commit cff83d30e95eb9081e02d0538864b6bb1b2e44b2
Author: matze <matthias.wagner444@gmail.com>
Date:   Tue Dec 10 15:54:55 2024 +0100

    removed cost calculation (do dynamically)

diff --git a/config/install/asset.type.batch.yml b/config/install/asset.type.batch.yml
new file mode 100644
index 0000000..458bae8
--- /dev/null
+++ b/config/install/asset.type.batch.yml
@@ -0,0 +1,12 @@
+langcode: en
+status: true
+dependencies:
+  enforced:
+    module:
+      - farm_agrikern
+id: batch
+label: Batch
+description: 'Batch Asset'
+name_pattern: 'Batch asset [asset:id]'
+workflow: asset_default
+new_revision: true
\ No newline at end of file
diff --git a/config/install/asset.type.chemical.yml b/config/install/asset.type.chemical.yml
new file mode 100644
index 0000000..53b7388
--- /dev/null
+++ b/config/install/asset.type.chemical.yml
@@ -0,0 +1,12 @@
+langcode: en
+status: true
+dependencies:
+  enforced:
+    module:
+      - farm_agrikern
+id: chemical
+label: Chemical
+description: 'Chemical Asset'
+name_pattern: 'Chemical asset [asset:id]'
+workflow: asset_default
+new_revision: true
\ No newline at end of file
diff --git a/config/install/asset.type.ingredient.yml b/config/install/asset.type.ingredient.yml
new file mode 100644
index 0000000..919eaad
--- /dev/null
+++ b/config/install/asset.type.ingredient.yml
@@ -0,0 +1,12 @@
+langcode: en
+status: true
+dependencies:
+  enforced:
+    module:
+      - farm_agrikern
+id: ingredient
+label: Ingredient
+description: 'Ingredient Asset'
+name_pattern: 'Ingredient asset [asset:id]'
+workflow: asset_default
+new_revision: true
\ No newline at end of file
diff --git a/config/install/asset.type.machine.yml b/config/install/asset.type.machine.yml
new file mode 100644
index 0000000..1c55c2f
--- /dev/null
+++ b/config/install/asset.type.machine.yml
@@ -0,0 +1,12 @@
+langcode: en
+status: true
+dependencies:
+  enforced:
+    module:
+      - farm_agrikern
+id: machine
+label: Machine
+description: 'Machine Asset'
+name_pattern: 'Machine asset [asset:id]'
+workflow: asset_default
+new_revision: true
\ No newline at end of file
diff --git a/config/install/asset.type.patch.yml b/config/install/asset.type.patch.yml
new file mode 100644
index 0000000..e007036
--- /dev/null
+++ b/config/install/asset.type.patch.yml
@@ -0,0 +1,12 @@
+langcode: en
+status: true
+dependencies:
+  enforced:
+    module:
+      - farm_agrikern
+id: patch
+label: Patch
+description: 'Patch Asset'
+name_pattern: 'Patch asset [asset:id]'
+workflow: asset_default
+new_revision: true
\ No newline at end of file
diff --git a/config/install/asset.type.substance.yml b/config/install/asset.type.substance.yml
new file mode 100644
index 0000000..d5bec1d
--- /dev/null
+++ b/config/install/asset.type.substance.yml
@@ -0,0 +1,12 @@
+langcode: en
+status: true
+dependencies:
+  enforced:
+    module:
+      - farm_agrikern
+id: substance
+label: Substance
+description: 'Substance Asset'
+name_pattern: 'Substance asset [asset:id]'
+workflow: asset_default
+new_revision: true
\ No newline at end of file
diff --git a/config/install/asset.type.usage_machine.yml b/config/install/asset.type.usage_machine.yml
new file mode 100644
index 0000000..c97cf7c
--- /dev/null
+++ b/config/install/asset.type.usage_machine.yml
@@ -0,0 +1,12 @@
+langcode: en
+status: true
+dependencies:
+  enforced:
+    module:
+      - farm_agrikern
+id: usage_machine
+label: MachineUsage
+description: 'Machine Usage Asset'
+name_pattern: 'MachineUsage asset [asset:id]'
+workflow: asset_default
+new_revision: true
