import { Collection } from "@discordjs/collection";
import { prisma } from "../../../constants";
import { redis } from "../../../constants";
import { CWMember } from "./fetchAllMembers";

const REDIS_KEY = "cw:members";

export interface ResolvedMember {
  /** Local database user ID (null if no matching local user) */
  id: string | null;
  /** CW member identifier (e.g. "jroberts") */
  identifier: string;
  /** Full name resolved from CW member cache, or raw identifier as fallback */
  name: string;
  /** ConnectWise member ID */
  cwMemberId: number | null;
}

/**
 * CW Member Cache
 *
 * Dual-layer cache (in-memory + Redis) of ConnectWise members keyed by
 * their identifier (e.g. "jroberts"). Populated by `refreshCwIdentifiers`
 * on startup and every 30 minutes thereafter.
 */
let memberCache = new Collection<string, CWMember>();

/**
 * Set the member cache contents.
 *
 * Replaces both the in-memory Collection and the Redis snapshot.
 *
 * @param members - Collection of CW members keyed by identifier
 */
export const setMemberCache = async (members: Collection<string, CWMember>) => {
  memberCache = members;
  await redis.set(REDIS_KEY, JSON.stringify([...members.values()]));
};

/**
 * Get the current member cache.
 *
 * Returns the in-memory Collection. If empty, attempts to hydrate from Redis
 * first. Returns whatever is available (may be empty if Redis is also cold).
 */
export const getMemberCache = async (): Promise<
  Collection<string, CWMember>
> => {
  if (memberCache.size > 0) return memberCache;

  const stored = await redis.get(REDIS_KEY);
  if (stored) {
    const parsed: CWMember[] = JSON.parse(stored);
    memberCache = new Collection(parsed.map((m) => [m.identifier, m]));
  }

  return memberCache;
};

/**
 * Resolve CW Identifier to Full Name
 *
 * Looks up a ConnectWise member by their identifier in the in-memory cache
 * and returns their full name. Falls back to the raw identifier if not found.
 *
 * @param identifier - The CW member identifier (e.g. "jroberts")
 * @returns The member's full name (e.g. "John Roberts") or the raw identifier
 */
export const resolveMemberName = (identifier: string): string => {
  const member = memberCache.get(identifier);
  if (!member) return identifier;
  return `${member.firstName} ${member.lastName}`.trim() || identifier;
};

/**
 * Resolve CW Identifier to Full Member Info
 *
 * Looks up a ConnectWise member by their identifier in the in-memory cache
 * and cross-references with the local database to return a complete member
 * reference including local user ID, CW identifier, full name, and CW member ID.
 *
 * @param identifier - The CW member identifier (e.g. "jroberts")
 * @returns {Promise<ResolvedMember>} Resolved member info
 */
export const resolveMember = async (
  identifier: string,
): Promise<ResolvedMember> => {
  const cwMember = memberCache.get(identifier);
  const name = cwMember
    ? `${cwMember.firstName} ${cwMember.lastName}`.trim() || identifier
    : identifier;

  const localUser = await prisma.user.findFirst({
    where: { cwIdentifier: identifier },
    select: { id: true },
  });

  return {
    id: localUser?.id ?? null,
    identifier,
    name,
    cwMemberId: cwMember?.id ?? null,
  };
};