Agricultural Production / Raw Materials
  ↓
Primary Processing (cleaning, sorting, initial processing)
  ↓
Secondary Processing / Manufacturing
  ↓
Co-Packers / Contract Manufacturers
  ↓
Distribution Centers (multi-temperature)
  ↓
Retail Distribution
  ├─ Grocery Retailers
  ├─ Foodservice (restaurants, institutions)
  ├─ Convenience Stores
  └─ Direct-to-Consumer
  ↓
Consumers

import pandas as pd
import numpy as np
from datetime import datetime, timedelta

class ShelfLifeManager:
    """
    Manage shelf life and freshness for perishable products
    """

    def __init__(self, products_df):
        """
        Initialize shelf life manager

        Parameters:
        - products_df: product master with shelf life parameters
        """
        self.products = products_df

    def calculate_remaining_shelf_life(self, inventory_df, current_date):
        """
        Calculate remaining shelf life for inventory

        Parameters:
        - inventory_df: current inventory with production/expiry dates
        - current_date: as-of date for calculation

        Returns:
        - inventory with remaining shelf life metrics
        """

        inventory_with_rsl = inventory_df.copy()

        for idx, item in inventory_with_rsl.iterrows():
            product_id = item['product_id']
            production_date = item.get('production_date')
            expiry_date = item.get('expiry_date')

            # Get product shelf life
            product_info = self.products[
                self.products['product_id'] == product_id
            ].iloc[0]

            total_shelf_life_days = product_info['shelf_life_days']

            # Calculate remaining shelf life
            if expiry_date:
                remaining_days = (expiry_date - current_date).days
            elif production_date:
                age_days = (current_date - production_date).days
                remaining_days = total_shelf_life_days - age_days
            else:
                remaining_days = None

            # Calculate as percentage
            remaining_pct = (remaining_days / total_shelf_life_days * 100
                           if remaining_days and total_shelf_life_days > 0 else None)

            inventory_with_rsl.loc[idx, 'remaining_shelf_life_days'] = remaining_days
            inventory_with_rsl.loc[idx, 'remaining_shelf_life_pct'] = remaining_pct

            # Classify freshness
            inventory_with_rsl.loc[idx, 'freshness_category'] = self._classify_freshness(
                remaining_pct
            )

        return inventory_with_rsl

    def _classify_freshness(self, remaining_pct):
        """Classify product freshness"""

        if remaining_pct is None:
            return 'unknown'
        elif remaining_pct >= 67:
            return 'fresh'
        elif remaining_pct >= 33:
            return 'medium'
        elif remaining_pct >= 0:
            return 'near_expiry'
        else:
            return 'expired'

    def optimize_fefo_picking(self, order, available_inventory):
        """
        Optimize picking sequence using FEFO logic

        Parameters:
        - order: customer order with required quantities
        - available_inventory: inventory with expiry dates

        Returns:
        - picking instructions prioritizing oldest stock
        """

        picking_plan = []

        for order_line in order:
            product_id = order_line['product_id']
            quantity_needed = order_line['quantity']

            # Get available inventory for this product, sorted by expiry
            product_inventory = available_inventory[
                available_inventory['product_id'] == product_id
            ].sort_values('expiry_date')

            quantity_allocated = 0

            for idx, inv_lot in product_inventory.iterrows():
                if quantity_allocated >= quantity_needed:
                    break

                # How much from this lot?
                available_qty = inv_lot['quantity_available']
                pick_qty = min(available_qty, quantity_needed - quantity_allocated)

                picking_plan.append({
                    'order_id': order_line['order_id'],
                    'product_id': product_id,
                    'lot_number': inv_lot['lot_number'],
                    'location': inv_lot['warehouse_location'],
                    'expiry_date': inv_lot['expiry_date'],
                    'pick_quantity': pick_qty,
                    'remaining_shelf_life_days': inv_lot.get('remaining_shelf_life_days'),
                    'pick_priority': 'FEFO'
                })

                quantity_allocated += pick_qty

            # Check if order is complete
            if quantity_allocated < quantity_needed:
                picking_plan.append({
                    'order_id': order_line['order_id'],
                    'product_id': product_id,
                    'status': 'insufficient_inventory',
                    'shortfall': quantity_needed - quantity_allocated
                })

        return pd.DataFrame(picking_plan)

    def identify_slow_moving_inventory(self, inventory_df, sales_velocity_df,
                                      near_expiry_threshold_days=30):
        """
        Identify at-risk inventory (slow moving + near expiry)

