refactor(chart): Added docstring in each file and function. Fixed long lines

chart/database/server.py

@@ -1,9 +1,27 @@
-import asyncpg
-import yaml
+"""
+This module initializes the database connection pool using asyncpg.
 
-config = yaml.safe_load(open("config.yaml", "r"))
+It reads database configuration from a YAML file and creates a connection pool
+that can be used throughout the application for database operations.
+"""
+
+import asyncpg
+
+from chart.utils.load_config import load_config
+
+config = load_config('config.yaml')
 
 async def create_pool() -> asyncpg.pool.Pool:
+    """
+    Creates and returns a connection pool for the PostgreSQL database.
+
+    The function uses configuration settings loaded from a YAML file to
+    establish the connection pool. The pool allows multiple database
+    connections to be reused efficiently across the application.
+
+    Returns:
+        asyncpg.pool.Pool: The connection pool object.
+    """
     pool = await asyncpg.create_pool(
         user=config['database']['user'],
         password=config['database']['password'],
@@ -14,4 +32,4 @@ async def create_pool() -> asyncpg.pool.Pool:
         max_size=20
     )
 
-    return pool
+    return pool

chart/function/create_chart.py

@@ -1,3 +1,8 @@
+"""
+This module provides functionality to generate currency rate charts
+based on historical data retrieved from the database.
+"""
+
 from datetime import datetime
 
 from matplotlib import pyplot as plt
@@ -5,7 +10,29 @@ from matplotlib import pyplot as plt
 from chart.function.gen_unique_name import generate_unique_name
 from ..database.server import create_pool
 
-async def create_chart(from_currency: str, conv_currency: str, start_date: str, end_date: str) -> (str, None):
+async def create_chart(
+        from_currency: str,
+        conv_currency: str,
+        start_date: str,
+        end_date: str
+) -> (str, None):
+    """
+    Generates a line chart of currency rates for a given date range.
+
+    The chart shows the exchange rate trend between `from_currency` and
+    `conv_currency` within the specified `start_date` and `end_date` range.
+    The generated chart is saved as a PNG file, and the function returns the
+    file name. If data is invalid or insufficient, the function returns `None`.
+
+    Args:
+        from_currency (str): The base currency (e.g., "USD").
+        conv_currency (str): The target currency (e.g., "EUR").
+        start_date (str): The start date in the format 'YYYY-MM-DD'.
+        end_date (str): The end date in the format 'YYYY-MM-DD'.
+
+    Returns:
+        str | None: The name of the saved chart file, or `None` if the operation fails.
+    """
     pool = await create_pool()
 
     if not validate_date(start_date) or not validate_date(end_date):
@@ -58,6 +85,15 @@ async def create_chart(from_currency: str, conv_currency: str, start_date: str,
 
 
 def validate_date(date_str: str) -> bool:
+    """
+    Validates whether the provided string is a valid date in the format 'YYYY-MM-DD'.
+
+    Args:
+        date_str (str): The date string to validate.
+
+    Returns:
+        bool: `True` if the string is a valid date, `False` otherwise.
+    """
     try:
         datetime.strptime(date_str, '%Y-%m-%d')
         return True

chart/function/gen_unique_name.py

@@ -1,9 +1,23 @@
+"""
+This module provides a function to generate a unique name for chart files.
+"""
 import datetime
 import random
 import string
 
 
 async def generate_unique_name(currency_pair: str, date: datetime) -> str:
+    """
+    Generates a unique name for a chart file based on the currency pair,
+    current date, and a random suffix.
+
+    Args:
+        currency_pair (str): A string representing the currency pair (e.g., "USD_EUR").
+        date (datetime.datetime): The current datetime object.
+
+    Returns:
+        str: A unique name in the format "CURRENCYPAIR_YYYYMMDD_RANDOMSUFFIX".
+    """
     date_str = date.strftime("%Y%m%d")
     random_suffix = ''.join(random.choices(string.ascii_uppercase + string.digits, k=6))
     unique_name = f"{currency_pair}_{date_str}_{random_suffix}"

chart/main.py

@@ -1,16 +1,22 @@
+"""
+This is the main application file for the chart service using FastAPI.
+
+The application serves static files, provides endpoints for generating charts,
+and integrates with Plausible Analytics for tracking usage.
+"""
+
 import os
 
