import { PublicKey, Connection } from "@solana/web3.js"
import BN from "bn.js" // eslint-disable-line @typescript-eslint/no-unused-vars
import * as borsh from "@project-serum/borsh" // eslint-disable-line @typescript-eslint/no-unused-vars
import * as types from "../types" // eslint-disable-line @typescript-eslint/no-unused-vars
import { PROGRAM_ID } from "../programId"

export interface TermsSignatureFields {
  signature: Array<number>
}

export interface TermsSignatureJSON {
  signature: Array<number>
}

export class TermsSignature {
  readonly signature: Array<number>

  static readonly discriminator = Buffer.from([
    197, 173, 136, 91, 182, 49, 113, 19,
  ])

  static readonly layout = borsh.struct([
    borsh.array(borsh.u8(), 64, "signature"),
  ])

  constructor(fields: TermsSignatureFields) {
    this.signature = fields.signature
  }

  static async fetch(
    c: Connection,
    address: PublicKey
  ): Promise<TermsSignature | null> {
    const info = await c.getAccountInfo(address)

    if (info === null) {
      return null
    }
    if (!info.owner.equals(PROGRAM_ID)) {
      throw new Error("account doesn't belong to this program")
    }

    return this.decode(info.data)
  }

  static async fetchMultiple(
    c: Connection,
    addresses: PublicKey[]
  ): Promise<Array<TermsSignature | null>> {
    const infos = await c.getMultipleAccountsInfo(addresses)

    return infos.map((info) => {
      if (info === null) {
        return null
      }
      if (!info.owner.equals(PROGRAM_ID)) {
        throw new Error("account doesn't belong to this program")
      }

      return this.decode(info.data)
    })
  }

  static decode(data: Buffer): TermsSignature {
    if (!data.slice(0, 8).equals(TermsSignature.discriminator)) {
      throw new Error("invalid account discriminator")
    }

    const dec = TermsSignature.layout.decode(data.slice(8))

    return new TermsSignature({
      signature: dec.signature,
    })
  }

  toJSON(): TermsSignatureJSON {
    return {
      signature: this.signature,
    }
  }

  static fromJSON(obj: TermsSignatureJSON): TermsSignature {
    return new TermsSignature({
      signature: obj.signature,
    })
  }
}