from __future__ import annotations

import atexit
import json
import re
import time
from datetime import date as date_cls, time as time_cls
from functools import wraps
from typing import Callable
from urllib.parse import urlparse

from flask import Flask, Response, flash, g, jsonify, redirect, render_template, request, session, stream_with_context, url_for

from core.config import AppConfig
from core.db import (
    DEFAULT_REGISTRATION_CODE_MAX_USES,
    Database,
    MAX_REFRESH_INTERVAL_SECONDS,
    MIN_REFRESH_INTERVAL_SECONDS,
    normalize_registration_code,
)
from core.runtime_logging import configure_logging, get_logger
from core.security import SecretBox, hash_password, verify_password
from core.task_manager import TaskManager


configure_logging()
APP_LOGGER = get_logger("sacc.web")

config = AppConfig.load()
store = Database(
    config.db_path,
    default_parallel_limit=config.default_parallel_limit,
    mysql_ssl_ca_path=config.mysql_ssl_ca_path,
)
store.init_db()
secret_box = SecretBox(config.encryption_key)
task_manager = TaskManager(config=config, store=store, secret_box=secret_box)


def _seed_legacy_user() -> None:
    if store.list_users():
        return

    legacy_path = config.root_dir / "user_data.json"
    if not legacy_path.exists():
        return

    try:
        payload = json.loads(legacy_path.read_text(encoding="utf-8"))
    except (OSError, json.JSONDecodeError):
        return

    student_id = str(payload.get("std_id", "")).strip()
    password = str(payload.get("password", "")).strip()
    if not student_id or not password:
        return

    user_id = store.create_user(student_id, secret_box.encrypt(password), "Legacy User")
    for source_key, category in (("a", "plan"), ("b", "free")):
        for course in payload.get("course", {}).get(source_key, []):
            course_id = str(course.get("course_id", "")).strip()
            course_index = str(course.get("course_index", "")).strip()
            if course_id and course_index:
                store.add_course(user_id, category, course_id, course_index)


_seed_legacy_user()
task_manager.start()
atexit.register(task_manager.shutdown)

app = Flask(__name__, template_folder="templates", static_folder="static")
app.secret_key = config.session_secret
app.config.update(SESSION_COOKIE_HTTPONLY=True, SESSION_COOKIE_SAMESITE="Lax")
APP_LOGGER.info(
    "Application bootstrap complete | data_dir=%s db_path=%s backend=%s chrome_binary=%s chromedriver_path=%s default_parallel_limit=%s schedule_timezone=%s",
    config.data_dir,
    config.db_path,
    config.database_backend,
    config.chrome_binary,
    config.chromedriver_path,
    config.default_parallel_limit,
    config.schedule_timezone,
)

CATEGORY_LABELS = {
    "plan": "方案选课",
    "free": "自由选课",
}
TASK_LABELS = {
    "pending": "排队中",
    "running": "执行中",
    "cancel_requested": "停止中",
    "completed": "已完成",
    "stopped": "已停止",
    "failed": "失败",
}

SKIPPED_REQUEST_LOG_PREFIXES = (
    "/static/",
    "/api/",
)
SKIPPED_REQUEST_LOG_PATHS = {
    "/favicon.ico",
}
COURSE_ID_PATTERN = re.compile(r"^[0-9A-Za-z]{1,32}$")
COURSE_INDEX_PATTERN = re.compile(r"^[0-9A-Za-z]{1,8}$")
REGISTRATION_CODE_PATTERN = re.compile(r"^[A-Z0-9-]{6,64}$")


def _current_actor_label() -> str:
    role = session.get("role", "guest")
    if role == "user":
        return f"user:{session.get('user_id', '-')}"
    if role == "admin":
        return f"admin:{session.get('admin_username', '-')}"
    return "guest"


@app.before_request
def before_request_logging() -> None:
    g.request_started_at = time.perf_counter()


