format amount

Previously, figures gotten from converting a single-unit fiat currency
to bitcoin were unreadable; mostly in the format `7.0297483496097E-8`
or `3.5258494994032E-5`. This commit will now render such figures in a
human readable format while taking into account, the significant figures
even in a 10th negative exponent!

README.md

@@ -35,9 +35,9 @@ use Coindesk;
  */
 Coindesk::toFiatCurrency($currency_code, $bitcoin_amount);
 
-Coindesk::toFiatCurrency('USD', 1); // This will return 34381.5206 stating that ₿1 = $34,381.5206
-Coindesk::toFiatCurrency('EUR', 1); // This will return 28431.5957 stating that ₿1 = €28,431.5957
-Coindesk::toFiatCurrency('NGN', 1); // This will return 14261794.0186 stating that ₿1 = ₦14,261,794.0186
+Coindesk::toFiatCurrency('USD', 1); // This will return 36579.71 stating that ₿1 = $36,579.71
+Coindesk::toFiatCurrency('EUR', 1); // This will return 29951.01 stating that ₿1 = €29,951.01
+Coindesk::toFiatCurrency('NGN', 1); // This will return 15028918.04 stating that ₿1 = ₦15,028,918.04
 ```
 
 ### To convert any Coindesk's supported fiat currency value to Bitcoin
@@ -55,9 +55,9 @@ use Coindesk;
  */
 Coindesk::toBtc($amount, $currency_code);
 
-Coindesk::toBtc(1, 'USD'); // This will return 2.8881896998808E-5
-Coindesk::toBtc(1, 'EUR'); // This will return 3.5258494994032E-5
-Coindesk::toBtc(1, 'NGN'); // This will return 7.0297483496097E-8
+Coindesk::toBtc(1, 'USD'); // This will return 0.000027 stating that $1 = ₿0.000027
+Coindesk::toBtc(1, 'EUR'); // This will return 0.000034 stating that €1 = ₿0.000034
+Coindesk::toBtc(1, 'NGN'); // This will return 0.000000067 stating that ₦1 = ₿0.000000067
 ```
 
 ## Changelog

src/Coindesk.php

@@ -200,11 +200,11 @@ protected function parseToExchangeRatesArray($rawJsonData)
      *
      * @param  string  $currencyCode
      * @param  float  $btcAmount
-     * @return float
+     * @return float|string
      *
      * @throws \GabrielAndy\Coindesk\Exceptions\CoindeskException
      */
-    public function toFiatCurrency($currencyCode, $btcAmount): float
+    public function toFiatCurrency($currencyCode, $btcAmount): float|string
     {
         if (! is_numeric($btcAmount)) {
             throw new CoindeskException("
@@ -228,7 +228,7 @@ public function computeCurrencyValue($btcAmount, $rate)
     {
         $rate = is_numeric($rate) ? $rate : (float) $rate;
 
-        return $btcAmount * $rate;
+        return $this->formatInteger($btcAmount * $rate);
     }
 
     /**
@@ -256,14 +256,49 @@ public function toBtc($amount, $currencyCode): string
      *
      * @param  float  $amount
      * @param  float  $rate
-     * @return float
+     * @return string
      *
      * @throws \GabrielAndy\Coindesk\Exceptions\CoindeskException
      */
     public function computeBtcValue($amount, $rate)
     {
         $rate = is_numeric($rate) ? $rate : (float) $rate;
 
-        return $amount / $rate;
+        return $this->formatInteger($amount / $rate);
+    }
+
+    /**
+     * Format integer for monetal use while preserving insignificant values.
+     *
+     * @param  float  $integer
+     * @return string
+     */
+    public function formatInteger(float $integer): string
+    {
+        // Get the float value of the integer
+        $amount = strval(floatval($integer));
+
+        // Split the amount to get the exponent
+        $amount = explode('E', $amount);
+
+        if (isset($amount[1])) {
+            $exponent = $amount[1];
+
+            $pos = strpos($exponent, '-', 0);
+
+            $exponent = abs($exponent);
+
+            if ($pos !== false) {
+                $digit = round($amount[0], 1);
+
+                $digit = bcdiv($digit, 10**$exponent, $exponent+1);
+            } else {
+                $digit = bcmul($amount[0], 10**$exponent, 2);
+            }
+        } else {
+            $digit = number_format($integer, 2, '.', '');
+        }
+
+        return $digit;
     }
 }