#!/opt/homebrew/bin/python3.11
"""Backfill face_id for existing face_detections rows using trace_id.

face_id is generated as 'face_{trace_id}' for each unique trace.
This covers past data where face_id was never written.
"""

import os
import psycopg2

DB_URL = os.environ.get("DATABASE_URL", "postgresql://accusys@localhost:5432/momentry")
SCHEMA = os.environ.get("MOMENTRY_DB_SCHEMA", "dev")


def get_conn():
    return psycopg2.connect(DB_URL)


def backfill_by_trace(file_uuid: str, schema: str = SCHEMA) -> int:
    """Set face_id = 'face_{trace_id}' for all rows with NULL face_id and non-NULL trace_id."""
    conn = get_conn()
    cur = conn.cursor()

    cur.execute(
        f"""
        UPDATE {schema}.face_detections
        SET face_id = 'face_' || trace_id::text
        WHERE file_uuid = %s
          AND face_id IS NULL
          AND trace_id IS NOT NULL
        """,
        (file_uuid,),
    )
    updated = cur.rowcount
    conn.commit()
    cur.close()
    conn.close()
    return updated


def main():
    conn = get_conn()
    cur = conn.cursor()

    # Count rows that need backfill
    cur.execute(
        f"""SELECT COUNT(*) FROM {SCHEMA}.face_detections
            WHERE face_id IS NULL AND trace_id IS NOT NULL"""
    )
    total_rows = cur.fetchone()[0]

    cur.execute(
        f"""SELECT DISTINCT file_uuid FROM {SCHEMA}.face_detections
            WHERE face_id IS NULL AND trace_id IS NOT NULL"""
    )
    uuids = [row[0] for row in cur.fetchall()]
    cur.close()
    conn.close()

    if not uuids:
        print("No rows need backfill (all face_id already set or no trace_id).")
        return

    print(f"Found {total_rows} rows across {len(uuids)} files to backfill")

    total_all = 0
    for uuid in uuids:
        count = backfill_by_trace(uuid)
        total_all += count
        print(f"  [{uuid}] updated {count} rows")

    print(f"\nDone: {len(uuids)} files, {total_all} rows updated")


if __name__ == "__main__":
    main()