"""Data processing pipeline for Francis Botcon."""

import json
from pathlib import Path
from typing import List, Dict, Tuple
import sys

from src.text_processor import TextCleaner, TextSegmenter, process_raw_file
from src.logger import LoggerSetup
from src.config_loader import config

logger = LoggerSetup.setup().getChild(__name__)


class DataProcessor:
    """Process raw texts into cleaned and segmented datasets."""

    def __init__(self, raw_dir: str = None, processed_dir: str = None):
        """Initialize data processor.

        Args:
            raw_dir: Directory containing raw text files
            processed_dir: Directory for processed outputs
        """
        self.raw_dir = Path(raw_dir or config.get("data.raw_dir", "./data/raw"))
        self.processed_dir = Path(processed_dir or config.get("data.processed_dir", "./data/processed"))

        # Create directories if they don't exist
        self.processed_dir.mkdir(parents=True, exist_ok=True)

        logger.info(f"Raw data directory: {self.raw_dir}")
        logger.info(f"Processed data directory: {self.processed_dir}")

    def process_all_files(self) -> List[Dict[str, str]]:
        """Process all raw text files.

        Returns:
            List of processed document records
        """
        raw_files = list(self.raw_dir.glob("*.txt"))
        logger.info(f"Found {len(raw_files)} raw text files")

        all_segments = []

        for i, file_path in enumerate(raw_files, 1):
            logger.info(f"Processing [{i}/{len(raw_files)}]: {file_path.name}")

            try:
                cleaned_text, filename = process_raw_file(file_path)
                title, author = TextSegmenter.extract_title_and_author(cleaned_text)

                # Segment text
                segments = TextSegmenter.segment_by_paragraphs(cleaned_text, min_length=100)
                logger.info(f"  → Segmented into {len(segments)} paragraphs")

                # Create records
                for j, segment in enumerate(segments):
                    record = {
                        "id": f"{filename}_para_{j}",
                        "source": filename,
                        "title": title,
                        "author": author,
                        "segment_index": j,
                        "text": segment,
                        "length": len(segment)
                    }
                    all_segments.append(record)

            except Exception as e:
                logger.error(f"  ✗ Error processing {file_path.name}: {str(e)}")
                continue

        logger.info(f"Total segments created: {len(all_segments)}")
        return all_segments

    def save_processed_data(self, segments: List[Dict[str, str]]) -> Path:
        """Save processed segments to JSONL file.

        Args:
            segments: List of processed segments

        Returns:
            Path to saved file
        """
        output_path = self.processed_dir / "processed_segments.jsonl"

        logger.info(f"Saving {len(segments)} segments to {output_path}")

        with open(output_path, 'w', encoding='utf-8') as f:
            for segment in segments:
                f.write(json.dumps(segment, ensure_ascii=False) + '\n')

        logger.info(f"✓ Saved to {output_path}")
        return output_path

    def create_training_examples(self, segments: List[Dict[str, str]]) -> List[Dict[str, str]]:
        """Create instruction-response training examples from segments.

        Args:
            segments: Processed text segments

        Returns:
            List of training examples
        """
        examples = []

        # Example templates for generating instruction-response pairs
        templates = [
            {
                "instruction": "Explain this passage from your works as if speaking to a contemporary scholar:",
                "prefix": "In this passage, I discuss: "
            },
            {
                "instruction": "What philosophical principle does this text embody?",
                "prefix": "This passage exemplifies the principle that "
            },
            {
                "instruction": "Summarize the main argument of this passage:",
                "prefix": "The essential point I make here is that "
            },
        ]

        logger.info(f"Creating training examples from {len(segments)} segments")

        for i, segment in enumerate(segments):
            text = segment["text"]

            # Skip very short segments
            if len(text.split()) < 20:
                continue

            # Create multiple examples from each segment
            for template in templates[:1]:  # Use at least first template
                example = {
                    "instruction": template["instruction"],
                    "input": text[:200] + "..." if len(text) > 200 else text,
                    "output": template["prefix"] + text[:300],
                    "source": segment["source"],
                    "segment_id": segment["id"]
                }
                examples.append(example)

        logger.info(f"Created {len(examples)} training examples")
        return examples

    def save_training_data(self, examples: List[Dict[str, str]]) -> Path:
        """Save training examples to JSON file.

        Args:
            examples: Training examples

        Returns:
            Path to saved file
        """
        output_path = self.processed_dir / "training_examples.json"

        logger.info(f"Saving {len(examples)} training examples to {output_path}")

        with open(output_path, 'w', encoding='utf-8') as f:
            json.dump(examples, f, ensure_ascii=False, indent=2)

        logger.info(f"✓ Saved to {output_path}")
        return output_path

    def process_pipeline(self) -> Tuple[Path, Path]:
        """Run complete data processing pipeline.

        Returns:
            Tuple of (processed_segments_path, training_data_path)
        """
        logger.info("=" * 60)
        logger.info("Starting data processing pipeline")
        logger.info("=" * 60)

        # Process all files
        segments = self.process_all_files()

        # Save processed segments
        segments_path = self.save_processed_data(segments)

        # Create training examples
        training_examples = self.create_training_examples(segments)

        # Save training data
        training_path = self.save_training_data(training_examples)

        logger.info("=" * 60)
        logger.info("Data processing pipeline completed successfully!")
        logger.info(f"Processed segments: {len(segments)}")
        logger.info(f"Training examples: {len(training_examples)}")
        logger.info("=" * 60)

        return segments_path, training_path


def main():
    """Main entry point for data processing."""
    processor = DataProcessor()
    processor.process_pipeline()


if __name__ == "__main__":
    main()