bwwc-utils.php

<?php
/*
Bitcoin SV Payments for WooCommerce
https://github.com/mboyd1/bitcoin-sv-payments-for-woocommerce
*/


//===========================================================================
/*
   Input:
   ------
      $order_info =
         array (
            'order_id'        => $order_id,
            'order_total'     => $order_total_in_btc,
            'order_datetime'  => date('Y-m-d H:i:s T'),
            'requested_by_ip' => @$_SERVER['REMOTE_ADDR'],
            );
*/
// Returns:
// --------
/*
    $ret_info_array = array (
       'result'                      => 'success', // OR 'error'
       'message'                     => '...',
       'host_reply_raw'              => '......',
       'generated_bitcoin_address'   => '18vzABPyVbbia8TDCKDtXJYXcoAFAPk2cj', // or false
       );
*/
//


function BWWC__get_bitcoin_address_for_payment__electrum($electrum_mpk, $order_info)
{
    global $wpdb;

    // status = "unused", "assigned", "used"
    $btc_addresses_table_name     = $wpdb->prefix . 'bwwc_btc_addresses';
    $origin_id                    = $electrum_mpk;

    $bwwc_settings = BWWC__get_settings();
    $funds_received_value_expires_in_secs = $bwwc_settings['funds_received_value_expires_in_mins'] * 60;
    $assigned_address_expires_in_secs     = $bwwc_settings['assigned_address_expires_in_mins'] * 60;

    $clean_address = null;
    $current_time = time();

    if ($bwwc_settings['reuse_expired_addresses']) {
        $reuse_expired_addresses_freshb_query_part =
          "OR (`status`='assigned'
      		AND (('$current_time' - `assigned_at`) > '$assigned_address_expires_in_secs')
      		AND (('$current_time' - `received_funds_checked_at`) < '$funds_received_value_expires_in_secs')
      		)";
    } else {
        $reuse_expired_addresses_freshb_query_part = "";
    }

    //-------------------------------------------------------
    // Quick scan for ready-to-use address
    // NULL == not found
    // Retrieve:
    //     'unused'   - with fresh zero balances
    //     'assigned' - expired, with fresh zero balances (if 'reuse_expired_addresses' is true)
    //
    // Hence - any returned address will be clean to use.
    $query =
      "SELECT `btc_address` FROM `$btc_addresses_table_name`
         WHERE `origin_id`='$origin_id'
         AND `total_received_funds`='0'
         AND (`status`='unused' $reuse_expired_addresses_freshb_query_part)
         ORDER BY `index_in_wallet` ASC
         LIMIT 1;"; // Try to use lower indexes first
    $clean_address = $wpdb->get_var($query);

    //-------------------------------------------------------

    if (!$clean_address) {

      //-------------------------------------------------------
        // Find all unused addresses belonging to this mpk with possibly (to be verified right after) zero balances
        // Array(rows) or NULL
        // Retrieve:
        //    'unused'    - with old zero balances
        //    'unknown'   - ALL
        //    'assigned'  - expired with old zero balances (if 'reuse_expired_addresses' is true)
        //
        // Hence - any returned address with freshened balance==0 will be clean to use.
        if ($bwwc_settings['reuse_expired_addresses']) {
            $reuse_expired_addresses_oldb_query_part =
              "OR (`status`='assigned'
	      		AND (('$current_time' - `assigned_at`) > '$assigned_address_expires_in_secs')
	      		AND (('$current_time' - `received_funds_checked_at`) > '$funds_received_value_expires_in_secs')
	      		)";
        } else {
            $reuse_expired_addresses_oldb_query_part = "";
        }

        $query =
         "SELECT * FROM `$btc_addresses_table_name`
            WHERE `origin_id`='$origin_id'
	         	AND `total_received_funds`='0'
            AND (
               `status`='unused'
               OR `status`='unknown'
               $reuse_expired_addresses_oldb_query_part
               )
            ORDER BY `index_in_wallet` ASC;"; // Try to use lower indexes first
        $addresses_to_verify_for_zero_balances_rows = $wpdb->get_results($query, ARRAY_A);

        if (!is_array($addresses_to_verify_for_zero_balances_rows)) {
            $addresses_to_verify_for_zero_balances_rows = array();
        }
        //-------------------------------------------------------

        //-------------------------------------------------------
        // Try to re-verify balances of existing addresses (with old or non-existing balances) before reverting to slow operation of generating new address.
        //
        $blockchains_api_failures = 0;
        foreach ($addresses_to_verify_for_zero_balances_rows as $address_to_verify_for_zero_balance_row) {
            // http://blockexplorer.com/q/getreceivedbyaddress/18vzABPyVbbia8TDCKDtXJYXcoAFAPk2cj
            // http://blockchain.info/q/getreceivedbyaddress/18vzABPyVbbia8TDCKDtXJYXcoAFAPk2cj [?confirmations=6]
            //
            $address_to_verify_for_zero_balance = $address_to_verify_for_zero_balance_row['btc_address'];

            $address_request_array = array();
            $address_request_array['btc_address'] = $address_to_verify_for_zero_balance;
            $address_request_array['required_confirmations'] = 0;
            $address_request_array['api_timeout'] = $bwwc_settings['blockchain_api_timeout_secs'];
            $ret_info_array = BWWC__getreceivedbyaddress_info($address_request_array, $bwwc_settings);

            if ($ret_info_array['balance'] === false) {
                $blockchains_api_failures ++;
                if ($blockchains_api_failures >= $bwwc_settings['max_blockchains_api_failures']) {
                    // Allow no more than 3 contigious blockchains API failures. After which return error reply.
                    $ret_info_array = array(
               'result'                      => 'error',
               'message'                     => $ret_info_array['message'],
               'host_reply_raw'              => $ret_info_array['host_reply_raw'],
               'generated_bitcoin_address'   => false,
               );
                    return $ret_info_array;
                }
            } else {
                if ($ret_info_array['balance'] == 0) {
                    // Update DB with balance and timestamp, mark address as 'assigned' and return this address as clean.
                    $clean_address    = $address_to_verify_for_zero_balance;
                    break;
                } else {
                    // Balance at this address suddenly became non-zero!
                    // It means either order was paid after expiration or "unknown" address suddenly showed up with non-zero balance or payment was sent to this address outside of this online store business.
                    // Mark it as 'revalidate' so cron job would check if that's possible delayed payment.
                    //
                    $address_meta    = BWWC_unserialize_address_meta(@$address_to_verify_for_zero_balance_row['address_meta']);
                    if (isset($address_meta['orders'][0])) {
                        $new_status = 'revalidate';
                    }	// Past orders are present. There is a chance (for cron job) to match this payment to past (albeit expired) order.
                    else {
                        $new_status = 'used';
                    }				// No orders were ever placed to this address. Likely payment was sent to this address outside of this online store business.

