import type { WatchlistItem } from '@/lib/types';
import { asErrorMessage, jsonError } from '@/lib/server/http';
import { getStoreSnapshot, withStore } from '@/lib/server/store';

function nowIso() {
  return new Date().toISOString();
}

export async function GET() {
  const snapshot = await getStoreSnapshot();
  const items = snapshot.watchlist
    .slice()
    .sort((a, b) => Date.parse(b.created_at) - Date.parse(a.created_at));

  return Response.json({ items });
}

export async function POST(request: Request) {
  try {
    const payload = await request.json() as {
      ticker?: string;
      companyName?: string;
      sector?: string;
    };

    if (!payload.ticker || payload.ticker.trim().length < 1) {
      return jsonError('ticker is required');
    }

    if (!payload.companyName || payload.companyName.trim().length < 1) {
      return jsonError('companyName is required');
    }

    let item: WatchlistItem | null = null;

    await withStore((store) => {
      const ticker = payload.ticker!.trim().toUpperCase();
      const existingIndex = store.watchlist.findIndex((entry) => entry.ticker === ticker);

      if (existingIndex >= 0) {
        const existing = store.watchlist[existingIndex];
        const updated: WatchlistItem = {
          ...existing,
          company_name: payload.companyName!.trim(),
          sector: payload.sector?.trim() || null
        };

        store.watchlist[existingIndex] = updated;
        item = updated;
        return;
      }

      store.counters.watchlist += 1;
      const created: WatchlistItem = {
        id: store.counters.watchlist,
        user_id: 1,
        ticker,
        company_name: payload.companyName!.trim(),
        sector: payload.sector?.trim() || null,
        created_at: nowIso()
      };

      store.watchlist.unshift(created);
      item = created;
    });

    return Response.json({ item });
  } catch (error) {
    return jsonError(asErrorMessage(error, 'Failed to create watchlist item'));
  }
}