window.nostr = {
  _requests: {},
  _pubkey: null,

  async getPublicKey() {
    if (this._pubkey) return this._pubkey
    this._pubkey = await this._call('getPublicKey', {})
    return this._pubkey
  },

  async signEvent(event) {
    return this._call('signEvent', {event})
  },

  _call(type, params) {
    return new Promise((resolve, reject) => {
      let id = Math.random().toString().slice(4)
      this._requests[id] = {resolve, reject}
      window.postMessage(
        {
          id,
          ext: 'nos2x',
          type,
          params
        },
        '*'
      )
    })
  }
}

window.addEventListener('message', message => {
  if (
    !message.data ||
    !message.data.response ||
    message.data.ext !== 'nos2x' ||
    !window.nostr._requests[message.data.id]
  )
    return

  if (message.data.response.error) {
    window.nostr._requests[message.data.id].reject(
      new Error(`nos2x returned an error: ${message.data.response.error}`)
    )
  } else {
    window.nostr._requests[message.data.id].resolve(message.data.response)
  }
})