code rewritted to modules; add local/server flags to build

build.rs

@@ -0,0 +1,17 @@
+fn main() {
+    println!("cargo:rerun-if-env-changed=LOCAL");
+    println!("cargo:rustc-check-cfg=cfg(local)");
+
+    let local_env = std::env::var("LOCAL")
+        .map(|v| {
+            let v = v.trim().to_ascii_lowercase();
+            matches!(v.as_str(), "true" | "1" | "yes" | "on")
+        })
+        .unwrap_or(false);
+
+    let local_feature = std::env::var("CARGO_FEATURE_LOCAL").is_ok();
+
+    if local_env || local_feature {
+        println!("cargo:rustc-cfg=local");
+    }
+}