats();
    }
  }

  removeAltPlate() {
    this.altPlate = false;
  }

  setAltPlate(altPlate) {
    if(!altPlate)
      return false;

    this.altPlate = altPlate;
    this.altPlate.totalByteCount = this.altPlate.byteCount1 + this.altPlate.byteCount2;
  }

  setMessage(message) {
    this.message = message;
    this.calculateStats();
  }

  setConstraints(constraints) {
    for(let constraint in constraints) {
      if(typeof this.constraints[constraint] !== 'undefined') {
        this.constraints[constraint] = constraints[constraint];
      } else {
        console.log('[MessageStats] Not a valid constraint: ', constraint);
      }
    }

    if(constraints.byteCount1 || constraints.byteCount2) {
      this.constraints.totalByteCount = this.constraints.byteCount1 + this.constraints.byteCount2;
    }
  }

  // Assumes valid plate
  setConstraintsFromPlate(plate) {
    this.setConstraints({
      byteCount1: plate.byteCount1,
      byteCount2: plate.byteCount2,
      minPlateNumberByteCount: plate.minPlateNumberByteCount,
      maxPlateNumberByteCount: plate.maxPlateNumberByteCount
    });
  }

  // Set calculated message stats
  calculateStats() {
    this.totalChars = this.message.length;
    this.messageChars = (this.message.match(/([a-z0-9])/g)||[]).length;
    this.specialChars = (this.message.match(/([ &-\.\*\@])/g)||[]).length;
    this.totalValidChars = this.messageChars + this.specialChars;
    this.invalidChars = this.totalChars - this.totalValidChars;
  }

  // Whether
  canAddByte() {
    let calculatedVals = this.getCalculatedPlateConstraints();

    return (calculatedVals.calculatedTotalByteCount > (this.totalChars || 0));
  }

  getCalculatedPlateConstraints() {
    let calculatedVals = {
      calculatedByteCount1: this.constraints.byteCount1,
      calculatedByteCount2: this.constraints.byteCount2,
      calculatedTotalByteCount: this.constraints.totalByteCount,
      calculatedMaxPlateNumberByteCount: this.constraints.maxPlateNumberByteCount
    };

    if(this.altPlate.type == "upgrade") {
      calculatedVals.calculatedByteCount1 = this.altPlate.byteCount1;
      calculatedVals.calculatedByteCount2 = this.altPlate.byteCount2;
      calculatedVals.totalByteCount = this.altPlate.totalByteCount;
      calculatedVals.calculatedMaxPlateNumberByteCount = this.altPlate.maxPlateNumberByteCount;
    }

    return calculatedVals;
  }

  // Returns an object with isValid bool, altPlateStatus string
  validate() {
    let calculatedMaxPlateNumberByteCount = this.constraints.maxPlateNumberByteCount;
    let calculatedMinPlateNumberByteCount = this.constraints.minPlateNumberByteCount;
    let calculatedTotalByteCount = this.constraints.totalByteCount;
    let altPlateStatus = false;

    if(this.altPlate) {
      // Message fits in upgrade plate
      if(this.altPlate.type == "upgrade"
        &&this.messageChars <= this.altPlate.maxPlateNumberByteCount && this.messageChars > this.constraints.maxPlateNumberByteCount
        && this.totalValidChars <= this.altPlate.totalByteCount) {

        calculatedTotalByteCount = this.altPlate.totalByteCount;
        calculatedMaxPlateNumberByteCount = this.altPlate.maxPlateNumberByteCount;

        altPlateStatus = "upgrade";
      }

      // Message fits in downgrade plate
      if(this.altPlate.type == "downgrade"
        && this.messageChars <= this.altPlate.maxPlateNumberByteCount
        && this.totalValidChars <= this.altPlate.totalByteCount) {

        calculatedTotalByteCount = this.altPlate.totalByteCount;
        calculatedMaxPlateNumberByteCount = this.altPlate.maxPlateNumberByteCount;

        altPlateStatus = "downgrade";
      }
    }

    let valid = (this.messageChars >= calculatedMinPlateNumberByteCount
    && this.messageChars <= calculatedMaxPlateNumberByteCount
    && this.totalValidChars <= calculatedTotalByteCount);

    return {isValid: valid, altPlateStatus: altPlateStatus};
  }
}