 import uvicorn
-import yaml
-
 from fastapi import FastAPI
 from starlette.staticfiles import StaticFiles
 
 from chart.middleware.plausible_analytics import PlausibleAnalytics
 from chart.routes import get_chart, get_chart_period
+from chart.utils.load_config import load_config
 
 app = FastAPI()
-config = yaml.safe_load(open('config.yaml'))
+config = load_config('config.yaml')
 
 if not os.path.exists('../charts'):
     os.mkdir('../charts')
@@ -23,11 +29,16 @@ app.include_router(get_chart_period.router)
 
 
 if __name__ == '__main__':
-
     uvicorn.run(
         app,
         host=config['server']['host'],
         port=3030,
-        ssl_keyfile=config['server']['ssl']['private_key'] if config['server']['ssl']['work'] else None,
-        ssl_certfile=config['server']['ssl']['cert'] if config['server']['ssl']['work'] else None
+        ssl_keyfile=
+        config['server']['ssl']['private_key']
+        if config['server']['ssl']['work']
+        else None,
+        ssl_certfile=
+        config['server']['ssl']['cert']
+        if config['server']['ssl']['work']
+        else None
     )

chart/middleware/plausible_analytics.py

@@ -1,12 +1,25 @@
-import httpx
-import yaml
-
-from user_agents import parse as ua_parse
+"""
+This module provides middleware for integrating Plausible Analytics
+into a FastAPI application.
+"""
 from http import HTTPStatus
 
-config = yaml.safe_load(open('../config.yaml'))
+import httpx
+from user_agents import parse as ua_parse
 
+from chart.utils.load_config import load_config
+
+config = load_config('config.yaml')
+
+# pylint: disable=too-few-public-methods
 class PlausibleAnalytics:
+    """
+    Middleware for sending events to Plausible Analytics.
+
+    This middleware intercepts each incoming request, collects metadata such as
+    user-agent, request path, and response status, and sends it as an event to
+    Plausible Analytics.
+    """
     async def __call__(self, request, call_next):
         response = await call_next(request)
 
@@ -23,8 +36,10 @@ class PlausibleAnalytics:
             "props": {
                 "method": request.method,
                 "statusCode": response.status_code,
-                "browser": f"{user_agent_parsed.browser.family} {user_agent_parsed.browser.version_string}",
-                "os": f"{user_agent_parsed.os.family} {user_agent_parsed.os.version_string}",
+                "browser": f"{user_agent_parsed.browser.family} "
+                           f"{user_agent_parsed.browser.version_string}",
+                "os": f"{user_agent_parsed.os.family} "
+                      f"{user_agent_parsed.os.version_string}",
                 "source": request.headers.get('referer', 'direct'),
             },
         }
@@ -40,7 +55,12 @@ class PlausibleAnalytics:
                         "User-Agent": request.headers.get('user-agent', 'unknown'),
                     },
                 )
+            except httpx.RequestError as e:
+                print(f"Request error while sending event to Plausible: {e}")
+            except httpx.HTTPStatusError as e:
+                print(f"HTTP status error while sending event to Plausible: {e}")
+            # pylint: disable=broad-exception-caught
             except Exception as e:
-                print(f"Error sending event to Plausible: {e}")
+                print(f"Unexpected error sending event to Plausible: {e}")
 
         return response

chart/routes/get_chart.py

@@ -1,34 +1,60 @@
+"""
+This module contains the route for retrieving a chart based on a given currency pair and date range.
+It defines the `/api/getChart/` endpoint that processes requests for generating charts.
+"""
 from fastapi import APIRouter, status, Request, Response
+from pydantic import BaseModel
 
 from chart.function.create_chart import create_chart
 from chart.routes.get_chart_period import prepare_chart_response
 
 router = APIRouter()
 
+class ChartRequestParams(BaseModel):
+    """
+    A Pydantic model that represents the request parameters for generating a chart.
+
+    This model is used to validate and group the request parameters:
+    from_currency, conv_currency, start_date, and end_date.
+    """
+    from_currency: str
+    conv_currency: str
+    start_date: str
+    end_date: str
+
 @router.get("/api/getChart/", status_code=status.HTTP_201_CREATED)
 async def get_chart(
         response: Response,
         request: Request,
-        from_currency: str = None,
-        conv_currency: str = None,
-        start_date: str = None,
-        end_date: str = None,
+        params: ChartRequestParams
 ):
+    """
+    Fetches a chart for a given currency pair and date range.
 
