feat(plan): split the Import p cell when the car's own rate diverges

apps/predbat/output.py

@@ -18,6 +18,7 @@
 
 import math
 import copy
+from html import escape as escape_html
 from datetime import datetime, timedelta
 from config import THIS_VERSION
 from const import TIME_FORMAT, PREDICT_STEP, EXPORT_LIMIT_FREEZE, EXPORT_LIMIT_IDLE, MINUTE_WATT
@@ -1069,6 +1070,16 @@ def publish_html_plan(self, pv_forecast_minute_step, pv_forecast_minute_step10,
         if self.rate_best_cost_threshold_export:
             export_cost_threshold = self.rate_best_cost_threshold_export
 
+        def import_rate_color(rate):
+            """Colour an import rate the same way as the plan's own Import p column (blue/green/yellow/red)."""
+            if rate <= 0:
+                return "#74C1FF"
+            elif rate <= import_cost_threshold:
+                return "#3AEE85"
+            elif rate > (import_cost_threshold * 1.5):
+                return "#F18261"
+            return "#FFFFAA"
+
         raw_plan["import_cost_threshold"] = import_cost_threshold
         raw_plan["export_cost_threshold"] = export_cost_threshold
         raw_plan["reason_templates"] = REASON_TEMPLATES
@@ -1310,12 +1321,7 @@ def publish_html_plan(self, pv_forecast_minute_step, pv_forecast_minute_step10,
             if plan_debug and load_forecast10 > 0.0:
                 load_forecast += " (%s)" % (str(load_forecast10))
 
-            if rate_value_import <= 0:  # colour the import rate, blue for negative, then green, yellow and red
-                rate_color_import = "#74C1FF"
-            elif rate_value_import <= import_cost_threshold:
-                rate_color_import = "#3AEE85"
-            elif rate_value_import > (import_cost_threshold * 1.5):
-                rate_color_import = "#F18261"
+            rate_color_import = import_rate_color(rate_value_import)  # blue for negative, then green, yellow and red
 
             if rate_value_export >= (1.5 * export_cost_threshold):
                 rate_color_export = "#F18261"
@@ -1501,16 +1507,26 @@ def publish_html_plan(self, pv_forecast_minute_step, pv_forecast_minute_step10,
                 cost_color = "#FFFFFF"
 
             # Car charging?
+            car_rate = None
             if self.num_cars > 0:
                 car_charging_kwh = self.car_charge_slot_kwh(minute_start, minute_end)
                 car_total += car_charging_kwh
                 if car_charging_kwh > 0.0:
                     car_charging_str = str(car_charging_kwh)
                     car_color = "FFFF00"
+                    car_rate = self.car_charge_slot_rate(minute_start, minute_end)
                 else:
                     car_charging_str = "&#9866;"
                     car_color = "#FFFFFF"
 
+            # The car's own rate can diverge from the general household rate once its IOG dispatch
+            # cap is used up for the day - the car falls back to the peak rate while the house keeps
+            # its real (possibly still cheap) rate for the same clock-time (batpred#4646). Split the
+            # Import p cell to show both when that happens.
+            rate_split = car_rate is not None and abs(car_rate - rate_value_import) > 0.01
+            if rate_split:
+                car_rate_color = import_rate_color(car_rate)
+
             # iBoost
             iboost_amount_str = "&#9866;"
             iboost_color = "#FFFFFF"
@@ -1582,7 +1598,16 @@ def publish_html_plan(self, pv_forecast_minute_step, pv_forecast_minute_step10,
             # Table row
             html += '<tr style="color:black">'
             html += "<td id=time bgcolor=#FFFFFF>" + rate_start.strftime("%a %H:%M") + "</td>"
-            html += "<td id=import data-minute=" + str(minute) + " data-rate=" + str(rate_value_import) + " " + cell_style + " bgcolor=" + rate_color_import + ">" + str(rate_str_import) + " </td>"
+            if rate_split:
+                house_title = escape_html("House rate: {:.2f}{}/kWh".format(rate_value_import, self.currency_symbols[1]), quote=True)
+                car_title = escape_html("Car rate: {:.2f}{}/kWh (differs from house rate)".format(car_rate, self.currency_symbols[1]), quote=True)
+                html += "<td id=import data-minute=" + str(minute) + " data-rate=" + str(rate_value_import) + ' style="padding:0;">'
+                html += '<div style="display:flex;">'
+                html += '<div style="flex:1;padding:4px;background-color:' + rate_color_import + ';" title="' + house_title + '">' + str(rate_str_import) + "</div>"
+                html += '<div style="flex:1;padding:4px;background-color:' + car_rate_color + ';" title="' + car_title + '">' + "{:.2f}".format(car_rate) + "</div>"
+                html += "</div></td>"
+            else:
+                html += "<td id=import data-minute=" + str(minute) + " data-rate=" + str(rate_value_import) + " " + cell_style + " bgcolor=" + rate_color_import + ">" + str(rate_str_import) + " </td>"
             html += "<td id=export data-minute=" + str(minute) + " data-rate=" + str(rate_value_export) + " " + cell_style + " bgcolor=" + rate_color_export + ">" + str(rate_str_export) + " </td>"
             if start_span:
                 if split:  # for slots that are both charging and exporting, just output the (split cell) state
@@ -1689,6 +1714,9 @@ def publish_html_plan(self, pv_forecast_minute_step, pv_forecast_minute_step10,
             if self.num_cars > 0:
                 json_row["car_charging"] = car_charging_kwh
                 json_row["car_color"] = car_color
+                json_row["car_rate"] = car_rate
+                json_row["car_rate_color"] = car_rate_color if rate_split else None
+                json_row["rate_split"] = rate_split
             if self.iboost_enable:
                 json_row["iboost"] = iboost_amount
                 json_row["iboost_change"] = iboost_change

