import assert from 'node:assert/strict'
import { readFileSync, readdirSync } from 'node:fs'
import { dirname, join } from 'node:path'
import { test } from 'node:test'
import { fileURLToPath } from 'node:url'

import { facetContextText, facetRuleText } from '../lib/scope.js'

const PRESETS = join(dirname(fileURLToPath(import.meta.url)), '..', 'presets')

/**
 * The prompt variables the harness registers for a section.
 *
 * `dsh-agent-loop` puts each of these into the prompt registry, and an assembly
 * substitutes only what is registered. An unknown reference is not rendered as
 * text — interpolation throws, and the throw takes the entire turn with it, so
 * the user sees "This turn failed" and nothing else. A harness release that
 * stopped registering `cwd` is exactly how this bundle's preset stopped
 * composing sessions: the persona suffix it copied from the deployment said
 * "Your working directory is …" with that variable in it.
 */
const REGISTERED = ['provider', 'model']

/** Every `{{name}}` reference in one text, as the name alone. */
function referencesIn(text) {
  return [...text.matchAll(/\{\{([^{}]*)\}\}/g)].map((match) => match[1])
}

test('no preset references a prompt variable the harness does not register', () => {
  const files = readdirSync(PRESETS).filter((name) => name.endsWith('.yml'))
  assert.ok(files.length > 0, 'the bundle ships at least one preset')

  const found = []
  for (const file of files) {
    for (const name of referencesIn(readFileSync(join(PRESETS, file), 'utf8'))) found.push([file, name])
  }

  // The model reference is the one that has to keep working, so the guard cannot
  // be satisfied by a preset that references nothing at all.
  assert.ok(
    found.some(([, name]) => name === 'model'),
    'a preset still names the model',
  )
  for (const [file, name] of found) {
    assert.ok(
      REGISTERED.includes(name),
      `${file} references {{${name}}}; the harness registers only ${REGISTERED.join(', ')}, and an unregistered reference fails the whole turn`,
    )
  }
})

test('the text this bundle contributes to the prompt holds no variable references', () => {
  // The rule and the binding are rebuilt from real values on every request, so a
  // placeholder in either would be a reference the harness never resolves — the
  // same failure, this time from the bundle's own hand.
  const rule = facetRuleText()
  const binding = facetContextText({ cwd: '/w', root: '/w/src', extras: ['/w/shared'], mode: 'ask' })
  assert.ok(rule.length > 0 && binding.length > 0, 'both halves contribute text')
  assert.deepEqual(referencesIn(rule), [])
  assert.deepEqual(referencesIn(binding), [])
})