use std::path::Path;
use std::process::Command;
fn main() {
// Only relevant when the serve feature is active
if std::env::var("CARGO_FEATURE_SERVE").is_err() {
return;
}
let dist_dir = Path::new("src/server/assets/dist");
let index_html = dist_dir.join("index.html");
// Re-run build.rs only when dist output is missing/changed
println!("cargo:rerun-if-changed=src/server/assets/dist/index.html");
if index_html.exists() {
// Dist already built — nothing to do
return;
}
// Dist missing — try to build frontend
let frontend_dir = Path::new("frontend");
if !frontend_dir.join("package.json").exists() {
emit_placeholder_and_warn(dist_dir);
return;
}
// Run npm install + build
println!("cargo:warning=Frontend dist not found, running npm install && npm run build...");
let npm_install = Command::new("npm")
.arg("install")
.current_dir(frontend_dir)
.status();
match npm_install {
Ok(s) if s.success() => {}
_ => {
emit_placeholder_and_warn(dist_dir);
return;
}
}
let npm_build = Command::new("npm")
.arg("run")
.arg("build")
.current_dir(frontend_dir)
.status();
match npm_build {
Ok(s) if s.success() => {
println!("cargo:warning=Frontend built successfully.");
}
_ => {
emit_placeholder_and_warn(dist_dir);
}
}
}
fn emit_placeholder_and_warn(dist_dir: &Path) {
// Create minimal placeholder files so compilation succeeds
std::fs::create_dir_all(dist_dir).ok();
std::fs::write(
dist_dir.join("index.html"),
"Frontend not built
Run: cd frontend && npm install && npm run build
",
)
.ok();
std::fs::write(dist_dir.join("app.js"), "// frontend not built\n").ok();
std::fs::write(dist_dir.join("style.css"), "/* frontend not built */\n").ok();
println!(
"cargo:warning=Node.js/npm not available — wrote placeholder frontend assets. Run 'cd frontend && npm install && npm run build' for the real UI."
);
}