"use client";

import * as signalR from "@microsoft/signalr";
import { Suit } from "../hokm/types";
import { MockOnlineService } from "./mock-service";
import {
  CreateRoomOptions,
  MatchmakingOptions,
  OnlineService,
  Unsubscribe,
} from "./service";
import {
  AuthSession,
  ChatMessage,
  Conversation,
  DailyRewardState,
  Friend,
  FriendRequest,
  LeaderboardEntry,
  MatchSummary,
  MatchmakingState,
  RewardResult,
  Room,
  ServerGameState,
  ShopItem,
  UserProfile,
} from "./types";

const SERVER = process.env.NEXT_PUBLIC_SERVER_URL || "http://localhost:5005";
const LS_SESSION = "hokm.session";

/**
 * Talks to the .NET SignalR backend for auth, matchmaking, live game state and
 * reactions. Everything not yet server-backed (profile, friends, shop, daily,
 * leaderboard, chat, private rooms) is delegated to the local mock so the app
 * stays fully functional during the incremental migration.
 */
export class SignalrService implements OnlineService {
  readonly live = true;

  private mock = new MockOnlineService();
  private conn: signalR.HubConnection | null = null;
  private session: AuthSession | null = null;
  private token: string | null = null;

  private mmRanked = true;
  private mmStake = 0;
  private mmCbs = new Set<(s: MatchmakingState) => void>();
  private stateCbs = new Set<(s: ServerGameState) => void>();
  private reactionCbs = new Set<(seat: number, reaction: string) => void>();

  constructor() {
    if (typeof window !== "undefined") {
      try {
        const raw = localStorage.getItem(LS_SESSION);
        if (raw) {
          this.session = JSON.parse(raw) as AuthSession;
          this.token = this.session.token;
        }
      } catch {
        /* ignore */
      }
    }
  }

  /* ------------------------------ helpers ---------------------------- */

  private async api<T>(path: string, body: unknown): Promise<T> {
    const res = await fetch(`${SERVER}${path}`, {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify(body),
    });
    if (!res.ok) throw new Error(await res.text());
    return (await res.json()) as T;
  }

  private async connect(): Promise<void> {
    if (this.conn || !this.token) return;
    const conn = new signalR.HubConnectionBuilder()
      .withUrl(`${SERVER}/hub/game`, { accessTokenFactory: () => this.token ?? "" })
      .withAutomaticReconnect()
      .configureLogging(signalR.LogLevel.Warning)
      .build();

    conn.on("matchmaking", (s: { phase: string; players: number; queuePosition: number | null }) =>
      this.emitMM(s.phase, s.queuePosition ?? undefined));
    conn.on("matchFound", () => this.emitMM("ready"));
    conn.on("state", (s: ServerGameState) => this.stateCbs.forEach((cb) => cb(s)));
    conn.on("reaction", (r: { seat: number; reaction: string }) =>
      this.reactionCbs.forEach((cb) => cb(r.seat, r.reaction)));

    this.conn = conn;
    try {
      await conn.start();
    } catch {
      this.conn = null; // server unreachable; UI degrades gracefully
    }
  }

  private emitMM(phase: string, queuePosition?: number) {
    const state: MatchmakingState = {
      phase: phase as MatchmakingState["phase"],
      players: [],
      elapsedMs: 0,
      ranked: this.mmRanked,
      stake: this.mmStake,
      queuePosition,
    };
    this.mmCbs.forEach((cb) => cb(state));
  }

  private async setSession(
    r: { token: string; userId: string; name: string },
    method: AuthSession["method"]
  ): Promise<AuthSession> {
    const session: AuthSession = { userId: r.userId, token: r.token, method, createdAt: Date.now() };
    this.session = session;
    this.token = r.token;
    if (typeof window !== "undefined") localStorage.setItem(LS_SESSION, JSON.stringify(session));
    const profile = await this.mock.getProfile();
    if (r.name && profile.displayName === "بازیکن") await this.mock.updateProfile({ displayName: r.name });
    await this.connect();
    return session;
  }

  /* ------------------------------- auth ------------------------------ */

  getSession() {
    return this.session;
  }

  async restore() {
    if (this.session && this.token) {
      void this.connect();
      return { session: this.session, profile: await this.mock.getProfile() };
    }
    return null;
  }

  requestOtp(phone: string) {
    return this.api<{ devCode?: string }>("/api/auth/otp/request", { phone });
  }

  async verifyOtp(phone: string, code: string) {
    const r = await this.api<{ token: string; userId: string; name: string }>(
      "/api/auth/otp/verify", { phone, code });
    return this.setSession(r, "phone");
  }

  async signInEmail(email: string, password: string) {
    const r = await this.api<{ token: string; userId: string; name: string }>(
      "/api/auth/email", { email, password });
    return this.setSession(r, "email");
  }

  async signUpEmail(email: string, password: string, displayName: string) {
    const r = await this.api<{ token: string; userId: string; name: string }>(
      "/api/auth/email", { email, password, name: displayName });
    return this.setSession(r, "email");
  }

  async signInGoogle() {
    // Server has no Google flow yet — mint a token via the email endpoint.
    const email = `google_${Math.random().toString(36).slice(2, 8)}@hokm.app`;
    const r = await this.api<{ token: string; userId: string; name: string }>(
      "/api/auth/email", { email, password: "google" });
    return this.setSession(r, "google");
  }

  async signOut() {
    this.session = null;
    this.token = null;
    if (typeof window !== "undefined") localStorage.removeItem(LS_SESSION);
    await this.conn?.stop();
    this.conn = null;
  }

