Maintenance Management

class SheetMaintenance(BaseModel):
    id = AutoField(primary_key=True)
    id_sheet_project = ForeignKey(SheetProject, on_delete=PROTECT)
    sheet_number = PositiveBigIntegerField(unique=True)  # Auto-generated
    status = CharField(
        choices=[
            ('DRAFT', 'BORRADOR'),
            ('CLOSED', 'EN PLANILLA'),
            ('VOID', 'ANULADO')
        ],
        default='DRAFT'
    )
    maintenance_type = CharField(
        choices=[
            ('PREVENTIVO', 'PREVENTIVO'),
            ('CORRECTIVO', 'CORRECTIVO')
        ],
        default='PREVENTIVO'
    )
    resource_item = ForeignKey(ResourceItem, on_delete=PROTECT)
    responsible_technical = ForeignKey(Technical, on_delete=PROTECT)

# Auto-generated on save
sheet_number = 1, 2, 3, 4...  # Never resets

# Daily interval: Maintenance every 2 days
frequency_type = 'DAY'
interval_days = 2

# Weekly schedule: Monday, Wednesday, Friday
frequency_type = 'WEEK'
weekdays = [0, 2, 4]  # 0=Monday, 6=Sunday

# Monthly schedule: 1st and 15th of month
frequency_type = 'MONTH'
monthdays = [1, 15]

requested_by = CharField(max_length=255)  # Who requested the maintenance
rig = CharField(max_length=50)  # RIG identifier at client site
code = CharField(max_length=100)  # Equipment code
location = CharField(max_length=255)  # Specific location
start_date = DateField()
end_date = DateField()
total_days = PositiveIntegerField()  # Duration in days

cost_day = DecimalField(max_digits=10, decimal_places=2)  # Daily rate
cost_total = DecimalField(max_digits=10, decimal_places=2)  # Total cost
cost_logistics = DecimalField(max_digits=10, decimal_places=2)  # Transport cost

cost_total = total_days * cost_day
# Logistics cost is added separately

sheet_project_maintenance_concept = CharField(
    max_length=255,
    default="SERVICIO TÉCNICO ESPECIALIZADO"
)
sheet_project_logistics_concept = CharField(
    max_length=255,
    default=None
)

# Technical staff who performed the work
performed_by = CharField(max_length=255)
performed_by_position = CharField(max_length=255)

# Supervisor who approved the work
approved_by = CharField(max_length=255)
approved_by_position = CharField(max_length=255)

maintenance_file = FileField(
    upload_to='projects/maintenance_sheets/',
    validators=[validate_pdf_file]
)

from projects.models import SheetMaintenance, SheetProject
from equipment.models import ResourceItem
from accounts.models import Technical
from datetime import date

# Create preventive maintenance
maintenance = SheetMaintenance.objects.create(
    id_sheet_project=sheet_project,
    # sheet_number is auto-generated
    maintenance_type='PREVENTIVO',
    resource_item=resource,
    responsible_technical=technical,
    requested_by='Supervisor de Campo',
    rig='RIG-45',
    code='BT-001',
    location='Campamento Norte',
    start_date=date(2026, 3, 15),
    end_date=date(2026, 3, 15),
    total_days=1,
    cost_day=150.00,
    cost_total=150.00,
    maintenance_description='''Mantenimiento preventivo:
        - Limpieza de tanques
        - Revisión de bombas
        - Lubricación de componentes
        - Inspección de mangueras y conexiones''',
    replaced_parts='Ninguno',
    observations='Equipo en buen estado. Próxima revisión en 7 días.',
    performed_by='Juan Técnico',
    performed_by_position='Técnico de Mantenimiento',
    approved_by='Carlos Supervisor',
    approved_by_position='Jefe de Operaciones'
)

# Create corrective maintenance
maintenance = SheetMaintenance.objects.create(
    id_sheet_project=sheet_project,
    maintenance_type='CORRECTIVO',
    resource_item=resource,
    responsible_technical=technical,
    requested_by='Cliente - Emergencia',
    rig='RIG-23',
    code='PTRTAR-005',
    location='Campamento Sur',
    start_date=date(2026, 3, 18),
    end_date=date(2026, 3, 19),
    total_days=2,
    cost_day=200.00,
    cost_total=400.00,
    cost_logistics=100.00,
    fault_description='Motor del blower no arranca. Sin funcionamiento de aireación.',
    possible_causes='''- Falla eléctrica en relay del motor
        - Daño en el motor eléctrico
        - Problema en panel de control''',
    maintenance_description='''Reparación realizada:
        - Diagnóstico eléctrico completo
        - Reemplazo de relay del motor
        - Pruebas de funcionamiento
        - Ajustes finales''',
    replaced_parts='''- Relay del motor (marca Schneider, ref. LRD10)
        - Fusibles 10A (cantidad: 3)''',
    observations='Motor funcionando correctamente. Se recomienda revisión del panel de control en 30 días.',
    performed_by='Pedro Electricista',
    performed_by_position='Técnico Eléctrico',
    approved_by='María Ingeniera',
    approved_by_position='Ingeniera de Mantenimiento'
)

# Finalize maintenance
maintenance.status = 'CLOSED'
maintenance.save()

# It will now appear in the SheetProject for billing
# The cost_total + cost_logistics will be added as line items

# Get all maintenance for an equipment item
history = SheetMaintenance.objects.filter(
    resource_item=resource,
    status='CLOSED',
    is_active=True
).order_by('-start_date')

# Get pending maintenance
pending = SheetMaintenance.objects.filter(
    status='DRAFT',
    id_sheet_project__project=project
)

# Get maintenance by type
preventive = SheetMaintenance.objects.filter(
    maintenance_type='PREVENTIVO',
    start_date__gte=date(2026, 1, 1)
)

corrective = SheetMaintenance.objects.filter(
    maintenance_type='CORRECTIVO',
    start_date__gte=date(2026, 1, 1)
)

from projects.models import ProjectResourceItem

# Get resources due for maintenance
resources = ProjectResourceItem.objects.filter(
    project=project,
    is_retired=False,
    operation_start_date__lte=today,
    operation_end_date__gte=today
)

# Check each resource's frequency
for resource in resources:
    if resource.frequency_type == 'DAY':
        # Check if interval_days has passed since last maintenance
        pass
    elif resource.frequency_type == 'WEEK':
        # Check if today is in weekdays list
        if today.weekday() in resource.weekdays:
            # Schedule maintenance
            pass
    elif resource.frequency_type == 'MONTH':
        # Check if today's day is in monthdays list
        if today.day in resource.monthdays:
            # Schedule maintenance
            pass

from django.db.models import Count, Sum, Avg
from datetime import timedelta

# Count maintenance by type
stats = SheetMaintenance.objects.filter(
    id_sheet_project__project=project,
    status='CLOSED'
).values('maintenance_type').annotate(
    count=Count('id'),
    total_cost=Sum('cost_total')
)

# Average maintenance duration
avg_duration = SheetMaintenance.objects.filter(
    status='CLOSED'
).aggregate(Avg('total_days'))

# Most maintained equipment
top_equipment = SheetMaintenance.objects.filter(
    status='CLOSED'
).values('resource_item__name').annotate(
    maintenance_count=Count('id')
).order_by('-maintenance_count')[:10]