\ No newline at end of file
diff --git a/config/install/asset.type.usage_substance.yml b/config/install/asset.type.usage_substance.yml
new file mode 100644
index 0000000..dbdc969
--- /dev/null
+++ b/config/install/asset.type.usage_substance.yml
@@ -0,0 +1,12 @@
+langcode: en
+status: true
+dependencies:
+  enforced:
+    module:
+      - farm_agrikern
+id: usage_substance
+label: SubstanceUsage
+description: 'Substance Usage Asset'
+name_pattern: 'SubstanceUsage asset [asset:id]'
+workflow: asset_default
+new_revision: true
\ No newline at end of file
diff --git a/config/install/log.type.field_work.yml b/config/install/log.type.field_work.yml
new file mode 100644
index 0000000..6b75d84
--- /dev/null
+++ b/config/install/log.type.field_work.yml
@@ -0,0 +1,12 @@
+langcode: en
+status: true
+dependencies:
+  enforced:
+    module:
+      - farm_agrikern
+id: field_work
+label: FieldWork
+description: 'Field work log'
+name_pattern: 'Field work log [log:id]'
+workflow: farm_log_workflow
+new_revision: true
diff --git a/farm_agrikern.info.yml b/farm_agrikern.info.yml
new file mode 100644
index 0000000..1d3e7f6
--- /dev/null
+++ b/farm_agrikern.info.yml
@@ -0,0 +1,12 @@
+name: AgriKern
+description: Customize the farmOS datamodel to fit a central european agriculture farm.
+type: module
+package: farmOS Contrib
+core_version_requirement: ^10
+dependencies:
+  - farm:farm_entity
+  - farm:asset
+  - farm:log
+  - farm_land
+  - farm_season
+  - fraction
\ No newline at end of file
diff --git a/src/Plugin/Asset/AssetType/Batch.php b/src/Plugin/Asset/AssetType/Batch.php
new file mode 100644
index 0000000..1a23084
--- /dev/null
+++ b/src/Plugin/Asset/AssetType/Batch.php
@@ -0,0 +1,43 @@
+<?php
+
+namespace Drupal\farm_agrikern\Plugin\Asset\AssetType;
+
+use Drupal\farm_entity\Plugin\Asset\AssetType\FarmAssetType;
+
+/**
+* Provides the batch asset type.
+*
+* @AssetType(
+*   id = "batch",
+*   label = @Translation("Batch"),
+* )
+*/
+class Batch extends FarmAssetType {
+    /**
+    * {@inheritdoc}
+    */
+    public function buildFieldDefinitions() {
+        $fields = parent::buildFieldDefinitions();
+        $field_info = [
+            'substance_field' => [
+                'type' => 'entity_reference',
+                'label' => $this->t('Substance'),
+                'description' => $this->t('What substance was added?'),
+                'target_type' => 'asset',
+                'target_bundle' => 'substance',
+                'multiple' => FALSE,
+                'required' => TRUE,
+            ],
+            'unit_price_field' => [
+                'type' => 'fraction',
+                'label' => $this->t('Unit price'),
+                'description' => $this->t('Price in Euro per unit of the substance. Price is positive if the batch was pruchased and is negative if the batch was produced.'),
+                'required' => TRUE,
+            ],
+        ];
+        foreach ($field_info as $name => $info) {
+            $fields[$name] = \Drupal::service('farm_field.factory')->bundleFieldDefinition($info);
+        }
+        return $fields;
+    }
+}
\ No newline at end of file
diff --git a/src/Plugin/Asset/AssetType/Chemical.php b/src/Plugin/Asset/AssetType/Chemical.php
new file mode 100644
index 0000000..dda418f
--- /dev/null
+++ b/src/Plugin/Asset/AssetType/Chemical.php
@@ -0,0 +1,23 @@
+<?php
+
+namespace Drupal\farm_agrikern\Plugin\Asset\AssetType;
+
+use Drupal\farm_entity\Plugin\Asset\AssetType\FarmAssetType;
+
+/**
+* Provides the chemical asset type.
