#!/usr/bin/env python3
"""One-time sync of post-order packaging balances into backup BOM snapshots."""
import argparse
import json
import sys
from pathlib import Path

ROOT = Path(__file__).resolve().parents[1]
if str(ROOT) not in sys.path:
    sys.path.insert(0, str(ROOT))


def post_pack_for_item(item, product_qty, bom_usage):
    """Mirror the value that pending detail displays as 下单后包材."""
    pre_pack = item.get('pre_pack_qty')
    usage = item.get('quantity')
    if usage in (None, ''):
        usage = bom_usage.get(str(item.get('material_code') or ''))
    if pre_pack in (None, '') or usage in (None, ''):
        stored = item.get('post_pack_qty')
        return float(stored) if stored not in (None, '') else 0
    try:
        return round(float(pre_pack) + float(item.get('actual_quantity') or 0)
                     - float(product_qty) * float(usage), 2)
    except (TypeError, ValueError):
        return 0


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('--local', action='store_true', help='Use the local test database')
    parser.add_argument('--dry-run', action='store_true')
    args = parser.parse_args()
    if args.local:
        import test_wsgi  # noqa: F401 - installs local DB configuration
    from routes.purchase import _extract_product_actual_qty
    from services.db import get_db, query

    rows = query(
        "SELECT id, product_code, formal_order_qty, actual_order_qty, bom_items "
        "FROM pending_orders WHERE status IN ('ordered','rolled_back') ORDER BY id"
    )
    usage_cache = {}
    updates = []
    changed_items = 0
    for row in rows:
        try:
            items = json.loads(row['bom_items']) if row.get('bom_items') else []
        except (TypeError, ValueError):
            continue
        if not isinstance(items, list) or not items:
            continue
        product_code = str(row.get('product_code') or '')
        product_qty = _extract_product_actual_qty(items, product_code)
        if product_qty is None:
            product_qty = int(row.get('formal_order_qty') or row.get('actual_order_qty') or 0)
        if product_code not in usage_cache:
            usage_cache[product_code] = {
                str(r.get('material_code') or ''): float(r.get('usage_qty') or 0)
                for r in query("SELECT material_code, quantity AS usage_qty FROM bom WHERE product_code=%s",
                               (product_code,))
            }
        changed = 0
        for item in items:
            if not isinstance(item, dict) or str(item.get('material_code') or '').startswith('成品_'):
                continue
            value = post_pack_for_item(item, product_qty, usage_cache[product_code])
            if item.get('post_pack_qty') != value:
                item['post_pack_qty'] = value
                changed += 1
        if changed:
            updates.append((json.dumps(items, ensure_ascii=False), row['id']))
            changed_items += changed
    if not args.dry_run and updates:
        conn = get_db()
        try:
            with conn.cursor() as cur:
                cur.executemany("UPDATE pending_orders SET bom_items=%s WHERE id=%s", updates)
            conn.commit()
        except Exception:
            conn.rollback()
            raise
        finally:
            conn.close()
    print(json.dumps({'records': len(rows), 'updated_records': len(updates),
                      'updated_items': changed_items, 'dry_run': args.dry_run},
                     ensure_ascii=False))


if __name__ == '__main__':
    main()