apps/predbat/plan.py

@@ -5256,6 +5256,37 @@ def car_charge_slot_kwh(self, minute_start, minute_end):
             car_charging_kwh = dp2(car_charging_kwh)
         return car_charging_kwh
 
+    def car_charge_slot_rate(self, minute_start, minute_end):
+        """
+        Work out the car's own effective import rate (p/kWh) for the given
+        self.plan_interval_minutes-minute slot - the kWh-weighted average across any
+        car_charging_slots windows active in it. This can differ from the general household
+        import rate once a car's IOG dispatch cap is exhausted for the day (batpred#4646).
+        Returns None if no car charging in this slot.
+        """
+        total_kwh = 0.0
+        total_cost = 0.0
+        if self.num_cars > 0:
+            for car_n in range(self.num_cars):
+                for window in self.car_charging_slots[car_n]:
+                    if "average" not in window:
+                        # Non-Octopus historical reconstruction (Yesterday view) appends slots from
+                        # the car's own energy sensor with no rate at all - treating that as 0p/kWh
+                        # would drag the weighted average down and falsely flag ordinary charging as
+                        # diverging from the house rate. Skip rather than guess.
+                        continue
+                    start = window["start"]
+                    end = window["end"]
+                    if start < minute_end and end > minute_start and end != start:
+                        overlap_start = max(start, minute_start)
+                        overlap_end = min(end, minute_end)
+                        kwh = dp2(window["kwh"]) * (overlap_end - overlap_start) / (end - start)
+                        total_kwh += kwh
+                        total_cost += kwh * window["average"]
+        if total_kwh > 0.0001:
+            return dp2(total_cost / total_kwh)
+        return None
+
     def hit_car_window(self, window_start, window_end, cache=None):
         """Does this window intersect a car charging window?
 

apps/predbat/tests/test_octopus_slots.py

@@ -80,6 +80,10 @@ def run_load_octopus_slots_tests(my_predbat):
     my_predbat.rate_max_base = 10
     my_predbat.car_charging_rate = [5.0]
     my_predbat.args["octopus_slot_max"] = 12
+    # load_octopus_slots() short-circuits to [] when car_n >= self.num_cars - set this explicitly
+    # rather than relying on whatever a previous test in the same run left num_cars as (a shared
+    # my_predbat instance persists across tests within a run).
+    my_predbat.num_cars = 1
 
     # Created 8 slots in total in the next 16 hours
     soc = 2.0

apps/predbat/tests/test_plan_json_rate_adjust.py

@@ -140,6 +140,70 @@ def run_test_plan_json_rate_adjust(my_predbat):
     my_predbat.rate_import_replicated = {}
     my_predbat.rate_export_replicated = {}
 
