import { existsSync, readdirSync, readFileSync } from 'node:fs'
import { dirname, join, resolve as resolvePath } from 'node:path'
import { pathToFileURL, fileURLToPath } from 'node:url'
const root = resolvePath(process.env.NETLIFY_VERIFY_REPO_ROOT || '/tmp/netliloop-work/build')
const { default: ts } = await import(pathToFileURL(join(root, 'node_modules/typescript/lib/typescript.js')).href)
const workspaces = new Map()
for (const dir of readdirSync(join(root, 'packages'))) {
  const manifestPath = join(root, 'packages', dir, 'package.json')
  if (!existsSync(manifestPath)) continue
  const manifest = JSON.parse(readFileSync(manifestPath, 'utf8'))
  workspaces.set(manifest.name, { dir: dirname(manifestPath), manifest })
}
const sourceFile = path => {
  const mapped = path.replace('/lib/', '/src/').replace('/dist/', '/src/')
  if (existsSync(mapped)) return mapped
  if (mapped.endsWith('.js') && existsSync(mapped.slice(0, -3) + '.ts')) return mapped.slice(0, -3) + '.ts'
}
const paths = {}
for (const [name, workspace] of workspaces) {
  const entry = typeof workspace.manifest.exports === 'string' ? workspace.manifest.exports : workspace.manifest.main
  if (typeof entry !== 'string') continue
  const source = sourceFile(join(workspace.dir, entry))
  if (source) paths[name] = [source]
}
let program
const emitTyped = (file) => {
  program ??= ts.createProgram([root + '/packages/build/src/plugins/child/main.js', ...Object.values(paths).flat()], {
    allowJs: true, module: ts.ModuleKind.NodeNext, moduleResolution: ts.ModuleResolutionKind.NodeNext,
    target: ts.ScriptTarget.ES2022, paths, noEmitOnError: false, skipLibCheck: true,
  })
  const source = program.getSourceFile(file)
  if (!source) throw new Error('Source outside compiler graph: ' + file)
  let output
  program.emit(source, (name, contents) => { if (name.endsWith('.js')) output = contents })
  return output
}
export async function resolve(specifier, context, nextResolve) {
  const workspace = workspaces.get(specifier)
  if (workspace) {
    const entry = typeof workspace.manifest.exports === 'string' ? workspace.manifest.exports : workspace.manifest.main
    if (typeof entry === 'string') {
      const source = sourceFile(join(workspace.dir, entry))
      if (source) return { url: pathToFileURL(source).href, shortCircuit: true }
    }
  }
  if (specifier.startsWith('.') && context.parentURL?.startsWith('file:')) {
    const url = new URL(specifier, context.parentURL)
    const path = fileURLToPath(url)
    if (path.startsWith(root + '/packages/')) {
      const source = sourceFile(path)
      if (source) return { url: pathToFileURL(source).href, shortCircuit: true }
    }
  }
  return nextResolve(specifier, context)
}
export async function load(url, context, nextLoad) {
  if (url.startsWith('file:') && url.endsWith('.ts')) {
    const source = emitTyped(fileURLToPath(url))
    return { format: 'module', source, shortCircuit: true }
  }
  return nextLoad(url, context)
}