#!/usr/bin/env python3
"""
Final training script for Elizabeth - proper tokenization and formatting
"""

import os
os.environ['HF_HOME'] = '/home/x/.cache/huggingface'

import torch
from transformers import (
    AutoModelForCausalLM, 
    AutoTokenizer, 
    TrainingArguments, 
    Trainer,
    DataCollatorForLanguageModeling
)
from datasets import Dataset
import json

# Configuration
MODEL_NAME = "Qwen/Qwen3-8B"
TRAIN_DATA_PATH = "/home/x/adaptai/aiml/e-train-1/elizabeth_tooluse_minipack_v1.jsonl"
OUTPUT_DIR = "/home/x/adaptai/experiments/qwen3-8b-elizabeth-final"

# YaRN Configuration
YARN_CONFIG = {
    "rope_scaling": {
        "type": "yarn",
        "factor": 8.0,
        "original_max_position_embeddings": 16384,
        "extrapolation_factor": 1.0,
        "attn_factor": 1.0,
        "beta_fast": 32.0,
        "beta_slow": 1.0
    }
}

class FinalTrainer:
    def __init__(self):
        self.model = None
        self.tokenizer = None
        
    def setup_model(self):
        """Load model with YaRN configuration"""
        print("🚀 Loading Qwen3-8B with YaRN configuration...")
        
        # Load tokenizer
        self.tokenizer = AutoTokenizer.from_pretrained(
            MODEL_NAME,
            trust_remote_code=True
        )
        
        if self.tokenizer.pad_token is None:
            self.tokenizer.pad_token = self.tokenizer.eos_token
        
        # Load model with YaRN
        self.model = AutoModelForCausalLM.from_pretrained(
            MODEL_NAME,
            torch_dtype=torch.bfloat16,
            device_map="auto",
            trust_remote_code=True,
            **YARN_CONFIG
        )
        
        print(f"✅ Model loaded with YaRN configuration")
        print(f"📏 Context length: {self.model.config.max_position_embeddings}")
        
    def tokenize_function(self, examples):
        """Tokenize the text examples"""
        # Convert messages to text format
        texts = []
        for messages in examples['messages']:
            text = ""
            for msg in messages:
                if msg['role'] == 'system':
                    text += f"<|im_start|>system\n{msg['content']}<|im_end|>\n"
                elif msg['role'] == 'user':
                    text += f"<|im_start|>user\n{msg['content']}<|im_end|>\n"
                elif msg['role'] == 'assistant':
                    text += f"<|im_start|>assistant\n{msg['content']}<|im_end|>\n"
                elif msg['role'] == 'tool':
                    text += f"<|im_start|>tool\n{json.dumps(msg['content'])}<|im_end|>\n"
            texts.append(text)
        
        # Tokenize
        tokenized = self.tokenizer(
            texts,
            truncation=True,
            padding=False,
            max_length=4096,
            return_tensors=None
        )
        
        # Add labels for language modeling
        tokenized["labels"] = tokenized["input_ids"].copy()
        return tokenized
    
    def load_dataset(self):
        """Load and tokenize dataset"""
        print("📊 Loading and tokenizing data...")
        
        # Load raw data
        data = []
        with open(TRAIN_DATA_PATH, 'r') as f:
            for line in f:
                data.append(json.loads(line))
        
        # Create dataset
        dataset = Dataset.from_list(data)
        
        # Tokenize
        tokenized_dataset = dataset.map(
            self.tokenize_function,
            batched=True,
            batch_size=10,
            remove_columns=dataset.column_names
        )
        
        print(f"✅ Tokenized {len(tokenized_dataset)} examples")
        return tokenized_dataset
    
    def train(self):
        """Start training"""
        self.setup_model()
        dataset = self.load_dataset()
        
        # Training arguments
        training_args = TrainingArguments(
            output_dir=OUTPUT_DIR,
            num_train_epochs=1,
            per_device_train_batch_size=1,
            gradient_accumulation_steps=16,
            learning_rate=2e-5,
            warmup_ratio=0.03,
            lr_scheduler_type="cosine",
            logging_steps=10,
            save_steps=100,
            bf16=True,
            gradient_checkpointing=True,
            remove_unused_columns=False,
            report_to=[],
        )
        
        # Data collator
        data_collator = DataCollatorForLanguageModeling(
            tokenizer=self.tokenizer,
            mlm=False,
        )
        
        # Trainer
        trainer = Trainer(
            model=self.model,
            args=training_args,
            train_dataset=dataset,
            data_collator=data_collator,
        )
        
        print("🎯 Starting training...")
        
        # Start training
        trainer.train()
        
        # Save final model
        trainer.save_model()
        
        print(f"✅ Training completed!")
        print(f"💾 Model saved to: {OUTPUT_DIR}")

if __name__ == "__main__":
    trainer = FinalTrainer()
    trainer.train()