display graphs for exchange rates

apps/monitor/graph.py

@@ -0,0 +1,96 @@
+from django.db import connection
+import datetime
+import matplotlib.pyplot as plt
+from io import StringIO
+from matplotlib.backends.backend_agg import FigureCanvasAgg
+from matplotlib.figure import Figure
+import matplotlib.ticker as plticker
+from django.http import HttpResponse
+
+class Graph:
+
+    def graph_days(self, Crypto, Fiat, DayDiff):
+
+        x = []
+        y = []
+
+        with connection.cursor() as cursor:
+            sql = """SELECT date(datetime_valid), rate FROM 
+                     (select date(datetime_valid) as day, max(datetime_valid) as last
+                        from exchangerate WHERE crypto_currency = %s AND fiat_currency = %s
+                        AND datetime_valid >= %s
+                        GROUP BY day
+                        ORDER BY datetime_valid DESC) AS a
+                     JOIN exchangerate AS b ON a.last = b.datetime_valid
+                     AND crypto_currency = %s AND fiat_currency = %s
+                     ORDER BY datetime_valid ASC"""
+            startDate = datetime.datetime.today().replace(hour=0, minute=0, second=0, microsecond=0) - datetime.timedelta(days=int(DayDiff))
+            cursor.execute(sql, [Crypto, Fiat, startDate, Crypto, Fiat])
+            rows = cursor.fetchall()
+            for row in rows:
+                x.append(datetime.datetime.strptime(row[0], '%Y-%m-%d'))
+                y.append(row[1])
+
+        if len(x) == 0:
+            raise Exception("no data for this time range in the database")
+
+        fig_size = plt.rcParams["figure.figsize"]
+        fig_size[0] = 5
+        fig_size[1] = 4
+        plt.rcParams["figure.figsize"] = fig_size
+
+        fig = Figure()
+        ax = fig.add_subplot(1, 1, 1)
+
+        ax.plot(x, y, color='green', linestyle='dashed', linewidth = 2,
+                 marker='o', markerfacecolor='blue', markersize=2)
+
+        loc = plticker.MultipleLocator(base=(len(x)/4.0))
+        ax.xaxis.set_major_locator(loc)
+
+        ax.set_xlabel("time")
+        ax.set_ylabel(Fiat)
+        ax.set_title(('%s in %s' % (Crypto, Fiat)))
+
+        response = HttpResponse(content_type = 'image/png')
+        canvas = FigureCanvasAgg(fig)
+        canvas.print_png(response)
+        return response
+
+    def graph_hours(self, Crypto, Fiat, HourDiff):
+
+        x = []
+        y = []
+
+        with connection.cursor() as cursor:
+            sql = """SELECT datetime_valid, rate FROM exchangerate
+                     WHERE crypto_currency = %s AND fiat_currency = %s
+                     AND datetime_valid >= %s
+                     ORDER BY datetime_valid ASC"""
+            startDate = datetime.datetime.today() - datetime.timedelta(hours=int(HourDiff))
+            cursor.execute(sql, [Crypto, Fiat, startDate])
+            rows = cursor.fetchall()
+            for row in rows:
+                x.append(row[0])
+                y.append(row[1])
+
+        if len(x) == 0:
+            raise Exception("no data for this time range in the database")
+
+        fig = Figure()
+        ax = fig.add_subplot(1, 1, 1)
+
+        ax.plot(x, y, color='green', linestyle='dashed', linewidth = 2,
+                 marker='o', markerfacecolor='blue', markersize=2)
+
+        loc = plticker.MultipleLocator(base=(len(x)/5.0))
+        ax.xaxis.set_major_locator(loc)
+
+        ax.set_xlabel("time")
+        ax.set_ylabel(Fiat)
+        ax.set_title(('%s in %s' % (Crypto, Fiat)))
+
+        response = HttpResponse(content_type = 'image/png')
+        canvas = FigureCanvasAgg(fig)
+        canvas.print_png(response)
+        return response

apps/monitor/templates/monitor.html

@@ -3,6 +3,7 @@
 {% block content %}
 <div class="form-box">
   <h2>Monitor</h2>
+  <a href="/monitor" class="button button-primary">Refresh</a><br/>
   <p>Hint: these numbers are not very accurate.</p>
   
