"""
Módulo para procesamiento por lotes de extracción de eventos 5W1H.
Incluye checkpoints, logging, batching para GPU y capacidad de retomar procesos.
"""

import json
import ast
import os
import logging
from typing import List, Dict, Any, Optional
from tqdm.auto import tqdm

from .classic import ClassicExtractorV3

logger = logging.getLogger(__name__)


def parse_dbpedia_entities(raw_entities) -> List[Dict]:
    """Parsea las entidades DBpedia de forma segura."""
    if not raw_entities:
        return []
    if isinstance(raw_entities, list):
        return raw_entities
    if isinstance(raw_entities, str):
        try:
            return ast.literal_eval(raw_entities)
        except (ValueError, SyntaxError):
            return []
    return []


def extract_events_from_doc(doc, extractor: ClassicExtractorV3, dbpedia_ents: List[Dict]) -> List[Dict]:
    """
    Extrae eventos 5W1H de un documento Stanza ya procesado.
    Procesa TODAS las oraciones del documento.
    """
    events = []
    for sent in doc.sentences:
        event = extractor.extract(sent, dbpedia_ents=dbpedia_ents)
        # Filtrar eventos vacíos
        if event['who'][0]['start'] != -1 or event['what'][0]['start'] != -1:
            events.append(event)
    return events


def process_corpus_batched(
    df,
    nlp,
    output_path: str,
    text_column: str = 'articleBody',
    entities_column: str = 'named_entities_dbpedia',
    checkpoint_interval: int = 500,
    resume_from: int = 0,
    batch_size: int = 32
):
    """
    Procesa corpus con BATCHING para máximo rendimiento en GPU.
    Procesa el texto COMPLETO de cada noticia (sin límite de caracteres).
    
    Args:
        df: DataFrame con el corpus
        nlp: Pipeline de Stanza
        output_path: Ruta para guardar resultados
        text_column: Nombre de columna con el texto
        entities_column: Nombre de columna con entidades DBpedia
        checkpoint_interval: Frecuencia de guardado automático
        resume_from: Índice desde donde retomar
        batch_size: Número de documentos por batch (32-64 recomendado para T4)
    """
    import pandas as pd
    
    results = ['[]'] * len(df)
    
    # Cargar resultados previos si existen
    if resume_from > 0 and os.path.exists(output_path):
        df_prev = pd.read_csv(output_path)
        for i in range(min(resume_from, len(df_prev))):
            results[i] = df_prev.iloc[i].get('events_5w1h', '[]')
        logger.info(f"Retomando desde índice {resume_from}")

    total_docs = len(df) - resume_from
    logger.info(f"Procesando {total_docs} documentos con batch_size={batch_size}")
    
    processed = 0
    errors = 0
    
    # Procesar en batches
    indices = list(range(resume_from, len(df)))
    
    for batch_start in tqdm(range(0, len(indices), batch_size), 
                            desc="Batches", 
                            total=(len(indices) + batch_size - 1) // batch_size):
        
        batch_indices = indices[batch_start:batch_start + batch_size]
        batch_rows = [df.iloc[i] for i in batch_indices]
        
        # Preparar textos del batch (sin límite de caracteres)
        batch_texts = []
        batch_entities = []
        valid_indices = []
        
        for idx, row in zip(batch_indices, batch_rows):
            text = row.get(text_column, '')
            if isinstance(text, str) and len(text) >= 20:
                batch_texts.append(text)
                batch_entities.append(parse_dbpedia_entities(row.get(entities_column)))
                valid_indices.append(idx)
            else:
                results[idx] = '[]'
        
        if not batch_texts:
            continue
            
        try:
            # Procesamiento batch con Stanza
            docs = nlp.bulk_process(batch_texts)
            
            # Extraer eventos de cada documento
            for doc, entities, idx in zip(docs, batch_entities, valid_indices):
                try:
                    extractor = ClassicExtractorV3()
                    extractor.reset_context()
                    events = extract_events_from_doc(doc, extractor, entities)
                    results[idx] = json.dumps(events, ensure_ascii=False)
                    processed += 1
                except Exception as e:
                    logger.error(f"Error extrayendo eventos doc {idx}: {e}")
                    results[idx] = '[]'
                    errors += 1
                    
        except Exception as e:
            logger.error(f"Error en batch {batch_start}: {e}")
            for idx in valid_indices:
                results[idx] = '[]'
                errors += 1
        
        # Checkpoint
        if processed > 0 and processed % checkpoint_interval == 0:
            df_temp = df.copy()
            df_temp['events_5w1h'] = results
            df_temp.to_csv(output_path, index=False)
            logger.info(f"Checkpoint: {processed} documentos procesados")

    df['events_5w1h'] = results
    logger.info(f"Completado: {processed} procesados, {errors} errores")
    return df


# Mantener función original para compatibilidad
def process_corpus(
    df,
    nlp,
    output_path: str,
    text_column: str = 'articleBody',
    entities_column: str = 'named_entities_dbpedia',
    checkpoint_interval: int = 500,
    resume_from: int = 0,
    max_text_length: int = None  # None = sin límite
):
    """
    Procesa corpus documento a documento (versión simple).
    Para mejor rendimiento GPU, usar process_corpus_batched.
    """
    import pandas as pd
    
    extractor = ClassicExtractorV3()
    results = ['[]'] * len(df)
    
    if resume_from > 0 and os.path.exists(output_path):
        df_prev = pd.read_csv(output_path)
        for i in range(min(resume_from, len(df_prev))):
            results[i] = df_prev.iloc[i].get('events_5w1h', '[]')
        logger.info(f"Retomando desde índice {resume_from}")

    logger.info(f"Procesando {len(df) - resume_from} documentos...")
    
    processed = 0
    errors = 0
    
    for index in tqdm(range(resume_from, len(df)), initial=resume_from, total=len(df)):
        row = df.iloc[index]
        try:
            text = row.get(text_column, '')
            if not isinstance(text, str) or len(text) < 20:
                continue
                
            # Aplicar límite solo si se especifica
            if max_text_length:
                text = text[:max_text_length]
                
            dbpedia_ents = parse_dbpedia_entities(row.get(entities_column))
            
            doc = nlp(text)
            extractor.reset_context()
            events = extract_events_from_doc(doc, extractor, dbpedia_ents)
            
            results[index] = json.dumps(events, ensure_ascii=False)
            processed += 1

            if processed % checkpoint_interval == 0:
                df_temp = df.copy()
                df_temp['events_5w1h'] = results
                df_temp.to_csv(output_path, index=False)
                logger.info(f"Checkpoint: {processed} documentos procesados")

        except Exception as e:
            logger.error(f"Error en doc {index}: {e}")
            results[index] = '[]'
            errors += 1

    df['events_5w1h'] = results
    logger.info(f"Completado: {processed} procesados, {errors} errores")
    return df