"""
Maintenance Tasks - ServiceManagerWeb Workers

Tareas de mantenimiento del sistema
"""

from celery import current_task
from datetime import datetime, timedelta
from typing import Dict, Any, List
import os
import structlog

from app.celery import celery_app
from app.core.config import get_settings
from app.core.logging import get_logger

settings = get_settings()
logger = get_logger(__name__)


@celery_app.task(bind=True)
def health_check(self) -> Dict[str, Any]:
    """
    Worker health check task.
    
    Returns basic health information about the worker.
    """
    task_logger = logger.bind(
        task_id=self.request.id,
        task_name=self.name
    )
    
    try:
        current_time = datetime.utcnow()
        
        # Basic health checks
        health_data = {
            "status": "healthy",
            "timestamp": current_time.isoformat(),
            "worker_id": self.request.hostname,
            "task_id": self.request.id,
            "environment": settings.ENVIRONMENT,
            "checks": {
                "redis": "unknown",  # TODO: Check Redis connectivity
                "database": "unknown",  # TODO: Check database connectivity
                "disk_space": "unknown",  # TODO: Check disk space
                "memory": "unknown"  # TODO: Check memory usage
            }
        }
        
        task_logger.info("Worker health check completed", status="healthy")
        
        return health_data
        
    except Exception as exc:
        task_logger.error(
            "Worker health check failed",
            error=str(exc),
            exc_info=True
        )
        
        return {
            "status": "unhealthy",
            "timestamp": datetime.utcnow().isoformat(),
            "error": str(exc)
        }


@celery_app.task(
    bind=True,
    time_limit=1800,  # 30 minutes
    soft_time_limit=1500  # 25 minutes
)
def cleanup_old_logs(self) -> Dict[str, Any]:
    """
    Clean up old log files and database records.
    
    Removes:
    - Log files older than LOG_RETENTION_DAYS
    - Old notification logs
    - Old audit logs (if configured)
    - Temp files
    """
    task_logger = logger.bind(
        task_id=self.request.id,
        task_name=self.name
    )
    
    task_logger.info("Starting cleanup of old logs")
    
    try:
        current_time = datetime.utcnow()
        cutoff_date = current_time - timedelta(days=settings.LOG_RETENTION_DAYS)
        
        cleanup_results = {
            "started_at": current_time.isoformat(),
            "cutoff_date": cutoff_date.isoformat(),
            "files_removed": 0,
            "bytes_freed": 0,
            "database_records_removed": 0,
            "errors": []
        }
        
        # TODO: Implement actual file cleanup
        # For now, simulate cleanup
        
        # Clean up log files
        log_dir = "/app/logs"
        if os.path.exists(log_dir):
            for filename in os.listdir(log_dir):
                filepath = os.path.join(log_dir, filename)
                if os.path.isfile(filepath):
                    file_mtime = datetime.fromtimestamp(os.path.getmtime(filepath))
                    if file_mtime < cutoff_date and filename.endswith('.log'):
                        try:
                            file_size = os.path.getsize(filepath)
                            os.remove(filepath)
                            cleanup_results["files_removed"] += 1
                            cleanup_results["bytes_freed"] += file_size
                            task_logger.info(f"Removed old log file", filename=filename)
                        except Exception as e:
                            cleanup_results["errors"].append(f"Failed to remove {filename}: {str(e)}")
        
        # TODO: Clean up database records
        # - Old notification_logs
        # - Old audit_logs (with retention policy)
        # - Expired refresh_tokens
        # - Old file attachments (if configured)
        
        task_logger.info(
            "Cleanup completed",
            files_removed=cleanup_results["files_removed"],
            bytes_freed=cleanup_results["bytes_freed"],
            errors=len(cleanup_results["errors"])
        )
        
        return cleanup_results
        
    except Exception as exc:
        task_logger.error(
            "Cleanup task failed",
            error=str(exc),
            exc_info=True
        )
        raise


@celery_app.task(
    bind=True,
    time_limit=3600,  # 1 hour
    soft_time_limit=3300  # 55 minutes
)
def generate_weekly_reports(self) -> Dict[str, Any]:
    """
    Generate weekly reports for all tenants.
    
    Creates:
    - SLA performance reports
    - Ticket volume reports
    - Agent performance reports
    - Customer satisfaction reports
    """
    task_logger = logger.bind(
        task_id=self.request.id,
        task_name=self.name
    )
    
    task_logger.info("Starting weekly reports generation")
    
    try:
        current_time = datetime.utcnow()
        week_start = current_time - timedelta(days=7)
        
        report_results = {
            "generated_at": current_time.isoformat(),
            "period_start": week_start.isoformat(),
            "period_end": current_time.isoformat(),
            "reports_generated": [],
            "errors": []
        }
        
        # TODO: Get list of active tenants from database
        mock_tenants = [
            {"id": "tenant-1", "name": "Aduanasoft Demo", "slug": "aduanasoft-demo"}
        ]
        
        for tenant in mock_tenants:
            try:
                task_logger.info(
                    "Generating report for tenant",
                    tenant_id=tenant["id"],
                    tenant_name=tenant["name"]
                )
                
