Fix build process for unified binary (parseablehq#24)

Fixes parseablehq#18

Author: trueleo

server/Cargo.toml

@@ -50,4 +50,12 @@ static-files = "0.2.1"
 walkdir = "2"
 
 [build-dependencies]
-static-files = "0.2.1"
+static-files = "0.2.1"
+cargo_toml = "0.11.5"
+ureq = "2.5.0"
+sha1_smol = { version = "1.0.0", features=["std"] }
+zip = { git = "https://github.com/zip-rs/zip" }
+
+[package.metadata.parseable_ui]
+assets-url = "https://github.com/parseablehq/frontend/releases/download/v0.0.1/build.zip"
+assets-sha1 = "d9243bde7a98bdd8a19ed47cca2f12f9a5ce40ba"

server/build.rs

@@ -16,8 +16,117 @@
  *
  */
 
-use static_files::resource_dir;
+fn main() {
+    println!("cargo:rerun-if-changed=build.rs");
+    println!("cargo:rerun-if-changed=Cargo.toml");
+    println!("cargo:rerun-if-env-changed=LOCAL_ASSETS_PATH");
+    println!("Build File running");
+    ui::setup().unwrap()
+}
+
+mod ui {
+
+    use std::fs::{self, create_dir_all, OpenOptions};
+    use std::io::{self, Cursor, Read, Write};
+    use std::path::{Path, PathBuf};
+    use std::{env, panic};
+
+    use cargo_toml::Manifest;
+    use sha1_smol::Sha1;
+    use static_files::resource_dir;
+    use ureq::get as get_from_url;
+
+    fn build_resource_from(local_path: impl AsRef<Path>) -> io::Result<()> {
+        let local_path = local_path.as_ref();
+        if local_path.exists() {
+            resource_dir(local_path).build()
+        } else {
+            Err(io::Error::new(
+                io::ErrorKind::NotFound,
+                "Local UI directory not found!",
+            ))
+        }
+    }
+
+    pub fn setup() -> io::Result<()> {
+        let cargo_manifest_dir = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
+        let cargo_toml = cargo_manifest_dir.join("Cargo.toml");
+        let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap());
+        let parseable_ui_path = out_dir.join("ui");
+        let checksum_path = out_dir.join("parseable_ui.sha1");
+
+        let manifest = Manifest::from_path(cargo_toml).unwrap();
+
+        let manifest = manifest
+            .package
+            .expect("package not specified in Cargo.toml")
+            .metadata
+            .expect("no metadata specified in Cargo.toml");
+
+        let metadata = manifest
+            .get("parseable_ui")
+            .expect("Parseable UI Metadata not defined correctly");
+
+        // try fetching frontend path from env var
+        let local_assets_path: Option<PathBuf> =
+            env::var("LOCAL_ASSETS_PATH").ok().map(PathBuf::from);
+
+        // If local build of ui is to be used
+        if let Some(ref path) = local_assets_path {
+            if path.exists() {
+                println!("cargo:rerun-if-changed={}", path.to_str().unwrap());
+                build_resource_from(path).unwrap();
+                return Ok(());
+            } else {
+                panic!("Directory specified in LOCAL_ASSETS_PATH is not found")
+            }
+        }
+
+        // If UI is already downloaded in the target directory then verify and return
+        if checksum_path.exists() && parseable_ui_path.exists() {
+            let checksum = fs::read_to_string(&checksum_path)?;
+            if checksum == metadata["assets-sha1"].as_str().unwrap() {
+                // Nothing to do.
+                return Ok(());
+            }
+        }
+
+        // If there is no UI in the target directory or checksum check failed
+        // then we downlaod the UI from given url in cargo.toml metadata
+        let url = metadata["assets-url"].as_str().unwrap();
+
+        // See https://docs.rs/ureq/2.5.0/ureq/struct.Response.html#method.into_reader
+        let parseable_ui_bytes = get_from_url(url)
+            .call()
+            .map(|data| {
+                let mut buf: Vec<u8> = Vec::new();
+                data.into_reader().read_to_end(&mut buf).unwrap();
+                buf
+            })
+            .expect("Failed to get resource from {url}");
+
+        let checksum = Sha1::from(&parseable_ui_bytes).hexdigest();
+
+        assert_eq!(
+            metadata["assets-sha1"].as_str().unwrap(),
+            checksum,
+            "Downloaded parseable UI shasum differs from the one specified in the Cargo.toml"
+        );
+
+        create_dir_all(&parseable_ui_path)?;
+        let mut zip = zip::read::ZipArchive::new(Cursor::new(&parseable_ui_bytes))?;
+        zip.extract(&parseable_ui_path)?;
+        resource_dir(&parseable_ui_path).build()?;
+
+        let mut file = OpenOptions::new()
+            .write(true)
+            .create(true)
+            .truncate(true)
+            .open(checksum_path)?;
+
+        file.write_all(checksum.as_bytes())?;
+        file.flush()?;
 
-fn main() -> std::io::Result<()> {
-    resource_dir("../ui/build").build()
+        Ok(())
+    }
 }