import { getGameDb } from '@/lib/db/client'
import { MAX_TEAM_SIZE } from '@/lib/game/crew'
import { checkJumpTarget, getWorldState, JumpError, queueStateFromSave, saveTaskRow } from '@/lib/game/save'
import { queueTask, TaskError } from '@/lib/game/tasks'

// Jump to a system within range: assign the crew team (lead + helpers) and queue the JUMP
// task — the move lands when the task completes on the turn tick (runTurn). Body:
// { systemId, leadCrewId, helperCrewIds? }. Queueing spends no turn; returns the same fresh
// world state as the instant jump did.
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 systemId = (body as { systemId?: unknown }).systemId
  if (typeof systemId !== 'number' || !Number.isInteger(systemId)) {
    return Response.json({ error: 'systemId must be an integer' }, { status: 400 })
  }
  const leadCrewId = (body as { leadCrewId?: unknown }).leadCrewId
  if (typeof leadCrewId !== 'number' || !Number.isInteger(leadCrewId)) {
    return Response.json({ error: 'leadCrewId must be an integer' }, { status: 400 })
  }
  let helperCrewIds: number[] = []
  const rawHelpers = (body as { helperCrewIds?: unknown }).helperCrewIds
  if (rawHelpers !== undefined) {
    if (!Array.isArray(rawHelpers) || !rawHelpers.every((h) => typeof h === 'number' && Number.isInteger(h))) {
      return Response.json({ error: 'helperCrewIds must be an array of integers' }, { status: 400 })
    }
    helperCrewIds = rawHelpers
  }
  // Team rules (route layer, not queueTask's): one task team, distinct members, size cap.
  const team = [leadCrewId, ...helperCrewIds]
  if (new Set(team).size !== team.length) {
    return Response.json({ error: 'crew members must be unique' }, { status: 400 })
  }
  if (team.length > MAX_TEAM_SIZE) {
    return Response.json({ error: `a task team holds at most ${MAX_TEAM_SIZE} crew members` }, { status: 400 })
  }

  try {
    const db = await getGameDb()
    const hops = await checkJumpTarget(db, systemId) // existing pre-checks: 404 unknown · 409 already there / out of range
    const state = await queueStateFromSave(db)
    const { task } = queueTask(state, { type: 'JUMP', payload: { systemId, hops }, leadCrewId, helperCrewIds })
    await saveTaskRow(db, task) // inventory is unchanged for a JUMP — no hold write
    return Response.json(await getWorldState(db))
  } catch (err) {
    if (err instanceof JumpError || err instanceof TaskError) {
      return Response.json({ error: err.message }, { status: err.status })
    }
    throw err
  }
}