Move images and solution under docs

docs/solutions/object_oriented_design/call_center/call_center.ipynb

@@ -0,0 +1,206 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "This notebook was prepared by [Donne Martin](https://github.com/donnemartin). Source and license info is on [GitHub](https://github.com/ido777/system-design-primer-update)."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Design a call center"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Constraints and assumptions\n",
+    "\n",
+    "* What levels of employees are in the call center?\n",
+    "    * Operator, supervisor, director\n",
+    "* Can we assume operators always get the initial calls?\n",
+    "    * Yes\n",
+    "* If there is no available operators or the operator can't handle the call, does the call go to the supervisors?\n",
+    "    * Yes\n",
+    "* If there is no available supervisors or the supervisor can't handle the call, does the call go to the directors?\n",
+    "    * Yes\n",
+    "* Can we assume the directors can handle all calls?\n",
+    "    * Yes\n",
+    "* What happens if nobody can answer the call?\n",
+    "    * It gets queued\n",
+    "* Do we need to handle 'VIP' calls where we put someone to the front of the line?\n",
+    "    * No\n",
+    "* Can we assume inputs are valid or do we have to validate them?\n",
+    "    * Assume they're valid"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Solution"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Overwriting call_center.py\n"
+     ]
+    }
+   ],
+   "source": [
+    "%%writefile call_center.py\n",
+    "from abc import ABCMeta, abstractmethod\n",
+    "from collections import deque\n",
+    "from enum import Enum\n",
+    "\n",
+    "\n",
+    "class Rank(Enum):\n",
+    "\n",
+    "    OPERATOR = 0\n",
+    "    SUPERVISOR = 1\n",
+    "    DIRECTOR = 2\n",
+    "\n",
+    "\n",
+    "class Employee(metaclass=ABCMeta):\n",
+    "\n",
+    "    def __init__(self, employee_id, name, rank, call_center):\n",
+    "        self.employee_id = employee_id\n",
+    "        self.name = name\n",
+    "        self.rank = rank\n",
+    "        self.call = None\n",
+    "        self.call_center = call_center\n",
+    "\n",
+    "    def take_call(self, call):\n",
+    "        \"\"\"Assume the employee will always successfully take the call.\"\"\"\n",
+    "        self.call = call\n",
+    "        self.call.employee = self\n",
+    "        self.call.state = CallState.IN_PROGRESS\n",
+    "\n",
+    "    def complete_call(self):\n",
+    "        self.call.state = CallState.COMPLETE\n",
+    "        self.call_center.notify_call_completed(self.call)\n",
+    "\n",
+    "    @abstractmethod\n",
+    "    def escalate_call(self):\n",
+    "        pass\n",
+    "\n",
+    "    def _escalate_call(self):\n",
+    "        self.call.state = CallState.READY\n",
+    "        call = self.call\n",
+    "        self.call = None\n",
+    "        self.call_center.notify_call_escalated(call)\n",
+    "\n",
+    "\n",
+    "class Operator(Employee):\n",
+    "\n",
+    "    def __init__(self, employee_id, name):\n",
+    "        super(Operator, self).__init__(employee_id, name, Rank.OPERATOR)\n",
+    "\n",
+    "    def escalate_call(self):\n",
+    "        self.call.rank = Rank.SUPERVISOR\n",
+    "        self._escalate_call()\n",
+    "\n",
+    "\n",
+    "class Supervisor(Employee):\n",
+    "\n",
+    "    def __init__(self, employee_id, name):\n",
+    "        super(Operator, self).__init__(employee_id, name, Rank.SUPERVISOR)\n",
+    "\n",
+    "    def escalate_call(self):\n",
+    "        self.call.rank = Rank.DIRECTOR\n",
+    "        self._escalate_call()\n",
+    "\n",
+    "\n",
+    "class Director(Employee):\n",
+    "\n",
+    "    def __init__(self, employee_id, name):\n",
+    "        super(Operator, self).__init__(employee_id, name, Rank.DIRECTOR)\n",
+    "\n",
+    "    def escalate_call(self):\n",
+    "        raise NotImplemented('Directors must be able to handle any call')\n",
+    "\n",
+    "\n",
+    "class CallState(Enum):\n",
+    "\n",
+    "    READY = 0\n",
+    "    IN_PROGRESS = 1\n",
+    "    COMPLETE = 2\n",
+    "\n",
+    "\n",
+    "class Call(object):\n",
+    "\n",
+    "    def __init__(self, rank):\n",
+    "        self.state = CallState.READY\n",
+    "        self.rank = rank\n",
+    "        self.employee = None\n",
+    "\n",
+    "\n",
+    "class CallCenter(object):\n",
+    "\n",
+    "    def __init__(self, operators, supervisors, directors):\n",
+    "        self.operators = operators\n",
+    "        self.supervisors = supervisors\n",
+    "        self.directors = directors\n",
+    "        self.queued_calls = deque()\n",
+    "\n",
+    "    def dispatch_call(self, call):\n",
+    "        if call.rank not in (Rank.OPERATOR, Rank.SUPERVISOR, Rank.DIRECTOR):\n",
+    "            raise ValueError('Invalid call rank: {}'.format(call.rank))\n",
+    "        employee = None\n",
+    "        if call.rank == Rank.OPERATOR:\n",
+    "            employee = self._dispatch_call(call, self.operators)\n",
+    "        if call.rank == Rank.SUPERVISOR or employee is None:\n",
+    "            employee = self._dispatch_call(call, self.supervisors)\n",
+    "        if call.rank == Rank.DIRECTOR or employee is None:\n",
+    "            employee = self._dispatch_call(call, self.directors)\n",
+    "        if employee is None:\n",
+    "            self.queued_calls.append(call)\n",
+    "\n",
+    "    def _dispatch_call(self, call, employees):\n",
+    "        for employee in employees:\n",
+    "            if employee.call is None:\n",
+    "                employee.take_call(call)\n",
+    "                return employee\n",
+    "        return None\n",
+    "\n",
+    "    def notify_call_escalated(self, call):  # ...\n",
+    "    def notify_call_completed(self, call):  # ...\n",
+    "    def dispatch_queued_call_to_newly_freed_employee(self, call, employee):  # ..."
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.4.3"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}

