"""
Django admin configuration for compliance_governance app
"""
from django.contrib import admin
from django.utils.html import format_html
from django.urls import reverse
from django.utils.safestring import mark_safe
from django.db.models import Count, Q
from django.utils import timezone
from datetime import timedelta

from .models import (
    RegulatoryFramework,
    ComplianceRequirement,
    RegulatoryWorkflow,
    WorkflowInstance,
    EvidenceCollection,
    RetentionPolicy,
    ExportRequest,
    ComplianceReport,
    LegalHold,
)


@admin.register(RegulatoryFramework)
class RegulatoryFrameworkAdmin(admin.ModelAdmin):
    """Admin interface for Regulatory Framework"""
    
    list_display = [
        'name', 'framework_type', 'version', 'is_active', 'effective_date', 
        'requirements_count', 'created_at'
    ]
    list_filter = [
        'framework_type', 'is_active', 'effective_date', 'created_at'
    ]
    search_fields = ['name', 'description', 'applicable_regions', 'industry_sectors']
    readonly_fields = ['id', 'created_at', 'updated_at']
    fieldsets = (
        ('Basic Information', {
            'fields': ('id', 'name', 'framework_type', 'version', 'description')
        }),
        ('Framework Details', {
            'fields': ('applicable_regions', 'industry_sectors', 'compliance_requirements')
        }),
        ('Status and Dates', {
            'fields': ('is_active', 'effective_date', 'review_date')
        }),
        ('Metadata', {
            'fields': ('created_by', 'created_at', 'updated_at'),
            'classes': ('collapse',)
        }),
    )
    
    def requirements_count(self, obj):
        """Display count of requirements"""
        count = obj.requirements.count()
        if count > 0:
            url = reverse('admin:compliance_governance_compliancerequirement_changelist')
            return format_html('<a href="{}?framework__id__exact={}">{} requirements</a>', url, obj.id, count)
        return '0 requirements'
    requirements_count.short_description = 'Requirements'


@admin.register(ComplianceRequirement)
class ComplianceRequirementAdmin(admin.ModelAdmin):
    """Admin interface for Compliance Requirement"""
    
    list_display = [
        'requirement_id', 'title', 'framework', 'requirement_type', 'priority',
        'compliance_status', 'is_implemented', 'assigned_to', 'next_assessment_date'
    ]
    list_filter = [
        'framework', 'requirement_type', 'priority', 'compliance_status', 
        'is_implemented', 'assigned_to', 'next_assessment_date'
    ]
    search_fields = ['requirement_id', 'title', 'description', 'responsible_team']
    readonly_fields = ['id', 'created_at', 'updated_at']
    fieldsets = (
        ('Basic Information', {
            'fields': ('id', 'framework', 'requirement_id', 'title', 'description')
        }),
        ('Requirement Details', {
            'fields': ('requirement_type', 'priority', 'implementation_guidance', 'evidence_requirements', 'testing_procedures')
        }),
        ('Compliance Tracking', {
            'fields': ('is_implemented', 'implementation_date', 'last_assessment_date', 'next_assessment_date', 'compliance_status')
        }),
        ('Assignment', {
            'fields': ('responsible_team', 'assigned_to')
        }),
        ('Metadata', {
            'fields': ('created_at', 'updated_at'),
            'classes': ('collapse',)
        }),
    )
    
    def get_queryset(self, request):
        return super().get_queryset(request).select_related('framework', 'assigned_to')


@admin.register(RegulatoryWorkflow)
class RegulatoryWorkflowAdmin(admin.ModelAdmin):
    """Admin interface for Regulatory Workflow"""
    
    list_display = [
        'name', 'workflow_type', 'status', 'version', 'is_template', 
        'instances_count', 'created_by', 'created_at'
    ]
    list_filter = [
        'workflow_type', 'status', 'is_template', 'created_at'
    ]
    search_fields = ['name', 'description']
    readonly_fields = ['id', 'created_at', 'updated_at']
    filter_horizontal = ['applicable_frameworks']
    
    def instances_count(self, obj):
        """Display count of workflow instances"""
        count = obj.instances.count()
        if count > 0:
            url = reverse('admin:compliance_governance_workflowinstance_changelist')
            return format_html('<a href="{}?workflow__id__exact={}">{} instances</a>', url, obj.id, count)
        return '0 instances'
    instances_count.short_description = 'Instances'


