"""
Admin configuration for Insurance Approvals 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 (
    InsuranceApprovalRequest,
    ApprovalDocument,
    ApprovalStatusHistory,
    ApprovalCommunicationLog,
    ApprovalTemplate
)


class ApprovalDocumentInline(admin.TabularInline):
    model = ApprovalDocument
    extra = 0
    fields = ('document_type', 'title', 'file', 'file_size_mb', 'uploaded_at', 'uploaded_by')
    readonly_fields = ('file_size_mb', 'uploaded_at', 'uploaded_by')
    
    def file_size_mb(self, obj):
        if obj.file_size:
            return f"{obj.file_size_mb} MB"
        return "-"
    file_size_mb.short_description = 'File Size'


class ApprovalStatusHistoryInline(admin.TabularInline):
    model = ApprovalStatusHistory
    extra = 0
    fields = ('from_status', 'to_status', 'reason', 'changed_at', 'changed_by')
    readonly_fields = ('changed_at', 'changed_by')
    can_delete = False


class ApprovalCommunicationLogInline(admin.TabularInline):
    model = ApprovalCommunicationLog
    extra = 0
    fields = ('communication_type', 'subject', 'contact_person', 'communicated_at', 'follow_up_required')
    readonly_fields = ('communicated_at',)


@admin.register(InsuranceApprovalRequest)
class InsuranceApprovalRequestAdmin(admin.ModelAdmin):
    list_display = (
        'approval_number',
        'patient_link',
        'request_type',
        'status_badge',
        'priority_badge',
        'insurance_company',
        'submitted_date',
        'decision_date',
        'expiration_status',
        'assigned_to'
    )
    list_filter = (
        'status',
        'priority',
        'request_type',
        'is_urgent',
        'is_expedited',
        'requires_peer_review',
        'submitted_date',
        'decision_date'
    )
    search_fields = (
        'approval_number',
        'authorization_number',
        'reference_number',
        'patient__first_name',
        'patient__last_name',
        'patient__mrn',
        'insurance_info__insurance_company',
        'service_description'
    )
    readonly_fields = (
        'approval_id',
        'approval_number',
        'created_at',
        'updated_at',
        'created_by',
        'turnaround_time_days',
        'days_until_expiry'
    )
    
    fieldsets = (
        ('Identification', {
            'fields': ('approval_id', 'approval_number', 'tenant')
        }),
        ('Patient & Insurance', {
            'fields': ('patient', 'insurance_info')
        }),
        ('Order Information', {
            'fields': ('content_type', 'object_id', 'request_type', 'service_description')
        }),
        ('Medical Codes', {
            'fields': ('procedure_codes', 'diagnosis_codes')
        }),
        ('Clinical Information', {
            'fields': ('clinical_justification', 'medical_necessity', 'alternative_treatments_tried')
        }),
        ('Requested Services', {
            'fields': (
                'requested_quantity',
                'requested_visits',
                'requested_units',
                'service_start_date',
                'service_end_date'
            )
        }),
        ('Status & Priority', {
            'fields': ('status', 'priority', 'is_urgent', 'is_expedited', 'requires_peer_review')
        }),
        ('Submission', {
            'fields': ('submission_method', 'submitted_date', 'submitted_by')
        }),
        ('Insurance Response', {
            'fields': (
                'decision_date',
                'authorization_number',
                'reference_number',
                'approved_quantity',
                'approved_visits',
                'approved_units',
                'approved_amount',
                'effective_date',
                'expiration_date'
            )
        }),
        ('Denial & Appeal', {
            'fields': ('denial_reason', 'denial_code', 'appeal_date', 'appeal_reason', 'appeal_deadline'),
            'classes': ('collapse',)
        }),
        ('Assignment & Tracking', {
            'fields': ('assigned_to', 'requesting_provider')
        }),
        ('Communication', {
            'fields': ('last_contact_date', 'last_contact_method', 'last_contact_notes'),
            'classes': ('collapse',)
        }),
        ('Notes', {
            'fields': ('internal_notes', 'insurance_notes'),
            'classes': ('collapse',)
        }),
        ('Metadata', {
            'fields': ('created_at', 'updated_at', 'created_by', 'turnaround_time_days', 'days_until_expiry'),
            'classes': ('collapse',)
        })
    )
    
    inlines = [ApprovalDocumentInline, ApprovalStatusHistoryInline, ApprovalCommunicationLogInline]
    
    def patient_link(self, obj):
        url = reverse('admin:patients_patientprofile_change', args=[obj.patient.id])
        return format_html('<a href="{}">{}</a>', url, obj.patient.get_full_name())
    patient_link.short_description = 'Patient'
    
    def insurance_company(self, obj):
        return obj.insurance_info.insurance_company
    insurance_company.short_description = 'Insurance'
    
    def status_badge(self, obj):
        colors = {
            'DRAFT': 'gray',
            'PENDING_SUBMISSION': 'orange',
            'SUBMITTED': 'blue',
            'UNDER_REVIEW': 'blue',
            'ADDITIONAL_INFO_REQUESTED': 'orange',
            'APPROVED': 'green',
            'PARTIALLY_APPROVED': 'lightgreen',
            'DENIED': 'red',
            'APPEALED': 'purple',
            'APPEAL_APPROVED': 'green',
            'APPEAL_DENIED': 'red',
            'EXPIRED': 'darkgray',
            'CANCELLED': 'gray'
        }
        color = colors.get(obj.status, 'gray')
        return format_html(
            '<span style="background-color: {}; color: white; padding: 3px 10px; border-radius: 3px;">{}</span>',
            color,
            obj.get_status_display()
        )
    status_badge.short_description = 'Status'
    
