"""
LoRA Knowledge Distillation Trainer for MangoMAS Local

This module implements the main training loop for knowledge distillation
with LoRA fine-tuning optimized for Mac Mini hardware constraints.
"""

import argparse
import json
import logging
import os
import sys
from datetime import datetime
from pathlib import Path
from typing import Dict, List

import torch
import torch.nn as nn
import yaml
from peft import LoraConfig, TaskType, get_peft_model
from torch.utils.data import DataLoader
from torch.utils.tensorboard import SummaryWriter
from tqdm import tqdm
from transformers import (AutoModelForCausalLM, AutoTokenizer,
                          get_linear_schedule_with_warmup)

# Try to import context7 for enhanced training
try:
    from context7 import Context7

    CONTEXT7_AVAILABLE = True
except ImportError:
    CONTEXT7_AVAILABLE = False
    Context7 = None

# Try to import MLflow for experiment tracking
try:
    import mlflow

    MLFLOW_AVAILABLE = True
except ImportError:
    MLFLOW_AVAILABLE = False
    mlflow = None

# Fix import path issues for distillation loss
sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
sys.path.append(os.path.dirname(os.path.abspath(__file__)))

try:
    from distillation_loss import AdaptiveDistillationLoss, DistillationLoss
except ImportError:
    try:
        from training.distillation_loss import (AdaptiveDistillationLoss,
                                                DistillationLoss)
    except ImportError:
        # Fallback: create minimal distillation loss if not available
        class DistillationLoss:
            def __init__(self, alpha=0.5, temperature=2.0):
                self.alpha = alpha
                self.temperature = temperature
                self.task_loss = nn.CrossEntropyLoss()

            def compute_loss(
                self, student_logits, teacher_logits, labels, attention_mask=None
            ):
                # Task loss (standard cross-entropy)
                shift_logits = student_logits[..., :-1, :].contiguous()
                shift_labels = labels[..., 1:].contiguous()
                task_loss = self.task_loss(
                    shift_logits.view(-1, shift_logits.size(-1)), shift_labels.view(-1)
                )

                # Distillation loss (KL divergence)
                if teacher_logits is not None:
                    student_probs = nn.functional.log_softmax(
                        student_logits / self.temperature, dim=-1
                    )
                    teacher_probs = nn.functional.softmax(
                        teacher_logits / self.temperature, dim=-1
                    )
                    distill_loss = nn.functional.kl_div(
                        student_probs, teacher_probs, reduction="batchmean"
                    )
                    distill_loss *= self.temperature**2
                else:
                    distill_loss = torch.tensor(0.0)

                # Combined loss
                total_loss = (1 - self.alpha) * task_loss + self.alpha * distill_loss

                return total_loss, {
                    "total_loss": total_loss.item(),
                    "task_loss": task_loss.item(),
                    "distillation_loss": (
                        distill_loss.item()
                        if isinstance(distill_loss, torch.Tensor)
                        else 0.0
                    ),
                }

        AdaptiveDistillationLoss = DistillationLoss  # Fallback

logger = logging.getLogger(__name__)


class ConversationDataset:
    """Dataset class for conversation-based training data."""

    def __init__(self, data_path: str, tokenizer, max_length: int = 512):
        self.tokenizer = tokenizer
        self.max_length = max_length
        self.data = self._load_data(data_path)

    def _load_data(self, data_path: str) -> List[Dict]:
        """Load conversation data from JSONL file."""
        data = []
        with open(data_path, "r", encoding="utf-8") as f:
            for line in f:
                data.append(json.loads(line.strip()))
        return data

    def __len__(self) -> int:
        return len(self.data)

    def __getitem__(self, idx: int) -> Dict[str, torch.Tensor]:
        """Get tokenized conversation item."""
        item = self.data[idx]

        # Handle different data formats
        if "messages" in item:
            # Chat format with messages
            conversation_text = ""
            for message in item["messages"]:
                role = message["role"]
                content = message["content"]
                conversation_text += f"<{role}>\n{content}\n</{role}>\n\n"
        elif "instruction" in item and "response" in item:
            # Instruction-response format
            instruction = item["instruction"]
            response = item["response"]
            conversation_text = f"<user>\n{instruction}\n</user>\n\n<assistant>\n{response}\n</assistant>\n\n"
        elif "prompt" in item and "completion" in item:
            # Prompt-completion format
            prompt = item["prompt"]
            completion = item["completion"]
            conversation_text = f"<user>\n{prompt}\n</user>\n\n<assistant>\n{completion}\n</assistant>\n\n"
        else:
            # Fallback - try to extract any text
            conversation_text = str(item)