+*
+* @AssetType(
+*   id = "chemical",
+*   label = @Translation("Chemical"),
+* )
+*/
+class Chemical extends FarmAssetType {
+    /**
+    * {@inheritdoc}
+    */
+    public function buildFieldDefinitions() {
+        $fields = parent::buildFieldDefinitions();
+        return $fields;
+    }
+}
\ No newline at end of file
diff --git a/src/Plugin/Asset/AssetType/Ingredient.php b/src/Plugin/Asset/AssetType/Ingredient.php
new file mode 100644
index 0000000..3606663
--- /dev/null
+++ b/src/Plugin/Asset/AssetType/Ingredient.php
@@ -0,0 +1,43 @@
+<?php
+
+namespace Drupal\farm_agrikern\Plugin\Asset\AssetType;
+
+use Drupal\farm_entity\Plugin\Asset\AssetType\FarmAssetType;
+
+/**
+* Provides the ingredient asset type.
+*
+* @AssetType(
+*   id = "ingredient",
+*   label = @Translation("Ingredient"),
+* )
+*/
+class Ingredient extends FarmAssetType {
+    /**
+    * {@inheritdoc}
+    */
+    public function buildFieldDefinitions() {
+        $fields = parent::buildFieldDefinitions();
+        $field_info = [
+            'chemical_field' => [
+                'type' => 'entity_reference',
+                'label' => $this->t('Chemical'),
+                'description' => $this->t('What chemical does the ingredient track?'),
+                'target_type' => 'asset',
+                'target_bundle' => 'chemical',
+                'multiple' => FALSE,
+                'required' => TRUE,
+            ],
+            'amount_field' => [
+                'type' => 'fraction',
+                'label' => $this->t('Amount'),
+                'description' => $this->t('How much of the chemical is in the ingredient in g/l'),
+                'required' => TRUE,
+            ],
+        ];
+        foreach ($field_info as $name => $info) {
+            $fields[$name] = \Drupal::service('farm_field.factory')->bundleFieldDefinition($info);
+        }
+        return $fields;
+    }
+}
\ No newline at end of file
diff --git a/src/Plugin/Asset/AssetType/Machine.php b/src/Plugin/Asset/AssetType/Machine.php
new file mode 100644
index 0000000..2ae1e18
--- /dev/null
+++ b/src/Plugin/Asset/AssetType/Machine.php
@@ -0,0 +1,44 @@
+<?php
+
+namespace Drupal\farm_agrikern\Plugin\Asset\AssetType;
+
+use Drupal\farm_entity\Plugin\Asset\AssetType\FarmAssetType;
+
+/**
+* Provides the machine asset type.
+*
+* @AssetType(
+*   id = "machine",
+*   label = @Translation("Machine"),
+* )
+*/
+class Machine extends FarmAssetType {
+    /**
+    * {@inheritdoc}
+    */
+    public function buildFieldDefinitions() {
+        $fields = parent::buildFieldDefinitions();
+        $field_info = [
+            'unit_price_field' => [
+                'type' => 'fraction',
+                'label' => $this->t('Unit price'),
+                'description' => $this->t('Price in Euro per unit of usage on the machine.'),
+                'required' => TRUE,
+            ],
+            'unit_field' => [
+                'type' => 'entity_reference',
+                'label' => $this->t('Unit'),
+                'description' => $this->t('What unit is used to track machine usage?'),
+                'target_type' => 'taxonomy_term',
+                'target_bundle' => 'unit',
+                'auto_create' => TRUE,
+                'multiple' => FALSE,
+                'required' => TRUE,
+            ],
+        ];
+        foreach ($field_info as $name => $info) {
+            $fields[$name] = \Drupal::service('farm_field.factory')->bundleFieldDefinition($info);
+        }
+        return $fields;
+    }
+}
\ No newline at end of file
diff --git a/src/Plugin/Asset/AssetType/MachineUsage.php b/src/Plugin/Asset/AssetType/MachineUsage.php
new file mode 100644
index 0000000..cd04c27
--- /dev/null
+++ b/src/Plugin/Asset/AssetType/MachineUsage.php
@@ -0,0 +1,37 @@
+<?php
+
+namespace Drupal\farm_agrikern\Plugin\Asset\AssetType;
+
+use Drupal\farm_entity\Plugin\Asset\AssetType\FarmAssetType;
+
+/**
+* Provides the machineusage asset type.
