import fs from 'fs'
import path from 'path'
import matter from 'gray-matter'

const CONTENT_DIR = path.join(process.cwd(), 'content')
const KNIEPUNKT_DIR = path.join(CONTENT_DIR, 'kniepunkt')
const POSTS_DIR = path.join(CONTENT_DIR, 'posts')

function getFiles(dir) {
  return fs.readdirSync(dir).map(f => path.join(dir, f)).filter(f => f.endsWith('.md'))
}

const allPosts = getFiles(POSTS_DIR)
const allKniepunkte = getFiles(KNIEPUNKT_DIR)
const all = [...allPosts, ...allKniepunkte]

function mergeFiles(headerPath, articlePath, outputPath, issueNum, issueDate) {
  if (fs.existsSync(headerPath) && fs.existsSync(articlePath)) {
    const headerData = matter(fs.readFileSync(headerPath, 'utf8'))
    const articleData = matter(fs.readFileSync(articlePath, 'utf8'))
    
    // Combine
    const mergedContent = headerData.content.trim() + '\n\n---\n\n' + articleData.content.trim()
    
    // Update frontmatter
    articleData.data.title = `Kniepunkt 0${issueNum}: ` + articleData.data.title.replace(/^Kniepunkt \d+: /, '')
    if (issueDate) articleData.data.date = issueDate
    
    fs.writeFileSync(outputPath, matter.stringify(mergedContent, articleData.data))
    
    // Delete old
    if (headerPath !== outputPath && fs.existsSync(headerPath)) fs.unlinkSync(headerPath)
    if (articlePath !== outputPath && fs.existsSync(articlePath)) fs.unlinkSync(articlePath)
    console.log(`Merged 0${issueNum} to ${path.basename(outputPath)}`)
  }
}

// 3. Merge 029
const article029 = allKniepunkte.find(f => f.includes('029-ki-nudelsuppe'))
const h29 = allPosts.find(f => fs.existsSync(f) && fs.readFileSync(f, 'utf8').includes('Nudelsuppe')) || allKniepunkte.find(f => fs.existsSync(f) && path.basename(f).includes('29.md'))
if (h29 && article029) mergeFiles(h29, article029, path.join(KNIEPUNKT_DIR, '029-ki-nudelsuppe.md'), 29)

// 4. Merge 031
const header031 = all.find(f => f.includes('031-ist-da'))
const article031 = all.find(f => f.includes('031-ki-verkaeufer-statt-ki-spielberg')) || path.join(KNIEPUNKT_DIR, '031-ki-verkaeufer-statt-ki-spielberg.md')
if (fs.existsSync(header031) && fs.existsSync(article031)) {
  mergeFiles(header031, article031, path.join(KNIEPUNKT_DIR, '031-ki-verkaeufer-statt-ki-spielberg.md'), 31)
} else {
  console.log(`Could not find 031 files`)
}

// 5. Rename 002-006 and move to kniepunkt
const renames = [
  { match: '2025-09-06-ki-als-fitnessstudio', newName: '002-ki-als-fitnessstudio-abo.md', issue: 2 },
  { match: '2025-09-12-wird-ki-wirklich-alle-jobs-uebernehmen', newName: '003-wird-ki-wirklich-alle-jobs-uebernehmen.md', issue: 3 },
  { match: '2025-09-20-die-ki-wetterkarte', newName: '004-die-ki-wetterkarte.md', issue: 4 },
  { match: '2025-09-26-enough-let-s-move-on', newName: '005-enough-lets-move-on.md', issue: 5 },
  { match: '2025-10-10-zwischen-gigafactories', newName: '006-zwischen-gigafactories.md', issue: 6 }
]

renames.forEach(r => {
  const f = allPosts.find(x => fs.existsSync(x) && x.includes(r.match))
  if (f) {
    const m = matter(fs.readFileSync(f, 'utf8'))
    m.data.title = `Kniepunkt 00${r.issue}: ` + m.data.title
    m.data.issue = r.issue
    const out = path.join(KNIEPUNKT_DIR, r.newName)
    fs.writeFileSync(out, matter.stringify(m.content, m.data))
    fs.unlinkSync(f)
    console.log(`Moved ${r.issue} to kniepunkt: ${r.newName}`)
  }
})