import { dbGlobal } from "drizzle-pkg/lib/db";
import { users } from "drizzle-pkg/lib/schema/auth";
import { and, asc, count, eq, isNotNull, ne } from "drizzle-orm";
import { DISCOVER_LIST_PAGE_SIZE } from "#server/constants/discover-list";
import { discoverCardAvatarUrl, discoverCardLocationLine } from "#server/utils/discover-card";
import { normalizePublicListPage } from "#server/utils/public-pagination";

const listWhere = and(
  eq(users.status, "active"),
  eq(users.discoverVisible, true),
  isNotNull(users.publicSlug),
  ne(users.publicSlug, ""),
);

export type DiscoverListItem = {
  publicSlug: string;
  displayName: string;
  avatar: string | null;
  location: string | null;
};

function mapRow(row: typeof users.$inferSelect): DiscoverListItem {
  const displayName = row.nickname?.trim() || row.username;
  const discoverVis = Boolean(row.discoverVisible);
  const showLoc = Boolean(row.discoverShowLocation);
  return {
    publicSlug: row.publicSlug as string,
    displayName,
    avatar: discoverCardAvatarUrl(row.avatar, row.avatarVisibility),
    location: discoverCardLocationLine(discoverVis, showLoc, row.discoverLocation),
  };
}

export async function listDiscoverUsersPage(pageRaw: unknown) {
  const page = normalizePublicListPage(pageRaw);
  const pageSize = DISCOVER_LIST_PAGE_SIZE;
  const offset = (page - 1) * pageSize;

  const [countRows, rows] = await Promise.all([
    dbGlobal.select({ total: count() }).from(users).where(listWhere),
    dbGlobal
      .select()
      .from(users)
      .where(listWhere)
      .orderBy(asc(users.id))
      .limit(pageSize)
      .offset(offset),
  ]);

  return {
    items: rows.map(mapRow),
    total: countRows[0]?.total ?? 0,
    page,
    pageSize,
  };
}