<?php

namespace blockchain\web3;

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

class SmartContract extends Contract
{
    protected $web3;

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

    protected $txMethods = [];
    protected $viewMethods = [];
    protected $eventSignatures = [];

    public function __construct($web3, $credential, $abi)
    {
        parent::__construct($web3->provider, $abi);
        $this->web3 = $web3;
        $this->credential = $credential;
        foreach ($this->events as $name => $event) {
            $sig = $this->ethabi->encodeEventSignature($event);
            $this->eventSignatures[$sig] = $event;
        }
        foreach ($this->functions as $function) {
            if ($function['stateMutability'] == 'view') {
                $this->viewMethods[] = $function['name'];
            } else {
                $this->txMethods[] = $function['name'];
            }
        }
    }

    public function setGasPrice($price)
    {
        if (!$price) {
            unset($this->gasPrice);
        } else {
            $this->gasPrice = $price;
        }
        return $this;
    }

    public function setGasLimit($limit)
    {
        if (!$limit) {
            unset($this->gasLimit);
        } else {
            $this->gasLimit = $limit;
        }
        return $this;
    }

    public function setValue($value)
    {
        if (!$value) {
            unset($this->value);
        } else {
            $this->value = $value;
        }
        return $this;
    }

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

    protected function transact($tx): string
    {
        if (!isset($this->credential)) {
            throw new \Exception('credential not set');
        }
        $transactor = new Transactor($this->web3, $this->credential);
        $tx['to'] = $this->getToAddress();
        return $transactor->transact($tx);
    }

    protected function isTxMethod($name)
    {
        return in_array($name, $this->txMethods);
    }

    protected function isViewMethod($name)
    {
        return in_array($name, $this->viewMethods);
    }

    public function instantiate()
    {
        $args = func_get_args();

        $data = $this->getData(...$args);
        $tx = [
            'data' => '0x' . $data
        ];
        return $this->transact($tx);
    }

    public function __call($name, $args)
    {
        if ($this->isTxMethod($name)) {
            $data = $this->getData($name, ...$args);
            $tx = [
                'data' => '0x' . $data
            ];
            return $this->transact($tx);
        }
        if ($this->isViewMethod($name)) {
            $cb = new Callback;
            $args[] = $cb;
            $this->call($name, ...$args);
            $values = array_values($cb->result);
            return count($values) > 1 ? $values : $values[0];
        }
        throw new Exception('method not supported');
    }

    public function queryEvents($topics = [], $fromBlock = 'latest', $toBlock = 'latest')
    {
        if (is_numeric($fromBlock)) {
            $fromBlock = Utils::toHex($fromBlock, true);
        }
        if (is_numeric($toBlock)) {
            $toBlock = Utils::toHex($toBlock, true);
        }
        $filter = [
            'fromBlock' => $fromBlock,
            'toBlock' => $toBlock,
            'address' => $this->getToAddress(),
            'topics' => $topics
        ];
        $cb = new Callback;
        $this->web3->eth->getLogs($filter, $cb);
        $decodedEvents = [];
        foreach ($cb->result as $log) {
            if (!array_key_exists($log->topics[0], $this->eventSignatures)) {
                $msg = sprintf("unknown event: %s, skip", $log->topics[0]);
                echo $msg . PHP_EOL;
                continue;
            }

            $eventAbi = $this->eventSignatures[$log->topics[0]];

            $types = [];
            $names = [];
            for ($i = 0; $i < count($eventAbi['inputs']); $i++) {
                $types[] = $eventAbi['inputs'][$i]['type'];
                $names[] = $eventAbi['inputs'][$i]['name'];
            }
            $params = '';
            for ($i = 1; $i < count($log->topics); $i++) {
                $params = $params . Utils::stripZero($log->topics[$i]);
            }
            $params = $params . Utils::stripZero($log->data);
            //echo $eventAbi['name'] . ' => ' . $params . PHP_EOL;
            $decodedParams = $this->ethabi->decodeParameters($types, $params);

            $decodedEvent = (object)[
                'blockHash' => $log->blockHash,
                'blockNumber' => $log->blockNumber,
                'transactionHash' => $log->transactionHash,
                'removed' => $log->removed,
                'address' => $log->address,
                'name' => $eventAbi['name'],
                'params' => []
            ];
            for ($i = 0; $i < count($names); $i++) {
                $decodedEvent->params[$names[$i]] = $decodedParams[$i];
            }
            $decodedEvents[] = $decodedEvent;
        }

        return $decodedEvents;
    }

}