import logging
import traceback
from asgiref.sync import async_to_sync
from celery import shared_task
from channels.layers import get_channel_layer
from django.utils import timezone

from apps.orgs.models import TrainingFile
from . import services
from .models import Agent, AgentEvent, AgentModel, AgentRun

logger = logging.getLogger(__name__)

def _send_group_event(room_group_name: str, event_type: str, content: dict):
    channel_layer = get_channel_layer()
    async_to_sync(channel_layer.group_send)(
        room_group_name,
        {
            "type": "mlstore_event",
            "event_type": event_type,
            "content": content,
            "timestamp": timezone.now().isoformat(),
        }
    )


def _persist_event(execution: AgentRun, event_type: str, content: dict):
    AgentEvent.objects.create(
        execution=execution,
        event_type=event_type,
        content=content,
    )


def _update_agent_status(agent: Agent, status: str):
    agent.status = status
    if status == "running":
        agent.started_at = timezone.now()
    elif status in ("completed", "failed"):
        agent.completed_at = timezone.now()
    agent.save()


@shared_task
def start_fine_tune_run_task(execution_id: str):
    logger.info(f"Fine-tune run task started for execution: {execution_id}")
    try:
        execution = AgentRun.objects.get(uuid=execution_id)
    except AgentRun.DoesNotExist:
        logger.error(f"Execution not found: {execution_id}")
        return {"status": "error", "error": "execution_not_found", "execution_id": execution_id}

    agent = execution.agent
    room_group_name = f"mlstore_agent_{agent.uuid}"
    logger.info(f"Agent: {agent.uuid}, User: {execution.user.email_address}")

    execution.status = "running"
    execution.started_at = timezone.now()
    execution.save()
    _update_agent_status(agent, "running")
    logger.info(f"Execution {execution_id} status updated to 'running'")

    from apps.mlstore.services import BASE_MODEL_CACHE
    logger.info(f"Base model cache directory: {BASE_MODEL_CACHE}")

    input_data = execution.input_data or {}
    base_model = input_data.get("base_model") or agent.model.name
    
    training_files = input_data.get("training_files") or []
    org_training_files = []
    if not training_files and agent.organization:
        org_training_files = list(TrainingFile.objects.filter(
            organization=agent.organization,
            is_processed=False
        ).select_related('uploaded_by'))
        training_files = [tf.file.path for tf in org_training_files if tf.file]
        logger.info(f"Fetched {len(training_files)} training files from organization {agent.organization.name}")
    
    hyperparams = input_data.get("hyperparams") or {}
    name = input_data.get("name") or agent.model.name
    
    if not input_data.get("version"):
        existing_models = AgentModel.objects.filter(name=name).order_by('-version')
        if existing_models.exists():
            last_version = existing_models.first().version
            try:
                if last_version.startswith('v'):
                    num = int(last_version[1:])
                    version = f"v{num + 1}"
                else:
                    version = f"v1"
            except:
                version = "v1"
        else:
            version = "v1"
    else:
        version = input_data.get("version")
    
    logger.info(f"Fine-tune parameters: base_model={base_model}, name={name}, version={version}")

    _send_group_event(room_group_name, "started", {"execution_id": str(execution.uuid), "action": "fine_tune"})
    _persist_event(execution, "started", {"execution_id": str(execution.uuid), "action": "fine_tune"})

    try:
        result = services.fine_tune_model(base_model, training_files, hyperparams, name, version)
        logger.info(f"Fine-tune result received: {result.get('status')}")
        logger.debug(f"Full fine-tune result: {result}")
        
        if isinstance(result, dict) and result.get("status") == "completed":
            model_path = result.get("model_path") or result.get("path") or ""
            model_version = result.get("version") or version
            new_model = AgentModel.objects.create(name=name, version=model_version, path=model_path)
            agent.model = new_model
            agent.save()
            logger.info(f"Fine-tune completed. New model created: {new_model.uuid} at {model_path}")
            
            if org_training_files:
                file_ids = [tf.id for tf in org_training_files]
                TrainingFile.objects.filter(id__in=file_ids).update(is_processed=True)
                logger.info(f"Marked {len(org_training_files)} training files as processed")
            

            execution.status = "completed"
            execution.output_data = {
                "result": result,
                "model_id": new_model.id,
                "model_uuid": str(new_model.uuid),
            }
            execution.completed_at = timezone.now()
            execution.save()
            _update_agent_status(agent, "completed")
            logger.info(f"Execution {execution_id} completed successfully")

            _send_group_event(room_group_name, "completed", {"execution_id": str(execution.uuid), "model_id": new_model.id, "model_path": model_path})
            _persist_event(execution, "completed", {"execution_id": str(execution.uuid), "model_id": new_model.id, "model_path": model_path})

            async_to_sync(get_channel_layer().group_send)(
                room_group_name,
                {
                    "type": "mlstore_completed",
                    "execution_id": str(execution.uuid),
                    "output_data": execution.output_data,
                },
            )

            return {"status": "completed", "execution_id": execution_id, "model_id": new_model.id}

        logger.warning(f"Fine-tune did not complete successfully. Status: {result.get('status')}")
        execution.status = "failed"
        execution.error_message = str(result)
        execution.completed_at = timezone.now()
        execution.save()
        _update_agent_status(agent, "failed")

