import EventEmitter from 'eventemitter3'
import { PublicKey, Transaction } from '@solana/web3.js'
import { notify } from '../../utils/notifications'
import { DEFAULT_PUBLIC_KEY, WalletAdapter } from '../../@types/types'

type SolflareExtensionEvent = 'disconnect' | 'connect'
type SolflareExtensionRequestMethod =
  | 'connect'
  | 'disconnect'
  | 'signTransaction'
  | 'signAllTransactions'

interface SolflareExtensionProvider {
  publicKey?: PublicKey
  isConnected?: boolean
  autoApprove?: boolean
  signTransaction: (transaction: Transaction) => Promise<Transaction>
  signAllTransactions: (transactions: Transaction[]) => Promise<Transaction[]>
  connect: () => Promise<void>
  disconnect: () => Promise<void>
  on: (event: SolflareExtensionEvent, handler: (args: any) => void) => void
  off: (event: SolflareExtensionEvent, handler: (args: any) => void) => void
  request: (method: SolflareExtensionRequestMethod, params: any) => Promise<any>
}

export class SolflareExtensionWalletAdapter
  extends EventEmitter
  implements WalletAdapter
{
  constructor() {
    super()
    this.connect = this.connect.bind(this)
  }

  private get _provider(): SolflareExtensionProvider | undefined {
    if ((window as any)?.solflare?.isSolflare) {
      return (window as any).solflare
    }
    return undefined
  }

  private _handleConnect = (...args) => {
    this.emit('connect', ...args)
  }

  private _handleDisconnect = (...args) => {
    this._provider?.off('connect', this._handleConnect)
    this._provider?.off('disconnect', this._handleDisconnect)
    this.emit('disconnect', ...args)
  }

  get connected() {
    return this._provider?.isConnected || false
  }

  get autoApprove() {
    return this._provider?.autoApprove || false
  }

  async signAllTransactions(
    transactions: Transaction[]
  ): Promise<Transaction[]> {
    if (!this._provider) {
      return transactions
    }

    return this._provider.signAllTransactions(transactions)
  }

  get publicKey() {
    const instance = this._provider?.publicKey
    
    if (instance) {
      return new PublicKey(instance.toString());
    }

    return DEFAULT_PUBLIC_KEY;
  }

  async signTransaction(transaction: Transaction) {
    if (!this._provider) {
      return transaction
    }

    return this._provider.signTransaction(transaction)
  }

  async connect() {
    if (!this._provider) {
      notify({
        title: 'Solflare Extension Error',
        type: 'error',
        description:
          'Please install the Solflare Extension and then reload this page.',
      })
      return
    }
    this._provider?.on('connect', this._handleConnect)
    this._provider?.on('disconnect', this._handleDisconnect)
    return this._provider?.connect()
  }

  async disconnect() {
    if (this._provider) {
      this._provider.disconnect()
    }
  }
}