import type {
  BlockhashWithExpiryBlockHeight,
  Cluster,
  Connection,
  Finality,
  SignatureResult,
  TransactionSignature,
} from "@solana/web3.js";
import promiseRetry from "promise-retry";
import type { WrapOptions } from "retry";

import { TransactionReceipt } from "./TransactionReceipt.js";

/**
 * Options for awaiting a transaction confirmation.
 */
export interface TransactionWaitOptions
  extends WrapOptions,
    Partial<BlockhashWithExpiryBlockHeight> {
  /**
   * Commitment of the transaction. Defaults to `confirmed`.
   */
  readonly commitment?: Finality;
  /**
   * Whether or not to use websockets for awaiting confirmation. Defaults to `false`.
   */
  readonly useWebsocket?: boolean;
}

/**
 * Transaction which may or may not be confirmed.
 */
export class PendingTransaction {
  private _receipt: TransactionReceipt | null = null;

  constructor(
    readonly connection: Connection,
    readonly signature: TransactionSignature
  ) {}

  /**
   * Gets the transaction receipt, if it has already been fetched.
   *
   * You probably want the async version of this function, `wait`.
   */
  get receipt(): TransactionReceipt | null {
    return this._receipt;
  }

  /**
   * Waits for the confirmation of the transaction.
   * @returns
   */
  async wait({
    commitment = "confirmed",
    useWebsocket = true,
    ...retryOpts
  }: TransactionWaitOptions = {}): Promise<TransactionReceipt> {
    if (this._receipt) {
      return this._receipt;
    }
    if (useWebsocket) {
      await this.confirm({ commitment, ...retryOpts });
      return await this.pollForReceipt({ commitment });
    }
    return await this.pollForReceipt({ commitment, ...retryOpts });
  }

  /**
   * Fetches the TransactionReceipt via polling.
   * @returns
   */
  async pollForReceipt({
    commitment = "confirmed",
    ...retryOpts
  }: Omit<
    TransactionWaitOptions,
    "useWebsocket"
  > = {}): Promise<TransactionReceipt> {
    const receipt = await promiseRetry(
      async (retry) => {
        const result = await this.connection.getTransaction(this.signature, {
          commitment,
        });
        if (!result) {
          retry(new Error("Error fetching transaction"));
          return;
        }
        return new TransactionReceipt(this.signature, result);
      },
      {
        retries: 5,
        minTimeout: 500,
        ...retryOpts,
      }
    );
    if (!receipt) {
      throw new Error("transaction could not be confirmed");
    }
    this._receipt = receipt;
    return receipt;
  }

  /**
   * Awaits the confirmation of the transaction, via onSignature subscription.
   *
   * @deprecated use {@link PendingTransaction#confirm}
   * @returns
   */
  async awaitSignatureConfirmation(
    commitment: Finality = "confirmed"
  ): Promise<TransactionSignature> {
    const { value } = await this.connection.confirmTransaction(
      this.signature,
      commitment
    );
    if (value.err) {
      throw value.err;
    }
    return this.signature;
  }

  /**
   * Awaits the confirmation of the transaction, via onSignature subscription.
   * @returns
   */
  async confirm({
    commitment = "confirmed",
    blockhash,
    lastValidBlockHeight,
  }: Pick<
    TransactionWaitOptions,
    "commitment" | "blockhash" | "lastValidBlockHeight"
  >): Promise<TransactionSignature> {
    let value: SignatureResult;
    if (blockhash && lastValidBlockHeight) {
      value = (
        await this.connection.confirmTransaction(
          {
            signature: this.signature,
            blockhash,
            lastValidBlockHeight,
          },
          commitment
        )
      ).value;
    } else {
      value = (
        await this.connection.confirmTransaction(this.signature, commitment)
      ).value;
    }

    if (value.err) {
      throw new Error(
        `Transaction ${this.signature} failed (${JSON.stringify(value)})`
      );
    }

    return this.signature;
  }

  /**
   * Generates a link to view this {@link PendingTransaction} on the official Solana explorer.
   * @param network
   * @returns
   */
  generateSolanaExplorerLink(cluster: Cluster = "mainnet-beta"): string {
    return `https://explorer.solana.com/tx/${this.signature}?cluster=${cluster}`;
  }
}