        _send_group_event(room_group_name, "error", {"execution_id": str(execution.uuid), "error": result})
        _persist_event(execution, "error", {"execution_id": str(execution.uuid), "error": result})

        async_to_sync(get_channel_layer().group_send)(
            room_group_name,
            {
                "type": "mlstore_error",
                "execution_id": str(execution.uuid),
                "error_message": str(result),
            },
        )
        return {"status": "failed", "execution_id": execution_id, "result": result}

    except Exception as e:
        logger.error(f"Fine-tune task failed with exception for execution {execution_id}: {str(e)}", exc_info=True)
        traceback.print_exc()
        execution.status = "failed"
        execution.error_message = str(e)
        execution.completed_at = timezone.now()
        execution.save()
        _update_agent_status(agent, "failed")
        _send_group_event(room_group_name, "error", {"execution_id": str(execution.uuid), "error": str(e)})
        _persist_event(execution, "error", {"execution_id": str(execution.uuid), "error": str(e)})
        async_to_sync(get_channel_layer().group_send)(
            room_group_name,
            {
                "type": "mlstore_error",
                "execution_id": str(execution.uuid),
                "error_message": str(e),
            },
        )
        return {"status": "error", "execution_id": execution_id, "error": str(e)}


@shared_task
def infer_run_task(execution_id: str):
    logger.info(f"Inference run task started for execution: {execution_id}")
    try:
        execution = AgentRun.objects.get(uuid=execution_id)
    except AgentRun.DoesNotExist:
        logger.error(f"Execution not found: {execution_id}")
        return {"status": "error", "error": "execution_not_found", "execution_id": execution_id}

    agent = execution.agent
    room_group_name = f"mlstore_agent_{agent.uuid}"
    logger.info(f"Agent: {agent.uuid}, User: {execution.user.email_address}")

    execution.status = "running"
    execution.started_at = timezone.now()
    execution.save()
    _update_agent_status(agent, "running")
    logger.info(f"Execution {execution_id} status updated to 'running'")

    input_data = execution.input_data or {}
    prompt = input_data.get("prompt") or input_data.get("query") or ""
    options = input_data.get("options") or {}
    logger.info(f"Prompt length: {len(prompt)} characters")

    if not prompt:
        logger.warning(f"No prompt provided for inference run {execution_id}")
        execution.status = "failed"
        execution.error_message = "prompt_required"
        execution.completed_at = timezone.now()
        execution.save()
        _update_agent_status(agent, "failed")
        _send_group_event(room_group_name, "error", {"execution_id": str(execution.uuid), "error": "prompt_required"})
        _persist_event(execution, "error", {"execution_id": str(execution.uuid), "error": "prompt_required"})
        async_to_sync(get_channel_layer().group_send)(
            room_group_name,
            {
                "type": "mlstore_error",
                "execution_id": str(execution.uuid),
                "error_message": "prompt_required",
            },
        )
        return {"status": "failed", "execution_id": execution_id, "error": "prompt_required"}

    _send_group_event(room_group_name, "started", {"execution_id": str(execution.uuid), "action": "infer"})
    _persist_event(execution, "started", {"execution_id": str(execution.uuid), "action": "infer"})

    try:
        try:
            logger.info(f"Loading model: {agent.model.path}")
            services.load_model_for_inference(agent.model.path)
        except Exception as e:
            logger.warning(f"Failed to preload model: {str(e)}")
            pass

        logger.info(f"Starting inference with model: {agent.model.path}")
        result = services.infer_with_model(agent.model.path, prompt, options)

        execution.status = "completed"
        execution.output_data = {"result": result}
        execution.completed_at = timezone.now()
        execution.save()
        _update_agent_status(agent, "completed")
        logger.info(f"Inference execution {execution_id} completed successfully")

        _send_group_event(room_group_name, "completed", {"execution_id": str(execution.uuid), "result": result})
        _persist_event(execution, "completed", {"execution_id": str(execution.uuid), "result": result})
        async_to_sync(get_channel_layer().group_send)(
            room_group_name,
            {
                "type": "mlstore_completed",
                "execution_id": str(execution.uuid),
                "output_data": execution.output_data,
            },
        )
        return {"status": "completed", "execution_id": execution_id}

    except Exception as e:
        logger.error(f"Inference task failed with exception for execution {execution_id}: {str(e)}", exc_info=True)
        traceback.print_exc()
        execution.status = "failed"
        execution.error_message = str(e)
        execution.completed_at = timezone.now()
        execution.save()
        _update_agent_status(agent, "failed")
        _send_group_event(room_group_name, "error", {"execution_id": str(execution.uuid), "error": str(e)})
        _persist_event(execution, "error", {"execution_id": str(execution.uuid), "error": str(e)})
        async_to_sync(get_channel_layer().group_send)(
            room_group_name,
            {
                "type": "mlstore_error",
                "execution_id": str(execution.uuid),
                "error_message": str(e),
            },
        )
        return {"status": "failed", "execution_id": execution_id, "error": str(e)}