import { NextRequest, NextResponse } from 'next/server';
import { setRulesDate } from '@/lib/db';
import { sortableIso } from '@/lib/kept-rules';

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

/** A rules date may run this far ahead of the server's clock — room for a
 *  browser whose clock or time zone is ahead, not for dating accounts later. */
const MAX_FUTURE_MS = 24 * 60 * 60 * 1000;

function parseAccountId(raw: string): number | null {
    const id = parseInt(raw, 10);
    return Number.isNaN(id) ? null : id;
}

/** Set an account's rules date by hand. The date decides which of its type's
 *  rule sets it trades on — one dated before a firm's rule change keeps the
 *  old rules — and a date set here is never moved by broker evidence again.
 *  The trade path reads it per tick, so nothing needs re-resolving. */
export async function PUT(req: NextRequest, { params }: Params) {
    const { id: idStr } = await params;
    const accountId = parseAccountId(idStr);
    if (accountId === null) return NextResponse.json({ error: 'Invalid id' }, { status: 400 });

    const body = await req.json().catch(() => null) as { rulesDate?: unknown } | null;
    const raw = body?.rulesDate;
    const ms = typeof raw === 'string' ? Date.parse(raw) : NaN;
    if (!Number.isFinite(ms)) {
        return NextResponse.json({ error: 'rulesDate must be an ISO date' }, { status: 400 });
    }
    if (ms > Date.now() + MAX_FUTURE_MS) {
        return NextResponse.json({ error: 'A rules date cannot be more than a day ahead' }, { status: 400 });
    }

    // Stored as a plain four-digit-year toISOString(), the one format every
    // rules-date writer uses — lowerAutoRulesDate compares them as strings,
    // so nothing before 2000 (or that doesn't print as one) gets in.
    const rulesDate = sortableIso(ms);
    if (!rulesDate) {
        return NextResponse.json({ error: 'A rules date cannot be before 2000' }, { status: 400 });
    }
    if (!setRulesDate(accountId, rulesDate, true)) {
        return NextResponse.json({ error: 'Unknown account' }, { status: 404 });
    }
    return NextResponse.json({ ok: true, rulesDate });
}