[fi_FI] Improve phone number generator

With this patch, generated phone numbers are more realistic.
It's also easier to improve the formats in the future, if needed.

src/Faker/Provider/fi_FI/PhoneNumber.php

@@ -4,17 +4,96 @@
 
 class PhoneNumber extends \Faker\Provider\PhoneNumber
 {
+    /**
+     * @link https://www.viestintavirasto.fi/en/internettelephone/numberingoftelecommunicationsnetworks/localcallsandtelecommunicationsareas/mapoftelecommunicationsareas.html
+     * @var array
+     */
+    protected static $landLineareaCodes = array(
+        '02',
+        '03',
+        '05',
+        '06',
+        '08',
+        '09',
+        '013',
+        '014',
+        '015',
+        '016',
+        '017',
+        '018',
+        '019',
+    );
+
+    /**
+     * @link https://www.viestintavirasto.fi/en/internettelephone/numberingoftelecommunicationsnetworks/mobilenetworks/mobilenetworkareacodes.html
+     * @var array
+     */
+    protected static $mobileNetworkAreaCodes = array(
+        '040',
+        '050',
+        '044',
+        '045',
+    );
+
+    protected static $numberFormats = array(
+        '### ####',
+        '#######',
+    );
+
     protected static $formats = array(
-        '+358 (40) ### ####',
-        '+358 (50) ### ####',
-        '+358 40 ### ####',
-        '+358 50 ### ####',
-        '040 ### ####',
-        '050 ### ####',
-        '###-########',
-        '### #######',
-        '040-#######',
-        '050-#######',
-        '(###) #######'
+        '+358 ({{ e164MobileNetworkAreaCode }}) {{ numberFormat }}',
+        '+358 {{ e164MobileNetworkAreaCode }} {{ numberFormat }}',
+        '+358 ({{ e164landLineAreaCode }}) {{ numberFormat }}',
+        '+358 {{ e164landLineAreaCode }} {{ numberFormat }}',
+        '{{ mobileNetworkAreaCode }}{{ separator }}{{ numberFormat }}',
+        '{{ landLineAreaCode }}{{ separator }}{{ numberFormat }}',
     );
+
+    /**
+     * @return string
+     */
+    public function landLineAreaCode()
+    {
+        return static::randomElement(static::$landLineareaCodes);
+    }
+
+    /**
+     * @return string
+     */
+    public function e164landLineAreaCode()
+    {
+        return substr(static::randomElement(static::$landLineareaCodes), 1);
+    }
+
+    /**
+     * @return string
+     */
+    public function mobileNetworkAreaCode()
+    {
+        return static::randomElement(static::$mobileNetworkAreaCodes);
+    }
+
+    /**
+     * @return string
+     */
+    public function e164MobileNetworkAreaCode()
+    {
+        return substr(static::randomElement(static::$mobileNetworkAreaCodes), 1);
+    }
+
+    /**
+     * @return string
+     */
+    public function numberFormat()
+    {
+        return static::randomElement(static::$numberFormats);
+    }
+
+    /**
+     * @return string
+     */
+    public function separator()
+    {
+        return static::randomElement(array(' ', '-'));
+    }
 }