"""
Admin configuration for pharmacy app.
"""

from django.contrib import admin
from django.utils.html import format_html
from django.urls import reverse
from django.utils import timezone
from .models import (
    Medication, Prescription, InventoryItem, DispenseRecord,
    MedicationAdministration, DrugInteraction
)


@admin.register(Medication)
class MedicationAdmin(admin.ModelAdmin):
    """
    Admin interface for Medication model.
    """
    list_display = [
        'generic_name', 'brand_name', 'strength', 'dosage_form',
        'controlled_substance_schedule', 'formulary_status', 'is_active'
    ]
    list_filter = [
        'dosage_form', 'controlled_substance_schedule', 'formulary_status',
        'is_active', 'drug_class', 'created_at'
    ]
    search_fields = [
        'generic_name', 'brand_name', 'ndc_number', 'rxcui', 'drug_class'
    ]
    readonly_fields = ['medication_id', 'created_at', 'updated_at']
    
    fieldsets = (
        ('Basic Information', {
            'fields': (
                'medication_id', 'generic_name', 'brand_name', 'drug_class'
            )
        }),
        ('Drug Identification', {
            'fields': (
                'ndc_number', 'rxcui', 'controlled_substance_schedule'
            )
        }),
        ('Formulation', {
            'fields': (
                'dosage_form', 'strength', 'unit_of_measure'
            )
        }),
        ('Clinical Information', {
            'fields': (
                'indications', 'contraindications', 'side_effects', 'warnings'
            )
        }),
        ('Dosing Information', {
            'fields': (
                'adult_dose_range', 'pediatric_dose_range', 'max_daily_dose',
                'routes_of_administration', 'administration_instructions'
            )
        }),
        ('Storage and Handling', {
            'fields': (
                'storage_requirements', 'special_handling'
            )
        }),
        ('Formulary and Availability', {
            'fields': (
                'formulary_status', 'is_active', 'is_available'
            )
        }),
        ('Pricing', {
            'fields': (
                'unit_cost', 'awp'
            )
        }),
        ('Manufacturer', {
            'fields': (
                'manufacturer', 'manufacturer_ndc'
            )
        }),
        ('Metadata', {
            'fields': (
                'created_at', 'updated_at', 'created_by'
            )
        }),
    )
    
    def get_queryset(self, request):
        """Filter by tenant."""
        qs = super().get_queryset(request)
        if hasattr(request.user, 'tenant'):
            return qs.filter(tenant=request.user.tenant)
        return qs.none()
    
    def save_model(self, request, obj, form, change):
        """Set tenant and created_by."""
        if not change:
            obj.tenant = request.user.tenant
            obj.created_by = request.user
        super().save_model(request, obj, form, change)


class DispenseRecordInline(admin.TabularInline):
    """
    Inline admin for dispense records.
    """
    model = DispenseRecord
    extra = 0
    readonly_fields = ['dispense_id', 'created_at']
    fields = [
        'inventory_item', 'quantity_dispensed', 'date_dispensed',
        'dispensed_by', 'status', 'patient_counseled'
    ]


@admin.register(Prescription)
class PrescriptionAdmin(admin.ModelAdmin):
    """
    Admin interface for Prescription model.
    """
    list_display = [
        'prescription_number', 'patient_name', 'medication_name',
        'prescriber', 'status', 'date_prescribed', 'expiration_date'
    ]
    list_filter = [
        'status', 'date_prescribed', 'verified', 'electronic_prescription',
        'generic_substitution_allowed', 'prior_authorization_required'
    ]
    search_fields = [
        'prescription_number', 'patient__first_name', 'patient__last_name',
        'patient__mrn', 'medication__generic_name', 'medication__brand_name'
    ]
    readonly_fields = [
        'prescription_id', 'prescription_number', 'created_at', 'updated_at'
    ]
    inlines = [DispenseRecordInline]
    
    fieldsets = (
        ('Prescription Information', {
            'fields': (
                'prescription_id', 'prescription_number', 'patient',
                'prescriber', 'encounter'
            )
        }),
        ('Medication', {
            'fields': (
                'medication', 'quantity_prescribed', 'quantity_unit'
            )
        }),
        ('Dosing Instructions', {
            'fields': (
                'dosage_instructions', 'frequency', 'duration'
            )
        }),
        ('Refills', {
            'fields': (
                'refills_authorized', 'refills_remaining'
            )
        }),
        ('Dates', {
            'fields': (
                'date_prescribed', 'date_written', 'expiration_date'
            )
        }),
        ('Status', {
            'fields': (
                'status', 'verified', 'verified_by', 'verified_datetime'
            )
        }),
        ('Clinical Information', {
            'fields': (
                'indication', 'diagnosis_code'
            )
        }),
        ('Instructions', {
            'fields': (
                'pharmacy_notes', 'patient_instructions'
            )
        }),
        ('Prior Authorization', {
            'fields': (
                'prior_authorization_required', 'prior_authorization_number',
                'prior_authorization_expiry'
            )
        }),
        ('Substitution', {
            'fields': (
                'generic_substitution_allowed', 'dispense_as_written'
            )
        }),
        ('Electronic Prescription', {
            'fields': (
                'electronic_prescription', 'e_prescription_id'
            )
        }),
        ('Metadata', {
            'fields': (
                'created_at', 'updated_at'
            )
        }),
    )
    
