import{readFileSync,writeFileSync,mkdirSync,cpSync,readdirSync,existsSync,statSync}from'fs'
import{join,extname}from'path'
import matter from'gray-matter'
import{marked}from'marked'

const ARTICLES='articles',DIST='dist',TEMPLATES='templates',STATIC='static'

const template=n=>readFileSync(join(TEMPLATES,n),'utf-8')
const articleTmpl=template('article.html')
const homeTmpl=template('home.html')

mkdirSync(DIST,{recursive:true})

if(existsSync(STATIC))
  cpSync(STATIC,DIST,{recursive:true})

const articles=[]

for(const slug of readdirSync(ARTICLES)){
  const dir=join(ARTICLES,slug)
  if(!statSync(dir).isDirectory()) continue

  const mdPath=join(dir,'index.md')
  if(!existsSync(mdPath)) continue

  const{data,content}=matter(readFileSync(mdPath,'utf-8'))
  const html=marked(content)

  const outDir=join(DIST,slug)
  mkdirSync(outDir,{recursive:true})

  // copy co-located assets
  for(const f of readdirSync(dir)){
    if(f==='index.md') continue
    cpSync(join(dir,f),join(outDir,f))
  }

  const page=articleTmpl
    .replace('{{title}}',data.title||slug)
    .replace('{{date}}',data.date?new Date(data.date).toLocaleDateString('en-US',{month:'long',day:'numeric',year:'numeric'}):'')
    .replace('{{date_iso}}',data.date?new Date(data.date).toISOString().split('T')[0]:'')
    .replace('{{tags}}', (data.tags||[]).map(t=>`<span class="inline-flex items-center rounded-full border border-gray-200 bg-gray-50 px-2 py-0.5 text-xs font-medium text-gray-600 mono">${t}</span>`).join(' '))
    .replace('{{excerpt}}',data.excerpt||'')
    .replace('{{slug}}',slug)
    .replace('{{body}}',html)

  writeFileSync(join(outDir,'index.html'),page)
  articles.push({slug,...data})
  console.log(`✅ ${slug}`)
}

articles.sort((a,b)=>new Date(b.date)-new Date(a.date))

const articleListHtml=articles.map(a=>`
  <a href="/${a.slug}/" class="block rounded-2xl border border-gray-200 bg-white shadow-sm hover:shadow-md transition-shadow overflow-hidden">
    <div class="px-5 py-4">
      <div class="flex items-start justify-between gap-4">
        <h2 class="text-base font-semibold text-gray-900">${a.title}</h2>
        <time datetime="${new Date(a.date).toISOString().split('T')[0]}" class="mono text-xs text-gray-400 whitespace-nowrap mt-0.5">${new Date(a.date).toLocaleDateString('en-US',{month:'short',day:'numeric'})}</time>
      </div>
      ${a.excerpt?`<p class="text-sm text-gray-500 mt-1.5">${a.excerpt}</p>`:''}
      <div class="flex gap-1.5 mt-3">${(a.tags||[]).map(t=>`<span class="inline-flex items-center rounded-full border border-gray-200 bg-gray-50 px-2 py-0.5 text-xs font-medium text-gray-600 mono">${t}</span>`).join('')}</div>
    </div>
  </a>`).join('\n')

const home=homeTmpl.replace('{{articles}}',articleListHtml)
writeFileSync(join(DIST,'index.html'),home)
console.log(`\n🏠 index.html → ${articles.length} article(s)`)