-    if not from_currency or not conv_currency:
+    :param response: The response object used for returning the HTTP response.
+    :param request: The request object containing details about the incoming request.
+    :param params: Contains the request parameters:
+    from_currency, conv_currency, start_date, and end_date.
+    :return: A chart or an error message if the request is invalid.
+    """
+    if not params.from_currency or not params.conv_currency:
         response.status_code = status.HTTP_400_BAD_REQUEST
         return {
             'status': status.HTTP_400_BAD_REQUEST,
             'message': 'The from_currency and conv_currency fields are required.',
         }
 
-    elif not start_date and not end_date:
+    if not params.start_date or not params.end_date:
         response.status_code = status.HTTP_400_BAD_REQUEST
         return {
             'status': status.HTTP_400_BAD_REQUEST,
             'message': 'The start_date and end_date fields are required.',
         }
 
-
-    chart = await create_chart(from_currency, conv_currency, start_date, end_date)
+    chart = await create_chart(
+        params.from_currency,
+        params.conv_currency,
+        params.start_date,
+        params.end_date
+    )
     return await prepare_chart_response(response, request, chart)

chart/routes/get_chart_period.py

@@ -1,5 +1,12 @@
+"""
+This module defines the route for fetching a chart for a specific currency pair and period.
+
+It includes the endpoint `/api/getChart/{period}` which allows users to request a chart for
+a given currency pair (from_currency and conv_currency)
+over a specified time period (week, month, quarter, or year).
+"""
 from datetime import datetime
-import dateutil.relativedelta
+from dateutil.relativedelta import relativedelta
 
 from fastapi import APIRouter, status, Request, Response
 
@@ -15,7 +22,20 @@ async def get_chart_period(
         conv_currency: str = None,
         period: str = None,
 ):
+    """
+    Fetches a chart for a given currency pair and a specific period.
 
+    The period can be one of the following: 'week', 'month', 'quarter', 'year'.
+    Based on the selected period, it calculates the start date and retrieves the chart data.
+
+    :param response: The response object used to set status and message.
+    :param request: The request object used to retrieve details of the incoming request.
+    :param from_currency: The base currency in the pair (e.g., 'USD').
+    :param conv_currency: The target currency in the pair (e.g., 'EUR').
+    :param period: The time period for which the chart is requested
+    (e.g., 'week', 'month', 'quarter', 'year').
+    :return: A response containing the chart URL or an error message if parameters are invalid.
+    """
     if not from_currency or not conv_currency:
         response.status_code = status.HTTP_400_BAD_REQUEST
         return {
@@ -39,7 +59,7 @@ async def get_chart_period(
         years = -1
 
     end_date = datetime.now()
-    start_date = end_date + dateutil.relativedelta.relativedelta(months=month, days=days, years=years)
+    start_date = end_date + relativedelta(months=month, days=days, years=years)
 
     chart = await create_chart(
         from_currency,
@@ -51,7 +71,22 @@ async def get_chart_period(
     return await prepare_chart_response(response, request, chart)
 
 
-async def prepare_chart_response(response: Response, request: Request, chart_name: str):
+async def prepare_chart_response(
+        response: Response,
+        request: Request,
+        chart_name: str
+):
+    """
+    Prepares the response to return the URL of the generated chart.
+
+    If the chart data is not found, it returns a 404 error with an appropriate message.
+    Otherwise, it returns a URL to access the chart image.
+
+    :param response: The response object used to set status and message.
+    :param request: The request object used to retrieve details of the incoming request.
+    :param chart_name: The name of the generated chart (used to build the URL).
+    :return: A dictionary with the chart URL or an error message if no chart is found.
+    """
     if not chart_name:
         response.status_code = status.HTTP_404_NOT_FOUND
         return {'message': 'No data found.', 'status_code': status.HTTP_404_NOT_FOUND}