import Link from "next/link";
import { getLocale, getTranslations } from "next-intl/server";
import { Printer } from "lucide-react";
import { PageHead } from "@/components/mockup-ui";
import { KindLabel, PendingBadge, formatDayKey } from "@/components/billing/ui";
import { buttonCls } from "@/components/work-orders/button-cls";
import { Empty, Field, inputCls, LinkTabs } from "@/components/work-orders/ui";
import { BILLING_KINDS, BILLING_STATUSES, type BillingKind, type BillingStatus } from "@/lib/billing/schemas";
import { formatHm } from "@/lib/billing/statement";
import { formatDate } from "@/lib/work-orders/time";
import { requirePageContext } from "@/server/api/context";
import { listBillingRecords, type BillingListItem } from "@/server/services/billing/queries";
import { tenantTimezone } from "@/server/services/work-orders/_shared";
import { customerDisplayName, customerFilterOptions, teamOptions } from "@/server/services/work-orders/options";

type SP = Record<string, string | string[] | undefined>;
const one = (v: string | string[] | undefined) => (Array.isArray(v) ? v[0] : v) || undefined;

/**
 * Backoffice `/billing` (L14): completed orders, confirmed milestones and approved daily reports that
 * the external accounting can invoice. Tabs Offen · Abgerechnet · Storniert, filters, multi-select →
 * print view. No prices, no export.
 */
export default async function BillingOverviewPage({ searchParams }: { searchParams: Promise<SP> }) {
  const ctx = await requirePageContext("billing");
  const t = await getTranslations("billing");
  if (!ctx.permissions.has("billing:read")) {
    return (
      <main className="flex-1 p-4 md:p-6">
        <PageHead crumb={t("crumb")} title={t("title")} />
        <Empty>{t("list.noPermission")}</Empty>
      </main>
    );
  }
  const sp = await searchParams;
  const statusParam = one(sp.status);
  const status: BillingStatus = (BILLING_STATUSES as readonly string[]).includes(statusParam ?? "") ? (statusParam as BillingStatus) : "open";
  const kindParam = one(sp.kind);
  const kind = (BILLING_KINDS as readonly string[]).includes(kindParam ?? "") ? (kindParam as BillingKind) : undefined;
  const base = { kind, customerId: one(sp.customerId), teamId: one(sp.teamId), from: one(sp.from), to: one(sp.to), q: one(sp.q) };
  const page = Math.max(1, Math.floor(Number(one(sp.page)) || 1));

  const [list, totals, customers, teams, tz, locale] = await Promise.all([
    listBillingRecords(ctx, { ...base, status, page }),
    Promise.all(BILLING_STATUSES.map((s) => listBillingRecords(ctx, { ...base, status: s, pageSize: 1 }).then((r) => r.total))),
    customerFilterOptions(ctx),
    teamOptions(ctx),
    tenantTimezone(ctx),
    getLocale(),
  ]);

  const qs = (extra: Record<string, string | number | undefined>) => {
    const p = new URLSearchParams();
    for (const [k, v] of Object.entries({ ...base, status, ...extra })) if (v !== undefined && v !== "") p.set(k, String(v));
    return `/billing?${p.toString()}`;
  };
  const period = (i: BillingListItem) =>
    i.kind === "daily_report" && i.reportDate ? formatDayKey(i.reportDate, locale) : `${formatDate(i.periodFrom, locale, tz)} – ${formatDate(i.periodTo, locale, tz)}`;
  const section = (i: BillingListItem) => (i.kind === "milestone" ? i.milestoneTitle : null);
  const pages = Math.max(1, Math.ceil(list.total / list.pageSize));

  return (
    <main className="flex-1 p-4 md:p-6">
      <PageHead crumb={t("crumb")} title={t("title")} sub={t("subtitle")} />

      <LinkTabs
        label={t("title")}
        items={BILLING_STATUSES.map((s, i) => ({ href: qs({ status: s, page: undefined }), label: t(`tabs.${s}`), active: s === status, count: totals[i] }))}
      />

      <details className="shadow-card my-4 rounded-xl border bg-card" open={Object.values(base).some(Boolean)}>
        <summary className="flex min-h-11 cursor-pointer items-center px-4 font-heading text-sm font-semibold">{t("filter.title")}</summary>
        <form method="get" action="/billing" className="grid gap-3 border-t p-4 sm:grid-cols-2 lg:grid-cols-3">
          <input type="hidden" name="status" value={status} />
          <Field label={t("filter.q")} htmlFor="b-q">
            <input id="b-q" type="search" name="q" defaultValue={base.q ?? ""} maxLength={100} placeholder={t("filter.qPlaceholder")} className={inputCls} />
          </Field>
          <Field label={t("filter.from")} htmlFor="b-from">
            <input id="b-from" type="date" name="from" defaultValue={base.from ?? ""} className={inputCls} />
          </Field>
          <Field label={t("filter.to")} htmlFor="b-to">
            <input id="b-to" type="date" name="to" defaultValue={base.to ?? ""} className={inputCls} />
          </Field>
          <Field label={t("filter.customer")} htmlFor="b-customer">
            <select id="b-customer" name="customerId" defaultValue={base.customerId ?? ""} className={inputCls}>
              <option value="">{t("filter.any")}</option>
              {customers.map((c) => (
                <option key={c.id} value={c.id}>
                  {customerDisplayName(c)}
                </option>
              ))}
            </select>
          </Field>
          <Field label={t("filter.team")} htmlFor="b-team">
            <select id="b-team" name="teamId" defaultValue={base.teamId ?? ""} className={inputCls}>
              <option value="">{t("filter.any")}</option>
              {teams.map((x) => (
                <option key={x.id} value={x.id}>
                  {x.name}
                </option>
              ))}
            </select>
          </Field>
          <Field label={t("filter.kind")} htmlFor="b-kind">
            <select id="b-kind" name="kind" defaultValue={kind ?? ""} className={inputCls}>
              <option value="">{t("filter.any")}</option>
              {BILLING_KINDS.map((k) => (
                <option key={k} value={k}>
                  {t(`kind.${k}`)}
                </option>
              ))}
            </select>
          </Field>
          <div className="flex items-end gap-2">
            <button type="submit" className={buttonCls("default")}>
              {t("filter.apply")}
            </button>
            <Link href={`/billing?status=${status}`} className={buttonCls("ghost")}>
              {t("filter.reset")}
            </Link>
          </div>
        </form>
      </details>

