Kekkai/chart/main.py

import os
import psycopg2
import uvicorn
import yaml
import matplotlib.pyplot as plt
import locale
import datetime
import dateutil.relativedelta

from fastapi import FastAPI, Response, status
from psycopg2.extras import DictCursor
from starlette.staticfiles import StaticFiles


app = FastAPI()

config = yaml.safe_load(open('../config.yaml'))

con = psycopg2.connect(host=config['database']['host'],
                       user=config['database']['user'],
                       password=config['database']['password'],
                       database=config['database']['name'],
                       port=config['database']['port'])

cur = con.cursor(cursor_factory=DictCursor)
con.autocommit = True

if not os.path.exists('../charts'):
    os.mkdir('../charts')

app.mount('/static/charts', StaticFiles(directory='../charts/'))


@app.get("/api/getChart/")
async def get_chart(response: Response,
                    from_currency: str, conv_currency: str,
                    start_date: str, end_date: str):

    chart = await create_chart(from_currency, conv_currency, start_date, end_date)

    if not chart:
        response.status_code = status.HTTP_404_NOT_FOUND
        return {'message': 'No data found.', 'status_code': status.HTTP_404_NOT_FOUND}

    return {'message': f'./static/charts/{from_currency}-{conv_currency}.png',
            'status_code': status.HTTP_201_CREATED,
            }


@app.get("/api/getChart/{period}")
async def get_chart_period(response: Response, from_currency: str, conv_currency: str, period: str):
    if period not in ['week', 'month', 'quarter', 'year']:
        response.status_code = status.HTTP_400_BAD_REQUEST
        return {'message': 'Invalid period.', 'status_code': status.HTTP_400_BAD_REQUEST}

    days, month, years = 0, 0, 0

    if period == 'week':
        days = -7
    elif period == 'month':
        month = -1
    elif period == 'quarter':
        month = -3
    elif period == 'year':
        years = -1

    end_date = datetime.datetime.now()
    start_date = end_date + dateutil.relativedelta.relativedelta(months=month, days=days, years=years)

    chart = await create_chart(from_currency,
                               conv_currency,
                               start_date.strftime('%Y-%m-%d'),
                               end_date.strftime('%Y-%m-%d')
                               )

    if not chart:
        response.status_code = status.HTTP_404_NOT_FOUND
        return {'message': 'No data found.', 'status_code': status.HTTP_404_NOT_FOUND}

    return {'message': f'./static/charts/{from_currency}-{conv_currency}.png',
            'status_code': status.HTTP_201_CREATED,
            }


async def create_chart(from_currency: str, conv_currency: str, start_date: str, end_date: str) -> bool:
    cur.execute('SELECT date, rate FROM currency WHERE (date BETWEEN %s AND %s) '
                'AND from_currency = %s AND conv_currency = %s ORDER BY date',
                [
                    start_date, end_date,
                    from_currency.upper(), conv_currency.upper()
                ])

    con.commit()
    data = cur.fetchall()

    if not data or len(data) <= 1:
        return False

    date, rate = [], []

    for i in range(len(data)):
        date.append(str(data[i][0]))
        rate.append(data[i][1])

    if rate[0] < rate[-1]:
        plt.plot(date, rate, color='green')
    elif rate[0] > rate[-1]:
        plt.plot(date, rate, color='red')
    else:
        plt.plot(date, rate, color='grey')

    plt.xlabel('Date')
    plt.ylabel('Rate')

    fig = plt.gcf()
    fig.set_size_inches(18.5, 9.5)

    fig.savefig(f'../charts/{from_currency}-{conv_currency}.png')
    fig.clear()

    return True


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
                )