[
  {
    "toc_id": "van_diesel",
    "name": "Diesel Van",
    "category": "road",
    "vehicle_type": "van",
    "fuel_type": "diesel",
    "emission_factor": 0.000396,
    "capacity": "< 3.5 ton"
  },
  {
    "toc_id": "van_electric",
    "name": "Electric Van",
    "category": "road",
    "vehicle_type": "van",
    "fuel_type": "electric",
    "emission_factor": 0.000098,
    "capacity": "< 3.5 ton"
  },
  {
    "toc_id": "truck_diesel",
    "name": "Diesel Rigid Truck",
    "category": "road",
    "vehicle_type": "truck",
    "fuel_type": "diesel",
    "emission_factor": 0.000512,
    "capacity": "3.5 - 7.5 ton"
  },
  {
    "toc_id": "truck_articulated",
    "name": "Articulated Truck",
    "category": "road",
    "vehicle_type": "truck",
    "fuel_type": "diesel",
    "emission_factor": 0.000673,
    "capacity": "> 33 ton"
  },
  {
    "toc_id": "rail_freight",
    "name": "Freight Train",
    "category": "rail",
    "vehicle_type": "train",
    "fuel_type": "electric",
    "emission_factor": 0.000025,
    "capacity": "High capacity"
  },
  {
    "toc_id": "air_freight",
    "name": "Cargo Airplane",
    "category": "air",
    "vehicle_type": "airplane",
    "fuel_type": "aviation_fuel",
    "emission_factor": 0.00245,
    "capacity": "Variable"
  },
  {
    "toc_id": "sea_container",
    "name": "Container Ship",
    "category": "sea",
    "vehicle_type": "ship",
    "fuel_type": "marine_fuel",
    "emission_factor": 0.000012,
    "capacity": "Very high capacity"
  }
]

def get_transport_options():
    """Get transport options for selector"""
    tocs = get_tocs()

    # Group by category
    by_category = {}
    for toc in tocs:
        category = toc['category']
        if category not in by_category:
            by_category[category] = []
        by_category[category].append({
            'value': toc['toc_id'],
            'label': toc['name'],
            'emissions': toc['emission_factor']
        })

    return by_category

# Result:
# {
#   "road": [{"value": "van_diesel", "label": "Diesel Van", ...}],
#   "rail": [...],
#   "air": [...],
#   "sea": [...]
# }

def compare_transport_modes():
    """Compare emissions by transport mode"""
    tocs = get_tocs()

    # Sort by emission factor (lowest to highest)
    sorted_tocs = sorted(tocs, key=lambda x: x['emission_factor'])

    print("🌿 Transport modes sorted by emissions (lowest to highest):\n")

    for i, toc in enumerate(sorted_tocs, 1):
        print(f"{i}. {toc['name']}")
        print(f"   Factor: {toc['emission_factor']} kg CO2e/ton-km")
        print(f"   Category: {toc['category']}\n")

# Output:
# 1. Container Ship
#    Factor: 0.000012 kg CO2e/ton-km
#    Category: sea
#
# 2. Freight Train
#    Factor: 0.000025 kg CO2e/ton-km
#    Category: rail
# ...

def calculate_mode_switch_impact(distance_km, load_kg, from_toc, to_toc):
    """Calculate impact of switching transport modes"""
    tocs = {toc['toc_id']: toc for toc in get_tocs()}

    load_ton = load_kg / 1000
    ton_km = distance_km * load_ton

    # Emissions with current mode
    current_emissions = ton_km * tocs[from_toc]['emission_factor']

    # Emissions with alternative mode
    new_emissions = ton_km * tocs[to_toc]['emission_factor']

    # Savings
    savings = current_emissions - new_emissions
    savings_percentage = (savings / current_emissions) * 100

    return {
        'current_mode': tocs[from_toc]['name'],
        'new_mode': tocs[to_toc]['name'],
        'current_emissions': current_emissions,
        'new_emissions': new_emissions,
        'savings_kg': savings,
        'savings_percentage': savings_percentage
    }

# Example: Switch from diesel truck to train
impact = calculate_mode_switch_impact(
    distance_km=500,
    load_kg=5000,
    from_toc='truck_diesel',
    to_toc='rail_freight'
)

print(f"Switching from {impact['current_mode']} to {impact['new_mode']}:")
print(f"Savings: {impact['savings_kg']:.2f} kg CO2e ({impact['savings_percentage']:.1f}%)")

def validate_toc(toc_id):
    """Validate that a TOC exists"""
    tocs = get_tocs()
    valid_toc_ids = [toc['toc_id'] for toc in tocs]

    if toc_id not in valid_toc_ids:
        raise ValueError(
            f"TOC '{toc_id}' not valid. "
            f"Valid options: {', '.join(valid_toc_ids)}"
        )

    return True

# Get only road transport
road_tocs = [toc for toc in get_tocs() if toc['category'] == 'road']

# Get only electric vehicles
electric_tocs = [toc for toc in get_tocs() if toc['fuel_type'] == 'electric']

# Get TOCs with low emissions (< 0.0001 kg/ton-km)
low_emission_tocs = [toc for toc in get_tocs() if toc['emission_factor'] < 0.0001]