02. Employees

function solveClasses() {

    class Developer {
        constructor(firstName, lastName) {
            this.firstName = firstName;
            this.lastName = lastName;
            this.baseSalary = 1000;
            this.tasks = [];
            this.experience = 0;
        }
        addTask(id, taskName, priority) {
            if (priority == "high") {
                this.tasks.unshift({ id, taskName, priority });
            } else {
                this.tasks.push({ id, taskName, priority });
            }
            return `Task id ${id}, with ${priority} priority, has been added.`
        }
        doTask() {
            if (this.tasks.length > 0) {
                return this.tasks.shift();
            } else {
                return `${this.firstName}, you have finished all your tasks. You can rest now.`
            }
        }
        getSalary() {
            return `${this.firstName} ${this.lastName} has a salary of: ${this.baseSalary}`;
        }
        reviewTasks() {
            let res = [];
            res.push("Tasks, that need to be completed:")
            this.tasks.forEach(x => {
                res.push(`${x.id}: ${x.taskName} - ${x.priority}`);
            })
            return res.join('\n');
        }
    }
    class Junior extends Developer {
        constructor(firstName, lastName, bonus, experience) {
            super(firstName, lastName);
            this.experience = experience;
            this.baseSalary = 1000 + bonus;
        }
        learn(years) {
            this.experience += years;
        }
    }
    class Senior extends Developer {
        constructor(firstName, lastName, bonus, experience) {
            super(firstName, lastName);
            this.experience = experience + 5;
            this.baseSalary = 1000 + bonus;
        }
        changeTaskPriority(taskId) {
            let taskIndex = this.tasks.findIndex(x => x.id == taskId);
            let currTask = this.tasks[taskIndex];
            this.tasks = this.tasks.splice(taskIndex, 1);
            if (currTask.priority == 'low') {
                currTask.priority = 'high'
                this.tasks.unshift(currTask);
            } else {
                currTask.priority = 'low';
                this.tasks.push(currTask);
            }
            return currTask;
        }

    }
    return {
        Developer,
        Junior,
        Senior
    }
}