+*
+* @AssetType(
+*   id = "usage_machine",
+*   label = @Translation("Machine Usage"),
+* )
+*/
+class MachineUsage extends Usage {
+    /**
+    * {@inheritdoc}
+    */
+    public function buildFieldDefinitions() {
+        $fields = parent::buildFieldDefinitions();
+        $field_info = [
+            'machine_field' => [
+                'type' => 'entity_reference',
+                'label' => $this->t('Machine'),
+                'description' => $this->t('What machine was used?'),
+                'target_type' => 'asset',
+                'target_bundle' => 'machine',
+                'multiple' => FALSE,
+                'required' => TRUE,
+            ],
+        ];
+        foreach ($field_info as $name => $info) {
+            $fields[$name] = \Drupal::service('farm_field.factory')->bundleFieldDefinition($info);
+        }
+        return $fields;
+    }
+}
\ No newline at end of file
diff --git a/src/Plugin/Asset/AssetType/Patch.php b/src/Plugin/Asset/AssetType/Patch.php
new file mode 100644
index 0000000..087ab1b
--- /dev/null
+++ b/src/Plugin/Asset/AssetType/Patch.php
@@ -0,0 +1,66 @@
+<?php
+
+namespace Drupal\farm_agrikern\Plugin\Asset\AssetType;
+
+use Drupal\farm_entity\Plugin\Asset\AssetType\FarmAssetType;
+use phpDocumentor\Reflection\PseudoTypes\False_;
+
+/**
+* Provides the patch asset type.
+*
+* @AssetType(
+*   id = "patch",
+*   label = @Translation("Patch"),
+* )
+*/
+class Patch extends FarmAssetType {
+    /**
+    * {@inheritdoc}
+    */
+    public function buildFieldDefinitions() {
+        $fields = parent::buildFieldDefinitions();
+        $field_info = [
+            'land_field' => [
+                'type' => 'entity_reference',
+                'label' => $this->t('Land'),
+                'description' => $this->t("At what Land asset is the patch located?"),
+                'target_type' => 'asset',
+                'target_bundle' => 'land',
+                'required' => TRUE,
+                'multiple' => FALSE,
+            ],
+            'crop_field' => [
+                'type' => 'entity_reference',
+                'label' => $this->t('Crop/variety'),
+                'description' => $this->t("Enter this patch asset's crop/variety."),
+                'target_type' => 'taxonomy_term',
+                'target_bundle' => 'crop',
+                'auto_create' => TRUE,
+                'required' => TRUE,
+                'multiple' => FALSE,
+            ],
+            'season_field' => [
+                'type' => 'entity_reference',
+                'label' => $this->t('Season'),
+                'description' => $this->t('Assign this to a season for easier searching later.'),
+                'target_type' => 'taxonomy_term',
+                'target_bundle' => 'season',
+                'auto_create' => TRUE,
+                'multiple' => FALSE,
+                'required' => TRUE,
+            ],
+            'area_field' => [
+                'type' => 'fraction',
+                'label' => $this->t('Area'),
+                'description' => $this->t('What is the area of the patch in hectares (ha)?'),
+                'required' => TRUE,
+            ],
+        ];
+
+        foreach ($field_info as $name => $info) {
+            $fields[$name] = \Drupal::service('farm_field.factory')->bundleFieldDefinition($info);
+        }
+
+        return $fields;
+    }
+}
\ No newline at end of file
diff --git a/src/Plugin/Asset/AssetType/Substance.php b/src/Plugin/Asset/AssetType/Substance.php
new file mode 100644
index 0000000..ae5b235
--- /dev/null
+++ b/src/Plugin/Asset/AssetType/Substance.php
@@ -0,0 +1,47 @@
+<?php
+
+namespace Drupal\farm_agrikern\Plugin\Asset\AssetType;
+
+use Drupal\farm_entity\Plugin\Asset\AssetType\FarmAssetType;
+
+/**
+* Provides the substance asset type.
