import BN from "bn.js";
import { Address } from "../utils/address";
import { BitString } from "./bitString";
import { Cell } from "./cell";

export class Builder {
  private bits = BitString.alloc(1023);
  private refs: Cell[] = [];
  private ended = false;

  storeRef = (src: Cell) => {
    if (this.ended) {
      throw Error("Already ended");
    }
    this.refs.push(src);
    return this;
  };

  storeBit = (value: boolean | number) => {
    if (this.ended) {
      throw Error("Already ended");
    }
    this.bits.writeBit(value);
    return this;
  };

  storeBitArray = (value: (boolean | number)[]) => {
    if (this.ended) {
      throw Error("Already ended");
    }
    this.bits.writeBitArray(value);
    return this;
  };

  storeUint = (value: number | BN, bitLength: number) => {
    if (this.ended) {
      throw Error("Already ended");
    }
    this.bits.writeUint(value, bitLength);
    return this;
  };

  storeInt = (value: number | BN, bitLength: number) => {
    if (this.ended) {
      throw Error("Already ended");
    }
    this.bits.writeInt(value, bitLength);
    return this;
  };

  storeUint8 = (value: number) => {
    if (this.ended) {
      throw Error("Already ended");
    }
    this.bits.writeUint8(value);
    return this;
  };

  storeVarUint = (value: number | BN, bitLength: number) => {
    if (this.ended) {
      throw Error("Already ended");
    }
    this.bits.writeVarUInt(value, bitLength);
    return this;
  };

  storeBuffer = (buffer: Buffer) => {
    if (this.ended) {
      throw Error("Already ended");
    }
    this.bits.writeBuffer(buffer);
    return this;
  };

  storeCoins = (amount: number | BN) => {
    if (this.ended) {
      throw Error("Already ended");
    }
    this.bits.writeCoins(amount);
    return this;
  };

  storeAddress = (address: Address | null) => {
    if (this.ended) {
      throw Error("Already ended");
    }
    this.bits.writeAddress(address);
    return this;
  };

  storeBitString = (value: BitString) => {
    if (this.ended) {
      throw Error("Already ended");
    }
    this.bits.writeBitString(value);
    return this;
  };

  storeDict = (src: Cell | null) => {
    if (this.ended) {
      throw Error("Already ended");
    }
    if (src) {
      this.bits.writeBit(true);
      this.refs.push(src);
    } else {
      this.bits.writeBit(false);
    }
    return this;
  };

  storeRefMaybe = (src: Cell | null) => {
    return this.storeDict(src);
  };

  storeCellCopy = (src: Cell) => {
    this.storeBitString(src.bits);
    for (let r of src.refs) {
      this.storeRef(r);
    }
    return this;
  };

  endCell() {
    if (this.ended) {
      throw Error("Already ended");
    }
    this.ended = true;
    let res = new Cell();
    res.bits = this.bits;
    res.isExotic = false;
    for (let r of this.refs) {
      res.refs.push(r);
    }
    return res;
  }
}

export function beginCell() {
  return new Builder();
}