chore: massive repo reorganization

build.rs

@@ -0,0 +1,66 @@
+use minijinja::{context, Environment};
+use owo_colors::OwoColorize;
+use std::fs;
+
+fn main() {
+    // Protocol tests run on the host without a board feature. Cargo doesn't
+    // expose `cfg(test)` to build scripts, so we rely on an env var set by
+    // the justfile `test` recipe. See: `just test`
+    if std::env::var_os("DONGLORA_HOST_TEST").is_some() {
+        return;
+    }
+
+    let board_dir = "src/board";
+    let boards: Vec<String> = fs::read_dir(board_dir)
+        .expect("failed to read src/board directory")
+        .filter_map(|e| {
+            let p = e.ok()?.path();
+            let stem = p.file_stem()?.to_str()?;
+            // Exclude non-board files: mod.rs, traits.rs, and platform helpers (esp32s3.rs).
+            if p.is_file()
+                && p.extension()? == "rs"
+                && !matches!(stem, "mod" | "traits" | "esp32s3")
+            {
+                return Some(p.file_stem()?.to_str()?.to_string());
+            }
+            None
+        })
+        .collect();
+
+    let enabled: Vec<_> = std::env::vars()
+        .filter(|(k, _)| k.starts_with("CARGO_FEATURE_"))
+        .map(|(k, _)| k.replace("CARGO_FEATURE_", "").to_lowercase())
+        .filter(|f| boards.contains(f))
+        .collect();
+
+    match enabled.len() {
+        0 => panic!(
+            "\n\n{}\n",
+            format!("No board selected! Found: {:?}", boards)
+                .red()
+                .bold()
+        ),
+        1 => println!("cargo:rustc-cfg=board_selected"),
+        _ => panic!(
+            "\n\n{}\n",
+            format!("Conflict: Multiple boards enabled {:?}", enabled)
+                .yellow()
+                .bold()
+        ),
+    }
+
+    let mut env = Environment::new();
+    let template =
+        fs::read_to_string("src/board/mod.rs.j2").expect("missing src/board/mod.rs.j2");
+    env.add_template("mod", &template)
+        .expect("failed to parse board template");
+    let rendered = env
+        .get_template("mod")
+        .expect("template not found")
+        .render(context!(boards => boards))
+        .expect("failed to render board module");
+    fs::write("src/board/mod.rs", rendered).expect("failed to write src/board/mod.rs");
+
+    println!("cargo:rerun-if-changed=src/board/mod.rs.j2");
+    println!("cargo:rerun-if-changed={}", board_dir);
+}