import { NextRequest, NextResponse } from 'next/server'
import { requireAdmin } from '@/lib/auth'
import { getLibrary } from '@/lib/libraries'
import { getDb } from '@/lib/db'

export async function POST(
  request: NextRequest,
  { params }: { params: Promise<{ id: string }> },
) {
  const auth = await requireAdmin(request)
  if (auth instanceof NextResponse) return auth

  const { id: libraryId } = await params
  const library = getLibrary(libraryId)
  if (!library) {
    return NextResponse.json({ error: 'Library not found' }, { status: 404 })
  }
  if (library.type !== 'comics') {
    return NextResponse.json({ error: 'Only comics libraries support bulk rename' }, { status: 400 })
  }

  const body = await request.json()
  const { pattern, preview } = body as { pattern: string; preview?: boolean }

  if (!pattern || typeof pattern !== 'string') {
    return NextResponse.json({ error: 'Pattern is required' }, { status: 400 })
  }

  // Validate regex
  let regex: RegExp
  try {
    regex = new RegExp(pattern, 'g')
  } catch {
    return NextResponse.json({ error: 'Invalid regex pattern' }, { status: 400 })
  }

  const db = getDb()

  const rows = db
    .prepare(
      `SELECT item_key, title FROM media_items
       WHERE library_id = ? AND item_type IN ('comic_series', 'comic_issue')`
    )
    .all(libraryId) as { item_key: string; title: string }[]

  const changes: { itemKey: string; oldTitle: string; newTitle: string }[] = []

  for (const row of rows) {
    // Reset lastIndex since we reuse the regex with 'g' flag
    regex.lastIndex = 0
    const newTitle = row.title.replace(regex, '').trim()
    if (newTitle && newTitle !== row.title) {
      changes.push({ itemKey: row.item_key, oldTitle: row.title, newTitle })
    }
  }

  if (preview) {
    return NextResponse.json({ changes })
  }

  // Apply
  const stmt = db.prepare('UPDATE media_items SET title = ? WHERE item_key = ?')
  db.transaction(() => {
    for (const c of changes) {
      stmt.run(c.newTitle, c.itemKey)
    }
  })()

  return NextResponse.json({ updated: changes.length })
}