docs/solutions/object_oriented_design/call_center/call_center.py

@@ -0,0 +1,142 @@
+from abc import ABCMeta, abstractmethod
+from collections import deque
+from enum import Enum
+
+
+class Rank(Enum):
+
+    OPERATOR = 0
+    SUPERVISOR = 1
+    DIRECTOR = 2
+
+
+class Employee(metaclass=ABCMeta):
+
+    def __init__(self, employee_id, name, rank):
+        self.employee_id = employee_id
+        self.name = name
+        self.rank = rank
+        self.call = None
+        self.call_center = None
+
+    def take_call(self, call):
+        """Assume the employee will always successfully take the call."""
+        self.call = call
+        self.call.employee = self
+        self.call.state = CallState.IN_PROGRESS
+
+    def complete_call(self):
+        assert self.call_center is not None
+        self.call.state = CallState.COMPLETE
+        self.call_center.notify_call_completed(self.call)
+
+    @abstractmethod
+    def escalate_call(self):
+        pass
+
+    def _escalate_call(self):
+        assert self.call_center is not None
+        self.call.state = CallState.READY
+        call = self.call
+        self.call = None
+        self.call_center.notify_call_escalated(call)
+
+    def set_call_center(self, call_center):
+        self.call_center = call_center
+
+
+class Operator(Employee):
+
+    def __init__(self, employee_id, name):
+        super(Operator, self).__init__(employee_id, name, Rank.OPERATOR)
+
+    def escalate_call(self):
+        self.call.level = Rank.SUPERVISOR
+        self._escalate_call()
+
+
+class Supervisor(Employee):
+
+    def __init__(self, employee_id, name):
+        super(Supervisor, self).__init__(employee_id, name, Rank.SUPERVISOR)
+
+    def escalate_call(self):
+        self.call.level = Rank.DIRECTOR
+        self._escalate_call()
+
+
+class Director(Employee):
+
+    def __init__(self, employee_id, name):
+        super(Director, self).__init__(employee_id, name, Rank.DIRECTOR)
+
+    def escalate_call(self):
+        raise NotImplementedError('Directors must be able to handle any call')
+
+
+class CallState(Enum):
+
+    READY = 0
+    IN_PROGRESS = 1
+    COMPLETE = 2
+
+
+class Call(object):
+
+    def __init__(self, rank):
+        self.state = CallState.READY
+        self.rank = rank
+        self.employee = None
+
+
+class CallCenter(object):
+
+    def __init__(self, operators, supervisors, directors):
+        self.operators = []
+        self.supervisors = []
+        self.directors = []
+        self.queued_calls = deque()
+        for employee in operators + supervisors + directors:
+            self.add_employee(employee)
+
+    def dispatch_call(self, call):
+        if call.rank not in (Rank.OPERATOR, Rank.SUPERVISOR, Rank.DIRECTOR):
+            raise ValueError('Invalid call rank: {}'.format(call.rank))
+        employee = None
+        if call.rank == Rank.OPERATOR:
+            employee = self._dispatch_call(call, self.operators)
+        if call.rank == Rank.SUPERVISOR or employee is None:
+            employee = self._dispatch_call(call, self.supervisors)
+        if call.rank == Rank.DIRECTOR or employee is None:
+            employee = self._dispatch_call(call, self.directors)
+
+        if employee is None:
+            self.queued_calls.append(call)
+
+    def _dispatch_call(self, call, employees):
+        for employee in employees:
+            if employee.call is None:
+                employee.take_call(call)
+                return employee
+        return None
+
+    def add_employee(self, employee: Employee):
+        if isinstance(employee, Operator):
+            self.operators.append(employee)
+        elif isinstance(employee, Supervisor):
+            self.supervisors.append(employee)
+        elif isinstance(employee, Director):
+            self.directors.append(employee)
+        else:
+            raise ValueError('Invalid employee type: {}'.format(type(employee)))
+        employee.set_call_center(self)
+
+
+    def notify_call_escalated(self, call):
+        pass
+
+    def notify_call_completed(self, call):
+        pass
+
+    def dispatch_queued_call_to_newly_freed_employee(self, call, employee):
+        pass

