import { Slab } from "@magiceden/aaob";
import { PublicKey, Connection } from "@solana/web3.js";
import { Market } from "./market";
import { throwIfNull } from "./utils";
import * as aaob from "@magiceden/aaob";
import { CALLBACK_INFO_LEN } from "./state";
import BN from "bn.js";

/**
 * Orderbook class
 */
export class Orderbook {
  /** Market of the orderbook
   * @private
   */
  private _market: Market;

  /** Slab that contains asks
   * @private
   */
  private _slabAsks: Slab;

  /** Slab that contains bids
   * @private
   */
  private _slabBids: Slab;

  constructor(market: Market, slabBids: Slab, slabAsks: Slab) {
    this._market = market;
    this._slabBids = slabBids;
    this._slabAsks = slabAsks;
  }

  /**
   * Returns the market object associated to the orderbook
   */
  get market(): Market {
    return this._market;
  }

  /**
   * Returns the asks slab of the orderbook
   */
  get slabAsks(): Slab {
    return this._slabAsks;
  }

  /**
   * Returns the bids slab of the orderbook
   */
  get slabBids(): Slab {
    return this._slabBids;
  }

  /**
   *
   * @param connection The solana connection object to the RPC node
   * @param slabAddress The address of the Slab
   * @returns A deserialized Slab object
   */
  static async loadSlab(connection, slabAddress: PublicKey) {
    const { data } = throwIfNull(await connection.getAccountInfo(slabAddress));
    const slab = aaob.Slab.deserialize(data, new BN(CALLBACK_INFO_LEN));
    return slab;
  }

  /**
   *
   * @param connection The solana connection object to the RPC node
   * @param marketAddress The address of the market
   * @returns Returns an orderbook object
   */
  static async load(connection: Connection, marketAddress: PublicKey) {
    const market = await Market.load(connection, marketAddress);
    const slabBids = await Orderbook.loadSlab(connection, market.bidsAddress);
    const slabAsks = await Orderbook.loadSlab(connection, market.asksAddress);
    return new Orderbook(market, slabBids, slabAsks);
  }

  // Comment to use Webassembly
  /**
   *
   * @param depth Depth of orders to deserialize
   * @param asks Asks or bids boolean
   * @param uiAmount Optional, whether to return the amounts in uiAmount
   * @returns Returns an L2 orderbook
   */
  getL2(depth: number, asks: boolean, uiAmount?: boolean) {
    const convert = (p: aaob.Price) => {
      return {
        price: p.price,
        size: p.size.divn(Math.pow(10, this.market.baseDecimals)),
      };
    };
    if (uiAmount) {
      return asks
        ? this._slabAsks.getL2DepthJS(depth, asks).map(convert)
        : this._slabBids.getL2DepthJS(depth, asks).map(convert);
    }
    return asks
      ? this._slabAsks.getL2DepthJS(depth, asks)
      : this._slabBids.getL2DepthJS(depth, asks);
  }
}