From 03e79685a121098f943e2a0f9f78e55607f5417c Mon Sep 17 00:00:00 2001
From: alceal <alceal@gmail.com>
Date: Sat, 4 Jan 2025 21:12:41 +0100
Subject: [PATCH] feat: Add PieChart support for visualizing categorical data

---
 src/lib.rs            |   1 +
 src/plots/mod.rs      |   1 +
 src/plots/piechart.rs | 155 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 157 insertions(+)
 create mode 100644 src/plots/piechart.rs

diff --git a/src/lib.rs b/src/lib.rs
index 400843d..780a658 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -23,6 +23,7 @@ pub use crate::plots::heatmap::HeatMap;
 pub use crate::plots::histogram::Histogram;
 pub use crate::plots::image::Image;
 pub use crate::plots::lineplot::LinePlot;
+pub use crate::plots::piechart::PieChart;
 pub use crate::plots::scatter3dplot::Scatter3dPlot;
 pub use crate::plots::scatterplot::ScatterPlot;
 pub use crate::plots::timeseriesplot::TimeSeriesPlot;
diff --git a/src/plots/mod.rs b/src/plots/mod.rs
index 7f67b42..ba736c5 100644
--- a/src/plots/mod.rs
+++ b/src/plots/mod.rs
@@ -4,6 +4,7 @@ pub(crate) mod heatmap;
 pub(crate) mod histogram;
 pub(crate) mod image;
 pub(crate) mod lineplot;
+pub(crate) mod piechart;
 pub(crate) mod scatter3dplot;
 pub(crate) mod scatterplot;
 pub(crate) mod timeseriesplot;
diff --git a/src/plots/piechart.rs b/src/plots/piechart.rs
new file mode 100644
index 0000000..da3496d
--- /dev/null
+++ b/src/plots/piechart.rs
@@ -0,0 +1,155 @@
+use bon::bon;
+
+use plotly::{Layout as LayoutPlotly, Pie, Trace};
+
+use polars::frame::DataFrame;
+use serde::Serialize;
+
+use crate::{
+    common::{Layout, PlotHelper, Polar},
+    components::Text,
+};
+
+/// A structure representing a pie chart.
+///
+/// The `PieChart` struct allows for the creation and customization of pie charts, supporting
+/// features such as labels, hole size for donut-style charts, slice pulling, rotation, and customizable plot titles.
+/// It is ideal for visualizing proportions and distributions in categorical data.
+///
+/// # Arguments
+///
+/// * `data` - A reference to the `DataFrame` containing the data to be plotted.
+/// * `labels` - A string slice specifying the column name to be used for slice labels.
+/// * `hole` - An optional `f64` value specifying the size of the hole in the center of the pie chart.
+///            A value of `0.0` creates a full pie chart, while a value closer to `1.0` creates a thinner ring.
+/// * `pull` - An optional `f64` value specifying the fraction by which each slice should be pulled out from the center.
+/// * `rotation` - An optional `f64` value specifying the starting angle (in degrees) of the first slice.
+/// * `plot_title` - An optional `Text` struct specifying the title of the plot.
+///
+/// # Example
+///
+/// ## Basic Pie Chart with Customization
+///
+/// ```rust
+/// use plotlars::{PieChart, Plot, Text};
+///
+/// let dataset = LazyCsvReader::new("data/penguins.csv")
+///     .finish()
+///     .unwrap()
+///     .select([
+///         col("species"),
+///     ])
+///     .collect()
+///     .unwrap();
+///
+/// PieChart::builder()
+///     .data(&dataset)
+///     .labels("species")
+///     .hole(0.4) // Creates a donut-style chart
+///     .pull(0.01) // Slightly separates each slice
+///     .rotation(20.0) // Rotates the chart by 20 degrees
+///     .plot_title(
+///         Text::from("Pie Chart")
+///             .font("Arial")
+///             .size(18)
+///     )
+///     .build()
+///     .plot();
+/// ```
+///
+/// ![Example](https://imgur.com/jE70hYS.png)
+#[derive(Clone, Serialize)]
+pub struct PieChart {
+    traces: Vec<Box<dyn Trace + 'static>>,
+    layout: LayoutPlotly,
+}
+
+#[bon]
+impl PieChart {
+    #[builder(on(String, into), on(Text, into))]
+    pub fn new(
+        data: &DataFrame,
+        labels: &str,
+        hole: Option<f64>,
+        pull: Option<f64>,
+        rotation: Option<f64>,
+        plot_title: Option<Text>,
+    ) -> Self {
+        let x_title = None;
+        let y_title = None;
+        let z_title = None;
+        let legend_title = None;
+        let x_axis = None;
+        let y_axis = None;
+        let z_axis = None;
+        let legend = None;
+
+        let layout = Self::create_layout(
+            plot_title,
+            x_title,
+            y_title,
+            z_title,
+            legend_title,
+            x_axis,
+            y_axis,
+            z_axis,
+            legend,
+        );
+
+        let mut traces = vec![];
+
+        let trace = Self::create_trace(data, labels, hole, pull, rotation);
+
+        traces.push(trace);
+
+        Self { traces, layout }
+    }
+
+    fn create_trace(
+        data: &DataFrame,
+        labels: &str,
+        hole: Option<f64>,
+        pull: Option<f64>,
+        rotation: Option<f64>,
+    ) -> Box<dyn Trace + 'static> {
+        let labels = Self::get_string_column(data, labels)
+            .iter()
+            .filter_map(|s| {
+                if s.is_some() {
+                    Some(s.clone().unwrap().to_owned())
+                } else {
+                    None
+                }
+            })
+            .collect::<Vec<String>>();
+
+        let mut trace = Pie::<u32>::from_labels(&labels);
+
+        if let Some(hole) = hole {
+            trace = trace.hole(hole);
+        }
+
+        if let Some(pull) = pull {
+            trace = trace.pull(pull);
+        }
+
+        if let Some(rotation) = rotation {
+            trace = trace.rotation(rotation);
+        }
+
+        trace
+    }
+}
+
+impl Layout for PieChart {}
+impl Polar for PieChart {}
+
+impl PlotHelper for PieChart {
+    fn get_layout(&self) -> &LayoutPlotly {
+        &self.layout
+    }
+
+    fn get_traces(&self) -> &Vec<Box<dyn Trace + 'static>> {
+        &self.traces
+    }
+}