        # Tokenize
        encoding = self.tokenizer(
            conversation_text,
            truncation=True,
            padding="max_length",
            max_length=self.max_length,
            return_tensors="pt",
        )

        return {
            "input_ids": encoding["input_ids"].squeeze(),
            "attention_mask": encoding["attention_mask"].squeeze(),
            "labels": encoding["input_ids"].squeeze().clone(),
            "agent_type": item.get("agent_type", "unknown"),
        }


class LoRADistillationTrainer:
    """Main trainer class for LoRA knowledge distillation."""

    def __init__(self, config_path: str):
        """Initialize trainer with configuration."""
        with open(config_path, "r") as f:
            self.config = yaml.safe_load(f)

        self.setup_logging()
        self.setup_device()
        self.setup_monitoring()

        logger.info("Initialized LoRA Distillation Trainer")
        logger.info(f"Device: {self.device}")
        logger.info(f"Config: {config_path}")

    def setup_logging(self) -> None:
        """Set up logging configuration."""
        log_dir = Path("logs")
        log_dir.mkdir(exist_ok=True)

        logging.basicConfig(
            level=logging.INFO,
            format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
            handlers=[
                logging.FileHandler(log_dir / "training.log"),
                logging.StreamHandler(),
            ],
        )

    def setup_device(self) -> None:
        """Set up compute device (MPS for Mac Mini)."""
        device_config = self.config["hardware"]["device"]

        if device_config == "mps" and torch.backends.mps.is_available():
            self.device = torch.device("mps")
            logger.info("Using Apple Metal Performance Shaders (MPS)")
        elif device_config == "cuda" and torch.cuda.is_available():
            self.device = torch.device("cuda")
            logger.info(f"Using CUDA: {torch.cuda.get_device_name()}")
        else:
            self.device = torch.device("cpu")
            logger.warning("Using CPU - training will be slow")

    def setup_monitoring(self) -> None:
        """Set up experiment tracking and monitoring."""
        self.use_tensorboard = self.config["monitoring"]["use_tensorboard"]
        self.use_mlflow = self.config["monitoring"]["use_mlflow"]

        if self.use_tensorboard:
            log_dir = self.config["monitoring"]["log_dir"]
            Path(log_dir).mkdir(parents=True, exist_ok=True)
            self.tb_writer = SummaryWriter(log_dir)
            logger.info(f"TensorBoard logging to: {log_dir}")

        if self.use_mlflow:
            try:
                import mlflow

                experiment_name = self.config["monitoring"]["experiment_name"]
                mlflow.set_experiment(experiment_name)
                logger.info(f"MLflow experiment: {experiment_name}")
            except (ImportError, AttributeError) as e:
                logger.warning(
                    f"MLflow not available or not properly initialized, disabling: {e}"
                )
                self.use_mlflow = False

    def load_models(self) -> None:
        """Load teacher and student models."""
        # Load tokenizer
        model_name = self.config["models"]["student"]["base_model"]
        self.tokenizer = AutoTokenizer.from_pretrained(model_name)

        # Add pad token if it doesn't exist
        if self.tokenizer.pad_token is None:
            self.tokenizer.pad_token = self.tokenizer.eos_token

        # Load student model - fix deprecated torch_dtype
        dtype = (
            torch.float16
            if self.config["optimization"]["use_fp16"] and self.device.type == "cuda"
            else torch.float32
        )

        self.student_model = AutoModelForCausalLM.from_pretrained(
            model_name,
            dtype=dtype,  # Use dtype instead of torch_dtype
            device_map="auto" if self.device.type == "cuda" else None,
            trust_remote_code=True,
        )

        # Apply LoRA to student model - fix target modules for DialoGPT
        target_modules = self.config["lora"]["target_modules"]
        # If using default transformer modules but this is DialoGPT, adjust
        if target_modules == ["q_proj", "v_proj", "k_proj", "o_proj"]:
            target_modules = ["c_attn", "c_proj", "c_fc"]  # DialoGPT modules
            logger.info("Adjusted LoRA target modules for DialoGPT architecture")

        lora_config = LoraConfig(
            r=self.config["lora"]["r"],
            lora_alpha=self.config["lora"]["lora_alpha"],
            target_modules=target_modules,
            lora_dropout=self.config["lora"]["lora_dropout"],
            bias=self.config["lora"]["bias"],
            task_type=TaskType.CAUSAL_LM,
        )

        self.student_model = get_peft_model(self.student_model, lora_config)
        self.student_model.to(self.device)

