import { sveltekit } from "@sveltejs/kit/vite";
import { defineConfig } from "vite";
import { readFileSync } from "node:fs";
import { fileURLToPath } from "node:url";

const pkg = JSON.parse(
	readFileSync(
		fileURLToPath(new URL("./package.json", import.meta.url)),
		"utf8",
	),
) as { version: string };

// Default upstream gateway addresses used by the dev proxy. Override
// by pointing `VITE_DEV_PROXY_TARGET` (REST surface) and
// `VITE_DEV_GRPC_PROXY_TARGET` (Connect-Web surface) at a different
// gateway when working with a remote stack instead of
// `tools/local-dev/`. In production the two surfaces sit behind a
// single host; the split here exists only because local-dev runs the
// REST listener on :8080 and the authenticated Connect-Web listener
// on :9090.
const DEV_PROXY_TARGET =
	process.env.VITE_DEV_PROXY_TARGET ?? "http://localhost:8080";
const DEV_GRPC_PROXY_TARGET =
	process.env.VITE_DEV_GRPC_PROXY_TARGET ?? "http://localhost:9090";

export default defineConfig({
	plugins: [sveltekit()],
	define: {
		__APP_VERSION__: JSON.stringify(pkg.version),
	},
	server: {
		// Same-origin proxy so the browser sees only `localhost:5173`
		// and never trips a cross-origin preflight against the
		// gateway's REST + Connect-Web surfaces. Production deployments
		// serve the UI and the gateway behind a single host, so the
		// proxy is purely a dev-time convenience.
		proxy: {
			"/api": {
				target: DEV_PROXY_TARGET,
				changeOrigin: false,
			},
			"/galaxy.gateway.v1.EdgeGateway": {
				target: DEV_GRPC_PROXY_TARGET,
				changeOrigin: false,
				// Connect-Web server-streaming (`SubscribeEvents`) uses
				// chunked HTTP responses; http-proxy passes them through
				// transparently as long as buffering stays off, which is
				// the default.
			},
		},
	},
});