@app.after_request
def after_request_logging(response):
    if request.path in SKIPPED_REQUEST_LOG_PATHS:
        return response
    if any(request.path.startswith(prefix) for prefix in SKIPPED_REQUEST_LOG_PREFIXES):
        return response

    started_at = getattr(g, "request_started_at", None)
    duration_ms = 0.0 if started_at is None else (time.perf_counter() - started_at) * 1000
    remote_addr = request.headers.get("x-forwarded-for") or request.remote_addr or "-"
    APP_LOGGER.info(
        "HTTP %s %s -> %s in %.1fms | actor=%s remote=%s",
        request.method,
        request.path,
        response.status_code,
        duration_ms,
        _current_actor_label(),
        remote_addr,
    )
    return response


@app.context_processor
def inject_globals() -> dict:
    return {
        "category_labels": CATEGORY_LABELS,
        "task_labels": TASK_LABELS,
        "session_role": session.get("role", "guest"),
        "refresh_interval_min": MIN_REFRESH_INTERVAL_SECONDS,
        "refresh_interval_max": MAX_REFRESH_INTERVAL_SECONDS,
        "default_refresh_interval_seconds": config.poll_interval_seconds,
        "default_registration_code_max_uses": DEFAULT_REGISTRATION_CODE_MAX_USES,
    }


def _login_required(role: str) -> Callable:
    def decorator(view: Callable) -> Callable:
        @wraps(view)
        def wrapped(*args, **kwargs):
            current_role = session.get("role")
            if role == "user" and current_role != "user":
                flash("请先登录学生账号。", "warning")
                return redirect(url_for("login"))
            if role == "admin" and current_role != "admin":
                flash("请先登录管理员账号。", "warning")
                return redirect(url_for("admin_login"))
            return view(*args, **kwargs)

        return wrapped

    return decorator


def _get_current_user() -> dict | None:
    user_id = session.get("user_id")
    if not user_id:
        return None
    return store.get_user(int(user_id))


def _get_admin_identity() -> dict:
    return {
        "username": session.get("admin_username", ""),
        "is_super_admin": bool(session.get("is_super_admin", False)),
    }


def _normalize_course_token(raw_value: str) -> str:
    return re.sub(r"\s+", "", str(raw_value or "")).upper()


def _validate_course_target(course_id: str, course_index: str) -> tuple[str, str] | None:
    normalized_course_id = _normalize_course_token(course_id)
    normalized_course_index = _normalize_course_token(course_index)
    if not COURSE_ID_PATTERN.fullmatch(normalized_course_id):
        return None
    if not COURSE_INDEX_PATTERN.fullmatch(normalized_course_index):
        return None
    return normalized_course_id, normalized_course_index


def _parse_refresh_interval(raw_value: str | None, *, default: int) -> int:
    raw_text = str(raw_value or "").strip()
    if not raw_text:
        return default
    try:
        interval = int(raw_text)
    except ValueError as exc:
        raise ValueError(f"刷新间隔必须是 {MIN_REFRESH_INTERVAL_SECONDS} 到 {MAX_REFRESH_INTERVAL_SECONDS} 之间的整数。") from exc
    if interval < MIN_REFRESH_INTERVAL_SECONDS or interval > MAX_REFRESH_INTERVAL_SECONDS:
        raise ValueError(f"刷新间隔必须在 {MIN_REFRESH_INTERVAL_SECONDS} 到 {MAX_REFRESH_INTERVAL_SECONDS} 秒之间。")
    return interval


def _parse_registration_code_max_uses(raw_value: str | None) -> int:
    raw_text = str(raw_value or "").strip()
    if not raw_text:
        return DEFAULT_REGISTRATION_CODE_MAX_USES
    try:
        value = int(raw_text)
    except ValueError as exc:
        raise ValueError("注册码可用次数必须是 1 到 99 之间的整数。") from exc
    if value < 1 or value > 99:
        raise ValueError("注册码可用次数必须在 1 到 99 之间。")
    return value


def _parse_iso_date(raw_value: str | None, label: str) -> str:
    raw_text = str(raw_value or "").strip()
    if not raw_text:
        raise ValueError(f"{label}不能为空。")
    try:
        return date_cls.fromisoformat(raw_text).isoformat()
    except ValueError as exc:
        raise ValueError(f"{label}格式无效，请使用 YYYY-MM-DD。") from exc