        # Setup teacher model
        self.teacher_manager = TeacherModelManager(
            self.config["models"]["teacher"], self.tokenizer
        )

        logger.info("Loaded student model with LoRA")
        logger.info(
            f"Trainable parameters: {self.student_model.num_parameters(only_trainable=True):,}"
        )
        logger.info("Loaded teacher model")

    def load_datasets(self, agent_type: str) -> tuple:
        """Load training and validation datasets for specific agent."""
        data_dir = Path("data/processed")

        train_path = data_dir / f"{agent_type}_train.jsonl"
        val_path = data_dir / f"{agent_type}_validation.jsonl"

        if not train_path.exists():
            raise FileNotFoundError(f"Training data not found: {train_path}")
        if not val_path.exists():
            raise FileNotFoundError(f"Validation data not found: {val_path}")

        max_length = self.config["data"]["max_sequence_length"]

        train_dataset = ConversationDataset(train_path, self.tokenizer, max_length)
        val_dataset = ConversationDataset(val_path, self.tokenizer, max_length)

        logger.info(
            f"Loaded datasets: {len(train_dataset)} train, {len(val_dataset)} val"
        )

        return train_dataset, val_dataset

    def create_data_loaders(self, train_dataset, val_dataset) -> tuple:
        """Create data loaders for training and validation."""
        batch_size = self.config["training"]["batch_size"]
        num_workers = self.config["optimization"]["dataloader_num_workers"]
        pin_memory = self.config["optimization"]["pin_memory"]

        train_loader = DataLoader(
            train_dataset,
            batch_size=batch_size,
            shuffle=True,
            num_workers=num_workers,
            pin_memory=pin_memory,
            drop_last=True,
        )

        val_loader = DataLoader(
            val_dataset,
            batch_size=batch_size,
            shuffle=False,
            num_workers=num_workers,
            pin_memory=pin_memory,
            drop_last=False,
        )

        return train_loader, val_loader

    def setup_training(self, train_dataset_size: int) -> None:
        """Set up optimizer, scheduler, and loss function."""
        # Calculate training steps
        batch_size = self.config["training"]["batch_size"]
        gradient_accumulation_steps = self.config["training"][
            "gradient_accumulation_steps"
        ]
        num_epochs = self.config["training"]["num_epochs"]

        steps_per_epoch = train_dataset_size // (
            batch_size * gradient_accumulation_steps
        )
        self.total_steps = steps_per_epoch * num_epochs

        # Setup optimizer
        self.optimizer = torch.optim.AdamW(
            self.student_model.parameters(),
            lr=self.config["training"]["learning_rate"],
            weight_decay=0.01,
        )

        # Setup scheduler
        self.scheduler = get_linear_schedule_with_warmup(
            self.optimizer,
            num_warmup_steps=self.config["training"]["warmup_steps"],
            num_training_steps=self.total_steps,
        )

        # Setup loss function
        self.distill_loss = DistillationLoss(
            alpha=self.config["distillation"]["alpha"],
            temperature=self.config["distillation"]["temperature"],
        )

        logger.info(f"Setup training: {self.total_steps} total steps")

    def train_epoch(self, train_loader: DataLoader, epoch: int) -> Dict[str, float]:
        """Train for one epoch."""
        self.student_model.train()

        total_loss = 0.0
        total_task_loss = 0.0
        total_distill_loss = 0.0
        num_batches = 0

        progress_bar = tqdm(train_loader, desc=f"Epoch {epoch+1}", disable=False)

        for batch_idx, batch in enumerate(progress_bar):
            # Move batch to device
            input_ids = batch["input_ids"].to(self.device)
            attention_mask = batch["attention_mask"].to(self.device)
            labels = batch["labels"].to(self.device)

            # Get student outputs
            student_outputs = self.student_model(
                input_ids=input_ids, attention_mask=attention_mask
            )
            student_logits = student_outputs.logits

            # Get teacher outputs
            with torch.no_grad():
                teacher_logits = self.teacher_manager.get_logits(
                    input_ids, attention_mask
                )

            # Compute distillation loss
            loss, loss_dict = self.distill_loss.compute_loss(
                student_logits, teacher_logits, labels, attention_mask
            )

            # Backward pass with gradient accumulation
            loss = loss / self.config["training"]["gradient_accumulation_steps"]
            loss.backward()

            # Update model
            if (batch_idx + 1) % self.config["training"][
                "gradient_accumulation_steps"
            ] == 0:
                torch.nn.utils.clip_grad_norm_(
                    self.student_model.parameters(),
                    self.config["training"]["max_grad_norm"],
                )
                self.optimizer.step()
                self.scheduler.step()
                self.optimizer.zero_grad()