    def patient_name(self, obj):
        """Get patient name."""
        return obj.patient.get_full_name()
    patient_name.short_description = 'Patient'
    
    def medication_name(self, obj):
        """Get medication name."""
        return obj.medication.display_name
    medication_name.short_description = 'Medication'
    
    def get_queryset(self, request):
        """Filter by tenant."""
        qs = super().get_queryset(request)
        if hasattr(request.user, 'tenant'):
            return qs.filter(tenant=request.user.tenant)
        return qs.none()
    
    def save_model(self, request, obj, form, change):
        """Set tenant."""
        if not change:
            obj.tenant = request.user.tenant
        super().save_model(request, obj, form, change)


@admin.register(InventoryItem)
class InventoryItemAdmin(admin.ModelAdmin):
    """
    Admin interface for InventoryItem model.
    """
    list_display = [
        'medication_name', 'lot_number', 'quantity_on_hand',
        'quantity_available', 'expiration_date', 'status', 'needs_reorder_display'
    ]
    list_filter = [
        'status', 'expiration_date', 'received_date', 'quality_checked',
        'storage_location'
    ]
    search_fields = [
        'medication__generic_name', 'medication__brand_name',
        'lot_number', 'supplier', 'storage_location'
    ]
    readonly_fields = [
        'inventory_id', 'quantity_available', 'total_cost',
        'created_at', 'updated_at'
    ]
    
    fieldsets = (
        ('Inventory Information', {
            'fields': (
                'inventory_id', 'medication', 'lot_number', 'expiration_date'
            )
        }),
        ('Quantity', {
            'fields': (
                'quantity_on_hand', 'quantity_allocated', 'quantity_available'
            )
        }),
        ('Reorder Information', {
            'fields': (
                'reorder_point', 'reorder_quantity'
            )
        }),
        ('Location', {
            'fields': (
                'storage_location', 'bin_location'
            )
        }),
        ('Cost Information', {
            'fields': (
                'unit_cost', 'total_cost'
            )
        }),
        ('Supplier Information', {
            'fields': (
                'supplier', 'purchase_order_number'
            )
        }),
        ('Dates', {
            'fields': (
                'received_date', 'last_counted'
            )
        }),
        ('Status', {
            'fields': (
                'status',
            )
        }),
        ('Quality Control', {
            'fields': (
                'quality_checked', 'quality_check_date', 'quality_notes'
            )
        }),
        ('Metadata', {
            'fields': (
                'created_at', 'updated_at', 'created_by'
            )
        }),
    )
    
    def medication_name(self, obj):
        """Get medication name."""
        return obj.medication.display_name
    medication_name.short_description = 'Medication'
    
    def needs_reorder_display(self, obj):
        """Display reorder status."""
        if obj.needs_reorder:
            return format_html('<span style="color: red;">Yes</span>')
        return format_html('<span style="color: green;">No</span>')
    needs_reorder_display.short_description = 'Needs Reorder'
    
    def get_queryset(self, request):
        """Filter by tenant."""
        qs = super().get_queryset(request)
        if hasattr(request.user, 'tenant'):
            return qs.filter(tenant=request.user.tenant)
        return qs.none()
    
    def save_model(self, request, obj, form, change):
        """Set tenant and created_by."""
        if not change:
            obj.tenant = request.user.tenant
            obj.created_by = request.user
        super().save_model(request, obj, form, change)


@admin.register(DispenseRecord)
class DispenseRecordAdmin(admin.ModelAdmin):
    """
    Admin interface for DispenseRecord model.
    """
    list_display = [
        'prescription_number', 'patient_name', 'medication_name',
        'quantity_dispensed', 'date_dispensed', 'dispensed_by', 'status'
    ]
    list_filter = [
        'status', 'date_dispensed', 'is_refill', 'patient_counseled',
        'quality_check_performed'
    ]
    search_fields = [
        'prescription__prescription_number', 'prescription__patient__first_name',
        'prescription__patient__last_name', 'inventory_item__medication__generic_name'
    ]
    readonly_fields = [
        'dispense_id', 'total_price', 'quantity_remaining',
        'created_at', 'updated_at'
    ]
    
    fieldsets = (
        ('Dispense Information', {
            'fields': (
                'dispense_id', 'prescription', 'inventory_item'
            )
        }),
        ('Quantity', {
            'fields': (
                'quantity_dispensed', 'quantity_remaining'
            )
        }),
        ('Date and Staff', {
            'fields': (
                'date_dispensed', 'dispensed_by', 'verified_by'
            )
        }),
        ('Pricing', {
            'fields': (
                'unit_price', 'total_price', 'copay_amount', 'insurance_amount'
            )
        }),
        ('Patient Information', {
            'fields': (
                'patient_counseled', 'counseling_notes'
            )
        }),
        ('Refill Information', {
            'fields': (
                'is_refill', 'refill_number'
            )
        }),
        ('Status', {
            'fields': (
                'status',
            )
        }),
        ('Pickup Information', {
            'fields': (
                'picked_up_by', 'pickup_datetime', 'identification_verified'
            )
        }),
        ('Quality Control', {
            'fields': (
                'quality_check_performed', 'quality_notes'
            )
        }),
        ('Metadata', {
            'fields': (
                'created_at', 'updated_at'
            )
        }),
    )
    
