#!/usr/bin/env python3
"""
Convert a directory of individual bicorder JSON reading files into a diagnostic CSV.

This is the reverse of convert_csv_to_json.py. Each JSON file becomes one row.
Handles readings across bicorder versions by matching on term_left/term_right pairs
rather than column names.

Null gradient values (e.g., shortform readings that skip non-key dimensions) are
written as empty cells so downstream analysis can treat them as NaN.

Usage:
  python3 scripts/json_to_csv.py data/readings/manual_20260320/json/
  python3 scripts/json_to_csv.py data/readings/manual_20260320/json/ -o data/readings/manual_20260320/readings.csv
  python3 scripts/json_to_csv.py data/readings/manual_20260320/json/ --shortform-only
"""

import argparse
import csv
import json
from pathlib import Path


# Map old term pairs to current column names (matches COLUMN_RENAMES in other scripts).
# Keys are (term_left, term_right) as found in older JSON files.
TERM_RENAMES = {
    ('elite', 'vernacular'): ('institutional', 'vernacular'),
    ('exclusive', 'non-exclusive'): ('monopolistic', 'pluralistic'),
    ('insufficient', 'sufficient'): ('sufficient', 'limited'),  # note: order swapped in old versions
    ('Kafka', 'Whitehead'): ('restraining', 'liberating'),
}


def load_bicorder_columns(bicorder_path):
    """Read ordered column definitions from bicorder.json."""
    with open(bicorder_path) as f:
        data = json.load(f)
    columns = []
    key_columns = set()
    for category in data['diagnostic']:
        set_name = category['set_name']
        for gradient in category['gradients']:
            col = f"{set_name}_{gradient['term_left']}_vs_{gradient['term_right']}"
            columns.append(col)
            if gradient.get('shortform', False):
                key_columns.add(col)
    return columns, key_columns


def normalize_terms(term_left, term_right):
    """Apply renames to match current bicorder.json terminology."""
    pair = (term_left, term_right)
    if pair in TERM_RENAMES:
        return TERM_RENAMES[pair]
    # Also check reversed pair (some old files had swapped left/right)
    reversed_pair = (term_right, term_left)
    if reversed_pair in TERM_RENAMES:
        new_left, new_right = TERM_RENAMES[reversed_pair]
        return new_right, new_left  # swap back
    return term_left, term_right


def json_to_row(json_path, all_columns):
    """Convert a single JSON reading file to a CSV row dict."""
    with open(json_path) as f:
        data = json.load(f)

    meta = data.get('metadata', {})
    row = {
        'Descriptor': meta.get('protocol', ''),
        'Description': '',  # not stored in individual reading files
        'analyst': meta.get('analyst', ''),
        'standpoint': meta.get('standpoint', ''),
        'timestamp': meta.get('timestamp', ''),
        'shortform': str(meta.get('shortform', '')),
        'version': data.get('version', ''),
    }

    # Build lookup: (normalized_term_left, normalized_term_right) -> value
    gradient_values = {}
    for category in data.get('diagnostic', []):
        set_name = category['set_name']
        for gradient in category.get('gradients', []):
            tl = gradient['term_left']
            tr = gradient['term_right']
            tl_norm, tr_norm = normalize_terms(tl, tr)
            col = f"{set_name}_{tl_norm}_vs_{tr_norm}"
            value = gradient.get('value')
            gradient_values[col] = '' if value is None else str(value)

    for col in all_columns:
        row[col] = gradient_values.get(col, '')

    return row


def main():
    parser = argparse.ArgumentParser(
        description='Convert directory of bicorder JSON files to a diagnostic CSV',
        formatter_class=argparse.RawDescriptionHelpFormatter,
        epilog="""
Example usage:
  python3 scripts/json_to_csv.py data/readings/manual_20260320/json/
  python3 scripts/json_to_csv.py data/readings/manual_20260320/json/ --shortform-only
  python3 scripts/json_to_csv.py data/readings/manual_20260320/json/ -o data/readings/manual_20260320/readings.csv
        """
    )
    parser.add_argument('json_dir', help='Directory containing bicorder JSON reading files')
    parser.add_argument('-o', '--output', default=None,
                        help='Output CSV path (default: <dataset_dir>/readings.csv)')
    parser.add_argument('-b', '--bicorder', default='../bicorder.json',
                        help='Path to bicorder.json (default: ../bicorder.json)')
    parser.add_argument('--shortform-only', action='store_true',
                        help='Include only the key shortform dimensions (useful when most readings are shortform)')
    args = parser.parse_args()

    json_dir = Path(args.json_dir)
    dataset_dir = json_dir.parent
    output_path = Path(args.output) if args.output else dataset_dir / 'readings.csv'

    all_columns, key_columns = load_bicorder_columns(args.bicorder)

    if args.shortform_only:
        columns = [c for c in all_columns if c in key_columns]
        print(f"Shortform mode: using {len(columns)} key dimensions")
    else:
        columns = all_columns

    json_files = sorted(json_dir.glob('*.json'))
    if not json_files:
        print(f"Error: no JSON files found in {json_dir}")
        return

    print(f"Converting {len(json_files)} JSON files → {output_path}")

    fieldnames = ['Descriptor', 'Description', 'analyst', 'standpoint',
                  'timestamp', 'shortform', 'version'] + columns

    rows = []
    for json_path in json_files:
        try:
            row = json_to_row(json_path, columns)
            rows.append(row)
        except Exception as e:
            print(f"  Warning: skipping {json_path.name}: {e}")

    with open(output_path, 'w', newline='', encoding='utf-8') as f:
        writer = csv.DictWriter(f, fieldnames=fieldnames)
        writer.writeheader()
        writer.writerows(rows)

    # Summary stats
    filled = {col: sum(1 for r in rows if r.get(col)) for col in columns}
    print(f"Done. {len(rows)} rows written.")
    print(f"\nDimension coverage (readings with a value):")
    for col, count in filled.items():
        pct = count / len(rows) * 100 if rows else 0
        marker = '* ' if col in key_columns else '  '
        print(f"  {marker}{col}: {count}/{len(rows)} ({pct:.0f}%)")
    print(f"\n(* = shortform/key dimension)")


if __name__ == '__main__':
    main()