cwicr-assembly-builder

# CWICR Assembly Builder

## Business Case

### Problem Statement
Estimating repetitive elements requires:
- Consistent item groupings
- Reusable templates
- Standard assemblies
- Quick application

### Solution
Build and manage assemblies of CWICR work items that can be applied as templates to speed up estimating and ensure completeness.

### Business Value
- **Speed** - Apply complete assemblies quickly
- **Consistency** - Standard item groupings
- **Completeness** - No missed items
- **Reusability** - Template library

## Technical Implementation

```python
import pandas as pd
import json
from typing import Dict, Any, List, Optional
from dataclasses import dataclass, field
from enum import Enum
from datetime import datetime


class AssemblyType(Enum):
    """Types of assemblies."""
    STRUCTURAL = "structural"
    ARCHITECTURAL = "architectural"
    MECHANICAL = "mechanical"
    ELECTRICAL = "electrical"
    SITEWORK = "sitework"
    GENERAL = "general"


@dataclass
class AssemblyItem:
    """Single item in assembly."""
    work_item_code: str
    description: str
    quantity_per_unit: float  # Quantity per assembly unit
    unit: str
    unit_cost: float
    total_cost: float
    notes: str = ""


@dataclass
class Assembly:
    """Complete assembly definition."""
    assembly_code: str
    name: str
    description: str
    assembly_type: AssemblyType
    unit: str  # Assembly unit (e.g., "m2", "each", "LF")
    items: List[AssemblyItem]
    total_cost_per_unit: float
    labor_hours_per_unit: float
    created_date: datetime
    version: int = 1


class CWICRAssemblyBuilder:
    """Build and manage assemblies from CWICR data."""

    def __init__(self, cwicr_data: pd.DataFrame):
        self.cwicr = cwicr_data
        self._index_cwicr()
        self._assemblies: Dict[str, Assembly] = {}

    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 _get_item_cost(self, code: str) -> Tuple[float, float, str]:
        """Get item unit cost and labor hours."""
        if self._cwicr_index is None or code not in self._cwicr_index.index:
            return (0, 0, 'unit')

        item = self._cwicr_index.loc[code]
        labor = float(item.get('labor_cost', 0) or 0)
        material = float(item.get('material_cost', 0) or 0)
        equipment = float(item.get('equipment_cost', 0) or 0)
        labor_hours = float(item.get('labor_norm', item.get('labor_hours', 0)) or 0)
        unit = str(item.get('unit', 'unit'))

        return (labor + material + equipment, labor_hours, unit)

    def create_assembly(self,
                        assembly_code: str,
                        name: str,
                        description: str,
                        assembly_type: AssemblyType,
                        unit: str,
                        items: List[Dict[str, Any]]) -> Assembly:
        """Create new assembly from work items."""

        assembly_items = []
        total_cost = 0
        total_hours = 0

        for item_def in items:
            code = item_def.get('work_item_code', item_def.get('code'))
            qty_per_unit = item_def.get('quantity_per_unit', 1)
            notes = item_def.get('notes', '')

            unit_cost, labor_hours, item_unit = self._get_item_cost(code)

            # Get description from CWICR
            if self._cwicr_index is not None and code in self._cwicr_index.index:
                desc = str(self._cwicr_index.loc[code].get('description', code))
            else:
                desc = item_def.get('description', code)

            item_total = unit_cost * qty_per_unit

            assembly_items.append(AssemblyItem(
                work_item_code=code,
                description=desc,
                quantity_per_unit=qty_per_unit,
                unit=item_unit,
                unit_cost=round(unit_cost, 2),
                total_cost=round(item_total, 2),
                notes=notes
            ))

            total_cost += item_total
            total_hours += labor_hours * qty_per_unit

        assembly = Assembly(
            assembly_code=assembly_code,
            name=name,
            description=description,
            assembly_type=assembly_type,
            unit=unit,
            items=assembly_items,
            total_cost_per_unit=round(total_cost, 2),
            labor_hours_per_unit=round(total_hours, 2),
            created_date=datetime.now(),
            version=1
        )

        self._assemblies[assembly_code] = assembly
        return assembly

    def apply_assembly(self,
                        assembly_code: str,
                        quantity: float,
                        location_factor: float = 1.0) -> Dict[str, Any]:
        """Apply assembly to get estimate."""

        assembly = self._assemblies.get(assembly_code)
        if assembly is None:
            return {'error': f"Assembly {assembly_code} not found"}

        items = []
        total_cost = 0
        total_hours = 0

        for item in assembly.items:
            qty = item.quantity_per_unit * quantity
            cost = item.total_cost * quantity * location_factor
            hours = qty * (item.unit_cost / 50 if item.unit_cost > 0 else 0)  # Approximate labor hours

            items.append({
                'work_item_code': item.work_item_code,
                'description': item.description,
                'quantity': round(qty, 2),
                'unit': item.unit,
                'cost': round(cost, 2)
            })

            total_cost += cost
            total_hours += hours

        return {
            'assembly_code': assembly_code,
            'assembly_name': assembly.name,
            'quantity': quantity,
            'unit': assembly.unit,
            'location_factor': location_factor,
            'items': items,
            'total_cost': roun