        Parameters:
        - inventory_df: current inventory with dates
        - sales_velocity_df: historical sales rates
        - near_expiry_threshold_days: days to expiry threshold

        Returns:
        - at-risk inventory with recommended actions
        """

        at_risk_inventory = []

        for idx, inv in inventory_df.iterrows():
            product_id = inv['product_id']
            quantity = inv['quantity_available']
            remaining_shelf_life = inv.get('remaining_shelf_life_days', 999)

            # Get sales velocity
            velocity = sales_velocity_df[
                sales_velocity_df['product_id'] == product_id
            ]

            if len(velocity) > 0:
                avg_daily_sales = velocity['avg_daily_units'].iloc[0]
                days_of_supply = quantity / avg_daily_sales if avg_daily_sales > 0 else 999
            else:
                days_of_supply = 999

            # Identify at-risk
            if remaining_shelf_life < near_expiry_threshold_days:
                risk_level = 'high' if days_of_supply > remaining_shelf_life else 'medium'

                # Recommend action
                if days_of_supply > remaining_shelf_life * 1.5:
                    action = 'markdown_promotion_immediate'
                elif days_of_supply > remaining_shelf_life:
                    action = 'redistribute_to_high_velocity_locations'
                else:
                    action = 'monitor_daily'

                at_risk_inventory.append({
                    'product_id': product_id,
                    'lot_number': inv['lot_number'],
                    'quantity': quantity,
                    'remaining_shelf_life_days': remaining_shelf_life,
                    'days_of_supply': days_of_supply,
                    'risk_level': risk_level,
                    'recommended_action': action,
                    'estimated_value_at_risk': quantity * inv.get('unit_cost', 0)
                })

        return pd.DataFrame(at_risk_inventory)

    def calculate_minimum_shelf_life_delivery(self, product_id, channel):
        """
        Calculate minimum remaining shelf life at delivery

        Parameters:
        - product_id: product identifier
        - channel: delivery channel (retail, foodservice, export)

        Returns:
        - minimum shelf life requirements
        """

        product_info = self.products[
            self.products['product_id'] == product_id
        ].iloc[0]

        total_shelf_life = product_info['shelf_life_days']

        # Industry standards by channel
        if channel == 'retail':
            # Retail typically requires 67-80% remaining shelf life
            min_rsl_pct = 0.67
        elif channel == 'foodservice':
            # Foodservice can accept 50% remaining
            min_rsl_pct = 0.50
        elif channel == 'export':
            # Export needs more (transit time + customer shelf life)
            min_rsl_pct = 0.80
        else:
            min_rsl_pct = 0.67

        min_rsl_days = int(total_shelf_life * min_rsl_pct)

        return {
            'product_id': product_id,
            'channel': channel,
            'total_shelf_life_days': total_shelf_life,
            'min_rsl_pct': min_rsl_pct * 100,
            'min_rsl_days': min_rsl_days,
            'reject_if_less_than_days': min_rsl_days
        }

---

class FoodSafetyManager:
    """
    Manage food safety and traceability requirements
    """

    def __init__(self):
        self.critical_control_points = []

    def define_haccp_plan(self, product_category):
        """
        Define HACCP critical control points for product category

        Parameters:
        - product_category: type of food product

        Returns:
        - HACCP plan with CCPs
        """

        haccp_plan = {
            'product_category': product_category,
            'hazard_analysis': [],
            'critical_control_points': []
        }

