import type { UnitOption } from "@/components/positions/CreatePositionModal";
import { PositionsPageClient } from "@/components/positions/PositionsPageClient";
import { currentUserId } from "@/lib/auth/session";
import { kostenstellenAbfrage } from "@/lib/cost-centers";
import { withUser } from "@/lib/db";
import { jsonArrayFrom } from "@/lib/db/json";
import { daysBetweenIso, todayIso } from "@/lib/format";
import { buildOrgMaps, orgMapsAbfragen } from "@/lib/org";
import { offeneStellenAbfrage, resolveOpenPositions, type OffeneStelle } from "@/lib/positions";

export default async function PositionsPage() {
  const today = todayIso();

  const { openPositions, orgMaps, chiefRows, kostenstellen } = await withUser(await currentUserId(), async (tx) => {
    // Alles, was ohne Vorwissen geht, in einer Rundreise (lib/db/json.ts).
    const g = await tx
      .selectNoFrom((eb) => [
        ...orgMapsAbfragen(eb),
        jsonArrayFrom(offeneStellenAbfrage(eb, today)).as("open"),
        jsonArrayFrom(kostenstellenAbfrage(eb, today)).as("kostenstellen"),
        // Wo es schon eine gültige Leitungsplanstelle gibt, lässt der
        // Unique-Index keine zweite zu — das gehört in den Dialog, nicht in eine
        // Fehlermeldung nach dem Absenden.
        jsonArrayFrom(
          eb.selectFrom("om_positions").select("org_unit_id").where("is_chief", "=", true).where("valid_to", "is", null)
        ).as("chiefRows"),
      ])
      .executeTakeFirstOrThrow();

    const orgMaps = buildOrgMaps(g.units as never, g.locations as never);
    return {
      orgMaps,
      chiefRows: g.chiefRows,
      kostenstellen: g.kostenstellen,
      openPositions: await resolveOpenPositions(tx, orgMaps, g.open as OffeneStelle[], today),
    };
  });

  const withChief = new Set(chiefRows.map((r) => r.org_unit_id));
  const units: UnitOption[] = orgMaps.unitList.map((u) => ({
    id: u.id,
    name: u.name,
    unit_type: u.unit_type,
    depth: orgMaps.depthOf.get(u.id) ?? 0,
    hasChief: withChief.has(u.id),
  }));

  const openPositionsWithDays = openPositions.map((p) => ({ ...p, daysOpen: daysBetweenIso(p.vacantSince) }));

  return <PositionsPageClient openPositions={openPositionsWithDays} units={units} kostenstellen={kostenstellen} />;
}