import { defineConfig, type Plugin } from "vite";
import react from "@vitejs/plugin-react-swc";
import { lingui } from "@lingui/vite-plugin";
import { readdirSync, readFileSync, statSync, writeFileSync } from "node:fs";
import { join, resolve } from "node:path";
import { brotliCompressSync, constants as zlib, gzipSync } from "node:zlib";
import linguiConfig from "./lingui.config.ts";
import { BASE_STYLE, isStyleName } from "./shared/theme.ts";

const SITE_NAME = process.env.GERBEUR_SITE_NAME || "gerbeur";
const SITE_EMOJI = process.env.GERBEUR_SITE_EMOJI || "🚚";
const BANDCAMP_PLAYER = process.env.GERBEUR_BANDCAMP_PLAYER?.trim() === "native"
  ? "native"
  : "embed";
const DEFAULT_STYLE = isStyleName(process.env.GERBEUR_DEFAULT_STYLE?.trim())
  ? process.env.GERBEUR_DEFAULT_STYLE!.trim()
  : BASE_STYLE;
const EMAIL_ENABLED = process.env.GERBEUR_SMTPS_URL?.trim() ? "on" : "off";
const FEDERATION_INCOMING =
  process.env.GERBEUR_FEDERATION_INCOMING?.trim() === "0" ? "off" : "on";
const FEDERATION_OUTGOING =
  process.env.GERBEUR_FEDERATION_OUTGOING?.trim() === "0" ? "off" : "on";

// Cache-busting token for the favicon URLs (see index.html). Changes when the
// emoji changes, so browsers don't keep serving a stale cached icon. Mirrors
// Twemoji's filename convention (kept trivial here to avoid the frontend build
// depending on backend code; the canonical version lives in api/lib/site-icons.ts).
function emojiToCodepoint(emoji: string): string {
  const cleaned = emoji.includes("‍") ? emoji : emoji.replace(/️/g, "");
  return [...cleaned].map((ch) => ch.codePointAt(0)!.toString(16)).join("-");
}
const ICON_VERSION = emojiToCodepoint(SITE_EMOJI);

// The emoji picker (frimousse) reads emojibase-data from ${url}/${locale}/{data,messages}.json.
// It is served from here rather than a CDN; the version is in the path so the
// files can be cached for good, and bumping the package moves the URL.
const EMOJIBASE_DIR = resolve("node_modules/emojibase-data");
const EMOJIBASE_VERSION =
  JSON.parse(readFileSync(join(EMOJIBASE_DIR, "package.json"), "utf8")).version;
const EMOJIBASE_URL = `/emojibase/${EMOJIBASE_VERSION}`;
const EMOJIBASE_FILES = linguiConfig.locales.flatMap((
  locale,
) => [`${locale}/data.json`, `${locale}/messages.json`]);

function emojibase(): Plugin {
  return {
    name: "emojibase",
    configureServer(server) {
      server.middlewares.use(EMOJIBASE_URL, (req, res, next) => {
        const file = req.url?.split("?")[0].slice(1) ?? "";
        if (!EMOJIBASE_FILES.includes(file)) return next();
        res.setHeader("Content-Type", "application/json");
        res.end(readFileSync(join(EMOJIBASE_DIR, file)));
      });
    },
    generateBundle() {
      for (const file of EMOJIBASE_FILES) {
        this.emitFile({
          type: "asset",
          fileName: `${EMOJIBASE_URL.slice(1)}/${file}`,
          source: readFileSync(join(EMOJIBASE_DIR, file)),
        });
      }
    },
  };
}

// Writes .br and .gz next to every compressible file in the build, which Oak's
// send() serves in place of the original when the browser accepts them. The
// server itself compresses nothing. index.html is left out: the server fills in
// its placeholders at runtime (see api/lib/static.ts).
const COMPRESSIBLE = /\.(js|css|json|svg|webmanifest)$/;
function precompress(): Plugin {
  let outDir = "";
  return {
    name: "precompress",
    apply: "build",
    configResolved(config) {
      outDir = resolve(config.root, config.build.outDir);
    },
    closeBundle() {
      const walk = (dir: string) => {
        for (const name of readdirSync(dir)) {
          const path = join(dir, name);
          if (statSync(path).isDirectory()) walk(path);
          else if (COMPRESSIBLE.test(name)) compress(path);
        }
      };
      const compress = (path: string) => {
        const raw = readFileSync(path);
        if (raw.length < 1024) return;
        const br = brotliCompressSync(raw, {
          params: {
            [zlib.BROTLI_PARAM_QUALITY]: 11,
            [zlib.BROTLI_PARAM_SIZE_HINT]: raw.length,
          },
        });
        const gz = gzipSync(raw, { level: 9 });
        if (br.length < raw.length * 0.9) writeFileSync(`${path}.br`, br);
        if (gz.length < raw.length * 0.9) writeFileSync(`${path}.gz`, gz);
      };
      walk(outDir);
    },
  };
}

// Each dev instance (dev/instances.ts) runs a Vite server of its own; sharing
// one dependency cache, two of them would rewrite it under each other.
const INSTANCE = process.env.GERBEUR_INSTANCE;

export default defineConfig({
  cacheDir: INSTANCE ? `node_modules/.vite/${INSTANCE}` : undefined,
  define: {
    "import.meta.env.VITE_EMOJIBASE_URL": JSON.stringify(EMOJIBASE_URL),
  },
  server: {
    port: 3000,
    watch: {
      ignored: ["**/api/**"],
    },
    // Another instance may know this one by its pages' address, and reads its
    // metadata there (resolveIssuer in api/remote/gerbeur-instance.ts), which
    // the API serves; in production, whatever serves the pages passes it on.
    proxy: {
      "/.well-known": `${process.env.VITE_API_PROTOCOL || "http"}://${
        process.env.VITE_API_HOSTNAME || "localhost"
      }:${process.env.VITE_API_PORT || "8000"}`,
    },
  },
  build: {
    rollupOptions: {
      output: {
        // Only the framework, which every page needs and which changes least, gets
        // a chunk of its own so it stays cached across deploys. Everything else is
        // left to the bundler, so libraries only the lazy chunks use (the emoji
        // picker, forms) stay out of the first load.
        manualChunks(id) {
          if (
            /node_modules\/(react|react-dom|scheduler|react-router)\//.test(id)
          ) {
            return "vendor";
          }
        },
      },
    },
  },
  plugins: [
    {
      // In dev the API server isn't serving index.html, so replace the placeholders here.
      // In production the Oak server does the replacement at runtime (see api/lib/static.ts).
      name: "inject-site-name",
      transformIndexHtml: {
        order: "pre",
        handler: (html, ctx) =>
          ctx.server
            ? html
              .replaceAll("__SITE_NAME__", SITE_NAME)
              .replaceAll("__SITE_EMOJI__", SITE_EMOJI)
              .replaceAll("__ICON_VERSION__", ICON_VERSION)
              .replaceAll("__BANDCAMP_PLAYER__", BANDCAMP_PLAYER)
              .replaceAll("__DEFAULT_STYLE__", DEFAULT_STYLE)
              .replaceAll("__EMAIL_ENABLED__", EMAIL_ENABLED)
              .replaceAll("__FEDERATION_INCOMING__", FEDERATION_INCOMING)
              .replaceAll("__FEDERATION_OUTGOING__", FEDERATION_OUTGOING)
            : html,
      },
    },
    emojibase(),
    precompress(),
    lingui(),
    react({
      plugins: [["@lingui/swc-plugin", {}]],
    }),
  ],
});