Work on products, first completed broadband

app/Models/Invoice.php

@@ -45,6 +45,46 @@ class Invoice extends Model implements IDs
 	protected $dates = ['date_orig','due_date'];
 	public $dateFormat = 'U';
 
+	/* Our available billing periods */
+	public const billing_periods = [
+			0 => [
+				'name' => 'Weekly',
+				'interval' => 0.25,
+			],
+			1 => [
+				'name' => 'Monthly',
+				'interval' => 1,
+			],
+			2 => [
+				'name' => 'Quarterly',
+				'interval' => 3,
+			],
+			3 => [
+				'name' => 'Semi-Annually',
+				'interval' => 6,
+			],
+			4 => [
+				'name' => 'Annually',
+				'interval' => 12,
+			],
+			5 => [
+				'name' => 'Two years',
+				'interval' => 24,
+			],
+			6 => [
+				'name' => 'Three Years',
+				'interval' => 36,
+			],
+			7 => [
+				'name' => 'Four Years',
+				'interval' => 48,
+			],
+			8 => [
+				'name' => 'Five Years',
+				'interval' => 60,
+			],
+		];
+
 	// Array of items that can be updated with PushNew
 	protected $pushable = ['items'];
 
@@ -61,6 +101,58 @@ class Invoice extends Model implements IDs
 	private int $_total = 0;
 	private int $_total_tax = 0;
 
+	/* STATIC */
+
+	/**
+	 * This works out what multiplier to use to change billing periods
+	 *
+	 * @param int $source
+	 * @param int $target
+	 * @return float
+	 */
+	public static function billing_change(int $source,int $target): float
+	{
+		return Arr::get(self::billing_periods,$target.'.interval')/Arr::get(self::billing_periods,$source.'.interval');
+	}
+
+	/**
+	 * Return the name for the billing interval
+	 *
+	 * @param int $interval
+	 * @return string
+	 */
+	public static function billing_name(int $interval): string
+	{
+		$interval = collect(self::billing_periods)->get($interval);
+
+		return Arr::get($interval,'name','Unknown');
+	}
+
+	/**
+	 * Return the number of months in the billing interval
+	 *
+	 * @param int $interval
+	 * @return int
+	 */
+	public static function billing_period(int $interval): int
+	{
+		$interval = collect(self::billing_periods)->get($interval);
+
+		return Arr::get($interval,'interval',0);
+	}
+
+	/**
+	 * Given a contract in months, this will calculate the number of billing intervals required
+	 *
+	 * @param int $contract_term
+	 * @param int $source
+	 * @return int
+	 */
+	public static function billing_term(int $contract_term,int $source): int
+	{
+		return ceil(($contract_term ?: 1)/(Arr::get(self::billing_periods,$source.'.interval') ?: 1));
+	}
+
 	/* RELATIONS */
 
 	public function account()
@@ -312,7 +404,7 @@ class Invoice extends Model implements IDs
 
 		$lo = $this->account->user->language;
 		return $return->sortBy(function ($item) use ($lo) {
-			return $item->name($lo);
+			return $item->name;
 		});
 	}