                    $current_time = time();
                    $query =
                  "UPDATE `$btc_addresses_table_name`
			         SET
			            `status`='$new_status',
			            `total_received_funds` = '{$ret_info_array['balance']}',
			            `received_funds_checked_at`='$current_time'
			        WHERE `btc_address`='$address_to_verify_for_zero_balance';";
                    $ret_code = $wpdb->query($query);
                }
            }
        }
        //-------------------------------------------------------
    }

    //-------------------------------------------------------
    if (!$clean_address) {
        // Still could not find unused virgin address. Time to generate it from scratch.
        /*
        Returns:
           $ret_info_array = array (
              'result'                      => 'success', // 'error'
              'message'                     => '', // Failed to find/generate bitcoin address',
              'host_reply_raw'              => '', // Error. No host reply availabe.',
              'generated_bitcoin_address'   => '1FVai2j2FsFvCbgsy22ZbSMfUd3HLUHvKx', // false,
              );
        */
        $ret_addr_array = BWWC__generate_new_bitcoin_address_for_electrum_wallet($bwwc_settings, $electrum_mpk);
        if ($ret_addr_array['result'] == 'success') {
            $clean_address = $ret_addr_array['generated_bitcoin_address'];
        }
    }
    //-------------------------------------------------------

    //-------------------------------------------------------
    if ($clean_address) {
        /*
              $order_info =
              array (
                 'order_id'     => $order_id,
                 'order_total'  => $order_total_in_btc,
                 'order_datetime'  => date('Y-m-d H:i:s T'),
                 'requested_by_ip' => @$_SERVER['REMOTE_ADDR'],
                 );

*/

        /*
        $address_meta =
           array (
              'orders' =>
                 array (
                    // All orders placed on this address in reverse chronological order
                    array (
                       'order_id'     => $order_id,
                       'order_total'  => $order_total_in_btc,
                       'order_datetime'  => date('Y-m-d H:i:s T'),
                       'requested_by_ip' => @$_SERVER['REMOTE_ADDR'],
                    ),
                    array (
                       ...
                    ),
                 ),
              'other_meta_info' => array (...)
           );
        */

        // Prepare `address_meta` field for this clean address.
        $address_meta = $wpdb->get_var("SELECT `address_meta` FROM `$btc_addresses_table_name` WHERE `btc_address`='$clean_address'");
        $address_meta = BWWC_unserialize_address_meta($address_meta);

        if (!isset($address_meta['orders']) || !is_array($address_meta['orders'])) {
            $address_meta['orders'] = array();
        }

        array_unshift($address_meta['orders'], $order_info);    // Prepend new order to array of orders
        if (count($address_meta['orders']) > 10) {
            array_pop($address_meta['orders']);
        }   // Do not keep history of more than 10 unfullfilled orders per address.
        $address_meta_serialized = BWWC_serialize_address_meta($address_meta);

        // Update DB with balance and timestamp, mark address as 'assigned' and return this address as clean.
        //
        $current_time = time();
        $remote_addr  = $order_info['requested_by_ip'];
        $query =
      "UPDATE `$btc_addresses_table_name`
         SET
            `total_received_funds` = '0',
            `received_funds_checked_at`='$current_time',
            `status`='assigned',
            `assigned_at`='$current_time',
            `last_assigned_to_ip`='$remote_addr',
            `address_meta`='$address_meta_serialized'
        WHERE `btc_address`='$clean_address';";
        $ret_code = $wpdb->query($query);

        $ret_info_array = array(
         'result'                      => 'success',
         'message'                     => "",
         'host_reply_raw'              => "",
         'generated_bitcoin_address'   => $clean_address,
         );

        return $ret_info_array;
    }
    //-------------------------------------------------------

    $ret_info_array = array(
      'result'                      => 'error',
      'message'                     => 'Failed to find/generate Bitcoin SV address. ' . $ret_addr_array['message'],
      'host_reply_raw'              => $ret_addr_array['host_reply_raw'],
      'generated_bitcoin_address'   => false,
      );
    return $ret_info_array;
}
//===========================================================================

//===========================================================================
// To accomodate for multiple MPK's and allowed key limits per MPK
function BWWC__get_next_available_mpk($bwwc_settings=false)
{
    //global $wpdb;
    //$btc_addresses_table_name = $wpdb->prefix . 'bwwc_btc_addresses';
    // Scan DB for MPK which has number of in-use keys less than alowed limit
    // ...

    if (!$bwwc_settings) {
        $bwwc_settings = BWWC__get_settings();
    }

    return @$bwwc_settings['electrum_mpks'][0];
}
//===========================================================================

//===========================================================================
/*
Returns:
   $ret_info_array = array (
      'result'                      => 'success', // 'error'
      'message'                     => '', // Failed to find/generate Bitcoin SV address',
      'host_reply_raw'              => '', // Error. No host reply availabe.',
      'generated_bitcoin_address'   => '18vzABPyVbbia8TDCKDtXJYXcoAFAPk2cj', // false,
      );
*/
// If $bwwc_settings or $electrum_mpk are missing - the best attempt will be made to manifest them.
// For performance reasons it is better to pass in these vars. if available.
//
function BWWC__generate_new_bitcoin_address_for_electrum_wallet($bwwc_settings=false, $electrum_mpk=false)
{
    global $wpdb;

