system design

Author: premaseem

system_design/design_chess_game.py

@@ -0,0 +1,33 @@
+"""
+@Author: Aseem Jain
+@profile: https://www.linkedin.com/in/premaseem/
+
+Chess is a two-player strategy board game played on a chessboard, which is a checkered gameboard with 64 squares arranged in an 8×8 grid. There are a few versions of game types that people play all over the world. In this design problem, we are going to focus on designing a two-player online chess game.
+
+System Requirements
+===================
+
+The system should support two online players to play a game of chess.
+All rules of international chess will be followed.
+Each player will be randomly assigned a side, black or white.
+Both players will play their moves one after the other. The white side plays the first move.
+Players can’t cancel or roll back their moves.
+The system should maintain a log of all moves by both players.
+Each side will start with 8 pawns, 2 rooks, 2 bishops, 2 knights, 1 queen, and 1 king.
+The game can finish either in a checkmate from one side, forfeit or stalemate (a draw), or resignation.
+
+Actors:
+=======
+Player: A registered account in the system, who will play the game. The player will play chess moves.
+Admin: To ban/modify players.
+
+Here are the top use cases for chess:
+======================================
+Player moves a piece: To make a valid move of any chess piece.
+Resign or forfeit a game: A player resigns from/forfeits the game.
+Register new account/Cancel membership: To add a new member or cancel an existing member.
+Update game log: To add a move to the game log.
+
+"""
+
+

system_design/stack_overflow.py

@@ -36,5 +36,185 @@
 Moderators can close, delete, and un-delete any question.
 
 """
+from datetime import datetime
+from enum import Enum
 
 
+class QuestionStatus(Enum):
+    OPEN, CLOSED, ON_HOLD, DELETED = 1, 2, 3, 4
+
+
+class QuestionClosingRemark(Enum):
+    DUPLICATE, OFF_TOPIC, TOO_BROAD, NOT_CONSTRUCTIVE, NOT_A_REAL_QUESTION, PRIMARILY_OPINION_BASED = 1, 2, 3, 4, 5, 6
+
+
+class AccountStatus(Enum):
+    ACTIVE, CLOSED, CANCELED, BLACKLISTED, BLOCKED = 1, 2, 3, 4, 5
+
+# For simplicity, we are not defining getter and setter functions. The reader can
+# assume that all class attributes are private and accessed through their respective
+# public getter methods and modified only through their public methods function.
+
+
+class Account:
+    def __init__(self, id, password, name, address, email, phone, status=AccountStatus.Active):
+        self.__id = id
+        self.__password = password
+        self.__name = name
+        self.__address = address
+        self.__email = email
+        self.__phone = phone
+        self.__status = status
+        self.__reputation = 0
+
+    def reset_password(self):
+        None
+
+
+class Member:
+    def __init__(self, account):
+        self.__account = account
+        self.__badges = []
+
+    def get_reputation(self):
+        return self.__account.get_reputation()
+
+    def get_email(self):
+        return self.__account.get_email()
+
+    def create_question(self, question):
+        None
+
+    def create_tag(self, tag):
+        None
+
+
+class Admin(Member):
+    def block_member(self, member):
+        None
+
+    def unblock_member(self, member):
+        None
+
+
+class Moderator(Member):
+    def close_question(self, question):
+        None
+
+    def undelete_question(self, question):
+        None
+
+class Badge:
+    def __init__(self, name, description):
+        self.__name = name
+        self.__description = description
+
+
+class Tag:
+    def __init__(self, name, description):
+        self.__name = name
+        self.__description = description
+        self.__daily_asked_frequency = 0
+        self.__weekly_asked_frequency = 0
+
+# import datetime
+
+
+class Notification:
+    def __init__(self, id, content):
+        self.__notification_id = id
+        self.__created_on = datetime.datetime.now()
+        self.__content = content
+
+    def send_notification(self):
+        None
+
+import datetime
+
+class Photo:
+    def __init__(self, id, path, member):
+        self.__photo_id = id
+        self.__photo_path = path
+        self.__creation_date = datetime.datetime.now()
+        self.__creating_member = member
+
+    def delete(self):
+        None
+
+# import datetime
+
+
+class Bounty:
+    def __init__(self, reputation, expiry):
+        self.__reputation = reputation
+        self.__expiry = expiry
+
+    def modify_reputation(self, reputation):
+        None
+
+from abc import ABC, abstractmethod
+
+class Search(ABC):
+    def search(self, query):
+        None
+
+import datetime
+
+class Question(Search):
+    def __init__(self, title, description, bounty, asking_member):
+        self.__title = title
+        self.__description = description
+        self.__view_count = 0
+        self.__vote_count = 0
+        self.__creation_time = datetime.datetime.now()
+        self.__update_time = datetime.datetime.now()
+        self.__status = QuestionStatus.OPEN
+        self.__closing_remark = QuestionClosingRemark.DUPLICATE
+
+        self.__bounty = bounty
+        self.__asking_member = asking_member
+        self.__photos = []
+        self.__comments = []
+        self.__answers = []
+
+    def close(self):
+        None
+
+    def undelete(self):
+        None
+
+    def add_comment(self, comment):
+        None
+
+    def add_bounty(self, bounty):
+        None
+
+    def search(self, query):
+        # return all questions containing the string query in their title or description.
+        None
+
+
+class Comment:
+    def __init__(self, text, member):
+        self.__text = text
+        self.__creation_time = datetime.datetime.now()
+        self.__flag_count = 0
+        self.__vote_count = 0
+        self.__asking_member = member
+
+    def increment_vote_count(self):
+        None
+
+
+class Answer:
+    def __init__(self, text, member):
+        self.__answer_text = text
+        self.__accepted = False
+        self.__vote_count = 0
+        self.__flag_count = 0
+        self.__creation_time = datetime.datetime.now()
+        self.__creating_member = member
+        self.__photos = []
+
+    def increment_vote_count(self):
+        None