+*
+* @AssetType(
+*   id = "substance",
+*   label = @Translation("Substance"),
+* )
+*/
+class Substance extends FarmAssetType {
+    /**
+    * {@inheritdoc}
+    */
+    public function buildFieldDefinitions() {
+        $fields = parent::buildFieldDefinitions();
+        $options = [
+            'type' => 'entity_reference',
+            'label' => $this->t('Ingredients'),
+            'description' => $this->t('What ingredients are in the substance?'),
+            'target_type' => 'asset',
+            'target_bundle' => 'ingredient',
+            'multiple' => TRUE,
+            'required' => FALSE,
+        ];
+        $fields['ingredients_field'] = \Drupal::service('farm_field.factory')->bundleFieldDefinition($options)
+            ->addConstraint('AgriKernSubstanceIngredients');
+
+        $options = [
+            'type' => 'entity_reference',
+            'label' => $this->t('Unit'),
+            'description' => $this->t('What unit is the substance measured in?'),
+            'target_type' => 'taxonomy_term',
+            'target_bundle' => 'unit',
+            'auto_create' => TRUE,
+            'multiple' => FALSE,
+            'required' => TRUE,
+        ];
+        $fields['unit_field'] = \Drupal::service('farm_field.factory')->bundleFieldDefinition($options);
+
+        return $fields;
+    }
+}
\ No newline at end of file
diff --git a/src/Plugin/Asset/AssetType/SubstanceUsage.php b/src/Plugin/Asset/AssetType/SubstanceUsage.php
new file mode 100644
index 0000000..8899bf0
--- /dev/null
+++ b/src/Plugin/Asset/AssetType/SubstanceUsage.php
@@ -0,0 +1,37 @@
+<?php
+
+namespace Drupal\farm_agrikern\Plugin\Asset\AssetType;
+
+use Drupal\farm_entity\Plugin\Asset\AssetType\FarmAssetType;
+
+/**
+* Provides the usage_substance asset type.
+*
+* @AssetType(
+*   id = "usage_substance",
+*   label = @Translation("Substance Usage"),
+* )
+*/
+class SubstanceUsage extends Usage {
+    /**
+    * {@inheritdoc}
+    */
+    public function buildFieldDefinitions() {
+        $fields = parent::buildFieldDefinitions();
+        $field_info = [
+            'batch_field' => [
+                'type' => 'entity_reference',
+                'label' => $this->t('Batch'),
+                'description' => $this->t('What batch of the substance was used?'),
+                'target_type' => 'asset',
+                'target_bundle' => 'batch',
+                'multiple' => FALSE,
+                'required' => TRUE,
+            ],
+        ];
+        foreach ($field_info as $name => $info) {
+            $fields[$name] = \Drupal::service('farm_field.factory')->bundleFieldDefinition($info);
+        }
+        return $fields;
+    }
+}
\ No newline at end of file
diff --git a/src/Plugin/Asset/AssetType/Usage.php b/src/Plugin/Asset/AssetType/Usage.php
new file mode 100644
index 0000000..e05f2f5
--- /dev/null
+++ b/src/Plugin/Asset/AssetType/Usage.php
@@ -0,0 +1,36 @@
+<?php
+
+namespace Drupal\farm_agrikern\Plugin\Asset\AssetType;
+
+use Drupal\farm_entity\Plugin\Asset\AssetType\FarmAssetType;
+
+/**
+ * Provides the usage asset type.