  /* --------------------------- matchmaking --------------------------- */

  async startMatchmaking(opts: MatchmakingOptions) {
    this.mmRanked = opts.ranked;
    this.mmStake = opts.stake;
    await this.connect();
    const p = await this.mock.getProfile();
    this.emitMM("searching");
    await this.conn?.invoke("StartMatchmaking", {
      name: p.displayName, avatar: p.avatar, level: p.level, plan: p.plan,
    });
  }

  async cancelMatchmaking() {
    await this.conn?.invoke("CancelMatchmaking");
    this.emitMM("idle");
  }

  onMatchmaking(cb: (s: MatchmakingState) => void): Unsubscribe {
    this.mmCbs.add(cb);
    return () => this.mmCbs.delete(cb);
  }

  getMatchPlayers() {
    return null; // server streams identities via the state event
  }

  submitMatchResult(summary: MatchSummary): Promise<RewardResult> {
    return this.mock.submitMatchResult(summary); // local rewards until server-side rewards land
  }

  /* ------------------------------ live game -------------------------- */

  onState(cb: (s: ServerGameState) => void): Unsubscribe {
    this.stateCbs.add(cb);
    return () => this.stateCbs.delete(cb);
  }

  playCard(cardId: string) {
    void this.conn?.invoke("PlayCard", cardId);
  }

  chooseTrump(suit: Suit) {
    void this.conn?.invoke("ChooseTrump", suit);
  }

  /* ----------------------------- reactions --------------------------- */

  async sendReaction(reaction: string) {
    await this.conn?.invoke("SendReaction", reaction);
  }

  onReaction(cb: (seat: number, reaction: string) => void): Unsubscribe {
    this.reactionCbs.add(cb);
    return () => this.reactionCbs.delete(cb);
  }

  /* ----- delegated to the mock (not yet on the server) ----- */

  getProfile() { return this.mock.getProfile(); }
  updateProfile(p: Parameters<OnlineService["updateProfile"]>[0]) { return this.mock.updateProfile(p); }
  upgradePlan() { return this.mock.upgradePlan(); }

  listFriends() { return this.mock.listFriends(); }
  listRequests() { return this.mock.listRequests(); }
  addFriend(q: string) { return this.mock.addFriend(q); }
  acceptRequest(id: string) { return this.mock.acceptRequest(id); }
  declineRequest(id: string) { return this.mock.declineRequest(id); }
  removeFriend(id: string) { return this.mock.removeFriend(id); }
  onFriends(cb: (f: Friend[]) => void) { return this.mock.onFriends(cb); }

  createRoom(o: CreateRoomOptions) { return this.mock.createRoom(o); }
  setPartner(roomId: string, friendId: string | null) { return this.mock.setPartner(roomId, friendId); }
  inviteToSeat(roomId: string, seat: 1 | 3, friendId: string) { return this.mock.inviteToSeat(roomId, seat, friendId); }
  addBot(roomId: string, seat: 1 | 2 | 3) { return this.mock.addBot(roomId, seat); }
  clearSeat(roomId: string, seat: 1 | 2 | 3) { return this.mock.clearSeat(roomId, seat); }
  startRoom(roomId: string) { return this.mock.startRoom(roomId); }
  leaveRoom(roomId: string) { return this.mock.leaveRoom(roomId); }
  onRoom(cb: (r: Room) => void) { return this.mock.onRoom(cb); }

  listConversations(): Promise<Conversation[]> { return this.mock.listConversations(); }
  getMessages(id: string): Promise<ChatMessage[]> { return this.mock.getMessages(id); }
  sendMessage(id: string, text: string) { return this.mock.sendMessage(id, text); }
  markRead(id: string) { return this.mock.markRead(id); }
  onChat(cb: (id: string, m: ChatMessage[]) => void) { return this.mock.onChat(cb); }

  getLeaderboard(): Promise<LeaderboardEntry[]> { return this.mock.getLeaderboard(); }
  getShopItems(): Promise<ShopItem[]> { return this.mock.getShopItems(); }
  buyItem(id: string) { return this.mock.buyItem(id); }
  getDailyState(): Promise<DailyRewardState> { return this.mock.getDailyState(); }
  claimDaily(): Promise<{ reward: number; profile: UserProfile; day: number }> { return this.mock.claimDaily(); }
}