import { bitcoin as BITCOIN_NETWORK } from '../networks';
import * as bscript from '../script';
import { Payment, PaymentOpts, StackFunction } from './index';
import * as lazy from './lazy';
const typef = require('typeforce');
const OPS = bscript.OPS;
const ecc = require('tiny-secp256k1');

// input: {signature}
// output: {pubKey} OP_CHECKSIG
export function p2pk(a: Payment, opts?: PaymentOpts): Payment {
  if (!a.input && !a.output && !a.pubkey && !a.input && !a.signature)
    throw new TypeError('Not enough data');
  opts = Object.assign({ validate: true }, opts || {});

  typef(
    {
      network: typef.maybe(typef.Object),
      output: typef.maybe(typef.Buffer),
      pubkey: typef.maybe(ecc.isPoint),

      signature: typef.maybe(bscript.isCanonicalScriptSignature),
      input: typef.maybe(typef.Buffer),
    },
    a,
  );

  const _chunks = lazy.value(() => {
    return bscript.decompile(a.input!);
  }) as StackFunction;

  const network = a.network || BITCOIN_NETWORK;
  const o: Payment = { network };

  lazy.prop(o, 'output', () => {
    if (!a.pubkey) return;
    return bscript.compile([a.pubkey, OPS.OP_CHECKSIG]);
  });
  lazy.prop(o, 'pubkey', () => {
    if (!a.output) return;
    return a.output.slice(1, -1);
  });
  lazy.prop(o, 'signature', () => {
    if (!a.input) return;
    return _chunks()[0] as Buffer;
  });
  lazy.prop(o, 'input', () => {
    if (!a.signature) return;
    return bscript.compile([a.signature]);
  });
  lazy.prop(o, 'witness', () => {
    if (!o.input) return;
    return [];
  });

  // extended validation
  if (opts.validate) {
    if (a.output) {
      if (a.output[a.output.length - 1] !== OPS.OP_CHECKSIG)
        throw new TypeError('Output is invalid');
      if (!ecc.isPoint(o.pubkey))
        throw new TypeError('Output pubkey is invalid');
      if (a.pubkey && !a.pubkey.equals(o.pubkey!))
        throw new TypeError('Pubkey mismatch');
    }

    if (a.signature) {
      if (a.input && !a.input.equals(o.input!))
        throw new TypeError('Signature mismatch');
    }

    if (a.input) {
      if (_chunks().length !== 1) throw new TypeError('Input is invalid');
      if (!bscript.isCanonicalScriptSignature(o.signature!))
        throw new TypeError('Input has invalid signature');
    }
  }

  return Object.assign(o, a);
}