+*/
+class Usage extends FarmAssetType {
+    /**
+    * {@inheritdoc}
+    */
+    public function buildFieldDefinitions() {
+        $fields = parent::buildFieldDefinitions();
+        $field_info = [
+            'amount_field' => [
+                'type' => 'fraction',
+                'label' => $this->t('Amount'),
+                'description' => $this->t('How much was the quantiy used in the quantities unit of measurement?'),
+                'required' => TRUE,
+            ],
+            // This field is automatically filled using LogEventSubscriber
+            'cost_field' => [
+                'type' => 'fraction',
+                'label' => $this->t('Cost'),
+                'description' => $this->t('THIS FIELD IS GENERATED AUTOMATICALLY AND SHOULD NOT BE ADJUSTED!'),
+                'required' => FALSE,
+            ],
+        ];
+        foreach ($field_info as $name => $info) {
+            $fields[$name] = \Drupal::service('farm_field.factory')->bundleFieldDefinition($info);
+        }
+        return $fields;
+    }
+}
\ No newline at end of file
diff --git a/src/Plugin/Log/LogType/FieldWork.php b/src/Plugin/Log/LogType/FieldWork.php
new file mode 100644
index 0000000..e065d02
--- /dev/null
+++ b/src/Plugin/Log/LogType/FieldWork.php
@@ -0,0 +1,53 @@
+<?php
+
+namespace Drupal\farm_agrikern\Plugin\Log\LogType;
+
+use Drupal\farm_entity\Plugin\Log\LogType\FarmLogType;
+
+/**
+ * Provides the field work log type.
+ *
+ * @LogType(
+ *   id = "field_work",
+ *   label = @Translation("Field work"),
+ * )
+ */
+class FieldWork extends FarmLogType {
+    /**
+    * {@inheritdoc}
+    */
+    public function buildFieldDefinitions() {
+        $fields = parent::buildFieldDefinitions();
+
+        $field_info = [
+            'patch_field' => [
+                'type' => 'entity_reference',
+                'label' => $this->t('Patch'),
+                'description' => $this->t("What patch was the work done on?"),
+                'target_type' => 'asset',
+                'target_bundle' => 'patch',
+                'required' => TRUE,
+                'multiple' => FALSE,
+            ],
+        ];
+
+        foreach ($field_info as $name => $info) {
+            $fields[$name] = \Drupal::service('farm_field.factory')->bundleFieldDefinition($info);
+        }
+        
+        $options = [
+            'type' => 'entity_reference',
+            'label' => $this->t('Machine usages'),
+            'description' => $this->t('What machines were used and how much?'),
+            'target_type' => 'asset',
+            'target_bundle' => 'usage_machine',
+            'multiple' => TRUE,
+            'required' => TRUE,
+            
+        ];
+        $fields['machine_usages_field'] = \Drupal::service('farm_field.factory')->bundleFieldDefinition($options)
+            ->addConstraint('AgriKernFieldWorkMachines');
+        
+        return $fields;
+    } 
+}
diff --git a/src/Plugin/Validation/Constraint/FieldWorkMachinesConstraint.php b/src/Plugin/Validation/Constraint/FieldWorkMachinesConstraint.php
new file mode 100644
index 0000000..303c7e1
--- /dev/null
+++ b/src/Plugin/Validation/Constraint/FieldWorkMachinesConstraint.php
@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\farm_agrikern\Plugin\Validation\Constraint;
+
+use Symfony\Component\Validator\Constraint;
+
+/**
+ * Provides a FieldWorkMachines constraint.
+ *
+ * @Constraint(
+ *   id = "AgriKernFieldWorkMachines",
+ *   label = @Translation("FieldWorkMachines", context = "Validation"),
+ * )
+ *
+ * @DCG
+ * To apply this constraint on third party entity types implement either
+ * hook_entity_base_field_info_alter() or hook_entity_bundle_field_info_alter().
+ *
+ * @see https://www.drupal.org/node/2015723
+ */
+final class FieldWorkMachinesConstraint extends Constraint {
+
+    public string $notUnique = 'Some machines were entered twice.';
+
+}
diff --git a/src/Plugin/Validation/Constraint/FieldWorkMachinesConstraintValidator.php b/src/Plugin/Validation/Constraint/FieldWorkMachinesConstraintValidator.php
new file mode 100644
index 0000000..b64a509
--- /dev/null
+++ b/src/Plugin/Validation/Constraint/FieldWorkMachinesConstraintValidator.php
@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\farm_agrikern\Plugin\Validation\Constraint;
+
+use Drupal\Core\Field\FieldItemListInterface;
+use Symfony\Component\Validator\Constraint;
+use Symfony\Component\Validator\ConstraintValidator;
+
+/**
+* Validates the FieldWorkMachines constraint.
