"""
Generic history endpoints for all entity types.

Provides cross-entity history operations and utilities.
"""

from typing import Optional
from uuid import UUID
from django.shortcuts import get_object_or_404
from django.http import Http404
from ninja import Router, Query

from api.v1.services.history_service import HistoryService
from api.v1.schemas import (
    HistoryEventDetailSchema,
    HistoryComparisonSchema,
    ErrorSchema
)

router = Router(tags=['History'])


@router.get(
    '/events/{event_id}',
    response={200: HistoryEventDetailSchema, 404: ErrorSchema},
    summary="Get event by ID",
    description="Retrieve any historical event by its ID (requires entity_type parameter)"
)
def get_event_by_id(
    request,
    event_id: int,
    entity_type: str = Query(..., description="Entity type (park, ride, company, ridemodel, review)")
):
    """Get a specific historical event by ID."""
    try:
        event = HistoryService.get_event(entity_type, event_id, request.user)
        if not event:
            return 404, {"error": "Event not found or not accessible"}
        
        # Get entity info for response
        entity_id = str(event['entity_id'])
        entity_name = event.get('entity_name', 'Unknown')
        
        # Build response
        response_data = {
            'id': event['id'],
            'timestamp': event['timestamp'],
            'operation': event['operation'],
            'entity_id': entity_id,
            'entity_type': entity_type,
            'entity_name': entity_name,
            'snapshot': event['snapshot'],
            'changed_fields': event.get('changed_fields'),
            'metadata': event.get('metadata', {}),
            'can_rollback': HistoryService.can_rollback(request.user),
            'rollback_preview': None  # Could add rollback preview logic if needed
        }
        
        return response_data
    except ValueError as e:
        return 404, {"error": str(e)}


@router.get(
    '/compare',
    response={200: HistoryComparisonSchema, 400: ErrorSchema, 404: ErrorSchema},
    summary="Compare two events",
    description="Compare two historical events (must be same entity)"
)
def compare_events(
    request,
    entity_type: str = Query(..., description="Entity type (park, ride, company, ridemodel, review)"),
    event1: int = Query(..., description="First event ID"),
    event2: int = Query(..., description="Second event ID")
):
    """Compare two historical events."""
    try:
        comparison = HistoryService.compare_events(
            entity_type, event1, event2, request.user
        )
        
        if not comparison:
            return 404, {"error": "One or both events not found or not accessible"}
        
        # Format response
        response_data = {
            'entity_id': comparison['entity_id'],
            'entity_type': entity_type,
            'entity_name': comparison.get('entity_name', 'Unknown'),
            'event1': comparison['event1'],
            'event2': comparison['event2'],
            'differences': comparison['differences'],
            'changed_field_count': comparison['changed_field_count'],
            'unchanged_field_count': comparison['unchanged_field_count'],
            'time_between': comparison['time_between']
        }
        
        return response_data
    except ValueError as e:
        return 400, {"error": str(e)}