"""PostgreSQL 测试库准备（一次性）。

做三件事：
1. 探测本机 PostgreSQL 连接（默认 127.0.0.1:5433，用户 postgres）；
2. 创建 `dealerhub`（开发）与 `dealerhub_test`（测试）两个库（幂等）；
3. 应用迁移到开发库，使 `DJANGO_SETTINGS_MODULE=config.settings.dev` 能直接连 PG 跑。

用法：
    python scripts/setup_pg.py                        # 用默认凭据探测
    PG_PORT=5432 PG_USER=me PG_PASSWORD=xx python scripts/setup_pg.py
"""

from __future__ import annotations

import os
import sys
from pathlib import Path

sys.path.insert(0, str(Path(__file__).resolve().parent.parent))

PG_HOST = os.environ.get("PG_HOST", "127.0.0.1")
PG_PORT = int(os.environ.get("PG_PORT", "5433"))
PG_USER = os.environ.get("PG_USER", "postgres")
PG_PASSWORD = os.environ.get("PG_PASSWORD", "postgres")

DEV_DB = os.environ.get("PG_DEV_DB", "dealerhub")
TEST_DB = os.environ.get("PG_TEST_DB", "dealerhub_test")

# 常见本地 PG 密码（只用于"探测"，不做暴力破解）
PASSWORD_CANDIDATES = [PG_PASSWORD, "", "postgres", "123456", "root", "pg123456", "admin"]


def probe_connection() -> str | None:
    """返回可用密码；失败返回 None。"""
    try:
        import psycopg
    except ImportError:
        print("✗ 未安装 psycopg：pip install 'psycopg[binary]'")
        return None

    seen = []
    for pw in PASSWORD_CANDIDATES:
        if pw in seen:
            continue
        seen.append(pw)
        try:
            conn = psycopg.connect(
                host=PG_HOST, port=PG_PORT, user=PG_USER, password=pw,
                dbname="postgres", connect_timeout=3,
            )
            conn.close()
            return pw
        except Exception as exc:
            print(f"  · {PG_USER}/{pw or '(空)'} → {str(exc)[:70]}")
    return None


def ensure_databases(password: str) -> bool:
    import psycopg

    ok = True
    conn = psycopg.connect(
        host=PG_HOST, port=PG_PORT, user=PG_USER, password=password,
        dbname="postgres", autocommit=True,
    )
    cur = conn.cursor()
    for db in (DEV_DB, TEST_DB):
        cur.execute("SELECT 1 FROM pg_database WHERE datname = %s", (db,))
        if cur.fetchone():
            print(f"  · {db} 已存在")
        else:
            cur.execute(f'CREATE DATABASE "{db}"')
            print(f"  ✓ 创建 {db}")
    cur.close()
    conn.close()
    return ok


def apply_migrations_to_dev(password: str) -> bool:
    """把迁移应用到开发库（让 dev 设置能直接用 PG）。"""
    os.environ.update({
        "DATABASE_URL": f"postgres://{PG_USER}:{password}@{PG_HOST}:{PG_PORT}/{DEV_DB}",
        "DJANGO_SETTINGS_MODULE": "config.settings.dev",
    })
    import django

    django.setup()
    from django.core.management import call_command

    call_command("migrate", "--noinput", verbosity=0)
    return True


def main() -> int:
    print(f"探测 PostgreSQL · {PG_HOST}:{PG_PORT} · user={PG_USER}")
    pw = probe_connection()
    if pw is None:
        print("\n✗ 无法连接。请确认：")
        print("  1. PostgreSQL 服务已启动")
        print("  2. 端口正确（PG_PORT=5433 是本机 PG 16 的常见端口）")
        print("  3. 凭据正确（PG_USER / PG_PASSWORD）")
        return 1
    print(f"  ✓ 连接成功（密码：{pw or '(空)'}）")

    print("\n创建数据库")
    ensure_databases(pw)

    print("\n应用迁移到开发库")
    apply_migrations_to_dev(pw)
    print(f"  ✓ {DEV_DB} 迁移完成")

    print(f"""
准备完成。运行方式：

  # 开发/手工验证（连 PG）
  export DATABASE_URL="postgres://{PG_USER}:{pw}@{PG_HOST}:{PG_PORT}/{DEV_DB}"
  DJANGO_SETTINGS_MODULE=config.settings.dev granian config.asgi:application --interface asgi --port 8000

  # 全量测试（含并发，PG 行锁语义）
  DJANGO_SETTINGS_MODULE=config.settings.pgtest python -m pytest tests/ -p no:cacheprovider

  # 只跑并发用例
  DJANGO_SETTINGS_MODULE=config.settings.pgtest python -m pytest tests/test_concurrency.py -p no:cacheprovider -m postgres
""")
    return 0


if __name__ == "__main__":
    sys.exit(main())