                # TODO: Generate actual reports
                # For now, simulate report generation
                
                report_data = {
                    "tenant_id": tenant["id"],
                    "tenant_name": tenant["name"],
                    "period_start": week_start.isoformat(),
                    "period_end": current_time.isoformat(),
                    "metrics": {
                        "tickets_created": 25,
                        "tickets_resolved": 23,
                        "avg_response_time_hours": 2.1,
                        "avg_resolution_time_hours": 18.5,
                        "sla_response_met_percentage": 92.0,
                        "sla_resolution_met_percentage": 87.0,
                        "customer_satisfaction_avg": 4.2
                    }
                }
                
                report_results["reports_generated"].append(report_data)
                
                # TODO: Store report in database
                # TODO: Send report email to admins
                
                # Update task progress
                current_task.update_state(
                    state='PROGRESS',
                    meta={
                        'current': len(report_results["reports_generated"]),
                        'total': len(mock_tenants)
                    }
                )
                
            except Exception as e:
                error_msg = f"Failed to generate report for tenant {tenant['id']}: {str(e)}"
                report_results["errors"].append(error_msg)
                task_logger.error(
                    "Report generation failed for tenant",
                    tenant_id=tenant["id"],
                    error=str(e)
                )
        
        task_logger.info(
            "Weekly reports generation completed",
            reports_generated=len(report_results["reports_generated"]),
            errors=len(report_results["errors"])
        )
        
        return report_results
        
    except Exception as exc:
        task_logger.error(
            "Weekly reports generation failed",
            error=str(exc),
            exc_info=True
        )
        raise


@celery_app.task(
    bind=True,
    time_limit=900,  # 15 minutes
    soft_time_limit=780  # 13 minutes
)
def cleanup_temp_files(self) -> Dict[str, Any]:
    """
    Clean up temporary files and orphaned uploads.
    
    Removes:
    - Temp upload files older than 24 hours
    - Orphaned attachment files (no DB reference)
    - Processing artifacts
    """
    task_logger = logger.bind(
        task_id=self.request.id,
        task_name=self.name
    )
    
    task_logger.info("Starting temp files cleanup")
    
    try:
        current_time = datetime.utcnow()
        cutoff_date = current_time - timedelta(hours=24)
        
        cleanup_results = {
            "started_at": current_time.isoformat(),
            "temp_files_removed": 0,
            "orphaned_files_removed": 0,
            "bytes_freed": 0,
            "errors": []
        }
        
        # Clean up temp directory
        temp_dirs = ["/tmp", "/app/temp", f"{settings.UPLOAD_PATH}/temp"]
        
        for temp_dir in temp_dirs:
            if os.path.exists(temp_dir):
                for filename in os.listdir(temp_dir):
                    filepath = os.path.join(temp_dir, filename)
                    if os.path.isfile(filepath):
                        try:
                            file_mtime = datetime.fromtimestamp(os.path.getmtime(filepath))
                            if file_mtime < cutoff_date:
                                file_size = os.path.getsize(filepath)
                                os.remove(filepath)
                                cleanup_results["temp_files_removed"] += 1
                                cleanup_results["bytes_freed"] += file_size
                        except Exception as e:
                            cleanup_results["errors"].append(f"Failed to remove temp file {filepath}: {str(e)}")
        
        # TODO: Check for orphaned files in uploads directory
        # - Query database for all attachment file_paths
        # - Compare with actual files in upload directory
        # - Remove orphaned files
        
        task_logger.info(
            "Temp files cleanup completed",
            temp_files_removed=cleanup_results["temp_files_removed"],
            orphaned_files_removed=cleanup_results["orphaned_files_removed"],
            bytes_freed=cleanup_results["bytes_freed"]
        )
        
        return cleanup_results
        
    except Exception as exc:
        task_logger.error(
            "Temp files cleanup failed",
            error=str(exc),
            exc_info=True
        )
        raise


@celery_app.task(
    bind=True,
    time_limit=300,
    soft_time_limit=240
)
def database_maintenance(self) -> Dict[str, Any]:
    """
    Perform database maintenance tasks.
    
    - VACUUM and ANALYZE tables
    - Update statistics
    - Check for slow queries
    - Optimize indices if needed
    """
    task_logger = logger.bind(
        task_id=self.request.id,
        task_name=self.name
    )
    
    task_logger.info("Starting database maintenance")
    
    try:
        # TODO: Implement database maintenance
        # For now, return placeholder results
        
        maintenance_results = {
            "started_at": datetime.utcnow().isoformat(),
            "tables_analyzed": 0,
            "indices_optimized": 0,
            "slow_queries_found": 0,
            "space_reclaimed_mb": 0
        }
        
        task_logger.info("Database maintenance completed (placeholder)")
        
        return maintenance_results
        
    except Exception as exc:
        task_logger.error(
            "Database maintenance failed",
            error=str(exc),
            exc_info=True
        )
        raise