Move shared constants, exceptions & helpers.py into /shared/

shared/constants.py

@@ -0,0 +1,156 @@
+from typing import List
+from collections import namedtuple
+
+import os
+import webcolors
+
+__BASE_DIR = os.path.dirname(os.path.abspath(__file__))
+
+HEADER_LENGTH = 10
+MINIMUM_CONTRAST = 4.65
+CLIENT_DATABASE = os.path.join(__BASE_DIR, 'client.db')
+SERVER_DATABASE = os.path.join(__BASE_DIR, 'server.db')
+
+DEFAULT_IP = "127.0.0.1"
+DEFAULT_PORT = 5555
+
+ConnectionOptions = namedtuple('ConnectionOptions', ['ip', 'port', 'nickname', 'password', 'remember'])
+
+
+class Types:
+    """
+    Types describe the types of messages sent between the client and server.
+    A message could be a request, a posting of information, a message etc.
+    The Types class provides a universal naming for the types of messages that will be exchanged.
+    """
+    REQUEST = 'REQUEST'
+    MESSAGE = 'MESSAGE'
+    NICKNAME = 'NICKNAME'
+    USER_LIST = 'USER_LIST'
+    MESSAGE_HISTORY = 'MESSAGE_HISTORY'
+
+
+class Requests:
+    """
+    Requests describe a request between the server and client to send a specific type of information.
+    The Requests class provides a universal naming for the types of requests that can be made and received.
+    """
+    REQUEST_NICK = 'REQUEST_NICK'  # Send the server the client's nickname
+    GET_MESSAGE_HISTORY = 'GET_MESSAGE_HISTORY'  # Send the client a detailed list of all messages sent up to a certain point.
+
+
+class Color():
+    """
+    Describes a basic RGB color.
+    """
+
+    def __init__(self, name: str, hex: str) -> None:
+        self.name, self.hex = name, hex
+        self.rgb = webcolors.hex_to_rgb(hex)
+
+    def __repr__(self) -> str:
+        return f'Color({self.name})'
+
+    @property
+    def id(self) -> str:
+        return '_'.join(self.name.split()).upper()
+
+    def relative_luminance(self) -> float:
+        """
+        Calculates the relative luminance of a given color, according to WCAG guidelines.
+
+        https://www.w3.org/TR/WCAG20/#relativeluminancedef
+
+        :return: The relative luminance of this color.
+        """
+        r, g, b = self.rgb.red / 255, self.rgb.green / 255, self.rgb.blue / 255
+        r = r / 12.92 if r <= 0.03928 else ((r + 0.055) / 1.055) ** 2.4
+        g = g / 12.92 if g <= 0.03928 else ((g + 0.055) / 1.055) ** 2.4
+        b = b / 12.92 if b <= 0.03928 else ((b + 0.055) / 1.055) ** 2.4
+        return 0.2126 * r + 0.7152 * g + 0.0722 * b
+
+    def contrast_ratio(self, other: 'Color') -> float:
+        """
+        Calculates the relative contrast between two colors in a ratio from 1:1 to 21:1, according to WCAG guidelines.
+
+        https://www.w3.org/TR/WCAG20/#contrast-ratiodef
+
+        :param other: The darker color.
+        :return:
+        """
+        l1 = self.relative_luminance()
+        l2 = other.relative_luminance()
+        return (l1 + 0.05) / (l2 + 0.05)
+
+
+class Colors:
+    """
+    Stores hexadecimal color codes of popular colors, with names.
+    """
+
+    AQUA = Color("Aqua", "#00ffff")
+    AZURE = Color("Azure", "#f0ffff")
+    BEIGE = Color("Beige", "#f5f5dc")
+    BLACK = Color("Black", "#000000")
+    BLUE = Color("Blue", "#0000ff")
+    BROWN = Color("Brown", "#a52a2a")
+    CYAN = Color("Cyan", "#00ffff")
+    DARKBLUE = Color("Dark Blue", "#00008b")
+    DARKCYAN = Color("Dark Cyan", "#008b8b")
+    DARKGREY = Color("Dark Grey", "#a9a9a9")
+    DARKGREEN = Color("Dark Green", "#006400")
+    DARKKHAKI = Color("Dark Khaki", "#bdb76b")
+    DARKMAGENTA = Color("Dark Magenta", "#8b008b")
+    DARKOLIVEGREEN = Color("Dark Olive Green", "#556b2f")
+    DARKORANGE = Color("Dark Orange", "#ff8c00")
+    DARKORCHID = Color("Dark Orchid", "#9932cc")
+    DARKRED = Color("Dark Red", "#8b0000")
+    DARKSALMON = Color("Dark Salmon", "#e9967a")
+    DARKVIOLET = Color("Dark Violet", "#9400d3")
+    FUCHSIA = Color("Fuchsia", "#ff00ff")
+    GOLD = Color("Gold", "#ffd700")
+    GREEN = Color("Green", "#008000")
+    INDIGO = Color("Indigo", "#4b0082")
+    KHAKI = Color("Khaki", "#f0e68c")
+    LIGHTBLUE = Color("Light Blue", "#add8e6")
+    LIGHTCYAN = Color("Light Cyan", "#e0ffff")
+    LIGHTGREEN = Color("Light Green", "#90ee90")
+    LIGHTGREY = Color("Light Grey", "#d3d3d3")
+    LIGHTPINK = Color("Light Pink", "#ffb6c1")
+    LIGHTYELLOW = Color("Light Yellow", "#ffffe0")
+    LIME = Color("Lime", "#00ff00")
+    MAGENTA = Color("Magenta", "#ff00ff")
+    MAROON = Color("Maroon", "#800000")
+    NAVY = Color("Navy", "#000080")
+    OLIVE = Color("Olive", "#808000")
+    ORANGE = Color("Orange", "#ffa500")
+    PINK = Color("Pink", "#ffc0cb")
+    PURPLE = Color("Purple", "#800080")
+    VIOLET = Color("Violet", "#800080")
+    RED = Color("Red", "#ff0000")
+    SILVER = Color("Silver", "#c0c0c0")
+    WHITE = Color("White", "#ffffff")
+    YELLOW = Color("Yellow", "#ffff00")
+
+    ALL = [AQUA, AZURE, BEIGE, BLACK, BLUE, BROWN, CYAN, DARKBLUE, DARKCYAN, DARKGREY, DARKGREEN, DARKKHAKI,
+           DARKMAGENTA, DARKOLIVEGREEN, DARKORANGE, DARKORCHID, DARKRED, DARKSALMON, DARKVIOLET, FUCHSIA, GOLD, GREEN,
+           INDIGO, KHAKI, LIGHTBLUE, LIGHTCYAN, LIGHTGREEN, LIGHTGREY, LIGHTPINK, LIGHTYELLOW, LIME, MAGENTA, MAROON,
+           NAVY, OLIVE, ORANGE, PINK, PURPLE, VIOLET, RED, SILVER, WHITE, YELLOW]
+
+    @staticmethod
+    def has_contrast(ratio: float, background: Color = WHITE) -> List[Color]:
+        """
+        Returns a list of Color objects with contrast ratios above the given minimum.
+
+        :param ratio: The minimum contrast ratio each color must adhere to.
+        :param background: Defaults to White, the background (lighter) for the other contrasting colors to be compared to.
+        :return: A list of Color objects with contrast ratios above the given minimum.
+        """
+        above_ratio = []
+
+        for color in Colors.ALL:
+            contrast = background.contrast_ratio(color)
+            if contrast >= ratio:
+                above_ratio.append(color)
+
+        return above_ratio

