cwicr-takeoff-helper

# CWICR Takeoff Helper

## Business Case

### Problem Statement
Quantity takeoff requires:
- Accurate calculations from dimensions
- Correct unit conversions
- Waste factor application
- Complete scope coverage

### Solution
Assist takeoff process with CWICR-based calculations, automatic waste factors, unit conversions, and related item suggestions.

### Business Value
- **Accuracy** - Validated calculations
- **Completeness** - Related items suggested
- **Speed** - Quick quantity calculations
- **Consistency** - Standard approaches

## Technical Implementation

```python
import pandas as pd
import numpy as np
from typing import Dict, Any, List, Optional, Tuple
from dataclasses import dataclass
from enum import Enum
import math


class TakeoffType(Enum):
    """Types of takeoff calculations."""
    LINEAR = "linear"        # Length
    AREA = "area"            # Square measure
    VOLUME = "volume"        # Cubic measure
    COUNT = "count"          # Each/number
    WEIGHT = "weight"        # By weight


class UnitSystem(Enum):
    """Unit systems."""
    METRIC = "metric"
    IMPERIAL = "imperial"


@dataclass
class TakeoffItem:
    """Single takeoff item."""
    work_item_code: str
    description: str
    takeoff_type: TakeoffType
    gross_quantity: float
    waste_factor: float
    net_quantity: float
    unit: str
    dimensions: Dict[str, float]
    calculation: str


@dataclass
class TakeoffResult:
    """Complete takeoff result."""
    items: List[TakeoffItem]
    total_items: int
    related_suggestions: List[str]


# Unit conversion factors
CONVERSIONS = {
    # Length
    ('m', 'ft'): 3.28084,
    ('ft', 'm'): 0.3048,
    ('m', 'in'): 39.3701,
    ('in', 'm'): 0.0254,

    # Area
    ('m2', 'sf'): 10.7639,
    ('sf', 'm2'): 0.0929,

    # Volume
    ('m3', 'cf'): 35.3147,
    ('cf', 'm3'): 0.0283,
    ('m3', 'cy'): 1.30795,
    ('cy', 'm3'): 0.7646,

    # Weight
    ('kg', 'lb'): 2.20462,
    ('lb', 'kg'): 0.453592,
    ('ton', 'kg'): 1000,
    ('kg', 'ton'): 0.001
}

# Standard waste factors
WASTE_FACTORS = {
    'concrete': 0.05,
    'rebar': 0.08,
    'formwork': 0.10,
    'brick': 0.10,
    'block': 0.08,
    'drywall': 0.12,
    'tile': 0.15,
    'lumber': 0.12,
    'roofing': 0.10,
    'paint': 0.10,
    'pipe': 0.05,
    'wire': 0.05,
    'duct': 0.08,
    'default': 0.05
}

# Related work items by category
RELATED_ITEMS = {
    'concrete': ['formwork', 'rebar', 'curing', 'finishing'],
    'masonry': ['mortar', 'reinforcement', 'ties', 'lintels'],
    'drywall': ['framing', 'insulation', 'taping', 'painting'],
    'roofing': ['underlayment', 'flashing', 'ventilation', 'insulation'],
    'flooring': ['underlayment', 'adhesive', 'trim', 'transitions']
}


class CWICRTakeoffHelper:
    """Assist with quantity takeoff using CWICR data."""

    def __init__(self, cwicr_data: pd.DataFrame = None):
        self.cwicr = cwicr_data
        if cwicr_data is not None:
            self._index_cwicr()

    def _index_cwicr(self):
        """Index CWICR data."""
        if 'work_item_code' in self.cwicr.columns:
            self._cwicr_index = self.cwicr.set_index('work_item_code')
        else:
            self._cwicr_index = None

    def convert_unit(self, value: float, from_unit: str, to_unit: str) -> float:
        """Convert between units."""
        if from_unit == to_unit:
            return value

        key = (from_unit.lower(), to_unit.lower())
        if key in CONVERSIONS:
            return value * CONVERSIONS[key]

        # Try reverse
        reverse_key = (to_unit.lower(), from_unit.lower())
        if reverse_key in CONVERSIONS:
            return value / CONVERSIONS[reverse_key]

        return value

    def get_waste_factor(self, work_item_code: str) -> float:
        """Get waste factor for work item."""
        code_lower = work_item_code.lower()

        for material, factor in WASTE_FACTORS.items():
            if material in code_lower:
                return factor

        return WASTE_FACTORS['default']

    def calculate_area(self,
                       length: float,
                       width: float,
                       deductions: List[Tuple[float, float]] = None) -> Dict[str, float]:
        """Calculate area with deductions."""

        gross_area = length * width

        deduction_area = 0
        if deductions:
            for d_length, d_width in deductions:
                deduction_area += d_length * d_width

        net_area = gross_area - deduction_area

        return {
            'gross_area': round(gross_area, 2),
            'deductions': round(deduction_area, 2),
            'net_area': round(net_area, 2),
            'calculation': f"{length} x {width} = {gross_area}, minus {deduction_area} deductions"
        }

    def calculate_volume(self,
                          length: float,
                          width: float,
                          depth: float) -> Dict[str, float]:
        """Calculate volume."""

        volume = length * width * depth

        return {
            'volume': round(volume, 3),
            'calculation': f"{length} x {width} x {depth} = {volume}"
        }

    def calculate_perimeter(self,
                            length: float,
                            width: float) -> Dict[str, float]:
        """Calculate perimeter."""

        perimeter = 2 * (length + width)

        return {
            'perimeter': round(perimeter, 2),
            'calculation': f"2 x ({length} + {width}) = {perimeter}"
        }

    def calculate_concrete(self,
                            length: float,
                            width: float,
                            thickness: float,
                            work_item_code: str = "CONC-001") -> TakeoffItem:
        """Calculate concrete quantity with related items."""

        volume = length * width * thickness
        waste = self.get_waste_factor(work_item_code)
        net_qty = volume * (1 + waste)

        return TakeoffItem(
            work_