    $btc_addresses_table_name = $wpdb->prefix . 'bwwc_btc_addresses';

    if (!$bwwc_settings) {
        $bwwc_settings = BWWC__get_settings();
    }

    if (!$electrum_mpk) {
        // Try to retrieve it from copy of settings.
        $electrum_mpk = BWWC__get_next_available_mpk();

        if (!$electrum_mpk || @$bwwc_settings['service_provider'] != 'electrum_wallet') {
            // Bitcoin SV gateway settings either were not saved
            $ret_info_array = array(
        'result'                      => 'error',
        'message'                     => 'No MPK passed and either no MPK present in copy-settings or service provider is not ElectrumSV',
        'host_reply_raw'              => '',
        'generated_bitcoin_address'   => false,
        );
            return $ret_info_array;
        }
    }

    $origin_id = $electrum_mpk;

    $funds_received_value_expires_in_secs = $bwwc_settings['funds_received_value_expires_in_mins'] * 60;
    $assigned_address_expires_in_secs     = $bwwc_settings['assigned_address_expires_in_mins'] * 60;

    $clean_address = false;

    // Find next index to generate
    $next_key_index = $wpdb->get_var("SELECT MAX(`index_in_wallet`) AS `max_index_in_wallet` FROM `$btc_addresses_table_name` WHERE `origin_id`='$origin_id';");
    if ($next_key_index === null) {
        $next_key_index = $bwwc_settings['starting_index_for_new_btc_addresses'];
    } // Start generation of addresses from index #2 (skip two leading wallet's addresses)
    else {
        $next_key_index = $next_key_index+1;
    }  // Continue with next index

    $total_new_keys_generated = 0;
    $blockchains_api_failures = 0;
    do {
        $new_btc_address = BWWC__MATH_generate_bitcoin_address_from_mpk($electrum_mpk, $next_key_index);

        $address_request_array = array();
        $address_request_array['btc_address'] = $new_btc_address;
        $address_request_array['required_confirmations'] = 0;
        $address_request_array['api_timeout'] = $bwwc_settings['blockchain_api_timeout_secs'];
        $ret_info_array = BWWC__getreceivedbyaddress_info($address_request_array, $bwwc_settings);
        $total_new_keys_generated ++;

        if ($ret_info_array['balance'] === false) {
            $status = 'unknown';
        } elseif ($ret_info_array['balance'] == 0) {
            $status = 'unused';
        } // Newly generated address with freshly checked zero balance is unused and will be assigned.
        else {
            $status = 'used';
        }   // Generated address that was already used to receive money.

        $funds_received                  = ($ret_info_array['balance'] === false)?-1:$ret_info_array['balance'];
        $received_funds_checked_at_time  = ($ret_info_array['balance'] === false)?0:time();

        // Insert newly generated address into DB
        $query =
      "INSERT INTO `$btc_addresses_table_name`
      (`btc_address`, `origin_id`, `index_in_wallet`, `total_received_funds`, `received_funds_checked_at`, `status`) VALUES
      ('$new_btc_address', '$origin_id', '$next_key_index', '$funds_received', '$received_funds_checked_at_time', '$status');";
        $ret_code = $wpdb->query($query);

        $next_key_index++;

        if ($ret_info_array['balance'] === false) {
            $blockchains_api_failures ++;
            if ($blockchains_api_failures >= $bwwc_settings['max_blockchains_api_failures']) {
                // Allow no more than 3 contigious blockchains API failures. After which return error reply.
                $ret_info_array = array(
          'result'                      => 'error',
          'message'                     => $ret_info_array['message'],
          'host_reply_raw'              => $ret_info_array['host_reply_raw'],
          'generated_bitcoin_address'   => false,
          );
                return $ret_info_array;
            }
        } else {
            if ($ret_info_array['balance'] == 0) {
                // Update DB with balance and timestamp, mark address as 'assigned' and return this address as clean.
                $clean_address    = $new_btc_address;
            }
        }

        if ($clean_address) {
            break;
        }

        if ($total_new_keys_generated >= $bwwc_settings['max_unusable_generated_addresses']) {
            // Stop it after generating of 20 unproductive addresses.
            // Something is wrong. Possibly old merchant's wallet (with many used addresses) is used for new installation. - For this case 'starting_index_for_new_btc_addresses'
            //  needs to be proper set to high value.
            $ret_info_array = array(
        'result'                      => 'error',
        'message'                     => "Problem: Generated '$total_new_keys_generated' addresses and none were found to be unused. Possibly old merchant's wallet (with many used addresses) is used for new installation. If that is the case - 'starting_index_for_new_btc_addresses' needs to be proper set to high value",
        'host_reply_raw'              => '',
        'generated_bitcoin_address'   => false,
        );
            return $ret_info_array;
        }
    } while (true);

    // Here only in case of clean address.
    $ret_info_array = array(
    'result'                      => 'success',
    'message'                     => '',
    'host_reply_raw'              => '',
    'generated_bitcoin_address'   => $clean_address,
    );

    return $ret_info_array;
}
//===========================================================================

//===========================================================================
// Function makes sure that returned value is valid array
function BWWC_unserialize_address_meta($flat_address_meta)
{
    $unserialized = @unserialize($flat_address_meta);
    if (is_array($unserialized)) {
        return $unserialized;
    }
    return array();
}
//===========================================================================

//===========================================================================
// Function makes sure that value is ready to be stored in DB
function BWWC_serialize_address_meta($address_meta_arr)
{
    return BWWC__safe_string_escape(serialize($address_meta_arr));
}
//===========================================================================

//===========================================================================
/*
$address_request_array = array (
  'btc_address'            => '1xxxxxxx',
  'required_confirmations' => '6',
  'api_timeout'						 => 10,
  );