def _parse_clock_time(raw_value: str | None, label: str) -> str:
    raw_text = str(raw_value or "").strip()
    if not raw_text:
        raise ValueError(f"{label}不能为空。")
    try:
        return time_cls.fromisoformat(raw_text).strftime("%H:%M")
    except ValueError as exc:
        raise ValueError(f"{label}格式无效，请使用 HH:MM。") from exc


def _parse_schedule_form(form) -> dict:
    enabled = str(form.get("schedule_enabled", "")).lower() in {"1", "true", "on", "yes"}
    start_date_raw = form.get("start_date", "")
    end_date_raw = form.get("end_date", "")
    daily_start_time_raw = form.get("daily_start_time", "")
    daily_stop_time_raw = form.get("daily_stop_time", "")
    has_any_value = enabled or any(str(value or "").strip() for value in (start_date_raw, end_date_raw, daily_start_time_raw, daily_stop_time_raw))
    if not has_any_value:
        return {
            "is_enabled": False,
            "start_date": None,
            "end_date": None,
            "daily_start_time": None,
            "daily_stop_time": None,
        }

    start_date = _parse_iso_date(start_date_raw, "开始日期")
    end_date = _parse_iso_date(end_date_raw, "结束日期")
    daily_start_time = _parse_clock_time(daily_start_time_raw, "每日启动时间")
    daily_stop_time = _parse_clock_time(daily_stop_time_raw, "每日停止时间")
    if end_date < start_date:
        raise ValueError("结束日期不能早于开始日期。")
    if daily_stop_time <= daily_start_time:
        raise ValueError("每日停止时间必须晚于每日启动时间。")
    return {
        "is_enabled": enabled,
        "start_date": start_date,
        "end_date": end_date,
        "daily_start_time": daily_start_time,
        "daily_stop_time": daily_stop_time,
    }


def _user_owns_course(user_id: int, course_target_id: int) -> bool:
    return any(course["id"] == course_target_id for course in store.list_courses_for_user(user_id))


def _build_user_dashboard_context(user: dict) -> dict:
    return {
        "current_user": user,
        "courses": store.list_courses_for_user(user["id"]),
        "task": store.get_latest_task_for_user(user["id"]),
        "schedule": store.get_user_schedule(user["id"]),
        "recent_logs": store.list_recent_logs(user_id=user["id"], limit=config.logs_page_size),
    }


def _load_admin_users(*, include_courses: bool = True, include_latest_task: bool = True, include_schedule: bool = True) -> list[dict]:
    users = store.list_users()
    for user in users:
        if include_courses:
            user["courses"] = store.list_courses_for_user(user["id"])
        if include_latest_task:
            user["latest_task"] = store.get_latest_task_for_user(user["id"])
        if include_schedule:
            user["schedule"] = store.get_user_schedule(user["id"])
    return users


def _build_admin_base_context(active_page: str, *, page_title: str, page_description: str) -> dict:
    admin_identity = _get_admin_identity()
    return {
        "admin_identity": admin_identity,
        "is_super_admin": admin_identity["is_super_admin"],
        "admin_page": active_page,
        "page_title": page_title,
        "page_description": page_description,
    }


def _build_admin_dashboard_context() -> dict:
    context = _build_admin_base_context(
        "overview",
        page_title="Overview",
        page_description="Review system metrics, recent tasks, and admin-level settings.",
    )
    context.update(
        {
            "stats": store.get_admin_stats(),
            "recent_tasks": store.list_recent_tasks(limit=18),
            "parallel_limit": store.get_parallel_limit(),
            "admins": store.list_admins(),
            "status_url": url_for("admin_status"),
        }
    )
    return context


def _build_admin_users_context() -> dict:
    context = _build_admin_base_context(
        "users",
        page_title="Users",
        page_description="Manage user accounts, course targets, and task operations.",
    )
    context.update(
        {
            "users": _load_admin_users(include_courses=True, include_latest_task=True, include_schedule=True),
        }
    )
    return context


