CDD-3295: Add chart labels, legends and chart settings

Author: tushortz

metrics/api/serializers/charts/dual_category_charts.py

@@ -116,6 +116,7 @@ def to_models(self, request: Request) -> DualCategoryChartRequestParams:
                     **static_fields,
                     secondary_category: segment["secondary_field_value"],
                     "chart_type": self.data["chart_type"],
+                    "label": segment["label"],
                 }
                 for segment in segments
             ]
@@ -132,6 +133,7 @@ def to_models(self, request: Request) -> DualCategoryChartRequestParams:
                         x_axis: primary_field_value,
                         secondary_category: segment["secondary_field_value"],
                         "chart_type": self.data["chart_type"],
+                        "label": segment["label"],
                     }
                     for segment in segments
                 ]
@@ -154,4 +156,5 @@ def to_models(self, request: Request) -> DualCategoryChartRequestParams:
             or DEFAULT_Y_AXIS_MINIMUM_VAlUE,
             y_axis_maximum_value=self.data["y_axis_maximum_value"],
             request=request,
+            legend_title=self.data.get("legend_title", ""),
         )

metrics/domain/charts/chart_settings/dual_category.py

@@ -0,0 +1,50 @@
+from metrics.domain.charts.chart_settings.single_category import (
+    SingleCategoryChartSettings,
+)
+from metrics.domain.models.plots import ChartGenerationPayload, PlotGenerationData
+
+
+class DualCategoryChartSettings(SingleCategoryChartSettings):
+    def __init__(self, *, chart_generation_payload: ChartGenerationPayload):
+        super().__init__(chart_generation_payload=chart_generation_payload)
+        self.plots_data: list[PlotGenerationData] = chart_generation_payload.plots
+
+    def get_stacked_bar_chart_config(self) -> dict:
+        """
+        Builds the configuration for the stacked bar chart.
+
+        Returns:
+            The configuration for the stacked bar chart.
+        """
+        chart_config = self._get_base_chart_config()
+
+        chart_config["barmode"] = "stack"
+
+        return {**chart_config, **self._get_legend_config()}
+
+    def _get_legend_config(self) -> dict:
+        """
+        Builds the configuration for the legend.
+
+        Returns:
+            The configuration for the legend.
+        """
+        legend_config = {
+            "font": self._get_tick_font_config(),
+            "orientation": "h",
+            "y": 1.0,
+            "x": 0.5,
+            "xanchor": "center",
+            "yanchor": "bottom",
+            "entrywidth": 80,
+        }
+
+        if legend_title := self._chart_generation_payload.legend_title:
+            legend_config["title"] = {
+                "text": f"<b>{legend_title}</b>",
+                "side": "top",
+            }
+
+        return {
+            "legend": legend_config,
+        }

metrics/domain/charts/stacked_bar/generation.py

@@ -2,6 +2,7 @@
 
 import plotly.graph_objects as go
 
+from metrics.domain.charts.chart_settings.dual_category import DualCategoryChartSettings
 from metrics.domain.models.plots import ChartGenerationPayload
 
 
@@ -26,19 +27,23 @@ def generate_stacked_bar(
 
     secondary_category = chart_generation_payload.secondary_category
     for plot in chart_generation_payload.plots:
-        group = plot.parameters.model_dump()[secondary_category]
+        group = getattr(plot.parameters, secondary_category)
         grouped[group]["x_axis_values"].extend(plot.x_axis_values)
         grouped[group]["y_axis_values"].extend(plot.y_axis_values)
+        grouped[group]["label"] = plot.parameters.label
 
     for label, data in grouped.items():
         figure.add_trace(
             go.Bar(
                 x=data["x_axis_values"],
                 y=data["y_axis_values"],
-                name=label,
+                name=data["label"] or label,
             )
         )
 
-    figure.update_layout({"xaxis": {"type": "category"}}, barmode="stack")
+    settings = DualCategoryChartSettings(
+        chart_generation_payload=chart_generation_payload,
+    )
+    figure.update_layout(**settings.get_stacked_bar_chart_config())
 
     return figure

metrics/domain/models/charts/dual_category_charts.py

@@ -22,3 +22,4 @@ class DualCategoryChartRequestParams(BaseChartRequestParams):
     primary_field_values: list[str]
     static_fields: StaticFields
     plots: list[PlotParameters]
+    legend_title: str | None = ""

tests/unit/metrics/domain/charts/chart_settings/test_chart_settings_dual_category.py

@@ -0,0 +1,104 @@
+import pytest
+
+from metrics.domain.charts.chart_settings.dual_category import DualCategoryChartSettings
+from metrics.domain.models import ChartGenerationPayload, PlotGenerationData
+from tests.conftest import fake_plot_data
+
+
+@pytest.fixture()
+def fake_dual_category_chart_settings(
+    fake_plot_data: PlotGenerationData,
+) -> DualCategoryChartSettings:
+    payload = ChartGenerationPayload(
+        chart_width=640,
+        chart_height=400,
+        plots=[fake_plot_data],
+        x_axis_title="Date",
+        y_axis_title="Cases",
+    )
+    return DualCategoryChartSettings(chart_generation_payload=payload)
+
+
+class TestDualCategoryChartSettings:
+    def test_get_legend_config(
+        self, fake_dual_category_chart_settings: DualCategoryChartSettings
+    ):
+        """
+        Given an instance of `DualCategoryChartSettings` without a legend title
+        When `_get_legend_config()` is called
+        Then the legend configuration is returned without a title
+        """
+        # Given
+        chart_settings = fake_dual_category_chart_settings
+
+        # When
+        legend_config = chart_settings._get_legend_config()
+
+        # Then
+        assert legend_config == {
+            "legend": {
+                "font": chart_settings._get_tick_font_config(),
+                "orientation": "h",
+                "y": 1.0,
+                "x": 0.5,
+                "xanchor": "center",
+                "yanchor": "bottom",
+                "entrywidth": 80,
+            },
+        }
+
+    def test_get_legend_config_includes_legend_title_when_provided(
+        self, fake_dual_category_chart_settings: DualCategoryChartSettings
+    ):
+        """
+        Given an instance of `DualCategoryChartSettings` with a legend title
+        When `_get_legend_config()` is called
+        Then the legend configuration includes a formatted title
+        """
+        # Given
+        chart_settings = fake_dual_category_chart_settings
+        legend_title = "Age group"
+        chart_settings._chart_generation_payload.legend_title = legend_title
+
+        # When
+        legend_config = chart_settings._get_legend_config()
+
+        # Then
+        assert legend_config == {
+            "legend": {
+                "font": chart_settings._get_tick_font_config(),
+                "orientation": "h",
+                "y": 1.0,
+                "x": 0.5,
+                "xanchor": "center",
+                "yanchor": "bottom",
+                "entrywidth": 80,
+                "title": {
+                    "text": f"<b>{legend_title}</b>",
+                    "side": "top",
+                },
+            },
+        }
+
+    def test_get_stacked_bar_chart_config(
+        self, fake_dual_category_chart_settings: DualCategoryChartSettings
+    ):
+        """
+        Given an instance of `DualCategoryChartSettings`
+        When `get_stacked_bar_chart_config()` is called
+        Then stacked bar layout and legend settings are merged
+        """
+        # Given
+        chart_settings = fake_dual_category_chart_settings
+
+        # When
+        stacked_bar_config = chart_settings.get_stacked_bar_chart_config()
+
+        expected_config = {
+            **chart_settings._get_base_chart_config(),
+            **chart_settings._get_legend_config(),
+            "barmode": "stack",
+        }
+
+        # Then
+        assert stacked_bar_config == expected_config