"""确保本地 PostgreSQL 就绪(开发/测试统一用 Docker PG)。

被三处复用:
  - run.sh / run.bat:`python -m scripts.ensure_pg`(CLI,失败退非 0)
  - tests/conftest.py:`from scripts.ensure_pg import ensure; ensure(test_url)`

流程:读 DATABASE_URL → TCP 探测 → 没起就(必要时启 Docker Desktop)→
`docker compose up -d` → 等 PG ready → 幂等确保测试库存在。全程无 SQLite 兜底。

生产用原生 PG(scripts/init_postgres.py),不走本模块。
"""
from __future__ import annotations

import os
import socket
import subprocess
import sys
import time
from pathlib import Path
from urllib.parse import urlsplit

ROOT = Path(__file__).resolve().parent.parent

# 日志里可能含 emoji(如 ✅);Windows GBK 控制台(cmd.exe)无法编码会抛 UnicodeEncodeError → 脚本崩、
# run.bat 误判 ensure_pg 失败。用 backslashreplace 保底:中文仍正常,仅不可编码字符被转义,不崩。
for _stream in (sys.stdout, sys.stderr):
    try:
        _stream.reconfigure(errors="backslashreplace")
    except (AttributeError, ValueError):
        pass

APP_DB = "shaguabijia"
TEST_DB = "shaguabijia_test"
DB_USER = "shaguabijia_app"
COMPOSE_SERVICE = "postgres"

DOCKER_START_TIMEOUT = int(os.environ.get("ENSURE_PG_DOCKER_TIMEOUT", "120"))
PG_READY_TIMEOUT = int(os.environ.get("ENSURE_PG_READY_TIMEOUT", "60"))
# 单条 docker 探测/exec 命令的超时:防 Docker 守护进程半死(尤其 Windows 冷启)时
# docker info / exec 无限挂起、绕过上面的总超时。
DOCKER_CMD_TIMEOUT = int(os.environ.get("ENSURE_PG_CMD_TIMEOUT", "15"))
POLL_INTERVAL = 3.0

SQLITE_FIX_HINT = (
    "postgresql+psycopg://shaguabijia_app:shaguabijia_dev_pw@localhost:5432/shaguabijia"
)


def _log(msg: str) -> None:
    print(f"[ensure_pg] {msg}", flush=True)


def _is_sqlite(url: str) -> bool:
    return url.strip().lower().startswith("sqlite")


def _parse_host_port(url: str) -> tuple[str, int]:
    """从 SQLAlchemy URL 取 host/port,缺省 localhost:5432。"""
    parts = urlsplit(url)
    return (parts.hostname or "localhost"), (parts.port or 5432)


def _port_open(host: str, port: int, timeout: float = 1.0) -> bool:
    try:
        with socket.create_connection((host, port), timeout=timeout):
            return True
    except OSError:
        return False


def _docker_desktop_cmd(platform: str, program_files: str) -> list[str] | None:
    """按平台给出启动 Docker Desktop 的命令;Linux 返回 None(daemon 需 sudo,让用户手动)。"""
    if platform.startswith("win"):
        return [str(Path(program_files) / "Docker" / "Docker" / "Docker Desktop.exe")]
    if platform == "darwin":
        return ["open", "-a", "Docker"]
    return None


def _docker_ok(subcmd: str) -> bool:
    """`docker version`(CLI 在不在)/`docker info`(daemon 起没起)成功与否。"""
    try:
        subprocess.run(
            ["docker", subcmd],
            cwd=ROOT,
            stdout=subprocess.DEVNULL,
            stderr=subprocess.DEVNULL,
            check=True,
            timeout=DOCKER_CMD_TIMEOUT,
        )
        return True
    except (OSError, subprocess.CalledProcessError, subprocess.TimeoutExpired):
        return False


def _docker_cli_ok() -> bool:
    return _docker_ok("version")


def _docker_daemon_ok() -> bool:
    return _docker_ok("info")


def _start_docker_daemon() -> bool:
    """守护进程没起时按平台拉起,轮询到就绪。返回是否成功。"""
    if _docker_daemon_ok():
        return True
    cmd = _docker_desktop_cmd(
        sys.platform, os.environ.get("ProgramFiles", r"C:\Program Files")
    )
    if cmd is None:
        _log("Docker 守护进程未运行。Linux 请手动:sudo systemctl start docker,然后重试。")
        return False
    if sys.platform.startswith("win") and not Path(cmd[0]).exists():
        _log(f"找不到 Docker Desktop:{cmd[0]}。请手动启动 Docker Desktop 后重试。")
        return False
    _log("启动 Docker Desktop(首次冷启可能 30-60s)…")
    try:
        subprocess.Popen(cmd, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
    except OSError as e:
        _log(f"启动 Docker Desktop 失败:{e}")
        return False
    deadline = time.monotonic() + DOCKER_START_TIMEOUT
    while time.monotonic() < deadline:
        if _docker_daemon_ok():
            _log("Docker 守护进程已就绪。")
            return True
        _log("等待 Docker 守护进程…")
        time.sleep(POLL_INTERVAL)
    _log(f"等待 Docker 守护进程超时({DOCKER_START_TIMEOUT}s)。")
    return False