        # Define CCPs based on product type
        if product_category in ['fresh_produce', 'salad', 'cut_fruit']:
            haccp_plan['critical_control_points'] = [
                {
                    'ccp_id': 'CCP-1',
                    'step': 'receiving',
                    'hazard': 'biological_contamination',
                    'critical_limit': 'temperature_<=_41F',
                    'monitoring': 'check_temp_every_lot',
                    'corrective_action': 'reject_if_out_of_range'
                },
                {
                    'ccp_id': 'CCP-2',
                    'step': 'washing',
                    'hazard': 'pathogen_survival',
                    'critical_limit': 'sanitizer_concentration_50-200ppm',
                    'monitoring': 'test_every_2_hours',
                    'corrective_action': 'adjust_concentration'
                },
                {
                    'ccp_id': 'CCP-3',
                    'step': 'cold_storage',
                    'hazard': 'pathogen_growth',
                    'critical_limit': 'temperature_<=_41F',
                    'monitoring': 'continuous_monitoring',
                    'corrective_action': 'investigate_temperature_excursion'
                }
            ]

        elif product_category in ['cooked_meat', 'ready_to_eat']:
            haccp_plan['critical_control_points'] = [
                {
                    'ccp_id': 'CCP-1',
                    'step': 'cooking',
                    'hazard': 'pathogen_survival',
                    'critical_limit': 'internal_temp_>=_165F',
                    'monitoring': 'check_temp_every_batch',
                    'corrective_action': 'continue_cooking_until_temp_reached'
                },
                {
                    'ccp_id': 'CCP-2',
                    'step': 'cooling',
                    'hazard': 'pathogen_growth',
                    'critical_limit': 'cool_to_41F_within_4hours',
                    'monitoring': 'time_temperature_logs',
                    'corrective_action': 'discard_if_cooling_too_slow'
                },
                {
                    'ccp_id': 'CCP-3',
                    'step': 'packaging',
                    'hazard': 'recontamination',
                    'critical_limit': 'environmental_monitoring_negative',
                    'monitoring': 'swab_testing_weekly',
                    'corrective_action': 'sanitize_and_retest'
                }
            ]

        elif product_category in ['juice', 'beverage']:
            haccp_plan['critical_control_points'] = [
                {
                    'ccp_id': 'CCP-1',
                    'step': 'pasteurization',
                    'hazard': 'pathogen_survival',
                    'critical_limit': 'temp_time_combination_per_FDA',
                    'monitoring': 'continuous_chart_recorder',
                    'corrective_action': 'repasteurize_or_discard'
                },
                {
                    'ccp_id': 'CCP-2',
                    'step': 'hot_fill',
                    'hazard': 'post_pasteurization_contamination',
                    'critical_limit': 'fill_temp_>=_185F',
                    'monitoring': 'check_every_hour',
                    'corrective_action': 'hold_and_reheat'
                }
            ]

        return haccp_plan

    def implement_traceability(self, product_lot, supply_chain_events):
        """
        Implement one-up/one-down traceability

        Parameters:
        - product_lot: finished product lot information
        - supply_chain_events: upstream and downstream transactions

        Returns:
        - complete traceability record
        """

        traceability_record = {
            'finished_product': {
                'lot_number': product_lot['lot_number'],
                'product_id': product_lot['product_id'],
                'production_date': product_lot['production_date'],
                'quantity': product_lot['quantity']
            },
            'one_up': [],  # Ingredients and packaging received
            'one_down': []  # Customers/locations shipped to
        }

        # One-up traceability (ingredients)
        for ingredient in product_lot.get('ingredients', []):
            traceability_record['one_up'].append({
                'supplier': ingredient['supplier'],
                'ingredient_id': ingredient['ingredient_id'],
                'lot_number': ingredient['lot_number'],
                'receive_date': ingredient['receive_date'],
                'quantity_used': ingredient['quantity_used']
            })

        # One-down traceability (shipments)
        lot_shipments = [
            e for e in supply_chain_events
            if e['type'] == 'shipment' and e['lot_number'] == product_lot['lot_number']
        ]

        for shipment in lot_shipments:
            traceability_record['one_down'].append({
                'customer': shipment['customer'],
                'ship_date': shipment['ship_date'],
                'quantity_shipped': shipment['quantity'],
                'destination': shipment['destination']
            })

        return traceability_record

    def execute_mock_recall(self, recalled_lot, traceability_data):
        """
        Execute mock recall to test traceability system