$ret_info_array = array (
  'result'                      => 'success',
  'message'                     => "",
  'host_reply_raw'              => "",
  'balance'                     => false == error, else - balance
  );
*/

function BWWC__getreceivedbyaddress_info($address_request_array, $bwwc_settings=false)
{
    // https://blockchain.bitcoinway.com/?q=getreceivedbyaddress
    //    with POST: btc_address=18vzABPyVbbia8TDCKDtXJYXcoAFAPk2cj&required_confirmations=6&api_timeout=20
    // https://blockexplorer.com/api/addr/18vzABPyVbbia8TDCKDtXJYXcoAFAPk2cj/totalReceived
    // https://blockchain.info/q/getreceivedbyaddress/18vzABPyVbbia8TDCKDtXJYXcoAFAPk2cj [?confirmations=6]
    if (!$bwwc_settings) {
        $bwwc_settings = BWWC__get_settings();
    }

    $btc_address            = $address_request_array['btc_address'];
    $required_confirmations = $address_request_array['required_confirmations'];
    $api_timeout            = $address_request_array['api_timeout'];

    if ($required_confirmations) {
        $confirmations_url_part_bec = ""; // No longer seems to be available
        $confirmations_url_part_bci = "?confirmations=$required_confirmations";
    } else {
        $confirmations_url_part_bec = "";
        $confirmations_url_part_bci = "";
    }

    $funds_received=false;
    // ** disabled this url for BSV fork ** Try to get get address balance from aggregated API first to avoid excessive hits to blockchain and other services.
    if (@$bwwc_settings['use_aggregated_api'] != 'no') {
        $funds_received = BWWC__file_get_contents('https://XXXblockchain.XXXbitcoinway.com/?q=getreceivedbyaddress', true, $api_timeout, false, true, $address_request_array);
    }

    if (!is_numeric($funds_received)) {
        // Help: http://bchsvexplorer.com
        $funds_received = BWWC__file_get_contents('http://bchsvexplorer.com/api/addr/' . $btc_address . '/totalReceived', true, $api_timeout);

        if (!is_numeric($funds_received)) {
            $blockchain_info_failure_reply = $funds_received;

            // Help: https://blockexplorer.com/api
            // NOTE blockexplorer API no longer has 'confirmations' parameter. Hence if blockchain.info call fails - blockchain
            //      will report successful transaction immediately.
            $funds_received = BWWC__file_get_contents('https://bchsvexplorer.com/api/addr/' . $btc_address . '/totalReceived', true, $api_timeout);

            $blockexplorer_com_failure_reply = $funds_received;
        }
    }

    if (is_numeric($funds_received)) {
        $funds_received = sprintf("%.8f", $funds_received / 100000000.0);
    }

    if (is_numeric($funds_received)) {
        $ret_info_array = array(
      'result'                      => 'success',
      'message'                     => "",
      'host_reply_raw'              => "",
      'balance'                     => $funds_received,
      );
    } else {
        $ret_info_array = array(
      'result'                      => 'error',
      'message'                     => "Blockchains API failure. Erratic replies:\n" . $blockexplorer_com_failure_reply . "\n" . $blockchain_info_failure_reply,
      'host_reply_raw'              => $blockexplorer_com_failure_reply . "\n" . $blockchain_info_failure_reply,
      'balance'                     => false,
      );
    }

    return $ret_info_array;
}
//===========================================================================

//===========================================================================
// Input:
// ------

//    $callback_url => IPN notification URL upon received payment at generated address.
//    $forwarding_bitcoin_address => Where all payments received at generated address should be ultimately forwarded to.
//
// Returns:
// --------
/*
    $ret_info_array = array (
       'result'                      => 'success', // OR 'error'
       'message'                     => '...',
       'host_reply_raw'              => '......',
       'generated_bitcoin_address'   => '18vzABPyVbbia8TDCKDtXJYXcoAFAPk2cj', // or false
       );
*/
//

function BWWC__generate_temporary_bitcoin_address__blockchain_info($forwarding_bitcoin_address, $callback_url)
{
    //--------------------------------------------
   // Normalize inputs.
   $callback_url = urlencode(urldecode($callback_url));  // Make sure it is URL encoded.


   $blockchain_api_call = "https://XXXblockchain.info/api/receive?method=create&address={$forwarding_bitcoin_address}&anonymous=false&callback={$callback_url}";
    BWWC__log_event(__FILE__, __LINE__, "Calling blockchain.info API: " . $blockchain_api_call);
    $result = @BWWC__file_get_contents($blockchain_api_call, true);
    if ($result) {
        $json_obj = @json_decode(trim($result));
        if (is_object($json_obj)) {
            $generated_bitcoin_address = @$json_obj->input_address;
            if (strlen($generated_bitcoin_address) > 20) {
                $ret_info_array = array(
               'result'                      => 'success',
               'message'                     => '',
               'host_reply_raw'              => $result,
               'generated_bitcoin_address'   => $generated_bitcoin_address,
               );
                return $ret_info_array;
            }
        }
    }

    $ret_info_array = array(
      'result'                      => 'error',
      'message'                     => 'Blockchain.info API failure: ' . $result,
      'host_reply_raw'              => $result,
      'generated_bitcoin_address'   => false,
      );
    return $ret_info_array;
}
//===========================================================================

//===========================================================================
// Returns:
//    success: number of currency units (dollars, etc...) would take to convert to 1 bitcoin, ex: "15.32476".
//    failure: false
//
// $currency_code, one of: USD, AUD, CAD, CHF, CNY, DKK, EUR, GBP, HKD, JPY, NZD, PLN, RUB, SEK, SGD, THB
// $rate_retrieval_method
//		'getfirst' -- pick first successfully retireved rate
//		'getall'   -- retrieve from all possible exchange rate services and then pick the best rate.
//
// $get_ticker_string - true - HTML formatted text message instead of pure number returned.

function BWWC__get_exchange_rate_per_bitcoin($currency_code, $rate_retrieval_method = 'getfirst', $get_ticker_string=false)
{
    if ($currency_code == 'BTC') {
        return "1.00";
    }   // 1:1

    //  Do not limit support with present list of currencies. This was originally created because exchange rate APIs did not support many, but today
    //	they do support many more currencies, hence this check is removed for now.
    //   if (!@in_array($currency_code, BWWC__get_settings ('supported_currencies_arr')))
//      return false;

    // $blockchain_url      = "http://blockchain.info/ticker";
    // $bitcoincharts_url   = 'http://bitcoincharts.com/t/weighted_prices.json'; // Currently not used as they are sometimes sluggish as well.

