3

class Parking {
  constructor(capacity) {
    this.capacity = capacity;
    this.vehicles = [];
  }

  emptySlots() {
    return this.capacity - this.vehicles.length;
  }

  addCar(carModel, carNumber) {
    // if not enough parking space in arr
    if (this.vehicles.length >= this.capacity) {
      throw new Error('Not enough parking space.');
    }

    // otherwise: carModel, carNumber, payed: default false
    this.vehicles.push({ carModel, carNumber, payed: false });

    return `The ${carModel}, with a registration number ${carNumber}, parked.`;
  }

  removeCar(carNumber) {
    // if car is not found: error
    const condition = (carObj) => {
      return carObj.carNumber === carNumber;
    };

    // get vehicle
    let currentVehicle = this.vehicles.find(condition);

    // get index
    let vehicleIndex = this.vehicles.indexOf(currentVehicle);

    if (!currentVehicle) {
      throw new Error("The car, you're looking for, is not found.");
    }

    // if car hasn't been payed for
    if (!currentVehicle.payed) {
      throw new Error(
        `${carNumber} needs to pay before leaving the parking lot.`
      );
    }

    // otherwise: remove from arr
    this.vehicles.splice(vehicleIndex, 1);
    return `${carNumber} left the parking lot.`;
  }

  pay(carNumber) {
    // if car is not found: error
    const condition = (carObj) => {
      return carObj.carNumber === carNumber;
    };

    // get vehicle
    let currentVehicle = this.vehicles.find(condition);

    if (!currentVehicle) {
      throw new Error(`${carNumber} is not in the parking lot.`);
    }

    // if already payed: error
    if (currentVehicle.payed) {
      throw new Error(`${carNumber}'s driver has already payed his ticket.`);
    }

    // otherwise: set payed to true
    currentVehicle.payed = true;
    return `${carNumber}'s driver successfully payed for his stay.`;
  }

  getStatistics(carNumber) {
    let output = [];

    // if param is provided
    // return only the information about the car with the given carNumber:
    // `{carModel} == {carNumber} - {Has payed / Not payed}`
    if (carNumber) {
      const condition = (carObj) => {
        return carObj.carNumber === carNumber;
      };

      // get vehicle
      let currentVehicle = this.vehicles.find(condition);

      if (currentVehicle.payed) {
        let str = `${currentVehicle.carModel} == ${currentVehicle.carNumber} - Has payed`;
        output.push(str);
      } else {
        let str = `${currentVehicle.carModel} == ${currentVehicle.carNumber} - Not payed`;
        output.push(str);
      }

      return output[0]; // MAY BE WRONG
    }

    // if no params
    // FULL INFO
    // empty slots in parking lot
    output.push(`The Parking Lot has ${this.emptySlots()} empty spots left.`);

    // sort vehicles alphabetically ascending by carModel
    const alphaSort = (objA, objB) => {
      // NOT TESTED
      return objA.carModel.localeCompare(objB.carModel);
    };

    this.vehicles.sort(alphaSort);

    // f/each vehicle:
    this.vehicles.forEach((vehicle) => {
      if (vehicle.payed) {
        let str = `${vehicle.carModel} == ${vehicle.carNumber} - Has payed`;
        output.push(str);
      } else {
        let str = `${vehicle.carModel} == ${vehicle.carNumber} - Not payed`;
        output.push(str);
      }
    });

    return output.join('\n'); // MAY BE WRONG
  }
}