import { getGameDb } from '@/lib/db/client'
import { ResearchError, researchTech } from '@/lib/game/research'

// Research one tech. Body: { "techId": number }. Costs inventory items + a turn; returns the fresh tech tree state.
export async function POST(req: Request) {
  let body: unknown
  try {
    body = await req.json()
  } catch {
    return Response.json({ error: 'Invalid JSON body' }, { status: 400 })
  }

  const techId = (body as { techId?: unknown }).techId
  if (typeof techId !== 'number' || !Number.isInteger(techId)) {
    return Response.json({ error: 'techId must be an integer' }, { status: 400 })
  }

  try {
    const db = await getGameDb()
    return Response.json(await researchTech(db, techId))
  } catch (err) {
    if (err instanceof ResearchError) {
      return Response.json({ error: err.message }, { status: err.status })
    }
    throw err
  }
}