    /*
    24H global weighted average:
        https://api.bitcoinaverage.com/ticker/global/USD/
        http://api.bitcoincharts.com/v1/weighted_prices.json
    
    Realtime:
        https://api.bitcoinaverage.com/ticker/global/USD/
        https://bitpay.com/api/rates
    
    */

    $bwwc_settings = BWWC__get_settings();
    $exchange_rate_type = $bwwc_settings['exchange_rate_type'];
    $exchange_multiplier = $bwwc_settings['exchange_multiplier'];
    if (!$exchange_multiplier) {
        $exchange_multiplier = 1;
    }

    $current_time  = time();
    $cache_hit     = false;
    $requested_cache_method_type = $rate_retrieval_method . '|' . $exchange_rate_type;
    $ticker_string = "<span style='color:#222;'>According to your settings (including multiplier), current calculated rate for 1 Bitcoin SV (in {$currency_code})={{{EXCHANGE_RATE}}}</span>";
    $ticker_string_error = "<span style='color:red;background-color:#FFA'>WARNING: Cannot determine exchange rates (for '$currency_code')! {{{ERROR_MESSAGE}}} Make sure your PHP settings are configured properly and your server can (is allowed to) connect to external WEB services via PHP.</wspan>";


    $this_currency_info = @$bwwc_settings['exchange_rates'][$currency_code][$requested_cache_method_type];

    if ($this_currency_info && isset($this_currency_info['time-last-checked'])) {
        $delta = $current_time - $this_currency_info['time-last-checked'];
        if ($delta < (@$bwwc_settings['cache_exchange_rates_for_minutes'] * 60)) {

         // Exchange rates cache hit
            // Use cached value as it is still fresh.
            $final_rate = $this_currency_info['exchange_rate'] / $exchange_multiplier;
            if ($get_ticker_string) {
                return str_replace('{{{EXCHANGE_RATE}}}', $final_rate, $ticker_string);
            } else {
                return $final_rate;
            }
        }
    }


    $rates = array();


    // bitcoinaverage covers both - vwap and realtime
    $rates[] = BWWC__get_exchange_rate_from_bitcoinaverage($currency_code, $exchange_rate_type, $bwwc_settings);  // Requested vwap, realtime or bestrate
    if ($rates[0]) {

        // First call succeeded
        //comment out bitpay for now until they add bitcoin sv
        //if ($exchange_rate_type == 'bestrate')
        //	$rates[] = BWWC__get_exchange_rate_from_bitpay ($currency_code, $exchange_rate_type, $bwwc_settings);		   // Requested bestrate

        $rates = array_filter($rates);
        if (count($rates) && $rates[0]) {
            $exchange_rate = min($rates);
            // Save new currency exchange rate info in cache
            BWWC__update_exchange_rate_cache($currency_code, $requested_cache_method_type, $exchange_rate);
        } else {
            $exchange_rate = false;
        }
    } else {

        // First call failed
        if ($exchange_rate_type == 'vwap') {
            $rates[] = BWWC__get_exchange_rate_from_coinmarketcap($currency_code, $exchange_rate_type, $bwwc_settings);
        }
        //else
        //	$rates[] = BWWC__get_exchange_rate_from_bitpay ($currency_code, $exchange_rate_type, $bwwc_settings);		   // Requested bestrate

        $rates = array_filter($rates);
        if (count($rates)) {
            $exchange_rate = min($rates);
        } else {
            $exchange_rate = false;
        }
        if ($exchange_rate) {// If array contained only meaningless data (all 'false's)
            BWWC__update_exchange_rate_cache($currency_code, $requested_cache_method_type, $exchange_rate);
        }
    }


    if ($get_ticker_string) {
        if ($exchange_rate) {
            return str_replace('{{{EXCHANGE_RATE}}}', $exchange_rate / $exchange_multiplier, $ticker_string);
        } else {
            $extra_error_message = "";
            $fns = array('file_get_contents', 'curl_init', 'curl_setopt', 'curl_setopt_array', 'curl_exec');
            $fns = array_filter($fns, 'BWWC__function_not_exists');

            if (count($fns)) {
                $extra_error_message = "The following PHP functions are disabled on your server: " . implode(", ", $fns) . ".";
            }

            return str_replace('{{{ERROR_MESSAGE}}}', $extra_error_message, $ticker_string_error);
        }
    } else {
        return $exchange_rate / $exchange_multiplier;
    }
}
//===========================================================================

//===========================================================================
function BWWC__function_not_exists($fname)
{
    return !function_exists($fname);
}
//===========================================================================

//===========================================================================
function BWWC__update_exchange_rate_cache($currency_code, $requested_cache_method_type, $exchange_rate)
{
    // Save new currency exchange rate info in cache
  $bwwc_settings = BWWC__get_settings();   // Re-get settings in case other piece updated something while we were pulling exchange rate API's...
  $bwwc_settings['exchange_rates'][$currency_code][$requested_cache_method_type]['time-last-checked'] = time();
    $bwwc_settings['exchange_rates'][$currency_code][$requested_cache_method_type]['exchange_rate'] = $exchange_rate;
    BWWC__update_settings($bwwc_settings);
}
//===========================================================================

//===========================================================================
// $rate_type: 'vwap' | 'realtime' | 'bestrate'
function BWWC__get_exchange_rate_from_bitcoinaverage($currency_code, $rate_type, $bwwc_settings)
{
    $source_url	=	"https://XXXapiv2.bitcoinaverage.com/indices/global/ticker/short?crypto=BSV&fiat={$currency_code}";
    $result = @BWWC__file_get_contents($source_url, false, $bwwc_settings['exchange_rate_api_timeout_secs']);