        Parameters:
        - recalled_lot: lot number being recalled
        - traceability_data: complete traceability records

        Returns:
        - recall execution report
        """

        start_time = datetime.now()

        # Find lot traceability
        lot_trace = traceability_data.get(recalled_lot, {})

        if not lot_trace:
            return {
                'success': False,
                'error': 'lot_not_found_in_traceability_system'
            }

        # Identify affected ingredients (one-up)
        affected_ingredients = lot_trace.get('one_up', [])

        # Identify affected customers (one-down)
        affected_customers = lot_trace.get('one_down', [])

        # Calculate execution time
        end_time = datetime.now()
        execution_time_minutes = (end_time - start_time).total_seconds() / 60

        # Total quantity to recall
        total_quantity = sum(c['quantity_shipped'] for c in affected_customers)

        recall_report = {
            'recalled_lot': recalled_lot,
            'execution_time_minutes': execution_time_minutes,
            'meets_target_4hours': execution_time_minutes <= 240,  # 4 hours
            'affected_ingredients': len(affected_ingredients),
            'affected_customers': len(affected_customers),
            'total_quantity_to_recall': total_quantity,
            'customer_list': [c['customer'] for c in affected_customers],
            'notification_method': 'email_phone_fax',
            'next_steps': [
                'issue_recall_notification_to_customers',
                'coordinate_product_return_or_destruction',
                'investigate_root_cause',
                'implement_corrective_actions',
                'notify_FDA_if_required'
            ]
        }

        return recall_report

    def manage_allergen_control(self, product_id, ingredients, facility_allergens):
        """
        Manage allergen controls and labeling

        Parameters:
        - product_id: product being manufactured
        - ingredients: list of ingredients with allergens
        - facility_allergens: allergens present in facility

        Returns:
        - allergen control plan
        """

        # Major allergens (FDA Big 8 + sesame)
        major_allergens = [
            'milk', 'eggs', 'fish', 'shellfish', 'tree_nuts',
            'peanuts', 'wheat', 'soybeans', 'sesame'
        ]

        # Identify allergens in product
        product_allergens = set()

        for ingredient in ingredients:
            if 'allergens' in ingredient:
                product_allergens.update(ingredient['allergens'])

        # Check for cross-contact risk
        cross_contact_risk = []

        for allergen in facility_allergens:
            if allergen not in product_allergens:
                # Allergen in facility but not in product = cross-contact risk
                cross_contact_risk.append(allergen)

        # Determine controls needed
        controls = []

        if len(cross_contact_risk) > 0:
            controls.extend([
                'dedicated_production_line_or_thorough_cleaning',
                'allergen_cleaning_verification_testing',
                'production_scheduling_to_minimize_risk',
                'may_contain_labeling_if_risk_cannot_be_eliminated'
            ])

        allergen_plan = {
            'product_id': product_id,
            'contains_allergens': list(product_allergens),
            'cross_contact_risks': cross_contact_risk,
            'required_label_statement': self._generate_allergen_statement(
                product_allergens
            ),
            'controls_required': controls,
            'requires_allergen_clean': len(cross_contact_risk) > 0
        }

        return allergen_plan

    def _generate_allergen_statement(self, allergens):
        """Generate allergen labeling statement"""

        if len(allergens) == 0:
            return None

        allergen_list = ', '.join(sorted(allergens))

        return f"Contains: {allergen_list}"

---

from pulp import *

class FoodDistributionOptimizer:
    """
    Optimize multi-temperature food distribution network
    """

    def __init__(self, facilities, customers, products):
        self.facilities = facilities
        self.customers = customers
        self.products = products

    def optimize_dc_network(self):
        """
        Optimize distribution center network for multi-temperature products

        Considers:
        - Ambient, refrigerated, frozen storage needs
        - Transportation costs and modes
        - Service level requirements (freshness)
        - Facility costs