+    # --- Test 3: car rate diverging from the house rate (batpred#4646) ---
+    print("Test plan JSON output with a car rate that diverges from the house rate")
+    my_predbat.num_cars = 1
+    car_minute = my_predbat.minutes_now
+    my_predbat.car_charging_slots[0] = [{"start": car_minute, "end": car_minute + 30, "kwh": 3.0, "average": 28.0, "cost": 84.0, "soc": 0.0, "octopus": True}]
+
+    html_plan, raw_plan = my_predbat.publish_html_plan(pv_step, pv_step, load_step, load_step, my_predbat.end_record, publish=False)
+    car_row = next((row for row in raw_plan["rows"] if row.get("slot_minute") == car_minute), None)
+    if car_row is None:
+        print("WARNING: Could not find row for car minute {} in plan output".format(car_minute))
+    else:
+        if car_row.get("car_rate") != 28.0:
+            print("ERROR: Expected car_rate=28.0 got {}".format(car_row.get("car_rate")))
+            failed = True
+        if car_row.get("rate_split") is not True:
+            print("ERROR: Expected rate_split=True when car rate (28.0) diverges from house rate (10.0), got {}".format(car_row.get("rate_split")))
+            failed = True
+        if not car_row.get("car_rate_color"):
+            print("ERROR: Expected car_rate_color to be set when rate_split is True")
+            failed = True
+        if "House rate: 10.00" not in html_plan or "Car rate: 28.00" not in html_plan:
+            print("ERROR: Expected split-cell HTML with house and car rate tooltips, got:\n{}".format(html_plan))
+            failed = True
+        if "differs from house rate" not in html_plan:
+            print("ERROR: Expected the car tooltip to use neutral 'differs from house rate' wording (not every divergence is an IOG cap), got:\n{}".format(html_plan))
+            failed = True
+
+    # currency_symbols is user-configurable free text - a value carrying a double-quote must not
+    # break out of the split cell's title="..." attribute in the server-rendered plan (batpred#4647
+    # review). Checking for the specific escaped form within the title, not a blanket string search -
+    # currency_symbols is also embedded unescaped elsewhere on the page (e.g. the Cost cell text,
+    # pre-existing and out of scope for this fix), which would give a false pass/fail either way.
+    saved_currency_symbols = my_predbat.currency_symbols
+    breakout = '"><script>alert(1)</script>'
+    my_predbat.currency_symbols = ["£", "p" + breakout]
+    html_plan, raw_plan = my_predbat.publish_html_plan(pv_step, pv_step, load_step, load_step, my_predbat.end_record, publish=False)
+    expected_escaped = "House rate: 10.00p&quot;&gt;&lt;script&gt;alert(1)&lt;/script&gt;/kWh"
+    if expected_escaped not in html_plan:
+        print("ERROR: expected the split-cell title to HTML-escape currency_symbols, wanted:\n{}\ngot:\n{}".format(expected_escaped, html_plan))
+        failed = True
+    my_predbat.currency_symbols = saved_currency_symbols
+
+    # Same car window, but priced the same as the house rate - must not split
+    my_predbat.car_charging_slots[0] = [{"start": car_minute, "end": car_minute + 30, "kwh": 3.0, "average": 10.0, "cost": 30.0, "soc": 0.0, "octopus": True}]
+    html_plan, raw_plan = my_predbat.publish_html_plan(pv_step, pv_step, load_step, load_step, my_predbat.end_record, publish=False)
+    car_row = next((row for row in raw_plan["rows"] if row.get("slot_minute") == car_minute), None)
+    if car_row is not None and car_row.get("rate_split") is not False:
+        print("ERROR: Expected rate_split=False when car rate matches house rate, got {}".format(car_row.get("rate_split")))
+        failed = True
+
+    # A window with no "average" key at all (non-Octopus historical reconstruction in
+    # calculate_yesterday() appends slots like this from the car's own energy sensor) must not be
+    # treated as a free/0p charge - that would drag the weighted average down and falsely flag
+    # ordinary charging as diverging from the house rate.
+    my_predbat.car_charging_slots[0] = [{"start": car_minute, "end": car_minute + 30, "kwh": 3.0, "octopus": False}]
+    rate = my_predbat.car_charge_slot_rate(car_minute, car_minute + 30)
+    if rate is not None:
+        print("ERROR: Expected car_charge_slot_rate to skip a window with no average key, got {}".format(rate))
+        failed = True
+
+    # Clean up
+    my_predbat.num_cars = 0
+    my_predbat.car_charging_slots[0] = []
+
     if not failed:
         print("All plan JSON rate adjust type tests passed")
     return failed

apps/predbat/web_helper.py

@@ -6526,6 +6526,17 @@ def get_plan_renderer_js():
                 }
                 if (editable) {
                     html += renderRateCell(row.import_rate, row.rate_color_import, 'import', row.time, timeDisplay, overrides, importText, row.slot_minute);
+                } else if (row.rate_split) {
+                    // Car's own rate has diverged from the house rate - not necessarily an IOG cap
+                    // (any car window with its own average can diverge, e.g. combined dynamic-rate
+                    // windows) - split the cell, house on the left, car on the right, own tooltip each.
+                    const houseTitle = escapeAttr(`House rate: ${row.import_rate.toFixed(2)}${currencyMinor}/kWh`);
+                    const carTitle = escapeAttr(`Car rate: ${row.car_rate.toFixed(2)}${currencyMinor}/kWh (differs from house rate)`);
+                    html += `<td id=import data-minute="${row.slot_minute}" data-rate="${row.import_rate}" style="padding:0;">`;
+                    html += `<div style="display:flex;">`;
+                    html += `<div style="flex:1;padding:4px;background-color:${row.rate_color_import || '#FFFFFF'};" title="${houseTitle}">${importText}</div>`;
+                    html += `<div style="flex:1;padding:4px;background-color:${row.car_rate_color || '#FFFFFF'};" title="${carTitle}">${row.car_rate.toFixed(2)}</div>`;
+                    html += `</div></td>`;
                 } else {
                     html += `<td id=import ${cellStyle} bgcolor=${row.rate_color_import || '#FFFFFF'}>${importText}</td>`;
                 }