import { jsonError } from '@/lib/server/http';
import { requireAuthenticatedSession } from '@/lib/server/auth-session';
import { recalculateHolding } from '@/lib/server/portfolio';
import { withStore } from '@/lib/server/store';

type Context = {
  params: Promise<{ id: string }>;
};

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

function asPositiveNumber(value: unknown) {
  const parsed = typeof value === 'number' ? value : Number(value);
  return Number.isFinite(parsed) && parsed > 0 ? parsed : null;
}

export async function PATCH(request: Request, context: Context) {
  const { session, response } = await requireAuthenticatedSession();
  if (response) {
    return response;
  }

  const userId = session.user.id;
  const { id } = await context.params;
  const numericId = Number(id);

  if (!Number.isInteger(numericId) || numericId <= 0) {
    return jsonError('Invalid holding id');
  }

  const payload = await request.json() as {
    shares?: number;
    avgCost?: number;
    currentPrice?: number;
  };

  let found = false;
  let updated: unknown = null;

  await withStore((store) => {
    const index = store.holdings.findIndex((entry) => entry.id === numericId && entry.user_id === userId);
    if (index < 0) {
      return;
    }

    found = true;
    const existing = store.holdings[index];

    const shares = asPositiveNumber(payload.shares) ?? Number(existing.shares);
    const avgCost = asPositiveNumber(payload.avgCost) ?? Number(existing.avg_cost);
    const currentPrice = asPositiveNumber(payload.currentPrice) ?? Number(existing.current_price ?? existing.avg_cost);

    const next = recalculateHolding({
      ...existing,
      shares: shares.toFixed(6),
      avg_cost: avgCost.toFixed(6),
      current_price: currentPrice.toFixed(6),
      updated_at: nowIso(),
      last_price_at: nowIso()
    });

    store.holdings[index] = next;
    updated = next;
  });

  if (!found) {
    return jsonError('Holding not found', 404);
  }

  return Response.json({ holding: updated });
}

export async function DELETE(_request: Request, context: Context) {
  const { session, response } = await requireAuthenticatedSession();
  if (response) {
    return response;
  }

  const userId = session.user.id;
  const { id } = await context.params;
  const numericId = Number(id);

  if (!Number.isInteger(numericId) || numericId <= 0) {
    return jsonError('Invalid holding id');
  }

  let removed = false;

  await withStore((store) => {
    const next = store.holdings.filter((holding) => !(holding.id === numericId && holding.user_id === userId));
    removed = next.length !== store.holdings.length;
    store.holdings = next;
  });

  if (!removed) {
    return jsonError('Holding not found', 404);
  }

  return Response.json({ success: true });
}