import { proxy, ref, subscribe as sub } from 'valtio';
import { subscribeKey as subKey } from 'valtio/utils';
import { OptionsController } from '@reown/appkit-core-react-native';
import type {
  SIWEClientMethods,
  SIWESession,
  SIWECreateMessageArgs,
  SIWEVerifyMessageArgs
} from '../utils/TypeUtils';

// -- Types --------------------------------------------- //
export interface SIWEControllerClient extends SIWEClientMethods {
  signIn: () => Promise<SIWESession>;
  options: {
    enabled: boolean;
    nonceRefetchIntervalMs: number;
    sessionRefetchIntervalMs: number;
    signOutOnDisconnect: boolean;
    signOutOnAccountChange: boolean;
    signOutOnNetworkChange: boolean;
  };
}

export interface SIWEControllerClientState {
  _client?: SIWEControllerClient;
  nonce?: string;
  session?: SIWESession;
  message?: string;
  status: 'uninitialized' | 'ready' | 'loading' | 'success' | 'rejected' | 'error';
}

type StateKey = keyof SIWEControllerClientState;

// -- State --------------------------------------------- //
const state = proxy<SIWEControllerClientState>({
  status: 'uninitialized'
});

// -- Controller ---------------------------------------- //
export const SIWEController = {
  state,

  subscribeKey<K extends StateKey>(
    key: K,
    callback: (value: SIWEControllerClientState[K]) => void
  ) {
    return subKey(state, key, callback);
  },

  subscribe(callback: (newState: SIWEControllerClientState) => void) {
    return sub(state, () => callback(state));
  },

  _getClient() {
    if (!state._client) {
      throw new Error('SIWEController client not set');
    }

    return state._client;
  },

  async getNonce(address?: string) {
    const client = this._getClient();
    const nonce = await client.getNonce(address);
    this.setNonce(nonce);

    return nonce;
  },

  async getSession() {
    try {
      const client = this._getClient();
      const session = await client.getSession();
      if (session?.address && session?.chainId) {
        this.setSession(session);
        this.setStatus('success');
      } else {
        this.setSession(undefined);
        this.setStatus('ready');
      }

      return session;
    } catch {
      return undefined;
    }
  },

  createMessage(args: SIWECreateMessageArgs) {
    const client = this._getClient();
    const message = client.createMessage(args);
    this.setMessage(message);

    return message;
  },

  async verifyMessage(args: SIWEVerifyMessageArgs) {
    const client = this._getClient();
    const isValid = await client.verifyMessage(args);

    return isValid;
  },

  async signIn() {
    try {
      this.setStatus('loading');
      const client = this._getClient();
      const session = await client.signIn();
      this.setStatus('success');

      return session;
    } catch (error) {
      this.setStatus('error');
      throw error;
    }
  },

  async signOut() {
    const client = this._getClient();
    await client.signOut();
    this.setStatus('ready');
    this.setSession(undefined);
    client.onSignOut?.();
  },

  onSignIn(args: SIWESession) {
    const client = this._getClient();
    client.onSignIn?.(args);
  },

  onSignOut() {
    const client = this._getClient();
    client.onSignOut?.();
  },

  setSIWEClient(client: SIWEControllerClient) {
    state._client = ref(client);
    state.status = 'ready';
    OptionsController.setIsSiweEnabled(client.options.enabled);
  },

  setNonce(nonce: SIWEControllerClientState['nonce']) {
    state.nonce = nonce;
  },

  setStatus(status: SIWEControllerClientState['status']) {
    state.status = status;
  },

  setMessage(message: SIWEControllerClientState['message']) {
    state.message = message;
  },

  setSession(session: SIWEControllerClientState['session']) {
    state.session = session;
    state.status = session ? 'success' : 'ready';
  }
};