            # Track metrics
            total_loss += loss_dict["total_loss"]
            total_task_loss += loss_dict["task_loss"]
            total_distill_loss += loss_dict["distillation_loss"]
            num_batches += 1

            # Update progress bar
            progress_bar.set_postfix(
                {
                    "loss": f"{loss_dict['total_loss']:.4f}",
                    "task": f"{loss_dict['task_loss']:.4f}",
                    "distill": f"{loss_dict['distillation_loss']:.4f}",
                }
            )

            # Log to tensorboard
            if (
                self.use_tensorboard
                and batch_idx % self.config["training"]["logging_steps"] == 0
            ):
                step = epoch * len(train_loader) + batch_idx
                self.tb_writer.add_scalar(
                    "train/total_loss", loss_dict["total_loss"], step
                )
                self.tb_writer.add_scalar(
                    "train/task_loss", loss_dict["task_loss"], step
                )
                self.tb_writer.add_scalar(
                    "train/distillation_loss", loss_dict["distillation_loss"], step
                )

        # Calculate epoch averages
        epoch_metrics = {
            "avg_loss": total_loss / num_batches,
            "avg_task_loss": total_task_loss / num_batches,
            "avg_distill_loss": total_distill_loss / num_batches,
        }

        return epoch_metrics

    def evaluate(self, val_loader: DataLoader) -> Dict[str, float]:
        """Evaluate model on validation set."""
        self.student_model.eval()

        total_loss = 0.0
        total_task_loss = 0.0
        total_distill_loss = 0.0
        num_batches = 0

        with torch.no_grad():
            for batch in tqdm(val_loader, desc="Evaluating"):
                # Move batch to device
                input_ids = batch["input_ids"].to(self.device)
                attention_mask = batch["attention_mask"].to(self.device)
                labels = batch["labels"].to(self.device)

                # Get model outputs
                student_outputs = self.student_model(
                    input_ids=input_ids, attention_mask=attention_mask
                )
                student_logits = student_outputs.logits

                # Get teacher outputs
                teacher_logits = self.teacher_manager.get_logits(
                    input_ids, attention_mask
                )

                # Compute loss
                loss, loss_dict = self.distill_loss.compute_loss(
                    student_logits, teacher_logits, labels, attention_mask
                )

                total_loss += loss_dict["total_loss"]
                total_task_loss += loss_dict["task_loss"]
                total_distill_loss += loss_dict["distillation_loss"]
                num_batches += 1

        val_metrics = {
            "val_loss": total_loss / num_batches,
            "val_task_loss": total_task_loss / num_batches,
            "val_distill_loss": total_distill_loss / num_batches,
        }

        return val_metrics

    def save_model(self, output_dir: str, agent_type: str, epoch: int) -> None:
        """Save model checkpoint."""
        output_path = Path(output_dir) / agent_type / f"epoch_{epoch}"
        output_path.mkdir(parents=True, exist_ok=True)

        # Save LoRA adapter
        self.student_model.save_pretrained(output_path)

        # Save tokenizer
        self.tokenizer.save_pretrained(output_path)

        # Save training config
        config_path = output_path / "training_config.yaml"
        with open(config_path, "w") as f:
            yaml.dump(self.config, f)

        logger.info(f"Saved model to: {output_path}")

    def train_agent(self, agent_type: str) -> None:
        """Train a specific agent with knowledge distillation."""
        logger.info(f"Starting training for {agent_type} agent")

        # Load models if not already loaded
        if not hasattr(self, "student_model"):
            self.load_models()

        # Load datasets
        train_dataset, val_dataset = self.load_datasets(agent_type)
        train_loader, val_loader = self.create_data_loaders(train_dataset, val_dataset)

        # Setup training components
        self.setup_training(len(train_dataset))

        # Start MLflow run
        if self.use_mlflow:
            mlflow.start_run(
                run_name=f"{agent_type}_{datetime.now().strftime('%Y%m%d_%H%M%S')}"
            )
            mlflow.log_params(
                {
                    "agent_type": agent_type,
                    "model_name": self.config["models"]["student"]["base_model"],
                    "lora_r": self.config["lora"]["r"],
                    "lora_alpha": self.config["lora"]["lora_alpha"],
                    "batch_size": self.config["training"]["batch_size"],
                    "learning_rate": self.config["training"]["learning_rate"],
                    "distillation_alpha": self.config["distillation"]["alpha"],
                    "temperature": self.config["distillation"]["temperature"],
                }
            )

        try:
            # Training loop
            best_val_loss = float("inf")
            num_epochs = self.config["training"]["num_epochs"]

            for epoch in range(num_epochs):
                logger.info(f"Epoch {epoch+1}/{num_epochs}")