def _build_admin_schedules_context() -> dict:
    context = _build_admin_base_context(
        "schedules",
        page_title="Schedules",
        page_description="Configure per-user auto start and stop windows by date and time.",
    )
    users = _load_admin_users(include_courses=False, include_latest_task=True, include_schedule=True)
    context.update(
        {
            "users": users,
            "stats": store.get_admin_stats(),
        }
    )
    return context


def _build_admin_registration_codes_context() -> dict:
    context = _build_admin_base_context(
        "registration_codes",
        page_title="Codes",
        page_description="Create registration codes and inspect their usage state.",
    )
    context.update(
        {
            "registration_codes": store.list_registration_codes(limit=60),
            "stats": store.get_admin_stats(),
        }
    )
    return context


def _build_admin_logs_context() -> dict:
    recent_logs = store.list_recent_logs(limit=config.logs_page_size)
    context = _build_admin_base_context(
        "logs",
        page_title="Logs",
        page_description="Review live global logs for task execution and troubleshooting.",
    )
    context.update(
        {
            "recent_logs": recent_logs,
            "log_stream_url": url_for("stream_admin_logs", last_id=recent_logs[-1]["id"] if recent_logs else 0),
        }
    )
    return context


def _queue_task_for_user(user: dict, *, requested_by: str, requested_by_role: str) -> tuple[dict, bool]:
    return task_manager.queue_task(user["id"], requested_by=requested_by, requested_by_role=requested_by_role)


def _latest_log_id(logs: list[dict]) -> int:
    if not logs:
        return 0
    return int(logs[-1]["id"])


def _admin_post_redirect(default_endpoint: str):
    target = (request.form.get("next") or request.referrer or "").strip()
    if target:
        parsed = urlparse(target)
        same_host = not parsed.netloc or parsed.netloc == request.host
        if same_host and (parsed.path or "").startswith("/admin"):
            safe_target = parsed.path or url_for(default_endpoint)
            if parsed.query:
                safe_target = f"{safe_target}?{parsed.query}"
            return redirect(safe_target)
    return redirect(url_for(default_endpoint))


@app.get("/")
def index():
    if session.get("role") == "user":
        return redirect(url_for("dashboard"))
    if session.get("role") == "admin":
        return redirect(url_for("admin_dashboard"))
    return redirect(url_for("login"))


@app.route("/login", methods=["GET", "POST"])
def login():
    if request.method == "POST":
        student_id = request.form.get("student_id", "").strip()
        password = request.form.get("password", "")
        user = store.get_user_by_student_id(student_id)
        if user is None:
            flash("没有找到该学号对应的账号。如果你有注册码，请先完成注册。", "danger")
            return render_template("login.html")
        if not user["is_active"]:
            flash("该账号已被管理员禁用。", "danger")
            return render_template("login.html")
        try:
            stored_password = secret_box.decrypt(user["password_encrypted"])
        except Exception:
            flash("账号数据损坏，请联系管理员重置密码。", "danger")
            return render_template("login.html")
        if stored_password != password:
            flash("学号或密码不正确。", "danger")
            return render_template("login.html")

        session.clear()
        session["role"] = "user"
        session["user_id"] = user["id"]
        return redirect(url_for("dashboard"))

    return render_template("login.html")


@app.route("/register", methods=["GET", "POST"])
def register():
    if request.method == "POST":
        registration_code = normalize_registration_code(request.form.get("registration_code", ""))
        student_id = request.form.get("student_id", "").strip()
        password = request.form.get("password", "").strip()
        display_name = request.form.get("display_name", "").strip()

        if not REGISTRATION_CODE_PATTERN.fullmatch(registration_code):
            flash("请输入有效的注册码。", "danger")
            return render_template("register.html")
        if not student_id.isdigit() or not password:
            flash("请填写学号和教务处密码。", "danger")
            return render_template("register.html")

        try:
            store.register_user_with_code(
                registration_code,
                student_id,
                secret_box.encrypt(password),
                display_name,
                refresh_interval_seconds=config.poll_interval_seconds,
            )
        except ValueError as exc:
            flash(str(exc), "danger")
            return render_template("register.html")

        flash("注册成功，请使用学号和教务处密码登录。", "success")
        return redirect(url_for("login"))

    return render_template("register.html")


