From fb3fa3dd1db3d9e0d0f608ca441ecabf71b46e1e Mon Sep 17 00:00:00 2001
From: "Christopher C. Wells" <git@chris-wells.net>
Date: Sun, 18 Apr 2021 13:46:20 -0700
Subject: [PATCH] Add nutrient calculation for recipe volumes

---
 app/Models/Recipe.php            |  3 +++
 app/Models/Traits/Ingredient.php |  3 +++
 app/Support/Nutrients.php        | 23 +++++++++++++----------
 3 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/app/Models/Recipe.php b/app/Models/Recipe.php
index e31e271..b856e4e 100644
--- a/app/Models/Recipe.php
+++ b/app/Models/Recipe.php
@@ -80,6 +80,9 @@ use Spatie\MediaLibrary\MediaCollections\Models\Media;
  * @property-read \Illuminate\Database\Eloquent\Collection|\App\Models\RecipeSeparator[] $separators
  * @property-read int|null $separators_count
  * @property-read Collection $units_supported
+ * @property float|null $volume
+ * @property-read string|null $volume_formatted
+ * @method static \Illuminate\Database\Eloquent\Builder|Recipe whereVolume($value)
  */
 final class Recipe extends Model implements HasMedia
 {
diff --git a/app/Models/Traits/Ingredient.php b/app/Models/Traits/Ingredient.php
index a81c339..81f5c2c 100644
--- a/app/Models/Traits/Ingredient.php
+++ b/app/Models/Traits/Ingredient.php
@@ -65,6 +65,9 @@ trait Ingredient
         if (!empty($this->serving_weight)) {
             $supported = $supported->merge($units->where('type', 'weight'));
         }
+        if (isset($this->volume) && !empty($this->volume)) {
+            $supported = $supported->merge($units->where('type', 'volume'));
+        }
         return $supported->sortBy('label');
     }
 }
diff --git a/app/Support/Nutrients.php b/app/Support/Nutrients.php
index 4daa135..24ec687 100644
--- a/app/Support/Nutrients.php
+++ b/app/Support/Nutrients.php
@@ -175,6 +175,8 @@ class Nutrients
 
     /**
      * Calculate a nutrient amount for a recipe.
+     *
+     * Weight base unit is grams, volume base unit is cups.
      */
     public static function calculateRecipeNutrientAmount(
         Recipe $recipe,
@@ -182,18 +184,19 @@ class Nutrients
         float $amount,
         string $fromUnit
     ): float {
-        if ($fromUnit === 'oz') {
-            return $amount * self::$gramsPerOunce / $recipe->weight * $recipe->{"{$nutrient}Total"}();
-        }
-        elseif ($fromUnit === 'serving') {
+        if ($fromUnit === 'serving') {
+            // Use "per serving" methods directly.
             return $recipe->{"{$nutrient}PerServing"}() * $amount;
         }
-        elseif ($fromUnit === 'gram') {
-            return $amount / $recipe->weight * $recipe->{"{$nutrient}Total"}();
-        }
-        else {
-            throw new \DomainException("Unsupported recipe unit: {$fromUnit}");
-        }
+        $multiplier = match ($fromUnit) {
+            'oz' => $amount * self::$gramsPerOunce / $recipe->weight,
+            'gram' => $amount / $recipe->weight,
+            'tsp' => $amount / 48 / $recipe->volume,
+            'tbsp' => $amount / 16 / $recipe->volume,
+            'cup' => $amount / $recipe->volume,
+            default => throw new \DomainException("Unsupported recipe unit: {$fromUnit}"),
+        };
+        return $multiplier * $recipe->{"{$nutrient}Total"}();
     }
 
     /**