def _compose_up() -> bool:
    _log("docker compose up -d(镜像缺失会自动拉取,首用约几十秒)…")
    try:
        subprocess.run(["docker", "compose", "up", "-d"], cwd=ROOT, check=True)
        return True
    except (OSError, subprocess.CalledProcessError) as e:
        _log(f"docker compose up 失败:{e}")
        return False


def _pg_isready() -> bool:
    try:
        r = subprocess.run(
            ["docker", "compose", "exec", "-T", COMPOSE_SERVICE,
             "pg_isready", "-U", DB_USER, "-d", APP_DB],
            cwd=ROOT, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL,
            timeout=DOCKER_CMD_TIMEOUT,
        )
    except (OSError, subprocess.TimeoutExpired):
        return False
    return r.returncode == 0


def _wait_pg_ready(host: str, port: int) -> bool:
    deadline = time.monotonic() + PG_READY_TIMEOUT
    while time.monotonic() < deadline:
        if _port_open(host, port) and _pg_isready():
            _log("PostgreSQL 已就绪。")
            return True
        _log("等待 PostgreSQL 就绪…")
        time.sleep(POLL_INTERVAL)
    _log(f"等待 PostgreSQL 就绪超时({PG_READY_TIMEOUT}s)。")
    return False


def _test_db_exists() -> bool:
    """测试库是否已存在(连业务库 shaguabijia 查 pg_database)。"""
    try:
        r = subprocess.run(
            ["docker", "compose", "exec", "-T", COMPOSE_SERVICE,
             "psql", "-U", DB_USER, "-d", APP_DB, "-tAc",
             f"SELECT 1 FROM pg_database WHERE datname='{TEST_DB}'"],
            cwd=ROOT, capture_output=True, text=True, timeout=DOCKER_CMD_TIMEOUT,
        )
    except (OSError, subprocess.TimeoutExpired):
        return False
    return r.returncode == 0 and r.stdout.strip() == "1"


def ensure_test_db() -> bool:
    """幂等建测试库(兼容老 pgdata 卷首启没跑 initdb 的情况)。返回测试库是否就绪。

    公开给 conftest 单独调用:ensure() 在「端口已通」时会短路返回、不建测试库,
    所以测试侧需在 ensure() 之后再显式补一刀(best-effort)。
    """
    if _test_db_exists():
        return True
    _log(f"建测试库 {TEST_DB}…")
    try:
        create = subprocess.run(
            ["docker", "compose", "exec", "-T", COMPOSE_SERVICE,
             "psql", "-U", DB_USER, "-d", APP_DB, "-c",
             f"CREATE DATABASE {TEST_DB} OWNER {DB_USER}"],
            cwd=ROOT, capture_output=True, text=True, timeout=DOCKER_CMD_TIMEOUT,
        )
    except (OSError, subprocess.TimeoutExpired) as e:
        _log(f"⚠️ 建测试库 {TEST_DB} 失败:{e}")
        return False
    # returncode==0=建成功;非 0 但库已存在=与并发创建者竞争失败(42P04),仍算就绪
    if create.returncode == 0 or _test_db_exists():
        return True
    _log(f"⚠️ 建测试库 {TEST_DB} 失败:{(create.stderr or '').strip()}")
    return False


def ensure(database_url: str | None = None) -> bool:
    """确保 PG 就绪,返回 True/False。database_url 缺省从 settings 读(尊重 .env)。"""
    if database_url is None:
        from app.core.config import settings  # 延迟导入,避免过早固化 settings

        database_url = settings.DATABASE_URL

    if _is_sqlite(database_url):
        _log("检测到 DATABASE_URL 仍是 SQLite。本地开发/测试已切 PostgreSQL,请改成:")
        _log(f"  DATABASE_URL={SQLITE_FIX_HINT}")
        return False

    host, port = _parse_host_port(database_url)

    if _port_open(host, port):
        _log(f"✅ PostgreSQL 已在 {host}:{port} 运行,跳过 Docker。")
        return True

    _log(f"{host}:{port} 无 PostgreSQL,准备用 Docker 拉起…")

    if not _docker_cli_ok():
        _log("未检测到 docker 命令。请先安装 Docker Desktop:")
        _log("  https://www.docker.com/products/docker-desktop/")
        return False
    if not _start_docker_daemon():
        return False
    if not _compose_up():
        return False
    if not _wait_pg_ready(host, port):
        return False
    if not ensure_test_db():
        return False
    return True


if __name__ == "__main__":
    sys.exit(0 if ensure() else 1)