"""
Persistence utilities for datasets and scores
"""

import json
from pathlib import Path
from datetime import datetime


class SessionManager:
    """Gère la persistance des sessions de scoring"""

    def __init__(self, data_dir="/app/data"):
        self.data_dir = Path(data_dir)
        self.data_dir.mkdir(exist_ok=True)

        self.dataset_file = self.data_dir / "dataset.jsonl"
        self.session_file = self.data_dir / "session.json"

    def save_dataset(self, dataset, source_info=None):
        """
        Sauvegarde le dataset en JSONL

        Args:
            dataset: Liste de dicts
            source_info: Dict avec info sur la source (nom HF, fichier, etc.)
        """
        # Sauvegarder le dataset
        with open(self.dataset_file, 'w', encoding='utf-8') as f:
            for item in dataset:
                f.write(json.dumps(item, ensure_ascii=False) + '\n')

        # Sauvegarder les métadonnées
        metadata = {
            'saved_at': datetime.now().isoformat(),
            'total_items': len(dataset),
            'source_info': source_info or {}
        }

        metadata_file = self.data_dir / "dataset_metadata.json"
        with open(metadata_file, 'w', encoding='utf-8') as f:
            json.dump(metadata, f, indent=2, ensure_ascii=False)

        return True

    def load_dataset(self):
        """
        Charge le dataset sauvegardé

        Returns:
            Tuple (dataset, metadata) ou (None, None) si pas de dataset sauvegardé
        """
        if not self.dataset_file.exists():
            return None, None

        # Charger le dataset
        dataset = []
        with open(self.dataset_file, 'r', encoding='utf-8') as f:
            for line in f:
                if line.strip():
                    dataset.append(json.loads(line))

        # Charger les métadonnées
        metadata_file = self.data_dir / "dataset_metadata.json"
        metadata = None
        if metadata_file.exists():
            with open(metadata_file, 'r', encoding='utf-8') as f:
                metadata = json.load(f)

        return dataset, metadata

    def save_session(self, feedback_scores, feedback_comments, scoring_index):
        """
        Sauvegarde l'état de la session (scores, commentaires, position)

        Args:
            feedback_scores: Dict {idx: score}
            feedback_comments: Dict {idx: comment}
            scoring_index: Index actuel
        """
        session_data = {
            'feedback_scores': {str(k): v for k, v in feedback_scores.items()},
            'feedback_comments': {str(k): v for k, v in feedback_comments.items()},
            'scoring_index': scoring_index,
            'last_saved': datetime.now().isoformat(),
            'total_scored': len(feedback_scores)
        }

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

        return True

    def load_session(self):
        """
        Charge l'état de la session sauvegardée

        Returns:
            Dict avec feedback_scores, feedback_comments, scoring_index
            ou None si pas de session sauvegardée
        """
        if not self.session_file.exists():
            return None

        with open(self.session_file, 'r', encoding='utf-8') as f:
            session_data = json.load(f)

        # Convertir les clés en int
        session_data['feedback_scores'] = {
            int(k): v for k, v in session_data['feedback_scores'].items()
        }
        session_data['feedback_comments'] = {
            int(k): v for k, v in session_data['feedback_comments'].items()
        }

        return session_data

    def has_saved_session(self):
        """Vérifie s'il existe une session sauvegardée"""
        return self.dataset_file.exists() and self.session_file.exists()

    def clear_session(self):
        """Supprime la session sauvegardée"""
        if self.dataset_file.exists():
            self.dataset_file.unlink()
        if self.session_file.exists():
            self.session_file.unlink()

        metadata_file = self.data_dir / "dataset_metadata.json"
        if metadata_file.exists():
            metadata_file.unlink()

        return True

    def get_session_info(self):
        """
        Récupère les informations sur la session sauvegardée

        Returns:
            Dict avec les infos ou None
        """
        if not self.has_saved_session():
            return None

        dataset, dataset_metadata = self.load_dataset()
        session_data = self.load_session()

        if dataset and session_data:
            return {
                'dataset_size': len(dataset),
                'total_scored': session_data['total_scored'],
                'last_saved': session_data['last_saved'],
                'scoring_index': session_data['scoring_index'],
                'source_info': dataset_metadata.get('source_info', {}) if dataset_metadata else {}
            }

        return None