/**
 * doxa-maps Vite config — per-bundle IIFE build.
 * WHY? -> !!! EACH BUNDLE ONLY BUNDLES WHAT IT NEEDS BASED ON ITS APP PROFILE :)
 * Layout:
 *   library/               ← shared library (components, composables, config, etc.; aliased as @map)
 *   plugin-designs/<name>/   ← bundle source folder
 *     ├── index.html       ← Vite html entry (staging page; loads index.js as a module in dev)
 *     ├── index.js         ← bundle entry — registers the custom element (globs ./*.vue)
 *     └── *.vue            ← profile components at the bundle root (auto-discovered via import.meta.glob('./*.vue'))
 *   app/doxa-maps/         ← build output tree (see below)
 *
 * Build mode: each invocation builds ONE bundle (selected via BUNDLE env var) so we can
 * use IIFE format with inlineDynamicImports. The npm `build` script runs vite once per
 * plugin-designs/<name>/ folder, emitting app/doxa-maps/<bundle>/<bundle>.js. After all
 * bundles are built, `generate-tree.mjs` writes the manifest + self-contained staging
 * HTML into the tree and copies the whole doxa-maps/ folder to every destination
 * (default ./app/ + each line in vite.destination.md).
 *
 * Dev mode (`npm run dev`): no BUNDLE selection — Vite serves all bundles at their html
 * paths under the dev server.
 */
import { defineConfig, loadEnv } from 'vite'
import vue from '@vitejs/plugin-vue'
import cssInjectedByJsPlugin from 'vite-plugin-css-injected-by-js'
import { autoSpaDevPlugin } from './internal/plugin-gallery/dev-plugin.mjs'
import { stripShadowCssCommentsPlugin } from './internal/vite-plugin-strip-shadow-css-comments.mjs'
import { fileURLToPath } from 'node:url'
import { resolve, dirname } from 'node:path'
import { readdirSync, statSync, existsSync } from 'node:fs'
import { TREE_NAME } from './internal/_tree-name.mjs'

const __dirname = dirname(fileURLToPath(import.meta.url))
const profilesDir = resolve(__dirname, 'plugin-designs')

// The multi-MFE output folder name is configured in vite.doxa-maps-build-config.json (`name`),
// so you can name the output tree independently of this bundler folder's own name. It is read in
// ONE place, internal/_tree-name.mjs, which every tool shares — so renaming the tree is a one-line
// config change rather than a hunt through the gates.
const MFE_NAME = TREE_NAME

// Default output tree. generate-tree.mjs reads the same name + copies it onward.
// DOXA_OUT_ROOT redirects a build's output WITHOUT touching public/: check:composite rebuilds each
// composite into a temp dir and compares bytes with the committed bundle. Unset = unchanged behaviour.
const OUT_ROOT = process.env.DOXA_OUT_ROOT ? resolve(process.env.DOXA_OUT_ROOT) : resolve(__dirname, 'public', MFE_NAME)

function discoverBundles() {
  if (!existsSync(profilesDir)) return {}
  const entries = {}
  for (const name of readdirSync(profilesDir)) {
    if (name.startsWith('_') || name.startsWith('.')) continue
    const dir = resolve(profilesDir, name)
    if (!statSync(dir).isDirectory()) continue
    const html = resolve(dir, 'index.html')
    const js = resolve(dir, 'index.js')
    if (!existsSync(html) || !existsSync(js)) continue
    entries[name] = { html, js }
  }
  return entries
}

export default defineConfig(({ command, mode }) => {
  // .env values (VITE_MAPBOX_TOKEN) are NOT on process.env inside this config —
  // load them explicitly so the dev plugin gallery can hand the token to each map.
  const env = loadEnv(mode, __dirname, '')
  const all = discoverBundles()
  const allNames = Object.keys(all)
  const target = process.env.BUNDLE
  const isBuild = command === 'build'

  if (isBuild && !target) {
    throw new Error(
      `[${MFE_NAME}] Set BUNDLE=<name> for build, or use \`npm run build\` (loops all).\n` +
      `Available: ${allNames.join(', ') || '(none)'}`
    )
  }

  if (isBuild && !all[target]) {
    // A plugin-designs/<name>/ folder was passed as BUNDLE but has no index.html+index.js
    // entry pair (e.g. a half-authored map, or a folder still being scaffolded). Fail with
    // a clear, actionable message instead of a `Cannot read properties of undefined` stack.
    throw new Error(
      `[${MFE_NAME}] Bundle "${target}" is not buildable: plugin-designs/${target}/ is missing ` +
      `index.html and/or index.js (the custom-element entry pair every bundle needs).\n` +
      `Buildable bundles: ${allNames.join(', ') || '(none)'}`
    )
  }

  const buildEntries = isBuild
    ? { [target]: all[target].js }
    : Object.fromEntries(allNames.map(n => [n, all[n].html]))

