Gulpify build pipeline (#3145)

* Gulpify build pipeline

* Update build frontend script

* Fixes

* Limit service worker to latest build

* Use shorthand

* Fix hassio build

build-scripts/gulp/gather-static.js

@@ -0,0 +1,87 @@
+// Gulp task to gather all static files.
+
+const gulp = require("gulp");
+const path = require("path");
+const fs = require("fs-extra");
+const zopfli = require("gulp-zopfli-green");
+const merge = require("merge-stream");
+const config = require("../paths");
+
+const npmPath = (...parts) =>
+  path.resolve(config.polymer_dir, "node_modules", ...parts);
+const polyPath = (...parts) => path.resolve(config.polymer_dir, ...parts);
+const staticPath = (...parts) => path.resolve(config.root, "static", ...parts);
+
+const copyFileDir = (fromFile, toDir) =>
+  fs.copySync(fromFile, path.join(toDir, path.basename(fromFile)));
+
+function copyTranslations() {
+  // Translation output
+  fs.copySync(
+    polyPath("build-translations/output"),
+    staticPath("translations")
+  );
+}
+
+function copyStatic() {
+  // Basic static files
+  fs.copySync(polyPath("public"), config.root);
+
+  // Web Component polyfills and adapters
+  copyFileDir(
+    npmPath("@webcomponents/webcomponentsjs/custom-elements-es5-adapter.js"),
+    staticPath("polyfills/")
+  );
+  copyFileDir(
+    npmPath("@webcomponents/webcomponentsjs/webcomponents-bundle.js"),
+    staticPath("polyfills/")
+  );
+  copyFileDir(
+    npmPath("@webcomponents/webcomponentsjs/webcomponents-bundle.js.map"),
+    staticPath("polyfills/")
+  );
+
+  // Local fonts
+  fs.copySync(npmPath("@polymer/font-roboto-local/fonts"), staticPath("fonts"));
+
+  // External dependency assets
+  copyFileDir(
+    npmPath("react-big-calendar/lib/css/react-big-calendar.css"),
+    staticPath("panels/calendar/")
+  );
+  copyFileDir(
+    npmPath("leaflet/dist/leaflet.css"),
+    staticPath("images/leaflet/")
+  );
+  fs.copySync(
+    npmPath("leaflet/dist/images"),
+    staticPath("images/leaflet/images/")
+  );
+}
+
+gulp.task("copy-static", (done) => {
+  copyStatic();
+  done();
+});
+
+gulp.task("compress-static", () => {
+  const fonts = gulp
+    .src(staticPath("fonts/**/*.ttf"))
+    .pipe(zopfli())
+    .pipe(gulp.dest(staticPath("fonts")));
+  const polyfills = gulp
+    .src(staticPath("polyfills/*.js"))
+    .pipe(zopfli())
+    .pipe(gulp.dest(staticPath("polyfills")));
+  const translations = gulp
+    .src(staticPath("translations/*.json"))
+    .pipe(zopfli())
+    .pipe(gulp.dest(staticPath("translations")));
+
+  return merge(fonts, polyfills, translations);
+});
+
+gulp.task("copy-translations", (done) => {
+  copyTranslations();
+  done();
+});