// The rooms list: IMVU rooms owned by linked accounts that chose to list them. The hub learns of a room when a T5DE
// user enters it, and asks IMVU about it (owner, public and listed or not); it's checked again while it's in use,
// so a room made unlisted or closed drops off the list.
import { and, desc, eq, gt, lt, schema, type Database } from "@t5de/db";
import type { ImvuClient } from "./imvu";

const { room, imvuLink } = schema;

export type Room = typeof room.$inferSelect;

const recheckAfter = 60 * 60 * 1000;
// Rooms nobody entered for this long aren't checked again or listed.
const forgetAfter = 30 * 24 * 60 * 60 * 1000;

/** Whether IMVU says anyone may find and enter the room. */
export const isListable = (r: Pick<Room, "privacy" | "type" | "expired">) =>
  r.privacy === "public" && r.type === "listed" && !r.expired;

/** Whether the room is for adults (Access Pass rooms). */
export const isAdultRoom = (r: Pick<Room, "contentRating" | "accessPass">) => r.accessPass || r.contentRating === "AP";

export class Rooms {
  private checking = new Set<string>();

  constructor(
    private readonly db: Database,
    private readonly imvu: ImvuClient,
  ) {}

  /** A T5DE user entered a room: remember it if its owner is linked, asking IMVU about it if it's due. */
  async seen(instanceId: string) {
    const ownerId = Number(instanceId.split("-")[0]);
    const [owner] = await this.db.select({ id: imvuLink.imvuId }).from(imvuLink).where(eq(imvuLink.imvuId, ownerId));
    if (!owner) return;
    const [known] = await this.db.select().from(room).where(eq(room.instanceId, instanceId));
    if (known && Date.now() - known.checkedAt.getTime() < recheckAfter) {
      await this.db.update(room).set({ seenAt: new Date() }).where(eq(room.instanceId, instanceId));
      return;
    }
    await this.check(instanceId);
  }

  /** Asks IMVU about a room again, and records what it says (or forgets the room if it's gone). */
  async check(instanceId: string) {
    if (this.checking.has(instanceId)) return;
    this.checking.add(instanceId);
    try {
      const r = await this.imvu.room(instanceId);
      if (!r || String(r.ownerId) !== instanceId.split("-")[0]) {
        await this.db.delete(room).where(eq(room.instanceId, instanceId));
        return;
      }
      const values = {
        ownerImvuId: r.ownerId,
        name: r.name,
        description: r.description,
        imageURL: r.imageURL,
        privacy: r.privacy,
        type: r.type,
        contentRating: r.contentRating,
        accessPass: r.accessPass,
        occupancy: r.occupancy,
        capacity: r.capacity,
        expired: r.expired,
        checkedAt: new Date(),
        seenAt: new Date(),
      };
      await this.db
        .insert(room)
        .values({ instanceId, ...values })
        .onConflictDoUpdate({ target: room.instanceId, set: values });
    } finally {
      this.checking.delete(instanceId);
    }
  }

  /** Checks again rooms in use whose answer is old (at most limit). */
  async recheckDue(limit = 20): Promise<number> {
    const due = await this.db
      .select({ instanceId: room.instanceId })
      .from(room)
      .where(and(lt(room.checkedAt, new Date(Date.now() - recheckAfter)), gt(room.seenAt, new Date(Date.now() - forgetAfter))))
      .limit(limit);
    let n = 0;
    for (const r of due) {
      try {
        await this.check(r.instanceId);
        n++;
      } catch {
        // IMVU unavailable: try again next time.
      }
    }
    return n;
  }

  /** The rooms to list: listable, owner chose to list, entered lately; with the owner's IMVU name. */
  async listed() {
    const rows = await this.db
      .select({ room, owner: imvuLink.username })
      .from(room)
      .innerJoin(imvuLink, eq(imvuLink.imvuId, room.ownerImvuId))
      .where(and(eq(imvuLink.listRooms, true), gt(room.seenAt, new Date(Date.now() - forgetAfter))))
      .orderBy(desc(room.seenAt));
    return rows.filter((r) => isListable(r.room));
  }

  /** Forgets an IMVU account's rooms (it was unlinked). */
  async forgetOwner(imvuId: number) {
    await this.db.delete(room).where(eq(room.ownerImvuId, imvuId));
  }
}