build.rs

use std::env;
use std::fs;
use std::fs::File;
use std::io::Write;
use std::path::Path;
use std::process::{Command, Stdio};

static ASSET_FILES: &'static [&'static str] = &[
    "node_modules/mozilla-fira-pack/Fira/woff/FiraMono-Regular.woff",
    "node_modules/mozilla-fira-pack/Fira/woff/FiraSans-Regular.woff",
    "node_modules/mozilla-fira-pack/Fira/woff/FiraSans-Light.woff",
    "node_modules/mozilla-fira-pack/Fira/woff/FiraSans-UltraLight.woff",
    "node_modules/dygraphs/dygraph-combined.js",
    "node_modules/preact/dist/preact.min.js",
    "app.js",
    "styles.css",
    "index.html",
];

fn main() {
    let out_dir_str = env::var("OUT_DIR").unwrap();
    let out_dir = Path::new(&out_dir_str);
    let proj_dir = env::current_dir().unwrap();
    let client_dir = proj_dir.join("client");

    let status =  match Command::new("npm")
                                .arg("install")
                                .current_dir(&client_dir)
                                .status() {
        Ok(o) => o,
        Err(e1) => match Command::new("npm.cmd")
                                 .arg("install")
                                 .current_dir(&client_dir)
                                 .stdout(Stdio::null())
                                 .stderr(Stdio::null())
                                 .status() {
            Ok(o) => o,
            Err(e2) => {
                println!("Tried both npm and npm.cmd, neither worked");
                println!("Error encountered for 'npm install': {:?}", e1);
                println!("Error encountered for 'npm.cmd install': {:?}", e2);
                panic!("Failed to execute NPM.");
            }
        }
    };

    if !status.success() {
        panic!("'npm install' did not succeed.")
    }

    let assets_out_dir = out_dir.join("assets");
    fs::create_dir_all(&assets_out_dir).unwrap();

    let mut wahb = String::new();
    wahb.push_str("fn _webassets_handler_body<'a>(path: &'a str) -> Option<(WebAssetContainer, &'static str)> {\n");
    wahb.push_str("match path {\n");

    for asset_source in ASSET_FILES {
        let source_path = client_dir.join(asset_source);
        let asset_filename = source_path.file_name().unwrap();
        let target_path = assets_out_dir.join(asset_filename);

        let ext = target_path.extension().unwrap().to_str().unwrap();
        let content_type = match ext {
            "html" | "htm" => "text/html",
            "js" => "application/javascript",
            "css" => "text/css",
            "woff" => "application/font-woff",
            _ => "text/plain"
        };
        let match_arm = format!(
            "r#\"{}\"# => Some(({}r#\"{}\"#)), \"{}\")),\n",
            asset_filename.to_str().unwrap(),
            match ext {
                "woff" => "WebAssetContainer::Binary(include_bytes!(",
                _ => "WebAssetContainer::Text(include_str!("
            },
            target_path.to_str().unwrap(),
            content_type
        );
        wahb.push_str(&match_arm);
        fs::copy(&source_path, &target_path).unwrap();
    }

    wahb.push_str("_ => None\n");
    wahb.push_str("}\n");
    wahb.push_str("}\n");

    let wa_handler_body_path = out_dir.join("webassets_handler_body.rs");
    let mut wa_handler_body_file = File::create(&wa_handler_body_path).unwrap();
    wa_handler_body_file.write_all(wahb.as_bytes()).unwrap();
}