const hourToNumber = (hour) => hour.split(':').map(n => Number(n));
const compareHour = (hourA, hourB) => {
  const [hA, mA] = hourToNumber(hourA);
  const [hB, mB] = hourToNumber(hourB);
  return hA - hB || mA - mB;
};

const isHourABeforeB = (hourA, hourB) => {
  return compareHour(hourA, hourB) <= 0;
}

const isTaskDoable = (dayAvaibility, dayCalendar, task) => {
  if (!dayAvaibility) {
    return false;
  }

  if (!isHourABeforeB(dayAvaibility.start, task.start) || !isHourABeforeB(task.end, dayAvaibility.end)) {
    return false;
  }

  const collidingTask = dayCalendar.find(plannedTaks => {
    const startAfter = isHourABeforeB(task.end, plannedTaks.start);
    const endBefore = isHourABeforeB(plannedTaks.end, task.start);
    return !startAfter && !endBefore;
  });
  return !collidingTask;
}

const findIndexRight = (array, predicate) => {
  for (let i = array.length - 1; i >= 0; i--) {
    if (predicate(array[i], i)) {
      return i;
    }
  }
  return -1;
}

const fullFillCalendar = (avaibility, tasks) => {
  const orderedTask = tasks.sort((a, b) => a.id - b.id);
  const calendarByDay = {};

  orderedTask.forEach(task => {
    if (!calendarByDay[task.day]) {
      calendarByDay[task.day] = [];
    }

    const dayCalendar = calendarByDay[task.day];

    if (isTaskDoable(avaibility.find(a => a.day === task.day), dayCalendar, task)) {
      const sortedIndex = findIndexRight(dayCalendar, plannedTask => {
        return !isHourABeforeB(plannedTask.start, task.start);
      });
      if (sortedIndex === - 1) {
        dayCalendar.push(task);
      } else {
        dayCalendar.splice(sortedIndex, 0, task);
      }
    };
  });

  return [
    { day: 0, booking: calendarByDay[0] || [] },
    { day: 1, booking: calendarByDay[1] || [] },
    { day: 2, booking: calendarByDay[2] || [] },
    { day: 3, booking: calendarByDay[3] || [] },
    { day: 4, booking: calendarByDay[4] || [] },
    { day: 5, booking: calendarByDay[5] || [] },
    { day: 6, booking: calendarByDay[6] || [] },
  ]
}

const bookings = [
  { "id": 0, "day": 6, "start": "14:22", "end": "15:05" },
  { "id": 1, "day": 4, "start": "12:43", "end": "13:34" },
  { "id": 2, "day": 1, "start": "10:46", "end": "11:31" },
  { "id": 3, "day": 2, "start": "14:36", "end": "17:48" },
  { "id": 4, "day": 1, "start": "09:55", "end": "13:10" },
  { "id": 5, "day": 5, "start": "11:20", "end": "14:37" },
  { "id": 6, "day": 5, "start": "12:58", "end": "13:50" },
  { "id": 7, "day": 0, "start": "10:01", "end": "11:10" },
  { "id": 8, "day": 4, "start": "09:33", "end": "10:25" },
  { "id": 9, "day": 4, "start": "11:52", "end": "13:51" },
  { "id": 10, "day": 3, "start": "09:58", "end": "17:43" },
  { "id": 11, "day": 2, "start": "10:09", "end": "15:52" },
  { "id": 12, "day": 1, "start": "10:55", "end": "14:32" },
  { "id": 13, "day": 1, "start": "15:55", "end": "16:24" },
  { "id": 14, "day": 0, "start": "15:07", "end": "17:21" },
  { "id": 15, "day": 3, "start": "12:20", "end": "14:54" },
  { "id": 16, "day": 4, "start": "12:21", "end": "16:20" },
  { "id": 17, "day": 3, "start": "14:11", "end": "17:49" },
  { "id": 18, "day": 2, "start": "09:33", "end": "14:03" },
  { "id": 19, "day": 1, "start": "13:38", "end": "15:42" }
]

const doctorAvailability = [
  {
    day: 0,
    start: "9:00",
    end: "18:00"
  },
  {
    day: 1,
    start: "9:00",
    end: "18:00"
  },
  {
    day: 2,
    start: "9:00",
    end: "18:00"
  },
  {
    day: 3,
    start: "9:00",
    end: "18:00"
  },
  {
    day: 4,
    start: "9:00",
    end: "18:00"
  },
  {
    day: 5,
    start: "9:00",
    end: "18:00"
  },
  {
    day: 6,
    start: "9:00",
    end: "18:00"
  }
];

console.log(JSON.stringify(fullFillCalendar(doctorAvailability, bookings), null, '  '));