import base64 from datetime import datetime from io import BytesIO import matplotlib.pyplot as plt import matplotlib.dates as mdates import pandas as pd from django.db.models import F, IntegerField, QuerySet, Sum from django.db.models.functions import TruncDay from games.models import Session def key_value_to_value_value(data): return {data["date"]: data["hours"]} def playtime_over_time_chart(queryset: QuerySet = Session.objects): microsecond_in_second = 1000000 result = ( queryset.exclude(timestamp_end__exact=None) .annotate(date=TruncDay("timestamp_start")) .values("date") .annotate( hours=Sum( F("duration_calculated"), output_field=IntegerField(), ) ) .values("date", "hours") ) keys = [] values = [] running_total = int(0) for item in result: # date_value = datetime.strftime(item["date"], "%d-%m-%Y") date_value = item["date"] keys.append(date_value) running_total += int(item["hours"] / (3600 * microsecond_in_second)) values.append(running_total) data = [keys, values] return get_chart( data, title="Playtime over time (manual excluded)", xlabel="Date", ylabel="Hours", ) def get_graph(): buffer = BytesIO() plt.savefig(buffer, format="svg", transparent=True) buffer.seek(0) image_png = buffer.getvalue() graph = base64.b64encode(image_png) graph = graph.decode("utf-8") buffer.close() return graph def get_chart(data, title="", xlabel="", ylabel=""): x = data[0] y = data[1] plt.style.use("dark_background") plt.switch_backend("SVG") fig, ax = plt.subplots() fig.set_size_inches(10, 4) ax.plot(x, y) first = x[0] last = x[-1] difference = last - first if difference.days <= 14: ax.xaxis.set_major_locator(mdates.DayLocator()) elif difference.days < 60 or len(x) < 60: ax.xaxis.set_major_locator(mdates.WeekdayLocator()) ax.xaxis.set_minor_locator(mdates.DayLocator()) elif difference.days < 720: ax.xaxis.set_major_locator(mdates.MonthLocator()) ax.xaxis.set_minor_locator(mdates.WeekdayLocator()) else: ax.xaxis.set_major_locator(mdates.YearLocator()) ax.xaxis.set_minor_locator(mdates.MonthLocator()) ax.xaxis.set_major_formatter(mdates.DateFormatter("%Y-%m-%d")) for label in ax.get_xticklabels(which="major"): label.set(rotation=30, horizontalalignment="right") ax.set_xlabel(xlabel) ax.set_ylabel(ylabel) ax.set_title(title) fig.tight_layout() chart = get_graph() return chart