"""
Retrosheet CSV Format Transformer

This module transforms newer Retrosheet CSV formats into the legacy format
expected by retrosheet_data.py. Includes smart caching to avoid redundant
transformations.

Author: Claude Code
"""

import os
import logging
from pathlib import Path
import pandas as pd
import numpy as np

# Set up logging
logger = logging.getLogger(f'{__name__}')


def get_normalized_csv_path(source_path: str) -> str:
    """
    Generate the cached/normalized CSV path from source path.

    Args:
        source_path: Path to the source CSV file

    Returns:
        Path to the normalized cache file
    """
    source = Path(source_path)
    cache_name = f"{source.stem}_normalized{source.suffix}"
    return str(source.parent / cache_name)


def needs_transformation(source_path: str, cache_path: str) -> bool:
    """
    Check if transformation is needed based on file modification times.

    Args:
        source_path: Path to source CSV
        cache_path: Path to cached normalized CSV

    Returns:
        True if transformation needed, False if cache is valid
    """
    if not os.path.exists(cache_path):
        logger.info(f"Cache file not found: {cache_path}")
        return True

    source_mtime = os.path.getmtime(source_path)
    cache_mtime = os.path.getmtime(cache_path)

    if source_mtime > cache_mtime:
        logger.info(f"Source file is newer than cache, transformation needed")
        return True

    logger.info(f"Using cached normalized file: {cache_path}")
    return False


def transform_event_type(row: pd.Series) -> str:
    """
    Derive event_type from boolean columns in new format.

    Priority order matches baseball scoring conventions.
    """
    if row['hr'] == 1:
        return 'home run'
    elif row['triple'] == 1:
        return 'triple'
    elif row['double'] == 1:
        return 'double'
    elif row['single'] == 1:
        return 'single'
    elif row['walk'] == 1 or row['iw'] == 1:
        return 'walk'
    elif row['k'] == 1:
        return 'strikeout'
    elif row['hbp'] == 1:
        return 'hit by pitch'
    else:
        return 'generic out'


def transform_batted_ball_type(row: pd.Series) -> str:
    """
    Derive batted_ball_type from boolean columns.

    Returns 'f' (fly), 'G' (ground), 'l' (line), or empty string.
    """
    if row['fly'] == 1:
        return 'f'
    elif row['ground'] == 1:
        return 'G'
    elif row['line'] == 1:
        return 'l'
    else:
        return ''


def transform_hit_val(row: pd.Series) -> str:
    """
    Derive hit_val from hit type columns.

    Returns '1', '2', '3', '4' for singles through home runs.
    """
    if row['hr'] == 1:
        return '4'
    elif row['triple'] == 1:
        return '3'
    elif row['double'] == 1:
        return '2'
    elif row['single'] == 1:
        return '1'
    else:
        return ''


def bool_to_tf(val) -> str:
    """Convert 1/0 or True/False to 't'/'f' strings."""
    if pd.isna(val):
        return 'f'
    return 't' if val == 1 or val is True else 'f'


def transform_retrosheet_csv(source_path: str) -> pd.DataFrame:
    """
    Transform new Retrosheet CSV format to legacy format.

    Args:
        source_path: Path to source CSV file

    Returns:
        Transformed DataFrame in legacy format
    """
    logger.info(f"Reading source CSV: {source_path}")
    df = pd.read_csv(source_path, low_memory=False)

    logger.info(f"Transforming {len(df)} rows to legacy format")

    # Create new dataframe with legacy column names
    transformed = pd.DataFrame()

    # Simple renames (with case conversion for handedness)
    transformed['game_id'] = df['gid']
    transformed['batter_id'] = df['batter']
    transformed['pitcher_id'] = df['pitcher']
    transformed['batter_hand'] = df['bathand'].str.lower()  # Convert R/L to r/l
    transformed['pitcher_hand'] = df['pithand'].str.lower()  # Convert R/L to r/l
    transformed['hit_location'] = df['loc'].astype(str)  # Ensure string type for .str operations

    # Derive event_type from multiple columns
    logger.info("Deriving event_type from hit/walk/strikeout columns")
    transformed['event_type'] = df.apply(transform_event_type, axis=1)

    # Derive batted_ball_type
    logger.info("Deriving batted_ball_type from fly/ground/line columns")
    transformed['batted_ball_type'] = df.apply(transform_batted_ball_type, axis=1).astype(str)

    # Derive hit_val
    logger.info("Deriving hit_val from hit type columns")
    transformed['hit_val'] = df.apply(transform_hit_val, axis=1).astype(str)

    # Boolean conversions to 't'/'f' format
    logger.info("Converting boolean columns to 't'/'f' format")
    transformed['batter_event'] = df['pa'].apply(bool_to_tf)
    transformed['ab'] = df['ab'].apply(bool_to_tf)
    transformed['bunt'] = df['bunt'].apply(bool_to_tf)
    transformed['tp'] = df['tp'].apply(bool_to_tf)

