"""
Queue Monitoring Router

Provides endpoints to monitor queue status, service limits, and processing counts
to help debug issues like Docling server overload.
"""

from fastapi import APIRouter, Depends
from typing import Dict, Any, List
from modules.auth.supabase_bearer import SupabaseBearer
from modules.queue_system import get_queue
from modules.redis_manager import get_redis_manager
from modules.logger_tool import initialise_logger
import os

router = APIRouter()
auth = SupabaseBearer()

logger = initialise_logger(__name__, os.getenv("LOG_LEVEL"), os.getenv("LOG_PATH"), 'default', True)

@router.get("/queue/status")
def get_queue_status(payload: Dict[str, Any] = Depends(auth)):
    """Get comprehensive queue status including service limits and current processing counts."""
    try:
        queue = get_queue()
        stats = queue.get_queue_stats()
        
        # Add environment configuration
        config = {
            'QUEUE_DOCLING_LIMIT': int(os.getenv('QUEUE_DOCLING_LIMIT', '2')),
            'QUEUE_TIKA_LIMIT': int(os.getenv('QUEUE_TIKA_LIMIT', '3')),
            'QUEUE_LLM_LIMIT': int(os.getenv('QUEUE_LLM_LIMIT', '5')),
            'BUNDLE_ARCHITECTURE_ENABLED': True,
            'AUTO_DOCLING_OCR': os.getenv('AUTO_DOCLING_OCR', 'true'),
            'AUTO_DOCLING_NO_OCR': os.getenv('AUTO_DOCLING_NO_OCR', 'true'),
            'AUTO_DOCLING_VLM': os.getenv('AUTO_DOCLING_VLM', 'false')
        }
        
        return {
            'queue_statistics': stats,
            'configuration': config,
            'redis_host': queue.redis_host,
            'redis_port': queue.redis_port,
            'service_limits': dict(queue.service_limits),
            'rate_limits': dict(queue.rate_limits)
        }
        
    except Exception as e:
        logger.error(f"Failed to get queue status: {e}")
        return {
            'error': str(e),
            'queue_available': False
        }

@router.get("/queue/tasks/by-file/{file_id}")
def get_file_queue_tasks(file_id: str, payload: Dict[str, Any] = Depends(auth)):
    """Get all queue tasks for a specific file (for debugging)."""
    try:
        # This would require extending the queue system to track tasks by file_id
        # For now, return a placeholder that indicates this feature needs implementation
        return {
            'message': 'File-specific task tracking not yet implemented',
            'file_id': file_id,
            'suggestion': 'Check Redis directly or extend queue system with file_id indexing'
        }
        
    except Exception as e:
        logger.error(f"Failed to get tasks for file {file_id}: {e}")
        return {
            'error': str(e),
            'file_id': file_id
        }

@router.get("/queue/health")
def get_comprehensive_queue_health(payload: Dict[str, Any] = Depends(auth)):
    """Get comprehensive queue and Redis health information with environment details."""
    try:
        # Determine environment
        environment = 'dev' if os.getenv('BACKEND_DEV_MODE', 'true').lower() == 'true' else 'prod'
        
        # Get Redis manager health
        redis_manager = get_redis_manager(environment)
        redis_health = redis_manager.health_check()
        
        # Get queue stats
        queue_stats = {}
        queue_available = False
        try:
            queue = get_queue()
            queue_stats = queue.get_queue_stats()
            queue_available = True
        except Exception as e:
            queue_stats = {'error': str(e)}
        
        # Environment configuration
        env_config = {
            'current_environment': environment,
            'redis_database': redis_health.get('database', 'unknown'),
            'persistence_enabled': os.getenv(f'REDIS_PERSIST_{environment.upper()}', 'unknown'),
            'task_ttl': os.getenv(f'REDIS_TASK_TTL_{environment.upper()}', 'unknown'),
            'service_limits': {
                'docling': int(os.getenv('QUEUE_DOCLING_LIMIT', '2')),
                'tika': int(os.getenv('QUEUE_TIKA_LIMIT', '3')),
                'llm': int(os.getenv('QUEUE_LLM_LIMIT', '5')),
                'split_map': int(os.getenv('QUEUE_SPLIT_MAP_LIMIT', '10')),
                'document_analysis': int(os.getenv('QUEUE_DOCUMENT_ANALYSIS_LIMIT', '5')),
                'page_images': int(os.getenv('QUEUE_PAGE_IMAGES_LIMIT', '3'))
            },
            'workers': int(os.getenv('QUEUE_WORKERS', '1'))
        }
        
        # Overall health status
        overall_status = 'healthy'
        issues = []
        
        if redis_health['status'] != 'healthy':
            overall_status = 'unhealthy'
            issues.append(f"Redis: {redis_health.get('error', 'Unknown issue')}")
        
        if not queue_available:
            overall_status = 'degraded'
            issues.append(f"Queue system: {queue_stats.get('error', 'Not accessible')}")
        
        # Check for concerning queue states
        if queue_available and queue_stats.get('dead_letter_count', 0) > 0:
            overall_status = 'warning'
            issues.append(f"Dead letter queue has {queue_stats['dead_letter_count']} failed tasks")
        
        return {
            'status': overall_status,
            'issues': issues,
            'timestamp': redis_health.get('timestamp'),
            'environment': env_config,
            'redis': redis_health,
            'queue': queue_stats,
            'recommendations': _get_health_recommendations(redis_health, queue_stats, environment)
        }
        
    except Exception as e:
        logger.error(f"Failed to get comprehensive queue health: {e}")
        return {
            'status': 'error',
            'error': str(e),
            'timestamp': None
        }

def _get_health_recommendations(redis_health: Dict, queue_stats: Dict, environment: str) -> List[str]:
    """Generate health recommendations based on current state."""
    recommendations = []
    
    # Redis recommendations
    if redis_health.get('status') != 'healthy':
        recommendations.append("Check Redis service status and connectivity")
    
    # Queue recommendations
    if queue_stats.get('dead_letter_count', 0) > 5:
        recommendations.append("High number of failed tasks - check task processing logic")
    
    # Processing recommendations
    processing_counts = queue_stats.get('processing', {})
    for service, count in processing_counts.items():
        if count < 0:
            recommendations.append(f"Negative processing counter for {service} - restart server to reset")
    
    # Environment-specific recommendations
    if environment == 'dev':
        recommendations.append("Development mode: Database will be cleared on restart")
    else:
        recommendations.append("Production mode: Tasks will be recovered on restart")
    
    if not recommendations:
        recommendations.append("System appears healthy - no specific recommendations")
    
    return recommendations