docs/solutions/object_oriented_design/call_center/tests/test_call_center.py

@@ -0,0 +1,76 @@
+
+# test_call_center.py - Generated by CodiumAI
+
+import pytest
+from call_center.call_center import Operator, Supervisor, Director, Call, CallCenter, Rank
+
+"""
+Code Analysis:
+- The CallCenter class is used to manage calls in a call center. 
+- It takes three parameters: operators, supervisors, and directors. 
+- The queued_calls attribute is a deque object, which is a double-ended queue. 
+- The dispatch_call() method is used to assign a call to an employee based on the call's rank. 
+- If an employee is not available, the call is added to the queued_calls deque. 
+- The _dispatch_call() method is used to assign a call to an employee. 
+- The notify_call_escalated() and notify_call_completed() methods are used to notify the call center when a call is escalated or completed. 
+- The dispatch_queued_call_to_newly_freed_employee() method is used to assign a queued call to an employee who has just become available.
+"""
+
+"""
+Test Plan:
+- test_dispatch_call(): tests that the dispatch_call() method assigns the call to the correct employee based on the call's rank
+- test_dispatch_call_with_no_available_employee(): tests that the dispatch_call() method adds the call to the queued_calls deque if no employee is available
+- test_add_employee(): tests that the add_employee() method adds the employee to the correct list based on the employee's type
+
+"""
+
+class TestCallCenter():
+
+    def setup_method(self, method):
+        self.operators = [Operator(1, 'John'), Operator(2, 'Jane')]
+        self.supervisors = [Supervisor(3, 'Bob')]
+        self.directors = [Director(4, 'Alice')]
+        self.call_center = CallCenter(self.operators, self.supervisors, self.directors)
+    
+    def test_dispatch_call(self):
+        call = Call(Rank.OPERATOR)
+        self.call_center.dispatch_call(call)
+        assert self.operators[0].call == call
+
+        call = Call(Rank.SUPERVISOR)
+        self.call_center.dispatch_call(call)
+        assert self.supervisors[0].call == call
+
+        call = Call(Rank.DIRECTOR)
+        self.call_center.dispatch_call(call)
+        assert self.directors[0].call == call
+
+    def test_dispatch_call_with_no_available_employee(self):
+        for employee in self.operators + self.supervisors + self.directors:
+            employee.take_call(Call(Rank.OPERATOR))
+            assert employee.call is not None
+
+        call = Call(Rank.OPERATOR)
+        self.call_center.dispatch_call(call)
+        assert len(self.call_center.queued_calls) == 1
+
+
+    def test_add_employee(self):
+        operator = Operator(5, 'Tom')
+        supervisor = Supervisor(6, 'Jerry')
+        director = Director(7, 'Sally')
+
+        self.call_center.add_employee(operator)
+        assert operator in self.call_center.operators
+
+        self.call_center.add_employee(supervisor)
+        assert supervisor in self.call_center.supervisors
+
+        self.call_center.add_employee(director)
+        assert director in self.call_center.directors
+
+
+
+
+
+