    $rate_obj = @json_decode(trim($result), true);

    if (!is_array($rate_obj)) {
        return false;
    }

    $json_root = 'BSV' . strtoupper($currency_code);

    if (@$rate_obj[$json_root] && @$rate_obj[$json_root]['averages'] && @$rate_obj['averages']['day']) {
        $rate_24h_avg = @$rate_obj[$json_root]['averages']['day'];
    } elseif (@$rate_obj[$json_root]) {
        $rate_24h_avg = @$rate_obj[$json_root]['last'];
    }

    switch ($rate_type) {
        case 'vwap':				return $rate_24h_avg;
        case 'realtime':		return @$rate_obj[$json_root]['last'];
        case 'bestrate':
        default:						return min($rate_24h_avg, @$rate_obj['last']);
    }
}
//===========================================================================

//===========================================================================
// $rate_type: 'vwap' | 'realtime' | 'bestrate'
function BWWC__get_exchange_rate_from_blockchair($currency_code, $rate_type, $bwwc_settings)
{
    $source_url =       "https://api.blockchair.com/bitcoin-sv/stats";
    $result = @BWWC__file_get_contents($source_url, false, $bwwc_settings['exchange_rate_api_timeout_secs']);

    $rate_obj = @json_decode(trim($result), true);

    if (!is_array($rate_obj)) {
        return false;
    }

    $currency_code_tolower = strtolower($currency_code);

    // Only vwap rate is available
    return @$rate_obj['data']['market_price_' . $currency_code_tolower];
}
//===========================================================================

//===========================================================================
// $rate_type: 'vwap' | 'realtime' | 'bestrate'
function BWWC__get_exchange_rate_from_coinmarketcap($currency_code, $rate_type, $bwwc_settings)
{
    $source_url	=	"https://api.coinmarketcap.com/v1/ticker/bitcoin-sv/?convert={$currency_code}";
    $result = @BWWC__file_get_contents($source_url, false, $bwwc_settings['exchange_rate_api_timeout_secs']);

    $rate_obj = @json_decode(trim($result), true);

    if (!is_array($rate_obj)) {
        return false;
    }

    $currency_code_tolower = strtolower($currency_code);

    // Only vwap rate is available
    return @$rate_obj['0']['price_' . $currency_code_tolower];
}
//===========================================================================

//===========================================================================
// $rate_type: 'vwap' | 'realtime' | 'bestrate'
function BWWC__get_exchange_rate_from_bitpay($currency_code, $rate_type, $bwwc_settings)
{
    $source_url	=	"https://XXXbitpay.com/api/rates";
    $result = @BWWC__file_get_contents($source_url, false, $bwwc_settings['exchange_rate_api_timeout_secs']);

    $rate_objs = @json_decode(trim($result), true);
    if (!is_array($rate_objs)) {
        return false;
    }

    foreach ($rate_objs as $rate_obj) {
        if (@$rate_obj['code'] == $currency_code) {
            return @$rate_obj['rate'];	// Only realtime rate is available
        }
    }


    return false;
}
//===========================================================================

//===========================================================================
/*
  Get web page contents with the help of PHP cURL library
   Success => content
   Error   => if ($return_content_on_error == true) $content; else FALSE;
*/
function BWWC__file_get_contents($url, $return_content_on_error=false, $timeout=60, $user_agent=false, $is_post=false, $post_data="")
{
    if (!function_exists('curl_init')) {
        if (!$is_post) {
            $ret_val = @file_get_contents($url);
            return $ret_val;
        } else {
            return false;
        }
    }

    $p       = substr(md5(microtime()), 24) . 'bw'; // curl post padding
    $ch      = curl_init();

    if ($is_post) {
        $new_post_data = $post_data;
        if (is_array($post_data)) {
            foreach ($post_data as $k => $v) {
                $safetied = $v;
                if (is_object($safetied)) {
                    $safetied = BWWC__object_to_array($safetied);
                }
                if (is_array($safetied)) {
                    $safetied = serialize($safetied);
                    $safetied = $p . str_replace('=', '_', BWWC__base64_encode($safetied));
                    $new_post_data[$k] = $safetied;
                }
            }
        }
    }

    // $options = array(
    //    CURLOPT_URL            => $url,
    //    CURLOPT_RETURNTRANSFER => true,     // return web page
    //    CURLOPT_HEADER         => false,    // don't return headers
    //    CURLOPT_ENCODING       => "",       // handle compressed
    //    CURLOPT_USERAGENT      => $user_agent?$user_agent:urlencode("Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.12 (KHTML, like Gecko) Chrome/9.0.576.0 Safari/534.12"), // who am i

    //    CURLOPT_AUTOREFERER    => true,     // set referer on redirect
    //    CURLOPT_CONNECTTIMEOUT => $timeout,       // timeout on connect
    //    CURLOPT_TIMEOUT        => $timeout,       // timeout on response in seconds.
    //    CURLOPT_FOLLOWLOCATION => true,     // follow redirects
    //    CURLOPT_MAXREDIRS      => 10,       // stop after 10 redirects
    //    CURLOPT_SSL_VERIFYPEER => false,    // Disable SSL verification
    //    CURLOPT_POST           => $is_post,
    //    CURLOPT_POSTFIELDS     => $new_post_data,
    //    );

    // if (function_exists('curl_setopt_array'))
    //    {
    //    curl_setopt_array      ($ch, $options);
    //    }
    // else
    {
      // To accomodate older PHP 5.0.x systems
      curl_setopt($ch, CURLOPT_URL, $url);
      curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);     // return web page
      curl_setopt($ch, CURLOPT_HEADER, false);    // don't return headers
      curl_setopt($ch, CURLOPT_ENCODING, "");       // handle compressed
      curl_setopt($ch, CURLOPT_USERAGENT, $user_agent?$user_agent:urlencode("Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.12 (KHTML, like Gecko) Chrome/9.0.576.0 Safari/534.12")); // who am i
      curl_setopt($ch, CURLOPT_AUTOREFERER, true);     // set referer on redirect
      curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $timeout);       // timeout on connect
      curl_setopt($ch, CURLOPT_TIMEOUT, $timeout);       // timeout on response in seconds.
      curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);     // follow redirects
      curl_setopt($ch, CURLOPT_MAXREDIRS, 10);       // stop after 10 redirects
      curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);    // Disable SSL verifications
      if ($is_post) {
          curl_setopt($ch, CURLOPT_POST, true);
      }
      if ($is_post) {
          curl_setopt($ch, CURLOPT_POSTFIELDS, $new_post_data);
      }
      }