@app.post("/logout")
def logout():
    session.clear()
    return redirect(url_for("login"))


@app.route("/admin", methods=["GET", "POST"])
def admin_login():
    if request.method == "POST":
        username = request.form.get("username", "").strip()
        password = request.form.get("password", "")
        is_super_admin = username == config.super_admin_username and password == config.super_admin_password
        admin_row = store.get_admin_by_username(username)
        is_regular_admin = bool(admin_row and verify_password(admin_row["password_hash"], password))
        if not is_super_admin and not is_regular_admin:
            flash("管理员账号或密码错误。", "danger")
            return render_template("admin_login.html")

        session.clear()
        session["role"] = "admin"
        session["admin_username"] = username
        session["is_super_admin"] = is_super_admin
        return redirect(url_for("admin_dashboard"))

    return render_template("admin_login.html")


@app.post("/admin/logout")
def admin_logout():
    session.clear()
    return redirect(url_for("admin_login"))

@app.get("/dashboard")
@_login_required("user")
def dashboard():
    user = _get_current_user()
    if user is None:
        session.clear()
        return redirect(url_for("login"))
    return render_template("dashboard.html", **_build_user_dashboard_context(user))


@app.post("/dashboard/profile")
@_login_required("user")
def update_profile():
    user = _get_current_user()
    if user is None:
        session.clear()
        return redirect(url_for("login"))

    password = request.form.get("password", "").strip()
    display_name = request.form.get("display_name", "").strip()
    if not password:
        flash("密码不能为空。", "danger")
        return redirect(url_for("dashboard"))

    store.update_user(user["id"], password_encrypted=secret_box.encrypt(password), display_name=display_name)
    flash("账号信息已更新。", "success")
    return redirect(url_for("dashboard"))


@app.post("/dashboard/settings/runtime")
@_login_required("user")
def update_runtime_settings():
    user = _get_current_user()
    if user is None:
        session.clear()
        return redirect(url_for("login"))

    try:
        refresh_interval_seconds = _parse_refresh_interval(
            request.form.get("refresh_interval_seconds"),
            default=int(user.get("refresh_interval_seconds") or config.poll_interval_seconds),
        )
    except ValueError as exc:
        flash(str(exc), "danger")
        return redirect(url_for("dashboard"))

    store.update_user(user["id"], refresh_interval_seconds=refresh_interval_seconds)
    flash(f"未命中课程后的刷新间隔已更新为 {refresh_interval_seconds} 秒。", "success")
    return redirect(url_for("dashboard"))


@app.post("/dashboard/courses")
@_login_required("user")
def add_course():
    user = _get_current_user()
    if user is None:
        session.clear()
        return redirect(url_for("login"))

    category = request.form.get("category", "free")
    course_id = request.form.get("course_id", "")
    course_index = request.form.get("course_index", "")
    normalized_target = _validate_course_target(course_id, course_index)
    if normalized_target is None:
        flash("课程号需要使用 1-32 位字母或数字，课序号需要使用 1-8 位字母或数字。", "danger")
        return redirect(url_for("dashboard"))

    normalized_course_id, normalized_course_index = normalized_target
    store.add_course(user["id"], category, normalized_course_id, normalized_course_index)
    flash("课程已加入任务列表。", "success")
    return redirect(url_for("dashboard"))


@app.post("/dashboard/courses/<int:course_target_id>/delete")
@_login_required("user")
def delete_course(course_target_id: int):
    user = _get_current_user()
    if user is None:
        session.clear()
        return redirect(url_for("login"))
    if not _user_owns_course(user["id"], course_target_id):
        flash("不能删除不属于当前账号的课程。", "danger")
        return redirect(url_for("dashboard"))
    store.delete_course(course_target_id)
    flash("课程已移除。", "success")
    return redirect(url_for("dashboard"))


