import { readFileSync, readdirSync, writeFileSync } from 'node:fs'
import { resolve } from 'node:path'
import type { Plugin } from 'vite'
import { configDefaults, defineConfig } from 'vitest/config'

// @ts-expect-error plain-node script, no type declarations
import { applyDevChannel } from './scripts/dev-channel.mjs'

// SUBSTANDARD_CHANNEL=dev builds the dev channel: inverted icons, a suffixed
// name, and the commit stamped into version_name, so an unpacked install is
// distinguishable from the store one in the same browser and says which build
// it is. See scripts/dev-channel.mjs.
function devChannel(): Plugin | undefined {
  if (process.env.SUBSTANDARD_CHANNEL !== 'dev') return undefined
  return {
    name: 'substandard:dev-channel',
    // Only the client environment copies public/ into dist/, and that copy
    // happens before the bundle is written — so patching here lands on top of
    // it, on the first build and on every watch rebuild.
    applyToEnvironment: (environment) => environment.name === 'client',
    writeBundle(options) {
      const dist = options.dir ?? resolve(__dirname, 'dist')
      const { name, version_name } = applyDevChannel(__dirname, dist)
      const build = version_name ? `, build ${version_name}` : ''
      console.log(`[dev-channel] ${dist}: icons inverted, name "${name}"${build}`)
    },
  }
}

// Ship sourcemaps carrying the source of the code we wrote, and not of the
// code we merely depend on.
//
// The store reviews minified code more slowly than readable code — Google's
// guidance is to submit code as authored where feasible — and this extension
// asks for all-hosts access, which already earns an in-depth review anyway.
// Maps let a reviewer read the TypeScript instead of the minified output.
//
// The catch is `sourcesContent`: it inlines the full text of every source in
// the chunk, and the OAuth chunk is mostly @atproto, so its map alone is
// 3.7 MB — tripling the upload and burying our ~2 kLOC in several megabytes
// of third-party source. That is more for a reviewer to wade through, not
// less, and those sources are public and versioned on npm regardless.
//
// So the mappings stay complete for every file (stack traces still resolve),
// and only the inlined *text* of node_modules sources is dropped.
//
// Done on disk in writeBundle, not by mutating `chunk.map` in generateBundle:
// changes there are not carried through to the file rollup writes, which
// shows up as a build log reporting the trimmed size while the artifact keeps
// the full one. The dev channel above patches build output the same way.
function ownCodeSourcemapsOnly(): Plugin {
  return {
    name: 'substandard:own-sourcemaps',
    writeBundle(options) {
      const dist = options.dir ?? resolve(__dirname, 'dist')
      for (const name of readdirSync(dist, { recursive: true })) {
        if (!String(name).endsWith('.js.map')) continue
        const file = resolve(dist, String(name))
        const map = JSON.parse(readFileSync(file, 'utf8')) as {
          sources: string[]
          sourcesContent?: (string | null)[]
        }
        if (!map.sourcesContent) continue
        map.sourcesContent = map.sourcesContent.map((content, i) =>
          map.sources[i]?.includes('node_modules') ? null : content,
        )
        writeFileSync(file, JSON.stringify(map))
      }
    },
  }
}

// One build, two environments (Vite 6 builder API — `vite build` builds both
// in order):
//
// - `client`: the popup/offscreen/welcome pages and the background service
//   worker, as ES modules. Empties dist/ and copies public/ (manifest, icons).
// - `content`: the content script as a single IIFE file, because MV3 content
//   scripts cannot be ES modules. Builds second, into the same dist/.
//
// scripts/dev.mjs runs the same two environments in watch mode.
export default defineConfig({
  test: {
    // web/ runs its own node:test suite (`npm --prefix web test`); vitest's
    // default glob would sweep those files up and fail on them. .claude/
    // holds agent worktrees — full repo copies whose tests are not ours to run.
    exclude: [...configDefaults.exclude, 'web/**', '.claude/**'],
  },
  plugins: [devChannel(), ownCodeSourcemapsOnly()],
  builder: {},
  environments: {
    client: {
      build: {
        modulePreload: false,
        sourcemap: true,
        rollupOptions: {
          input: {
            popup: resolve(__dirname, 'popup.html'),
            offscreen: resolve(__dirname, 'offscreen.html'),
            welcome: resolve(__dirname, 'welcome.html'),
            background: resolve(__dirname, 'src/background.ts'),
          },
          output: {
            entryFileNames: '[name].js',
            chunkFileNames: 'chunks/[name]-[hash].js',
            assetFileNames: 'assets/[name][extname]',
          },
        },
      },
    },
    content: {
      consumer: 'client',
      build: {
        sourcemap: true,
        emptyOutDir: false, // shares dist/ with the client environment
        copyPublicDir: false,
        lib: {
          entry: resolve(__dirname, 'src/content.ts'),
          name: 'substandardContent',
          formats: ['iife'],
          fileName: () => 'content.js',
        },
      },
    },
  },
})