<?php

namespace blockchain\web3;

use BI\BigInteger;
use Exception;
use blockchain\web3\src\Contract;
use blockchain\web3\src\Utils;

class Transactor
{
    protected $web3;

    //context
    protected $gasPrice;
    protected $gasLimit;
    protected $value;
    protected $credential;

    public function __construct($web3, $credential)
    {
        $this->web3 = $web3;
        $this->credential = $credential;
    }

    public function setGasPrice($price = null)
    {
        $this->gasPrice = $price;
        return $this;
    }

    public function setGasLimit($limit = null)
    {
        $this->gasLimit = $limit;
        return $this;
    }

    public function setValue($value = null)
    {
        $this->value = $value;
        return $this;
    }

    public function setCredential($credential)
    {
        $this->credential = $credential;
        return $this;
    }

    protected function netVersion()
    {
        $cb = new Callback;
        $this->web3->net->version($cb);
        return $cb->result;
    }

    protected function getTransactionCount($address)
    {
        $cb = new Callback;
        $this->web3->eth->getTransactionCount($address, 'pending', $cb);
        return '0x' . ($cb->result->toHex() ?: '0');
    }

    protected function estimateGasPrice()
    {
        $cb = new Callback;
        $this->web3->eth->gasPrice($cb);
        return '0x' . $cb->result->toHex();
    }

    protected function estimateGasUsage($tx)
    {
        //var_dump($tx);
        $cb = new Callback;
        $this->web3->eth->estimateGas($tx, $cb);
        return '0x' . $cb->result->toHex();
    }

    public function transact($tx): string
    {
        if (!isset($this->credential)) {
            throw new Exception('credential not set');
        }

        $from = $this->credential->getAddress();

        $tx['from'] = $from;

        if (!isset($tx['nonce'])) {
            $tx['nonce'] = $this->getTransactionCount($from);
        }

        if (!isset($tx['chainId'])) {
            $tx['chainId'] = $this->netVersion();
        }

        if (!isset($tx['value'])) {
            if (isset($this->value)) {
                $tx['value'] = $this->value;
            } else {
                $tx['value'] = '0x0';
            }
        }

        if (!isset($tx['gasPrice'])) {
            if (isset($this->gasPrice)) {
                $tx['gasPrice'] = $this->gasPrice;
            } else {
                $tx['gasPrice'] = $this->estimateGasPrice();
            }
        }


        if (!isset($tx['gasLimit'])) {
            if (isset($this->gasLimit)) {
                $tx['gasLimit'] = $this->gasLimit;
            } else {
                $originChainId = $tx['chainId'];
                $tx['chainId'] = '0x' . (new BigInteger($originChainId))->toHex();
                $tx['gasLimit'] = $this->estimateGasUsage($tx);
                $tx['chainId'] = $originChainId;
            }
        }


        $stx = $this->credential->signTransaction($tx);

        $cb = new Callback;
        $this->web3->eth->sendRawTransaction($stx, $cb);

        return $cb->result;
    }

}