  return {
    // COMPILE-TIME QA GATE (release governance): the QA corner widget references
    // the maintainer's internal platform and must NOT exist in public
    // artifacts. Default FALSE strips it from every bundle (dead-branch +
    // treeshake); an explicitly-flagged platform build sets DOXA_QA=1.
    // The dev server listens on THIS MACHINE ONLY. A reachable one serves the source tree, node_modules
    // and the token baked into /; a remote viewer reaches it through an ssh tunnel (ssh -L), never a public
    // port. `--host` on the command line still overrides this for a deliberate LAN session.
    server: { host: '127.0.0.1' },
    define: {
      __DOXA_QA__: JSON.stringify(process.env.DOXA_QA === '1'),
      // The output tree's name (vite.doxa-maps-build-config.json `name`, the same value OUT_ROOT uses),
      // for the few runtime paths that must name the tree — so renaming the tree needs no source edit.
      __DOXA_TREE_NAME__: JSON.stringify(MFE_NAME),
    },
    // Build only: shadow-DOM CSS is injected from useShadowStyles(`…`) literals that
    // ship verbatim, so their block comments are stripped before the Vue compiler
    // runs (enforce: 'pre'). Dev keeps the comments.
    plugins: [
      stripShadowCssCommentsPlugin(),
      // ─── STRUCTURAL shadow-DOM CSS fix (customElement mode) ──────────────────
      // WHY: every bundle here is a `defineCustomElement(...)` that renders inside a
      // SHADOW ROOT. In @vitejs/plugin-vue's DEFAULT mode, each SFC <style> compiles
      // to a CSS *asset* that vite-plugin-css-injected-by-js dumps into document.head —
      // which a shadow root CANNOT see, so Vue's _applyStyles gets an empty styles[]
      // and the element renders unstyled (a list of naked buttons / a collapsed shell).
      // Running the plugin in customElement mode makes it compile each SFC <style> as an
      // INLINE string and attach it to the component's `styles: [...]` array (see
      // genStyleCode in @vitejs/plugin-vue: `directQuery = &inline`, then
      // attachedProps.push(['styles', ...])). Vue's defineCustomElement then injects that
      // array into EVERY instance's shadow root automatically — correct-by-construction,
      // so no element can forget it. This replaces the per-element useShadowStyles()
      // discipline for each SFC's OWN <style>; the remaining useShadowStyles() calls stay
      // (they inject a child's critical CSS and are idempotent-by-key, so a double inject
      // is harmless). `true` = ALL .vue in this build are custom-element SFCs, which is
      // exactly what this repo builds (one defineCustomElement per bundle).
      vue({ customElement: true }),
      cssInjectedByJsPlugin(),
      autoSpaDevPlugin(env.VITE_MAPBOX_TOKEN || process.env.VITE_MAPBOX_TOKEN || ''),
    ],
    resolve: {
      alias: { '@map': resolve(__dirname, 'library') },
    },
    // NEVER copy public/ into a bundle's output. Vite's default publicDir is
    // 'public', and the build runs vite ONCE PER PROFILE — so the default copied
    // the entire 95MB shared asset tree into all nine bundle folders, taking the
    // served tree to 717MB (assets/previews/west-africa.webp existed nine times)
    // and making `cap sync` push 717MB into the APK, past Play's 150MB ceiling.
    // public/ is the SHARED web-root: bundles reach it via the `assetsBase` that
    // generate-tree stamps into each page, not via a private copy.
    publicDir: false,
    build: {
      // Each bundle lands in its own folder: public/<name>/<bundle>/<bundle>.js.
      // public/ IS the served web-root and is committed, so the build writes there
      // DIRECTLY — no intermediate tree and no copy step migrating files in from
      // elsewhere. generate-tree.mjs then fills in the index.html files + manifest.
      outDir: isBuild ? resolve(OUT_ROOT, target) : OUT_ROOT,
      emptyOutDir: false,
      cssCodeSplit: false,
      assetsInlineLimit: Number.MAX_SAFE_INTEGER,
      sourcemap: false,
      assetsDir: '',                  // emit assets next to the .js, no assets/ subfolder
      chunkSizeWarningLimit: 2500,    // research-map is ~1.2 MB; tree-shaking already done
      rollupOptions: {
        input: buildEntries,
        // Externalize jspdf — it is used ONLY by the lazy poster/packet export
        // (`await import('jspdf')` in useMapPoster/useMapPacket). Because the IIFE
        // build uses inlineDynamicImports, that "lazy" import was being INLINED,
        // bloating every research/countries/upg bundle by ~0.6 MB (jspdf pulls in
        // html2canvas + canvg). Marking it external + mapping it to a CDN ESM URL
        // keeps it out of the bundle entirely; the browser fetches it at runtime
        // ONLY when the user actually exports a poster/packet. (Build-only — dev
        // still resolves jspdf from node_modules.)
        external: isBuild ? ['jspdf'] : [],
        output: isBuild ? {
          format: 'iife',
          name: `MapForge_${(target || '').replace(/[^a-zA-Z0-9_]/g, '_')}`,
          entryFileNames: '[name].js',
          assetFileNames: () => `${target}.[ext]`,
          inlineDynamicImports: true,
          // Resolve the externalized `import('jspdf')` to a CDN ESM module at runtime.
          paths: { jspdf: 'https://esm.sh/jspdf@4.2.1' },
        } : {
          entryFileNames: '[name].js',
        },
      },
    },
  }
})