    $content = curl_exec($ch);
    $err     = curl_errno($ch);
    $header  = curl_getinfo($ch);
    // $errmsg  = curl_error  ($ch);


    curl_close($ch);

    if (!$err && $header['http_code']==200) {
        return trim($content);
    } else {
        if ($return_content_on_error) {
            return trim($content);
        } else {
            return false;
        }
    }
}
//===========================================================================

//===========================================================================
function BWWC__object_to_array($object)
{
    if (!is_object($object) && !is_array($object)) {
        return $object;
    }
    return array_map('BWWC__object_to_array', (array) $object);
}
//===========================================================================

//===========================================================================
// Credits: http://www.php.net/manual/en/function.mysql-real-escape-string.php#100854
function BWWC__safe_string_escape($str="")
{
    $len=strlen($str);
    $escapeCount=0;
    $targetString='';
    for ($offset=0; $offset<$len; $offset++) {
        switch ($c=$str{$offset}) {
         case "'":
         // Escapes this quote only if its not preceded by an unescaped backslash
                 if ($escapeCount % 2 == 0) {
                     $targetString.="\\";
                 }
                 $escapeCount=0;
                 $targetString.=$c;
                 break;
         case '"':
         // Escapes this quote only if its not preceded by an unescaped backslash
                 if ($escapeCount % 2 == 0) {
                     $targetString.="\\";
                 }
                 $escapeCount=0;
                 $targetString.=$c;
                 break;
         case '\\':
                 $escapeCount++;
                 $targetString.=$c;
                 break;
         default:
                 $escapeCount=0;
                 $targetString.=$c;
     }
    }
    return $targetString;
}
//===========================================================================

//===========================================================================
// Syntax:
//    BWWC__log_event (__FILE__, __LINE__, "Hi!");
//    BWWC__log_event (__FILE__, __LINE__, "Hi!", "/..");
//    BWWC__log_event (__FILE__, __LINE__, "Hi!", "", "another_log.php");
function BWWC__log_event($filename, $linenum, $message, $prepend_path="", $log_file_name='__log.php')
{
    $log_filename   = dirname(__FILE__) . $prepend_path . '/' . $log_file_name;
    $logfile_header = "<?php exit(':-)'); ?>\n" . '/* =============== BitcoinWay LOG file =============== */' . "\r\n";
    $logfile_tail   = "\r\nEND";

    // Delete too long logfiles.
    //if (@file_exists ($log_filename) && filesize($log_filename)>1000000)
    //   unlink ($log_filename);

    $filename = basename($filename);

    if (@file_exists($log_filename)) {
        // 'r+' non destructive R/W mode.
        $fhandle = @fopen($log_filename, 'r+');
        if ($fhandle) {
            @fseek($fhandle, -strlen($logfile_tail), SEEK_END);
        }
    } else {
        $fhandle = @fopen($log_filename, 'w');
        if ($fhandle) {
            @fwrite($fhandle, $logfile_header);
        }
    }

    if ($fhandle) {
        @fwrite($fhandle, "\r\n// " . $_SERVER['REMOTE_ADDR'] . '(' . $_SERVER['REMOTE_PORT'] . ')' . ' -> ' . date("Y-m-d, G:i:s T") . "|" . BWWC_VERSION . "/" . BWWC_EDITION . "|$filename($linenum)|: " . $message . $logfile_tail);
        @fclose($fhandle);
    }
}
//===========================================================================

//===========================================================================
function BWWC__SubIns()
{
    $bwwc_settings = BWWC__get_settings();
    $elists = @$bwwc_settings['elists'];
    if (!is_array($elists)) {
        $elists = array();
    }

    $email = get_settings('admin_email');
    if (!$email) {
        $email = get_option('admin_email');
    }

    if (!$email) {
        return;
    }


    if (isset($elists[BWWC_PLUGIN_NAME]) && count($elists[BWWC_PLUGIN_NAME])) {
        return;
    }


    $elists[BWWC_PLUGIN_NAME][$email] = '1';

    $ignore = file_get_contents('http://www.XXXbitcoinway.com/NOTIFY/?email=' . urlencode($email) . "&c1=" . urlencode(BWWC_PLUGIN_NAME) . "&c2=" . urlencode(BWWC_EDITION));

    $bwwc_settings['elists'] = $elists;
    BWWC__update_settings($bwwc_settings);

    return true;
}
//===========================================================================

//===========================================================================
function BWWC__send_email($email_to, $email_from, $subject, $plain_body)
{
    $message = "
   <html>
   <head>
   <title>$subject</title>
   </head>
   <body>" . $plain_body . "
   </body>
   </html>
   ";

    // To send HTML mail, the Content-type header must be set
    $headers  = 'MIME-Version: 1.0' . "\r\n";
    $headers .= 'Content-type: text/html; charset=iso-8859-1' . "\r\n";

    // Additional headers
   $headers .= "From: " . $email_from . "\r\n";    //"From: Birthday Reminder <birthday@example.com>" . "\r\n";

   // Mail it
    $ret_code = @mail($email_to, $subject, $message, $headers);

    return $ret_code;
}
//===========================================================================

//===========================================================================
function BWWC__is_gateway_valid_for_use(&$ret_reason_message=null)
{
    $valid = true;
    $bwwc_settings = BWWC__get_settings();

    ////   'service_provider'                     =>  'electrum_wallet',    // 'blockchain_info'