shared/exceptions.py

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+class TCPChatException(BaseException):
+    pass
+
+class DataReceptionException(TCPChatException):
+    pass

shared/helpers.py

@@ -0,0 +1,76 @@
+import html
+import json
+import time
+from typing import List, Tuple, Any
+
+from shared import constants
+
+HEADER_LENGTH = 10
+
+
+def prepare(message: str, encoding='utf-8') -> bytes:
+    """Prepares a message for sending through a socket by adding a proper header and encoding it."""
+    header = f'{len(message):<{HEADER_LENGTH}}'
+    return (header + message).encode(encoding)
+
+
+def prepare_json(obj: Any) -> bytes:
+    """
+    Prepares a object for sending as encoded JSON with a header.
+
+    :param obj: A JSON-encodable object
+    :return: Encoded JSON
+    """
+    return prepare(json.dumps(obj))
+
+
+def prepare_message(nickname: str, message: str, color: str, message_id: int, timestamp: int = None) -> bytes:
+    return prepare_json(
+        {
+            'type': constants.Types.MESSAGE,
+            'nickname': nickname,
+            'content': message,
+            'color': color,
+            'time': timestamp or int(time.time()),
+            'id': message_id,
+        }
+    )
+
+
+def prepare_message_history(messages: List[Tuple[int, str, str, str, int]]) -> bytes:
+    """Returns a encoded JSON message history object with the messages provided"""
+    return prepare_json(
+        {
+            'type': constants.Types.MESSAGE_HISTORY,
+            'messages': [
+                {
+                    'type': constants.Types.MESSAGE,
+                    'nickname': nickname,
+                    'content': message,
+                    'color': color,
+                    'time': timestamp,
+                    'id': message_id
+                } for message_id, nickname, color, message, timestamp in messages
+            ]
+        }
+    )
+
+
+def prepare_request(request: str) -> bytes:
+    """Helper function for creating a request message."""
+    return prepare_json({'type': constants.Types.REQUEST, 'request': request})
+
+
+def formatted_message(message: dict) -> str:
+    """Given a message dict object, return a color formatted and GUI ready string."""
+    nick_esc = html.escape(message["nickname"])
+    msg_esc = html.escape(message["message"])
+    return f'&lt;<span style="color: {message["color"]}">{nick_esc}</span>&gt; {msg_esc}'
+
+
+def sizeof_fmt(num, suffix='B'):
+    for unit in ['', 'Ki', 'Mi', 'Gi', 'Ti', 'Pi', 'Ei', 'Zi']:
+        if abs(num) < 1024.0:
+            return "%3.0f%s%s" % (num, unit, suffix)
+        num /= 1024.0
+    return "%.1f%s%s" % (num, 'Yi', suffix)