Refactor the server

server-rs/src/routes/features.rs

@@ -0,0 +1,87 @@
+use std::sync::Arc;
+
+use axum::response::Json;
+use serde::Serialize;
+use tracing::info;
+
+use crate::data::Histogram;
+use crate::state::AppState;
+
+#[derive(Serialize)]
+#[serde(tag = "type")]
+pub enum FeatureInfo {
+    #[serde(rename = "numeric")]
+    Numeric {
+        name: String,
+        label: String,
+        min: f64,
+        max: f64,
+        histogram: Histogram,
+    },
+    #[serde(rename = "enum")]
+    Enum {
+        name: String,
+        label: String,
+        values: Vec<String>,
+    },
+}
+
+#[derive(Serialize)]
+pub struct FeaturesResponse {
+    features: Vec<FeatureInfo>,
+}
+
+fn snake_to_label(name: &str) -> String {
+    // If name contains '/' or uppercase, assume it's already human-readable
+    if name.contains('/') || name.chars().any(|c| c.is_uppercase()) {
+        return name.to_string();
+    }
+    name.split('_')
+        .map(|word| {
+            let mut chars = word.chars();
+            match chars.next() {
+                None => String::new(),
+                Some(c) => {
+                    let mut s = c.to_uppercase().to_string();
+                    s.extend(chars);
+                    s
+                }
+            }
+        })
+        .collect::<Vec<_>>()
+        .join(" ")
+}
+
+pub async fn get_features(state: Arc<AppState>) -> Json<FeaturesResponse> {
+    let mut features: Vec<FeatureInfo> = state
+        .data
+        .feature_names
+        .iter()
+        .enumerate()
+        .map(|(i, name): (usize, &String)| {
+            let stats = &state.data.feature_stats[i];
+            FeatureInfo::Numeric {
+                name: name.clone(),
+                label: snake_to_label(name),
+                min: stats.p_low,
+                max: stats.p_high,
+                histogram: stats.histogram.clone(),
+            }
+        })
+        .collect();
+
+    for ef in &state.data.enum_features {
+        features.push(FeatureInfo::Enum {
+            name: ef.name.clone(),
+            label: snake_to_label(&ef.name),
+            values: ef.values.clone(),
+        });
+    }
+
+    info!(
+        numeric = features.iter().filter(|f| matches!(f, FeatureInfo::Numeric { .. })).count(),
+        enums = features.iter().filter(|f| matches!(f, FeatureInfo::Enum { .. })).count(),
+        "GET /api/features"
+    );
+    Json(FeaturesResponse { features })
+}