    def prescription_number(self, obj):
        """Get prescription number."""
        return obj.prescription.prescription_number
    prescription_number.short_description = 'Prescription #'
    
    def patient_name(self, obj):
        """Get patient name."""
        return obj.patient.get_full_name()
    patient_name.short_description = 'Patient'
    
    def medication_name(self, obj):
        """Get medication name."""
        return obj.medication.display_name
    medication_name.short_description = 'Medication'


@admin.register(MedicationAdministration)
class MedicationAdministrationAdmin(admin.ModelAdmin):
    """
    Admin interface for MedicationAdministration model.
    """
    list_display = [
        'patient_name', 'medication_name', 'scheduled_datetime',
        'actual_datetime', 'status', 'administered_by'
    ]
    list_filter = [
        'status', 'scheduled_datetime', 'route_given', 'double_checked'
    ]
    search_fields = [
        'patient__first_name', 'patient__last_name',
        'prescription__medication__generic_name'
    ]
    readonly_fields = [
        'administration_id', 'created_at', 'updated_at'
    ]
    
    fieldsets = (
        ('Administration Information', {
            'fields': (
                'administration_id', 'prescription', 'patient', 'encounter'
            )
        }),
        ('Scheduled vs Actual', {
            'fields': (
                'scheduled_datetime', 'actual_datetime'
            )
        }),
        ('Dosage', {
            'fields': (
                'dose_given', 'route_given'
            )
        }),
        ('Status', {
            'fields': (
                'status',
            )
        }),
        ('Staff', {
            'fields': (
                'administered_by', 'witnessed_by'
            )
        }),
        ('Reason for Not Given', {
            'fields': (
                'reason_not_given', 'reason_notes'
            )
        }),
        ('Patient Response', {
            'fields': (
                'patient_response', 'side_effects_observed'
            )
        }),
        ('Site Information', {
            'fields': (
                'injection_site', 'site_condition'
            )
        }),
        ('Verification', {
            'fields': (
                'double_checked', 'double_checked_by'
            )
        }),
        ('Metadata', {
            'fields': (
                'created_at', 'updated_at'
            )
        }),
    )
    
    def patient_name(self, obj):
        """Get patient name."""
        return obj.patient.get_full_name()
    patient_name.short_description = 'Patient'
    
    def medication_name(self, obj):
        """Get medication name."""
        return obj.medication.display_name
    medication_name.short_description = 'Medication'


@admin.register(DrugInteraction)
class DrugInteractionAdmin(admin.ModelAdmin):
    """
    Admin interface for DrugInteraction model.
    """
    list_display = [
        'medication_1_name', 'medication_2_name', 'severity',
        'interaction_type', 'evidence_level', 'is_active'
    ]
    list_filter = [
        'severity', 'interaction_type', 'evidence_level', 'is_active'
    ]
    search_fields = [
        'medication_1__generic_name', 'medication_1__brand_name',
        'medication_2__generic_name', 'medication_2__brand_name'
    ]
    readonly_fields = [
        'interaction_id', 'created_at', 'updated_at'
    ]
    
    fieldsets = (
        ('Interaction Information', {
            'fields': (
                'interaction_id', 'medication_1', 'medication_2'
            )
        }),
        ('Severity and Type', {
            'fields': (
                'severity', 'interaction_type'
            )
        }),
        ('Interaction Details', {
            'fields': (
                'mechanism', 'clinical_effect'
            )
        }),
        ('Management', {
            'fields': (
                'management_recommendations', 'monitoring_parameters'
            )
        }),
        ('Evidence', {
            'fields': (
                'evidence_level', 'references'
            )
        }),
        ('Status', {
            'fields': (
                'is_active',
            )
        }),
        ('Metadata', {
            'fields': (
                'created_at', 'updated_at', 'created_by'
            )
        }),
    )
    
    def medication_1_name(self, obj):
        """Get first medication name."""
        return obj.medication_1.display_name
    medication_1_name.short_description = 'Medication 1'
    
    def medication_2_name(self, obj):
        """Get second medication name."""
        return obj.medication_2.display_name
    medication_2_name.short_description = 'Medication 2'
    
    def get_queryset(self, request):
        """Filter by tenant."""
        qs = super().get_queryset(request)
        if hasattr(request.user, 'tenant'):
            return qs.filter(tenant=request.user.tenant)
        return qs.none()
    
    def save_model(self, request, obj, form, change):
        """Set tenant and created_by."""
        if not change:
            obj.tenant = request.user.tenant
            obj.created_by = request.user
        super().save_model(request, obj, form, change)