    # Combine gdp + othdp for double play indicator
    transformed['dp'] = (df['gdp'].fillna(0) + df['othdp'].fillna(0)).apply(lambda x: 't' if x > 0 else 'f')

    # Use batter_hand as result_batter_hand (assumption: most batters don't switch mid-AB)
    # This may need refinement if we have switch hitter data
    transformed['result_batter_hand'] = df['bathand'].str.lower()  # Convert R/L to r/l

    # Add placeholder columns that may be referenced but aren't critical for stats
    # These can be populated if needed in the future
    transformed['event_id'] = range(1, len(df) + 1)
    transformed['batting_team'] = ''
    transformed['inning'] = df['inning'] if 'inning' in df.columns else ''
    transformed['outs'] = ''
    transformed['balls'] = ''
    transformed['strikes'] = ''
    transformed['pitch_seq'] = ''
    transformed['vis_score'] = ''
    transformed['home_score'] = ''
    transformed['result_batter_id'] = df['batter']
    transformed['result_pitcher_id'] = df['pitcher']
    transformed['result_pitcher_hand'] = df['pithand']
    transformed['def_c'] = ''
    transformed['def_1b'] = ''
    transformed['def_2b'] = ''
    transformed['def_3b'] = ''
    transformed['def_ss'] = ''
    transformed['def_lf'] = ''
    transformed['def_cf'] = ''
    transformed['def_rf'] = ''
    transformed['run_1b'] = ''
    transformed['run_2b'] = ''
    transformed['run_3b'] = ''
    transformed['event_scoring'] = ''
    transformed['leadoff'] = ''
    transformed['pinch_hit'] = ''
    transformed['batt_def_pos'] = ''
    transformed['batt_lineup_pos'] = ''
    transformed['sac_hit'] = df['sh'].apply(bool_to_tf) if 'sh' in df.columns else 'f'
    transformed['sac_fly'] = df['sf'].apply(bool_to_tf) if 'sf' in df.columns else 'f'
    transformed['event_outs'] = ''
    transformed['rbi'] = ''
    transformed['wild_pitch'] = df['wp'].apply(bool_to_tf) if 'wp' in df.columns else 'f'
    transformed['passed_ball'] = df['pb'].apply(bool_to_tf) if 'pb' in df.columns else 'f'
    transformed['fielded_by'] = ''
    transformed['foul_ground'] = ''

    logger.info(f"Transformation complete: {len(transformed)} rows")
    return transformed


def load_retrosheet_csv(source_path: str, force_transform: bool = False) -> pd.DataFrame:
    """
    Load Retrosheet CSV, using cached normalized version if available.

    This is the main entry point for loading Retrosheet data. It handles:
    - Checking for cached normalized data
    - Transforming if needed
    - Saving transformed data for future use

    Args:
        source_path: Path to source Retrosheet CSV
        force_transform: If True, ignore cache and force transformation

    Returns:
        DataFrame in legacy format ready for retrosheet_data.py
    """
    logger.info(f"Loading Retrosheet CSV: {source_path}")

    if not os.path.exists(source_path):
        raise FileNotFoundError(f"Source file not found: {source_path}")

    cache_path = get_normalized_csv_path(source_path)

    # Check if we need to transform
    if force_transform or needs_transformation(source_path, cache_path):
        # Transform the data
        df = transform_retrosheet_csv(source_path)

        # Save to cache
        logger.info(f"Saving normalized data to cache: {cache_path}")
        df.to_csv(cache_path, index=False)
        logger.info(f"Cache saved successfully")

        return df
    else:
        # Load from cache
        logger.info(f"Loading from cache: {cache_path}")
        # Explicitly set dtypes for string columns to ensure .str accessor works
        dtype_dict = {
            'game_id': 'str',
            'hit_val': 'str',
            'hit_location': 'str',
            'batted_ball_type': 'str'
        }
        return pd.read_csv(cache_path, dtype=dtype_dict, low_memory=False)


if __name__ == '__main__':
    # Test the transformer
    import sys

    logging.basicConfig(
        level=logging.INFO,
        format='%(asctime)s - %(name)s - %(levelname)s - %(message)s'
    )

    if len(sys.argv) > 1:
        test_file = sys.argv[1]
    else:
        test_file = 'data-input/retrosheet/retrosheets_events_2005.csv'

    print(f"\n{'='*60}")
    print(f"Testing Retrosheet Transformer")
    print(f"{'='*60}\n")

    df = load_retrosheet_csv(test_file)

    print(f"\nTransformed DataFrame Info:")
    print(f"Shape: {df.shape}")
    print(f"\nColumns: {list(df.columns)}")
    print(f"\nSample rows:")
    print(df.head(3))

    print(f"\nEvent type distribution:")
    print(df['event_type'].value_counts())

    print(f"\nBatted ball type distribution:")
    print(df['batted_ball_type'].value_counts())