/**
 * Migration des données du site Astro vers les fichiers plats OKI (ADR-001,
 * mission §7). Extrait les 55 ToolCard des MDX français + métadonnées de
 * src/data/{tools,directory}.json et produit :
 *   content/outils/<slug>.md   (frontmatter JSON-par-ligne + sections HTML)
 *   content/categories.json    (catégories dérivées des sections sources)
 *
 * Idempotent : relançable, écrase la sortie. Usage : pnpm migrate
 */
import { readFile, readdir, writeFile, mkdir } from 'node:fs/promises'
import path from 'node:path'
import { fileURLToPath } from 'node:url'

const ROOT = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '..', '..')
const SRC = path.join(ROOT, 'src')
const OUT = path.join(ROOT, 'content')

const DIFFICULTY = { 1: 'beginner', 2: 'intermediate', 3: 'advanced' }

const tools = JSON.parse(await readFile(path.join(SRC, 'data', 'tools.json'), 'utf8'))
const directory = JSON.parse(await readFile(path.join(SRC, 'data', 'directory.json'), 'utf8'))
const toolById = new Map(tools.map((t) => [t.id, t]))
const dirById = new Map(directory.map((d) => [d.id, d]))

function parseFrontmatter(raw) {
  const m = raw.match(/^---\n([\s\S]*?)\n---\n?/)
  if (!m) return [{}, raw]
  const meta = {}
  for (const line of m[1].split('\n')) {
    const i = line.indexOf(':')
    if (i === -1) continue
    const key = line.slice(0, i).trim()
    let value = line.slice(i + 1).trim()
    if (/^'.*'$/.test(value)) value = value.slice(1, -1)
    meta[key] = /^\d+$/.test(value) ? Number(value) : value
  }
  return [meta, raw.slice(m[0].length)]
}

/** Extrait le contenu d'un slot (Fragment/ol/ul) dans un bloc ToolCard. */
function slot(block, name) {
  const re = new RegExp(
    `<(Fragment|ol|ul)([^>]*slot="${name}"[^>]*)>([\\s\\S]*?)</\\1>`
  )
  const m = block.match(re)
  if (!m) return null
  // Les listes gardent leur balise (le HTML passe tel quel dans le markdown) ;
  // les Fragments sont déballés.
  return m[1] === 'Fragment' ? m[3].trim() : `<${m[1]}>${m[3]}</${m[1]}>`.trim()
}

/** Tags = textes des <span class="tool-tag"> hors difficulté (déjà structurée). */
function extractTags(block) {
  const html = slot(block, 'tags') ?? ''
  const tags = [...html.matchAll(/<span class="tool-tag">([\s\S]*?)<\/span>/g)]
    .map((m) => m[1].replace(/\s+/g, ' ').trim())
    .filter((t) => !/^[🟢🟡🔴]/u.test(t))
  return tags
}

/** Difficulté : `level` de tools.json, sinon l'emoji du tag MDX (🟢/🟡/🔴). */
function difficulty(tool, block) {
  if (DIFFICULTY[tool.level]) return DIFFICULTY[tool.level]
  const html = slot(block, 'tags') ?? ''
  if (html.includes('🟢')) return 'beginner'
  if (html.includes('🟡')) return 'intermediate'
  if (html.includes('🔴')) return 'advanced'
  console.warn(`⚠ ${tool.id} : difficulté introuvable — « intermediate » par défaut`)
  return 'intermediate'
}

const fm = (key, value) => (value == null ? null : `${key}: ${JSON.stringify(value)}`)

const sectionsDir = path.join(SRC, 'content', 'sections', 'fr')
const files = (await readdir(sectionsDir)).filter((f) => f.endsWith('.mdx')).sort()

await mkdir(path.join(OUT, 'outils'), { recursive: true })

const categories = []
const seen = new Set()
let written = 0

for (const file of files) {
  const raw = await readFile(path.join(sectionsDir, file), 'utf8')
  const [meta, body] = parseFrontmatter(raw)
  const blocks = [...body.matchAll(/<ToolCard tool="([^"]+)"[^>]*>([\s\S]*?)<\/ToolCard>/g)]
  if (blocks.length === 0) continue

  categories.push({
    slug: meta.id,
    title: meta.title,
    order: meta.order,
    part: meta.part
  })

  for (const [, toolId, block] of blocks) {
    const tool = toolById.get(toolId)
    if (!tool) {
      console.warn(`⚠ ${file} : ToolCard "${toolId}" absent de tools.json — ignoré`)
      continue
    }
    const slug = toolId.replace(/^t-/, '')
    if (seen.has(slug)) {
      console.warn(`⚠ ${slug} : doublon (déjà émis) — ignoré dans ${file}`)
      continue
    }
    seen.add(slug)
    const dir = dirById.get(slug)
    const nameOverride = slot(block, 'name')

    const front = [
      fm('name', nameOverride ?? tool.name),
      fm('slug', slug),
      fm('category', meta.id),
      fm('difficulty', difficulty(tool, block)),
      fm('license', dir?.license),
      fm('url', tool.url),
      fm('color', tool.color),
      fm('monogram', tool.monogram),
      fm('iconSlug', tool.iconSlug),
      fm('tags', extractTags(block)),
      fm('lang', 'fr')
    ]
      .filter(Boolean)
      .join('\n')

    const sections = [
      ['what', slot(block, 'what')],
      ['why', slot(block, 'why')],
      ['who', slot(block, 'who')],
      ['install', slot(block, 'install')],
      ['extra', slot(block, 'extra')]
    ]
      .filter(([, html]) => html)
      .map(([key, html]) => `## ${key}\n\n${html}`)
      .join('\n\n')

    await writeFile(path.join(OUT, 'outils', `${slug}.md`), `---\n${front}\n---\n\n${sections}\n`)
    written++
  }
}

await writeFile(path.join(OUT, 'categories.json'), JSON.stringify(categories, null, 2) + '\n')
console.log(`✔ ${written} fiches écrites dans content/outils/, ${categories.length} catégories`)

const missing = tools.filter((t) => !seen.has(t.id.replace(/^t-/, '')))
if (missing.length) {
  console.warn(`⚠ outils de tools.json sans ToolCard fr : ${missing.map((t) => t.id).join(', ')}`)
}