                # Train
                train_metrics = self.train_epoch(train_loader, epoch)
                logger.info(
                    f"Train - Loss: {train_metrics['avg_loss']:.4f}, "
                    f"Task: {train_metrics['avg_task_loss']:.4f}, "
                    f"Distill: {train_metrics['avg_distill_loss']:.4f}"
                )

                # Evaluate
                val_metrics = self.evaluate(val_loader)
                logger.info(
                    f"Val - Loss: {val_metrics['val_loss']:.4f}, "
                    f"Task: {val_metrics['val_task_loss']:.4f}, "
                    f"Distill: {val_metrics['val_distill_loss']:.4f}"
                )

                # Log to MLflow
                if self.use_mlflow:
                    mlflow.log_metrics({**train_metrics, **val_metrics}, step=epoch)

                # Log to TensorBoard
                if self.use_tensorboard:
                    for key, value in train_metrics.items():
                        self.tb_writer.add_scalar(f"epoch/{key}", value, epoch)
                    for key, value in val_metrics.items():
                        self.tb_writer.add_scalar(f"epoch/{key}", value, epoch)

                # Save checkpoint if best model
                if val_metrics["val_loss"] < best_val_loss:
                    best_val_loss = val_metrics["val_loss"]
                    self.save_model(
                        self.config["output"]["base_dir"], agent_type, epoch
                    )
                    logger.info(f"New best model saved (val_loss: {best_val_loss:.4f})")

        finally:
            if self.use_mlflow:
                mlflow.end_run()

        logger.info(f"Training completed for {agent_type} agent")


class TeacherModelManager:
    """Manages teacher model interactions (API or local)."""

    def __init__(self, teacher_config: Dict, tokenizer):
        self.config = teacher_config
        self.tokenizer = tokenizer

        if teacher_config["type"] == "api":
            self.setup_api_teacher()
        else:
            self.setup_local_teacher()

    def setup_api_teacher(self) -> None:
        """Set up API-based teacher model."""
        self.model_name = self.config["model_name"]
        logger.info(f"Using API teacher model: {self.model_name}")

        # This would integrate with OpenAI/Anthropic APIs
        # For now, we'll use a placeholder that returns random logits
        # In production, you'd implement actual API calls here

    def setup_local_teacher(self) -> None:
        """Set up local teacher model."""
        model_path = self.config.get("local_model_path", "microsoft/DialoGPT-large")

        self.teacher_model = AutoModelForCausalLM.from_pretrained(
            model_path, torch_dtype=torch.float16, device_map="auto"
        )
        logger.info(f"Loaded local teacher model: {model_path}")

    def get_logits(
        self, input_ids: torch.Tensor, attention_mask: torch.Tensor
    ) -> torch.Tensor:
        """Get teacher model logits."""
        if self.config["type"] == "api":
            # Placeholder for API-based teacher
            # In practice, you'd call the API and convert responses to logits
            batch_size, seq_len = input_ids.shape
            vocab_size = self.tokenizer.vocab_size
            return torch.randn(batch_size, seq_len, vocab_size).to(input_ids.device)
        else:
            # Local teacher model
            with torch.no_grad():
                outputs = self.teacher_model(
                    input_ids=input_ids, attention_mask=attention_mask
                )
                return outputs.logits


def main():
    parser = argparse.ArgumentParser(
        description="Train MangoMAS agents with LoRA and knowledge distillation"
    )
    parser.add_argument(
        "--config",
        type=str,
        default="config/training/distillation.yaml",
        help="Path to training configuration file",
    )
    parser.add_argument(
        "--agent",
        type=str,
        choices=["infrastructure", "devsecops", "risk_assessment", "all"],
        default="all",
        help="Which agent to train",
    )
    parser.add_argument("--data", type=str, help="Path to training data file")

    args = parser.parse_args()

    # Initialize trainer
    trainer = LoRADistillationTrainer(args.config)

    # If data path is provided, update the trainer to use it
    if args.data:
        trainer.custom_data_path = args.data

    # Train specified agent(s)
    if args.agent == "all":
        agents = ["infrastructure", "devsecops", "risk_assessment"]
    else:
        agents = [args.agent]

    for agent_type in agents:
        trainer.train_agent(agent_type)


if __name__ == "__main__":
    main()