@admin.register(WorkflowInstance)
class WorkflowInstanceAdmin(admin.ModelAdmin):
    """Admin interface for Workflow Instance"""
    
    list_display = [
        'title', 'workflow', 'status', 'assigned_to', 'related_incident',
        'started_at', 'due_date', 'is_overdue'
    ]
    list_filter = [
        'workflow', 'status', 'assigned_to', 'started_at', 'due_date'
    ]
    search_fields = ['title', 'description', 'current_step']
    readonly_fields = ['id', 'started_at', 'updated_at']
    filter_horizontal = ['stakeholders']
    
    def is_overdue(self, obj):
        """Check if workflow instance is overdue"""
        if obj.due_date and obj.status in ['PENDING', 'IN_PROGRESS']:
            if timezone.now() > obj.due_date:
                return format_html('<span style="color: red;">Yes</span>')
        return 'No'
    is_overdue.short_description = 'Overdue'


@admin.register(EvidenceCollection)
class EvidenceCollectionAdmin(admin.ModelAdmin):
    """Admin interface for Evidence Collection"""
    
    list_display = [
        'title', 'evidence_type', 'status', 'incident', 'collected_by',
        'collection_timestamp', 'file_size_display'
    ]
    list_filter = [
        'evidence_type', 'status', 'collected_by', 'collection_timestamp'
    ]
    search_fields = ['title', 'description', 'collection_notes']
    readonly_fields = ['id', 'collection_timestamp', 'created_at', 'updated_at']
    
    def file_size_display(self, obj):
        """Display file size in human readable format"""
        if not obj.file_size:
            return 'N/A'
        
        size = obj.file_size
        for unit in ['B', 'KB', 'MB', 'GB', 'TB']:
            if size < 1024.0:
                return f"{size:.1f} {unit}"
            size /= 1024.0
        return f"{size:.1f} PB"
    file_size_display.short_description = 'File Size'


@admin.register(RetentionPolicy)
class RetentionPolicyAdmin(admin.ModelAdmin):
    """Admin interface for Retention Policy"""
    
    list_display = [
        'name', 'policy_type', 'retention_period', 'retention_unit',
        'is_active', 'effective_date', 'created_by'
    ]
    list_filter = [
        'policy_type', 'is_active', 'effective_date', 'created_at'
    ]
    search_fields = ['name', 'description']
    readonly_fields = ['id', 'created_at', 'updated_at']
    filter_horizontal = ['applicable_frameworks']


@admin.register(ExportRequest)
class ExportRequestAdmin(admin.ModelAdmin):
    """Admin interface for Export Request"""
    
    list_display = [
        'title', 'request_type', 'status', 'requester_name', 'requester_organization',
        'requested_at', 'due_date', 'is_overdue'
    ]
    list_filter = [
        'request_type', 'status', 'requester_organization', 'requested_at', 'due_date'
    ]
    search_fields = ['title', 'description', 'requester_name', 'requester_email']
    readonly_fields = ['id', 'requested_at', 'updated_at']
    filter_horizontal = ['applicable_frameworks']
    
    def is_overdue(self, obj):
        """Check if export request is overdue"""
        if obj.due_date and obj.status not in ['COMPLETED', 'CANCELLED']:
            if timezone.now() > obj.due_date:
                return format_html('<span style="color: red;">Yes</span>')
        return 'No'
    is_overdue.short_description = 'Overdue'


@admin.register(ComplianceReport)
class ComplianceReportAdmin(admin.ModelAdmin):
    """Admin interface for Compliance Report"""
    
    list_display = [
        'title', 'report_type', 'framework', 'status', 'overall_compliance_score',
        'report_period_start', 'report_period_end', 'prepared_by'
    ]
    list_filter = [
        'report_type', 'status', 'framework', 'report_period_start', 'report_period_end'
    ]
    search_fields = ['title', 'description', 'executive_summary']
    readonly_fields = ['id', 'created_at', 'updated_at']
    filter_horizontal = ['applicable_requirements']


@admin.register(LegalHold)
class LegalHoldAdmin(admin.ModelAdmin):
    """Admin interface for Legal Hold"""
    
    list_display = [
        'case_name', 'case_number', 'status', 'legal_counsel', 'hold_date',
        'expiration_date', 'affected_data_count', 'is_active'
    ]
    list_filter = [
        'status', 'hold_date', 'expiration_date', 'created_at'
    ]
    search_fields = ['case_name', 'case_number', 'description', 'legal_counsel', 'law_firm']
    readonly_fields = ['id', 'created_at', 'updated_at']
    filter_horizontal = ['related_incidents', 'related_evidence']
    
    def affected_data_count(self, obj):
        """Display count of affected data items"""
        count = obj.get_affected_data_count()
        return f"{count} items"
    affected_data_count.short_description = 'Affected Data'
    
    def is_active(self, obj):
        """Check if legal hold is active"""
        if obj.is_active():
            return format_html('<span style="color: green;">Active</span>')
        return format_html('<span style="color: red;">Inactive</span>')
    is_active.short_description = 'Status'


# Custom admin site configuration
admin.site.site_header = "ETB Compliance & Governance Administration"
admin.site.site_title = "ETB Compliance Admin"
admin.site.index_title = "Compliance & Governance Management"