        Returns:
        - optimal network configuration
        """

        prob = LpProblem("Food_Distribution_Network", LpMinimize)

        # Decision variables: assign customer to DC
        x = {}

        for facility in self.facilities:
            for customer in self.customers:
                x[facility['id'], customer['id']] = LpVariable(
                    f"Assign_{facility['id']}_{customer['id']}",
                    cat='Binary'
                )

        # Use facility or not
        y = {}
        for facility in self.facilities:
            y[facility['id']] = LpVariable(f"Use_{facility['id']}", cat='Binary')

        # Objective: minimize total cost
        # Fixed costs + transportation costs

        fixed_costs = lpSum([
            facility['fixed_cost_annual'] * y[facility['id']]
            for facility in self.facilities
        ])

        transport_costs = lpSum([
            facility['transport_cost_per_mile'] *
            self._distance(facility['location'], customer['location']) *
            customer['annual_volume_cases'] *
            x[facility['id'], customer['id']]
            for facility in self.facilities
            for customer in self.customers
        ])

        prob += fixed_costs + transport_costs

        # Constraints

        # Each customer assigned to exactly one DC
        for customer in self.customers:
            prob += lpSum([
                x[facility['id'], customer['id']]
                for facility in self.facilities
            ]) == 1

        # Can only assign to open DCs
        for facility in self.facilities:
            for customer in self.customers:
                prob += x[facility['id'], customer['id']] <= y[facility['id']]

        # DC capacity constraints (by temperature zone)
        for facility in self.facilities:
            # Ambient capacity
            ambient_volume = lpSum([
                customer['annual_volume_cases'] *
                self._ambient_pct(customer['product_mix']) *
                x[facility['id'], customer['id']]
                for customer in self.customers
            ])
            prob += ambient_volume <= facility['capacity_ambient_cases']

            # Refrigerated capacity
            refrigerated_volume = lpSum([
                customer['annual_volume_cases'] *
                self._refrigerated_pct(customer['product_mix']) *
                x[facility['id'], customer['id']]
                for customer in self.customers
            ])
            prob += refrigerated_volume <= facility['capacity_refrigerated_cases']

            # Frozen capacity
            frozen_volume = lpSum([
                customer['annual_volume_cases'] *
                self._frozen_pct(customer['product_mix']) *
                x[facility['id'], customer['id']]
                for customer in self.customers
            ])
            prob += frozen_volume <= facility['capacity_frozen_cases']

        # Service level constraint: max distance for fresh products
        for facility in self.facilities:
            for customer in self.customers:
                if customer.get('requires_fresh_daily_delivery'):
                    # Fresh products need close proximity
                    distance = self._distance(facility['location'], customer['location'])
                    prob += distance * x[facility['id'], customer['id']] <= 150  # miles

        # Solve
        prob.solve(PULP_CBC_CMD(msg=0))

        # Extract solution
        network_design = {
            'total_cost_annual': value(prob.objective),
            'facilities_used': [],
            'customer_assignments': []
        }

        for facility in self.facilities:
            if y[facility['id']].varValue > 0.5:
                network_design['facilities_used'].append(facility['id'])

        for facility in self.facilities:
            for customer in self.customers:
                if x[facility['id'], customer['id']].varValue > 0.5:
                    network_design['customer_assignments'].append({
                        'customer': customer['id'],
                        'assigned_dc': facility['id'],
                        'distance_miles': self._distance(
                            facility['location'], customer['location']
                        )
                    })

        return network_design

    def _distance(self, loc1, loc2):
        """Calculate distance between two locations (simplified)"""
        # Simplified Euclidean distance
        return np.sqrt((loc1[0] - loc2[0])**2 + (loc1[1] - loc2[1])**2)

    def _ambient_pct(self, product_mix):
        """Percentage of ambient products"""
        return product_mix.get('ambient', 0.4)

    def _refrigerated_pct(self, product_mix):
        """Percentage of refrigerated products"""
        return product_mix.get('refrigerated', 0.4)

    def _frozen_pct(self, product_mix):
        """Percentage of frozen products"""
        return product_mix.get('frozen', 0.2)