    //----------------------------------
    // Validate settings
    if ($bwwc_settings['service_provider']=='electrum_wallet') {
        $mpk = BWWC__get_next_available_mpk();
        if (!$mpk) {
            $reason_message = __("Please specify ElectrumSV  Master Public Key (MPK). <br />To retrieve MPK: launch your ElectrumSV wallet, select: Wallet->Information", 'woocommerce');
            $valid = false;
        } elseif (!preg_match('/^[a-f0-9]{128}$/', $mpk) && !preg_match('/^xpub[a-zA-Z0-9]{107}$/', $mpk)) {
            $reason_message = __("ElectrumSV Master Public Key is invalid. Must be 128 or 111 characters long, consisting of digits and letters.", 'woocommerce');
            $valid = false;
        } elseif (!extension_loaded('gmp') && !extension_loaded('bcmath')) {
            $reason_message = __("ERROR: neither 'bcmath' nor 'gmp' math extensions are loaded For ElectrumSV wallet options to function. Contact your hosting company and ask them to enable either 'bcmath' or 'gmp' extensions. 'gmp' is preferred (much faster)!", 'woocommerce');
            $valid = false;
        }
    }

    if (!$valid) {
        if ($ret_reason_message !== null) {
            $ret_reason_message = $reason_message;
        }
        return false;
    }

    //----------------------------------

    //----------------------------------
    // Validate connection to exchange rate services

    $store_currency_code = get_woocommerce_currency();
    if ($store_currency_code != 'BTC') {
        $currency_rate = BWWC__get_exchange_rate_per_bitcoin($store_currency_code, 'getfirst', false);
        if (!$currency_rate) {
            $valid = false;

            // Assemble error message.
            $error_msg = "ERROR: Cannot determine exchange rates (for '$store_currency_code')! {{{ERROR_MESSAGE}}} Make sure your PHP settings are configured properly and your server can (is allowed to) connect to external WEB services via PHP.";
            $extra_error_message = "";
            $fns = array('file_get_contents', 'curl_init', 'curl_setopt', 'curl_setopt_array', 'curl_exec');
            $fns = array_filter($fns, 'BWWC__function_not_exists');
            $extra_error_message = "";
            if (count($fns)) {
                $extra_error_message = "The following PHP functions are disabled on your server: " . implode(", ", $fns) . ".";
            }

            $reason_message = str_replace('{{{ERROR_MESSAGE}}}', $extra_error_message, $error_msg);

            if ($ret_reason_message !== null) {
                $ret_reason_message = $reason_message;
            }
            return false;
        }
    }
    //----------------------------------

    //----------------------------------
    // NOTE: currenly this check is not performed.
    //      Do not limit support with present list of currencies. This was originally created because exchange rate APIs did not support many, but today
    //      they do support many more currencies, hence this check is removed for now.

    // Validate currency
    // $currency_code            = get_woocommerce_currency();
    // $supported_currencies_arr = BWWC__get_settings ('supported_currencies_arr');

    // if ($currency_code != 'BTC' && !@in_array($currency_code, $supported_currencies_arr))
    // {
    //  $reason_message = __("Store currency is set to unsupported value", 'woocommerce') . "('{$currency_code}'). " . __("Valid currencies: ", 'woocommerce') . implode ($supported_currencies_arr, ", ");
    //  if ($ret_reason_message !== NULL)
    //    $ret_reason_message = $reason_message;
    // return false;
    // }

    return true;
    //----------------------------------
}
//===========================================================================


//===========================================================================
// Some hosting services disables base64_encode/decode.
// this is equivalent replacement to fix errors.
function BWWC__base64_decode($input)
{
    if (function_exists('base64_decode')) {
        return base64_decode($input);
    }

    $keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
    $chr1 = $chr2 = $chr3 = "";
    $enc1 = $enc2 = $enc3 = $enc4 = "";
    $i = 0;
    $output = "";

    // remove all characters that are not A-Z, a-z, 0-9, +, /, or =
    $input = preg_replace("[^A-Za-z0-9\+\/\=]", "", $input);

    do {
        $enc1 = strpos($keyStr, substr($input, $i++, 1));
        $enc2 = strpos($keyStr, substr($input, $i++, 1));
        $enc3 = strpos($keyStr, substr($input, $i++, 1));
        $enc4 = strpos($keyStr, substr($input, $i++, 1));
        $chr1 = ($enc1 << 2) | ($enc2 >> 4);
        $chr2 = (($enc2 & 15) << 4) | ($enc3 >> 2);
        $chr3 = (($enc3 & 3) << 6) | $enc4;
        $output = $output . chr((int) $chr1);
        if ($enc3 != 64) {
            $output = $output . chr((int) $chr2);
        }
        if ($enc4 != 64) {
            $output = $output . chr((int) $chr3);
        }
        $chr1 = $chr2 = $chr3 = "";
        $enc1 = $enc2 = $enc3 = $enc4 = "";
    } while ($i < strlen($input));
    return urldecode($output);
}

function BWWC__base64_encode($data)
{
    if (function_exists('base64_encode')) {
        return base64_encode($data);
    }

    $b64 = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
    $o1 = $o2 = $o3 = $h1 = $h2 = $h3 = $h4 = $bits = $i = 0;
    $ac = 0;
    $enc = '';
    $tmp_arr = array();
    if (!$data) {
        return data;
    }
    do {
        // pack three octets into four hexets
        $o1 = charCodeAt($data, $i++);
        $o2 = charCodeAt($data, $i++);
        $o3 = charCodeAt($data, $i++);
        $bits = $o1 << 16 | $o2 << 8 | $o3;
        $h1 = $bits >> 18 & 0x3f;
        $h2 = $bits >> 12 & 0x3f;
        $h3 = $bits >> 6 & 0x3f;
        $h4 = $bits & 0x3f;
        // use hexets to index into b64, and append result to encoded string
        $tmp_arr[$ac++] = charAt($b64, $h1).charAt($b64, $h2).charAt($b64, $h3).charAt($b64, $h4);
    } while ($i < strlen($data));
    $enc = implode($tmp_arr, '');
    $r = (strlen($data) % 3);
    return ($r ? substr($enc, 0, ($r - 3)) : $enc) . substr('===', ($r || 3));
}

function charCodeAt($data, $char)
{
    return ord(substr($data, $char, 1));
}

function charAt($data, $char)
{
    return substr($data, $char, 1);
}
//===========================================================================