import { execSync } from "node:child_process";
import { existsSync, readFileSync } from "node:fs";
import { defineConfig } from "vite";
import { svelte } from "@sveltejs/vite-plugin-svelte";
import tailwindcss from "@tailwindcss/vite";
import { VitePWA } from "vite-plugin-pwa";

// Build-time identity: short git SHA + ISO date. Surfaced in the footer
// as "kez-chat <sha>" so users can eyeball which build they're on (handy
// when verifying that a deploy actually landed instead of being cached).
//
// Resolution order, so it works both locally (with .git) and in the
// Docker build on the remote (no .git copied):
//   1. process.env.BUILD_SHA              — set by deploy script
//   2. ./BUILD_SHA file in this dir       — set by deploy script
//   3. `git rev-parse --short HEAD`       — local dev
//   4. "dev"                              — give up
const BUILD_SHA = (() => {
  if (process.env.BUILD_SHA) return process.env.BUILD_SHA.trim();
  if (existsSync("./BUILD_SHA")) {
    return readFileSync("./BUILD_SHA", "utf-8").trim();
  }
  try {
    return execSync("git rev-parse --short HEAD").toString().trim();
  } catch {
    return "dev";
  }
})();
const BUILD_TIME = new Date().toISOString();

export default defineConfig({
  define: {
    __BUILD_SHA__: JSON.stringify(BUILD_SHA),
    __BUILD_TIME__: JSON.stringify(BUILD_TIME),
  },
  plugins: [
    svelte(),
    tailwindcss(),
    VitePWA({
      // Auto-update: a new SW activates on next page load. No "click to
      // update" prompt — chat needs to stay fresh and we don't want users
      // stuck on an old build.
      registerType: "autoUpdate",
      injectRegister: "auto",
      manifest: {
        name: "kez-chat",
        short_name: "kez-chat",
        description:
          "End-to-end encrypted chat on top of KEZ — portable cross-app identity.",
        start_url: "/",
        scope: "/",
        display: "standalone",
        background_color: "#0b0c0e",
        theme_color: "#0b0c0e",
        categories: ["social", "communication"],
        icons: [
          { src: "pwa-64x64.png", sizes: "64x64", type: "image/png" },
          { src: "pwa-192x192.png", sizes: "192x192", type: "image/png" },
          { src: "pwa-512x512.png", sizes: "512x512", type: "image/png" },
          {
            src: "maskable-icon-512x512.png",
            sizes: "512x512",
            type: "image/png",
            purpose: "maskable",
          },
        ],
      },
      workbox: {
        // Activate new SW immediately + take control of existing pages
        // without waiting for them to close. Paired with the
        // controllerchange reload in main.ts, this means deploys land
        // on the first refresh instead of the second.
        skipWaiting: true,
        clientsClaim: true,
        // Precache the SPA shell. Chat data is fetched live from /v1/*
        // and we DON'T want it cached — see runtimeCaching below.
        globPatterns: ["**/*.{js,css,html,svg,png,ico,wasm}"],
        // zstd wasm is ~350 KB; raise the per-file cap.
        maximumFileSizeToCacheInBytes: 5 * 1024 * 1024,
        // Same-origin navigation requests fall back to the SPA shell so
        // /messages, /claims, etc. work after a refresh while offline.
        navigateFallback: "index.html",
        navigateFallbackDenylist: [/^\/v1\//, /^\/internal\//, /^\/\.well-known\//],
        runtimeCaching: [
          {
            // Never cache API responses — they're authenticated + dynamic.
            urlPattern: /\/v1\//,
            handler: "NetworkOnly",
          },
        ],
        navigationPreload: true,
        cleanupOutdatedCaches: true,
      },
      devOptions: {
        enabled: false,
      },
    }),
  ],
  server: {
    // For dev: proxy API calls to the locally-running chat-server.
    // The deployed SPA (served by the same chat-server) doesn't need this.
    proxy: {
      "/v1": "http://localhost:6969",
      "/internal": "http://localhost:6969",
      "/.well-known": "http://localhost:6969",
    },
  },
  build: {
    outDir: "dist",
    emptyOutDir: true,
  },
});