    def priority_badge(self, obj):
        colors = {
            'ROUTINE': 'green',
            'URGENT': 'orange',
            'STAT': 'red',
            'EMERGENCY': 'darkred'
        }
        color = colors.get(obj.priority, 'gray')
        return format_html(
            '<span style="background-color: {}; color: white; padding: 3px 10px; border-radius: 3px;">{}</span>',
            color,
            obj.get_priority_display()
        )
    priority_badge.short_description = 'Priority'
    
    def expiration_status(self, obj):
        if not obj.expiration_date:
            return '-'
        
        if obj.is_expired:
            return format_html('<span style="color: red;">Expired</span>')
        elif obj.is_expiring_soon:
            days = obj.days_until_expiry
            return format_html('<span style="color: orange;">Expires in {} days</span>', days)
        else:
            return format_html('<span style="color: green;">Valid</span>')
    expiration_status.short_description = 'Expiration'
    
    def save_model(self, request, obj, form, change):
        if not change:
            obj.created_by = request.user
        super().save_model(request, obj, form, change)


@admin.register(ApprovalDocument)
class ApprovalDocumentAdmin(admin.ModelAdmin):
    list_display = ('title', 'approval_request', 'document_type', 'file_size_mb', 'uploaded_at', 'uploaded_by')
    list_filter = ('document_type', 'uploaded_at')
    search_fields = ('title', 'description', 'approval_request__approval_number')
    readonly_fields = ('document_id', 'file_size_mb', 'uploaded_at', 'uploaded_by')
    
    def save_model(self, request, obj, form, change):
        if not change:
            obj.uploaded_by = request.user
            if obj.file:
                obj.file_size = obj.file.size
                obj.mime_type = obj.file.content_type or 'application/octet-stream'
        super().save_model(request, obj, form, change)


@admin.register(ApprovalStatusHistory)
class ApprovalStatusHistoryAdmin(admin.ModelAdmin):
    list_display = ('approval_request', 'from_status', 'to_status', 'changed_at', 'changed_by')
    list_filter = ('to_status', 'changed_at')
    search_fields = ('approval_request__approval_number', 'reason', 'notes')
    readonly_fields = ('changed_at', 'changed_by')
    
    def save_model(self, request, obj, form, change):
        if not change:
            obj.changed_by = request.user
        super().save_model(request, obj, form, change)


@admin.register(ApprovalCommunicationLog)
class ApprovalCommunicationLogAdmin(admin.ModelAdmin):
    list_display = (
        'approval_request',
        'communication_type',
        'subject',
        'contact_person',
        'communicated_at',
        'follow_up_badge'
    )
    list_filter = ('communication_type', 'follow_up_required', 'communicated_at')
    search_fields = (
        'approval_request__approval_number',
        'subject',
        'message',
        'contact_person'
    )
    readonly_fields = ('communication_id', 'communicated_at', 'communicated_by')
    
    fieldsets = (
        ('Approval Request', {
            'fields': ('approval_request',)
        }),
        ('Communication Details', {
            'fields': (
                'communication_id',
                'communication_type',
                'contact_person',
                'contact_number',
                'subject',
                'message',
                'response'
            )
        }),
        ('Outcome & Follow-up', {
            'fields': ('outcome', 'follow_up_required', 'follow_up_date')
        }),
        ('Metadata', {
            'fields': ('communicated_at', 'communicated_by')
        })
    )
    
    def follow_up_badge(self, obj):
        if obj.follow_up_required:
            if obj.follow_up_date and obj.follow_up_date < timezone.now().date():
                return format_html('<span style="color: red;">Overdue</span>')
            return format_html('<span style="color: orange;">Required</span>')
        return format_html('<span style="color: green;">None</span>')
    follow_up_badge.short_description = 'Follow-up'
    
    def save_model(self, request, obj, form, change):
        if not change:
            obj.communicated_by = request.user
        super().save_model(request, obj, form, change)


@admin.register(ApprovalTemplate)
class ApprovalTemplateAdmin(admin.ModelAdmin):
    list_display = ('name', 'request_type', 'insurance_company', 'is_active', 'usage_count', 'created_at')
    list_filter = ('request_type', 'is_active', 'created_at')
    search_fields = ('name', 'description', 'insurance_company')
    readonly_fields = ('template_id', 'usage_count', 'created_at', 'updated_at', 'created_by')
    
    fieldsets = (
        ('Template Information', {
            'fields': ('template_id', 'name', 'description', 'tenant')
        }),
        ('Scope', {
            'fields': ('request_type', 'insurance_company')
        }),
        ('Template Content', {
            'fields': (
                'clinical_justification_template',
                'medical_necessity_template',
                'required_documents',
                'required_codes'
            )
        }),
        ('Status & Usage', {
            'fields': ('is_active', 'usage_count')
        }),
        ('Metadata', {
            'fields': ('created_at', 'updated_at', 'created_by'),
            'classes': ('collapse',)
        })
    )
    
    def save_model(self, request, obj, form, change):
        if not change:
            obj.created_by = request.user
        super().save_model(request, obj, form, change)