+*/
+final class FieldWorkMachinesConstraintValidator extends ConstraintValidator {
+    
+    /**
+    * {@inheritdoc}
+    */
+    public function validate(mixed $items, Constraint $constraint): void {
+        if (!$items instanceof FieldItemListInterface) {
+            throw new \InvalidArgumentException(
+                sprintf('The validated value must be instance of \Drupal\Core\Field\FieldItemListInterface, %s was given.', get_debug_type($items))
+            );
+        }
+        $seen_machines = [];
+        foreach ($items as $delta => $item) {
+            $machine_usage = \Drupal::entityTypeManager()->getStorage('asset')->load($item->target_id);
+            $machine_id = $machine_usage->machine_field->target_id;
+            if (isset($seen_machines[$machine_id])) {
+                $this->context->buildViolation($constraint->notUnique)
+                ->atPath($delta)
+                ->addViolation();
+            }
+            $seen_machines[$machine_id] = true;
+        }
+    }
+    
+}
diff --git a/src/Plugin/Validation/Constraint/SubstanceIngredientsConstraint.php b/src/Plugin/Validation/Constraint/SubstanceIngredientsConstraint.php
new file mode 100644
index 0000000..873c2e1
--- /dev/null
+++ b/src/Plugin/Validation/Constraint/SubstanceIngredientsConstraint.php
@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\farm_agrikern\Plugin\Validation\Constraint;
+
+use Symfony\Component\Validator\Constraint;
+
+/**
+* Provides a SubstanceIngredients constraint.
+*
+* @Constraint(
+*   id = "AgriKernSubstanceIngredients",
+*   label = @Translation("SubstanceIngredients", context = "Validation"),
+* )
+*
+* @DCG
+* To apply this constraint on third party entity types implement either
+* hook_entity_base_field_info_alter() or hook_entity_bundle_field_info_alter().
+*
+* @see https://www.drupal.org/node/2015723
+*/
+final class SubstanceIngredientsConstraint extends Constraint {
+    
+    public string $notUnique = 'Some chemicals were entered twice.';
+    
+}
diff --git a/src/Plugin/Validation/Constraint/SubstanceIngredientsConstraintValidator.php b/src/Plugin/Validation/Constraint/SubstanceIngredientsConstraintValidator.php
new file mode 100644
index 0000000..3426aaf
--- /dev/null
+++ b/src/Plugin/Validation/Constraint/SubstanceIngredientsConstraintValidator.php
@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\farm_agrikern\Plugin\Validation\Constraint;
+
+use Drupal\Core\Field\FieldItemListInterface;
+use Symfony\Component\Validator\Constraint;
+use Symfony\Component\Validator\ConstraintValidator;
+
+/**
+* Validates the SubstanceIngredients constraint.
+* Ensures there are no duplicate Chemicals in the Ingredients of a Substance.
+*/
+final class SubstanceIngredientsConstraintValidator extends ConstraintValidator {
+    /**
+    * {@inheritdoc}
+    */
+    public function validate(mixed $items, Constraint $constraint): void {
+        if (!$items instanceof FieldItemListInterface) {
+            throw new \InvalidArgumentException(
+                sprintf('The validated value must be instance of \Drupal\Core\Field\FieldItemListInterface, %s was given.', get_debug_type($items))
+            );
+        }
+        $seen_quantities = [];
+        foreach ($items as $delta => $item) {
+            $ingredient = \Drupal::entityTypeManager()->getStorage('asset')->load($item->target_id);
+            $chemical_id = $ingredient->chemical_field->target_id;
+            if (isset($seen_quantities[$chemical_id])) {
+                $this->context->buildViolation($constraint->notUnique)
+                ->atPath($delta)
+                ->addViolation();
+            }
+            $seen_quantities[$chemical_id] = true;
+        }
+    }
+}