@app.post("/dashboard/task/start")
@_login_required("user")
def start_task():
    user = _get_current_user()
    if user is None:
        session.clear()
        return redirect(url_for("login"))
    task, created = _queue_task_for_user(user, requested_by=user["student_id"], requested_by_role="user")
    flash("任务已启动。" if created else f"已有任务处于 {TASK_LABELS.get(task['status'], task['status'])} 状态。", "success" if created else "warning")
    return redirect(url_for("dashboard"))


@app.post("/dashboard/task/stop")
@_login_required("user")
def stop_task():
    user = _get_current_user()
    if user is None:
        session.clear()
        return redirect(url_for("login"))
    active_task = store.find_active_task_for_user(user["id"])
    if active_task and task_manager.stop_task(active_task["id"]):
        flash("停止请求已发送。", "success")
    else:
        flash("当前没有可停止的任务。", "warning")
    return redirect(url_for("dashboard"))


@app.get("/admin/dashboard")
@_login_required("admin")
def admin_dashboard():
    return render_template("admin_dashboard.html", **_build_admin_dashboard_context())


@app.get("/admin/users")
@_login_required("admin")
def admin_users():
    return render_template("admin_users.html", **_build_admin_users_context())


@app.get("/admin/schedules")
@_login_required("admin")
def admin_schedules():
    return render_template("admin_schedules.html", **_build_admin_schedules_context())


@app.get("/admin/registration-codes")
@_login_required("admin")
def admin_registration_codes():
    return render_template("admin_registration_codes.html", **_build_admin_registration_codes_context())


@app.get("/admin/logs")
@_login_required("admin")
def admin_logs():
    return render_template("admin_logs.html", **_build_admin_logs_context())


@app.post("/admin/settings/parallel-limit")
@_login_required("admin")
def update_parallel_limit():
    try:
        parallel_limit = max(1, min(8, int(request.form.get("parallel_limit", str(config.default_parallel_limit)))))
    except ValueError:
        flash("并行数必须是 1 到 8 的整数。", "danger")
        return _admin_post_redirect("admin_dashboard")
    store.set_parallel_limit(parallel_limit)
    flash(f"并行数已更新为 {parallel_limit}。", "success")
    return _admin_post_redirect("admin_dashboard")


@app.post("/admin/users")
@_login_required("admin")
def create_user():
    student_id = request.form.get("student_id", "").strip()
    password = request.form.get("password", "").strip()
    display_name = request.form.get("display_name", "").strip()
    try:
        refresh_interval_seconds = _parse_refresh_interval(
            request.form.get("refresh_interval_seconds"),
            default=config.poll_interval_seconds,
        )
    except ValueError as exc:
        flash(str(exc), "danger")
        return _admin_post_redirect("admin_users")
    if not student_id.isdigit() or not password:
        flash("请填写有效的学号和密码。", "danger")
        return _admin_post_redirect("admin_users")
    if store.get_user_by_student_id(student_id):
        flash("该学号已经存在。", "warning")
        return _admin_post_redirect("admin_users")
    store.create_user(
        student_id,
        secret_box.encrypt(password),
        display_name,
        refresh_interval_seconds=refresh_interval_seconds,
    )
    flash("用户已创建。", "success")
    return _admin_post_redirect("admin_users")


@app.post("/admin/users/<int:user_id>/update")
@_login_required("admin")
def update_user(user_id: int):
    user = store.get_user(user_id)
    if user is None:
        flash("用户不存在。", "danger")
        return _admin_post_redirect("admin_users")
    display_name = request.form.get("display_name", user["display_name"]).strip()
    password = request.form.get("password", "").strip()
    try:
        refresh_interval_seconds = _parse_refresh_interval(
            request.form.get("refresh_interval_seconds"),
            default=int(user.get("refresh_interval_seconds") or config.poll_interval_seconds),
        )
    except ValueError as exc:
        flash(str(exc), "danger")
        return _admin_post_redirect("admin_users")
    if password:
        store.update_user(
            user_id,
            display_name=display_name,
            password_encrypted=secret_box.encrypt(password),
            refresh_interval_seconds=refresh_interval_seconds,
        )
    else:
        store.update_user(user_id, display_name=display_name, refresh_interval_seconds=refresh_interval_seconds)
    flash("用户信息已更新。", "success")
    return _admin_post_redirect("admin_users")


