"""
One-off bulk update: set Current Owner for a list of phone numbers, without touching any other
field (Plan, Venue, Contract Expiration, Eligibility, Comment are left exactly as they are).

Usage:
    python apply_owner_mapping.py /path/to/telco.db mapping.csv

mapping.csv has two columns: phone_number,current_owner (phone_number in the same raw format as
the source Excel - digits only, with or without the leading 0; it is normalized the same way the
original import did).
"""

import argparse
import csv
import sqlite3


def normalize_phone(value):
    s = str(value).strip()
    if s.isdigit() and not s.startswith("0"):
        s = "0" + s
    return s or None


def main():
    parser = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
    parser.add_argument("db_path")
    parser.add_argument("mapping_csv")
    args = parser.parse_args()

    con = sqlite3.connect(args.db_path)
    cur = con.cursor()

    updated, missing = [], []
    with open(args.mapping_csv, newline="", encoding="utf-8-sig") as f:
        reader = csv.DictReader(f)
        for row in reader:
            phone_number = normalize_phone(row["phone_number"])
            owner = row["current_owner"]
            cur.execute("UPDATE phones SET current_owner = ? WHERE phone_number = ?", (owner, phone_number))
            if cur.rowcount == 0:
                missing.append(phone_number)
            else:
                updated.append(phone_number)

    con.commit()
    con.close()

    print(f"Updated {len(updated)} rows.")
    if missing:
        print(f"No matching phone found for {len(missing)} entries: {missing}")


if __name__ == "__main__":
    main()