 {% for c in cryptos %}
@@ -29,6 +30,7 @@
     {% if c.bought_tax_free %}
     We can sell without paying taxes: {{ c.bought_tax_free|floatformat:3 }} {{ c.crypto }} for {{ c.value_tax_free|floatformat:2 }} EUR<br/>
     {% endif %}
+    <br/><a href="/transactions/show?crypto={{ c.crypto }}">My transactions</a><br/>
 
     {% if c.rates %}
       <table>
@@ -44,9 +46,55 @@
         </tr>
         {% endfor %}
       </table>
+
+      <ul class="tab-nav">
+          <li>
+            <a class="button active" href="#h48{{ c.crypto }}">48 hours</a>
+          </li>
+          <li>
+            <a class="button" href="#d3{{ c.crypto }}">3 days</a>
+          </li>
+          <li>
+            <a class="button" href="#w1{{ c.crypto }}">1 week</a>
+          </li>
+          <li>
+            <a class="button" href="#m1{{ c.crypto }}">1 month</a>
+          </li>
+          <li>
+            <a class="button" href="#m6{{ c.crypto }}">6 months</a>
+          </li>
+          <li>
+            <a class="button" href="#y1{{ c.crypto }}">1 year</a>
+          </li>
+      </ul>
+      <div class="tab-content">
+          <div class="tab-pane active" id="h48{{ c.crypto }}">
+              48 hours
+              <img src="/graph?crypto={{ c.crypto }}&fiat=EUR&number_of_hours=48" loading="lazy">
+          </div>
+          <div class="tab-pane" id="d3{{ c.crypto }}">
+              3 days
+              <img src="/graph?crypto={{ c.crypto }}&fiat=EUR&number_of_days=3" loading="lazy">
+          </div>
+          <div class="tab-pane" id="w1{{ c.crypto }}">
+              1 week
+              <img src="/graph?crypto={{ c.crypto }}&fiat=EUR&number_of_days=7" loading="lazy">
+          </div>
+          <div class="tab-pane" id="m1{{ c.crypto }}">
+              1 month
+              <img src="/graph?crypto={{ c.crypto }}&fiat=EUR&number_of_days=30" loading="lazy">
+          </div>
+          <div class="tab-pane" id="m6{{ c.crypto }}">
+              6 months
+              <img src="/graph?crypto={{ c.crypto }}&fiat=EUR&number_of_days=180" loading="lazy">
+          </div>
+          <div class="tab-pane" id="y1{{ c.crypto }}">
+              1 year
+              <img src="/graph?crypto={{ c.crypto }}&fiat=EUR&number_of_days=360" loading="lazy">
+          </div>
+      </div>
     {% endif %}
 
-    <br/><a href="/transactions/show?crypto={{ c.crypto }}">My transactions</a><br/>
     <br/>
     Google: <br/>
     <a href='https://www.google.com/search?channel=crow2&client=firefox-b-d&q={{ c.crypto }}+in+eur%3D' target='_blank'>{{ c.crypto }} in EUR</a><br/>

apps/monitor/views.py

@@ -3,6 +3,7 @@ from django.contrib.auth.decorators import login_required
 from apps.transactions.models import Transaction
 from apps.rates.models import ExchangeRate
 from apps.monitor.calc import Calc
+from apps.monitor.graph import Graph
 
 @login_required
 def monitor(request):
@@ -20,3 +21,17 @@ def monitor(request):
         cryptos.append({"crypto": crypto, "rateEUR": rateEUR, "rateUSD": rateUSD, **out2})
 
     return render(request,"monitor.html",{'cryptos':cryptos, 'total_tax_free': total_tax_free, 'total_investment': total_investment, 'current_value': current_value})
+
+@login_required
+def graph(request):
+    if not 'crypto' in request.GET:
+        return
+    if not 'fiat' in request.GET:
+        return
+    Crypto = request.GET['crypto']
+    Fiat = request.GET['fiat']
+
+    if 'number_of_days' in request.GET:
+        return Graph().graph_days(Crypto, Fiat, request.GET['number_of_days'])
+    if 'number_of_hours' in request.GET:
+        return Graph().graph_hours(Crypto, Fiat, request.GET['number_of_hours'])