@app.post("/admin/users/<int:user_id>/toggle")
@_login_required("admin")
def toggle_user(user_id: int):
    updated = store.toggle_user_active(user_id)
    if updated is None:
        flash("用户不存在。", "danger")
    else:
        flash("用户状态已切换。", "success")
    return _admin_post_redirect("admin_users")


@app.post("/admin/users/<int:user_id>/delete")
@_login_required("admin")
def delete_user_by_admin(user_id: int):
    user = store.get_user(user_id)
    if user is None:
        flash("用户不存在。", "danger")
        return _admin_post_redirect("admin_users")
    active_task = store.find_active_task_for_user(user_id)
    if active_task is not None:
        flash("请先停止该用户当前任务，再删除用户。", "danger")
        return _admin_post_redirect("admin_users")
    store.delete_user(user_id)
    flash("用户及其课程、日志、定时设置已删除。", "success")
    return _admin_post_redirect("admin_users")


@app.post("/admin/users/<int:user_id>/schedule")
@_login_required("admin")
def update_user_schedule(user_id: int):
    if store.get_user(user_id) is None:
        flash("用户不存在。", "danger")
        return _admin_post_redirect("admin_schedules")
    try:
        schedule_payload = _parse_schedule_form(request.form)
    except ValueError as exc:
        flash(str(exc), "danger")
        return _admin_post_redirect("admin_schedules")
    store.upsert_user_schedule(user_id, **schedule_payload)
    flash("定时启动终止设置已更新。", "success")
    return _admin_post_redirect("admin_schedules")


@app.post("/admin/users/<int:user_id>/courses")
@_login_required("admin")
def admin_add_course(user_id: int):
    if store.get_user(user_id) is None:
        flash("用户不存在。", "danger")
        return _admin_post_redirect("admin_users")
    category = request.form.get("category", "free")
    course_id = request.form.get("course_id", "")
    course_index = request.form.get("course_index", "")
    normalized_target = _validate_course_target(course_id, course_index)
    if normalized_target is None:
        flash("课程号需要使用 1-32 位字母或数字，课序号需要使用 1-8 位字母或数字。", "danger")
        return _admin_post_redirect("admin_users")
    normalized_course_id, normalized_course_index = normalized_target
    store.add_course(user_id, category, normalized_course_id, normalized_course_index)
    flash("课程已添加到对应用户。", "success")
    return _admin_post_redirect("admin_users")


@app.post("/admin/courses/<int:course_target_id>/delete")
@_login_required("admin")
def admin_delete_course(course_target_id: int):
    store.delete_course(course_target_id)
    flash("课程已删除。", "success")
    return _admin_post_redirect("admin_users")


@app.post("/admin/users/<int:user_id>/task/start")
@_login_required("admin")
def admin_start_user_task(user_id: int):
    user = store.get_user(user_id)
    if user is None:
        flash("用户不存在。", "danger")
        return _admin_post_redirect("admin_users")
    admin_identity = _get_admin_identity()
    task, created = _queue_task_for_user(user, requested_by=admin_identity["username"], requested_by_role="admin")
    flash("任务已加入队列。" if created else f"该用户已有任务处于 {TASK_LABELS.get(task['status'], task['status'])} 状态。", "success" if created else "warning")
    return _admin_post_redirect("admin_users")


@app.post("/admin/users/<int:user_id>/task/stop")
@_login_required("admin")
def admin_stop_user_task(user_id: int):
    active_task = store.find_active_task_for_user(user_id)
    if active_task and task_manager.stop_task(active_task["id"]):
        flash("已发送停止请求。", "success")
    else:
        flash("当前没有可停止任务。", "warning")
    return _admin_post_redirect("admin_users")


