#!/usr/bin/env python3
"""Renumber the current history import to its source application IDs."""
import argparse
import gzip
import json
import re
import sys
from datetime import datetime
from pathlib import Path

ROOT = Path(__file__).resolve().parents[1]
sys.path.insert(0, str(ROOT))


def run(local=False):
    if local:
        import test_wsgi  # noqa: F401
    from services.db import get_db

    conn = get_db()
    foreign_keys_disabled = False
    try:
        with conn.cursor() as cur:
            cur.execute("""SELECT a.id,a.status,a.product_name,a.image_path
                FROM spot_applications a ORDER BY a.id FOR UPDATE""")
            applications = cur.fetchall()
            imported = []
            for row in applications:
                match = re.fullmatch(r'/static/uploads/spot_application/history_(\d+)_[0-9a-f]{16}\.[A-Za-z0-9]+',
                                     row.get('image_path') or '')
                if match:
                    imported.append((row['id'], int(match.group(1))))
            if len(imported) != 547 or {target for _, target in imported} != set(range(1, 548)):
                raise RuntimeError('导入记录不是完整且唯一的1-547，停止重排')
            imported_ids = {old for old, _ in imported}
            retained = [row for row in applications if row['id'] not in imported_ids]
            max_id = max(row['id'] for row in applications)
            retained_moves = []
            next_id = max_id + 1000
            targets = {target for _, target in imported}
            for row in retained:
                if row['id'] in targets:
                    retained_moves.append((row['id'], next_id))
                    next_id += 1
            backup = ROOT / 'var/manual-updates' / ('spot-confirmation-renumber-' + datetime.now().strftime('%Y%m%dT%H%M%S') + '.json.gz')
            backup.parent.mkdir(parents=True, exist_ok=True)
            with gzip.open(backup, 'wt', encoding='utf-8') as handle:
                json.dump({'imported': imported, 'retained_moves': retained_moves}, handle, ensure_ascii=False)

            offset = next_id + 1000
            cur.execute('SET FOREIGN_KEY_CHECKS=0')
            foreign_keys_disabled = True
            for old, new in retained_moves:
                cur.execute('UPDATE spot_confirmations SET application_id=%s WHERE application_id=%s', (new, old))
                cur.execute('UPDATE spot_applications SET id=%s WHERE id=%s', (new, old))
            for old, target in imported:
                temporary = offset + target
                cur.execute('UPDATE spot_confirmations SET application_id=%s WHERE application_id=%s', (temporary, old))
                cur.execute('UPDATE spot_applications SET id=%s WHERE id=%s', (temporary, old))
            for _, target in imported:
                temporary = offset + target
                cur.execute('UPDATE spot_applications SET id=%s WHERE id=%s', (target, temporary))
                cur.execute('UPDATE spot_confirmations SET application_id=%s WHERE application_id=%s', (target, temporary))
            cur.execute('SET FOREIGN_KEY_CHECKS=1')
            foreign_keys_disabled = False
        conn.commit()
        print(json.dumps({'renumbered': len(imported), 'retained_moved': retained_moves,
                          'backup': str(backup.relative_to(ROOT))}, ensure_ascii=False))
    except Exception:
        conn.rollback()
        raise
    finally:
        if foreign_keys_disabled:
            try:
                with conn.cursor() as cur:
                    cur.execute('SET FOREIGN_KEY_CHECKS=1')
            except Exception:
                pass
        conn.close()


if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.add_argument('--local', action='store_true')
    run(parser.parse_args().local)