      {list.items.length === 0 ? (
        <Empty>{t(`list.empty.${status}`)}</Empty>
      ) : (
        <form method="get" action="/billing/print" className="shadow-card rounded-xl border bg-card">
          <div className="flex flex-wrap items-center justify-between gap-2 border-b p-3">
            <p className="text-sm text-muted-foreground">{t("list.selectHint")}</p>
            <button type="submit" className={buttonCls("outline")}>
              <Printer className="size-4" aria-hidden />
              {t("list.print")}
            </button>
          </div>
          <div className="overflow-x-auto">
            <table className="w-full min-w-[960px] text-sm">
              <thead>
                <tr className="border-b text-left text-xs text-muted-foreground">
                  <th className="p-3">
                    <span className="sr-only">{t("list.select")}</span>
                  </th>
                  <th className="p-3">{t("list.order")}</th>
                  <th className="p-3">{t("list.customerSite")}</th>
                  <th className="p-3">{t("list.section")}</th>
                  <th className="p-3">{t("list.period")}</th>
                  <th className="p-3 text-right">{t("list.work")}</th>
                  <th className="p-3 text-right">{t("list.travel")}</th>
                  <th className="p-3 text-right">{t("list.trips")}</th>
                  <th className="p-3 text-right">{t("list.material")}</th>
                  <th className="p-3">{status === "open" ? t("list.readySince") : status === "billed" ? t("list.billedAt") : t("list.voidedAt")}</th>
                </tr>
              </thead>
              <tbody>
                {list.items.map((i) => (
                  <tr key={i.id} className="border-b align-top last:border-0">
                    <td className="p-3">
                      <input type="checkbox" name="ids" value={i.id} aria-label={t("list.selectRow", { number: i.workOrder.number })} className="size-5 accent-[var(--ui-primary)]" />
                    </td>
                    <td className="p-3">
                      <Link href={`/billing/${i.id}`} className="font-mono font-semibold text-[var(--primary)] hover:underline">
                        {i.workOrder.number}
                      </Link>
                      <div className="text-xs text-muted-foreground">{i.workOrder.title}</div>
                    </td>
                    <td className="p-3">
                      <div>{i.customer.name}</div>
                      <div className="text-xs text-muted-foreground">{i.site?.name ?? "—"}</div>
                    </td>
                    <td className="p-3">
                      <KindLabel kind={i.kind} label={t(`kind.${i.kind}`)} />
                      {section(i) && <div className="text-xs text-muted-foreground">{section(i)}</div>}
                      {i.summary.pendingMinutes > 0 && (
                        <div className="mt-1">
                          <PendingBadge label={t("list.pending", { value: formatHm(i.summary.pendingMinutes) })} />
                        </div>
                      )}
                    </td>
                    <td className="p-3 whitespace-nowrap">{period(i)}</td>
                    <td className="p-3 text-right whitespace-nowrap">{t("hm", { value: formatHm(i.summary.workMinutes) })}</td>
                    <td className="p-3 text-right whitespace-nowrap">{t("hm", { value: formatHm(i.summary.travelMinutes) })}</td>
                    <td className="p-3 text-right">{i.summary.trips}</td>
                    <td className="p-3 text-right">{i.summary.materialCount}</td>
                    <td className="p-3 whitespace-nowrap">
                      {status === "open" && formatDate(i.readySince, locale, tz)}
                      {status === "billed" && (
                        <>
                          {formatDate(i.billedAt, locale, tz)}
                          {i.invoiceNumber && <div className="text-xs text-muted-foreground">{t("list.invoice", { number: i.invoiceNumber })}</div>}
                        </>
                      )}
                      {status === "voided" && (
                        <>
                          {formatDate(i.voidedAt, locale, tz)}
                          {i.voidReason && <div className="max-w-56 truncate text-xs text-muted-foreground">{i.voidReason}</div>}
                        </>
                      )}
                    </td>
                  </tr>
                ))}
              </tbody>
            </table>
          </div>
        </form>
      )}

      {pages > 1 && (
        <nav aria-label={t("list.pagination")} className="mt-4 flex items-center justify-between gap-2">
          {page > 1 ? (
            <Link href={qs({ page: page - 1 })} className={buttonCls("outline")}>
              {t("list.prev")}
            </Link>
          ) : (
            <span />
          )}
          <span className="text-sm text-muted-foreground">{t("list.page", { page, pages })}</span>
          {page < pages ? (
            <Link href={qs({ page: page + 1 })} className={buttonCls("outline")}>
              {t("list.next")}
            </Link>
          ) : (
            <span />
          )}
        </nav>
      )}
    </main>
  );
}