@app.post("/admin/admins")
@_login_required("admin")
def create_admin():
    if not session.get("is_super_admin", False):
        flash("只有超级管理员可以新增管理员。", "danger")
        return _admin_post_redirect("admin_dashboard")
    username = request.form.get("username", "").strip()
    password = request.form.get("password", "").strip()
    if not username or not password:
        flash("请填写管理员账号和密码。", "danger")
        return _admin_post_redirect("admin_dashboard")
    if username == config.super_admin_username or store.get_admin_by_username(username):
        flash("该管理员账号已存在。", "warning")
        return _admin_post_redirect("admin_dashboard")
    store.create_admin(username, hash_password(password))
    flash("管理员已创建。", "success")
    return _admin_post_redirect("admin_dashboard")


@app.post("/admin/registration-codes")
@_login_required("admin")
def create_registration_code():
    note = request.form.get("note", "").strip()
    try:
        max_uses = _parse_registration_code_max_uses(request.form.get("max_uses"))
    except ValueError as exc:
        flash(str(exc), "danger")
        return _admin_post_redirect("admin_registration_codes")
    admin_identity = _get_admin_identity()
    created = store.create_registration_code(created_by=admin_identity["username"], note=note, max_uses=max_uses)
    flash(f"注册码已创建：{created['code']}", "success")
    return _admin_post_redirect("admin_registration_codes")


@app.post("/admin/registration-codes/<int:registration_code_id>/toggle")
@_login_required("admin")
def toggle_registration_code(registration_code_id: int):
    updated = store.toggle_registration_code_active(registration_code_id)
    if updated is None:
        flash("注册码不存在。", "danger")
    else:
        flash("注册码状态已更新。", "success")
    return _admin_post_redirect("admin_registration_codes")

@app.get("/api/user/status")
@_login_required("user")
def user_status():
    user = _get_current_user()
    if user is None:
        return jsonify({"ok": False}), 401
    task = store.get_latest_task_for_user(user["id"])
    return jsonify(
        {
            "ok": True,
            "task": task,
            "courses": store.list_courses_for_user(user["id"]),
            "user": {
                "refresh_interval_seconds": int(user.get("refresh_interval_seconds") or config.poll_interval_seconds),
            },
        }
    )


@app.get("/api/admin/status")
@_login_required("admin")
def admin_status():
    return jsonify(
        {
            "ok": True,
            "stats": store.get_admin_stats(),
            "parallel_limit": store.get_parallel_limit(),
            "recent_tasks": store.list_recent_tasks(limit=12),
        }
    )


@app.get("/api/user/logs/stream")
@_login_required("user")
def stream_user_logs():
    user = _get_current_user()
    if user is None:
        return jsonify({"ok": False}), 401
    last_id = int(request.args.get("last_id", _latest_log_id(store.list_recent_logs(user_id=user["id"], limit=1))))

    @stream_with_context
    def generate():
        current_last_id = last_id
        while True:
            logs = store.list_logs_after(current_last_id, user_id=user["id"], limit=60)
            if logs:
                for log in logs:
                    current_last_id = int(log["id"])
                    yield f"id: {log['id']}\ndata: {json.dumps(log, ensure_ascii=False)}\n\n"
            else:
                yield ": keep-alive\n\n"
            time.sleep(1)

    response = Response(generate(), mimetype="text/event-stream")
    response.headers["Cache-Control"] = "no-cache"
    response.headers["X-Accel-Buffering"] = "no"
    return response


@app.get("/api/admin/logs/stream")
@_login_required("admin")
def stream_admin_logs():
    last_id = int(request.args.get("last_id", _latest_log_id(store.list_recent_logs(limit=1))))

    @stream_with_context
    def generate():
        current_last_id = last_id
        while True:
            logs = store.list_logs_after(current_last_id, limit=80)
            if logs:
                for log in logs:
                    current_last_id = int(log["id"])
                    yield f"id: {log['id']}\ndata: {json.dumps(log, ensure_ascii=False)}\n\n"
            else:
                yield ": keep-alive\n\n"
            time.sleep(1)

    response = Response(generate(), mimetype="text/event-stream")
    response.headers["Cache-Control"] = "no-cache"
    response.headers["X-Accel-Buffering"] = "no"
    return response