# System Library
from flask import Blueprint, session, render_template, request, flash

# Personal library
from Yaml import yml
from model.user import get_users, update_password_by_username
from model.user import update_expiry_time_by_username, get_user_by_username
from model.article import get_number_of_articles, get_page_articles
from model.article import delete_article_by_id, add_article
ADMIN_NAME = "lanhui"  # unique admin name
_cur_page = 1  # current article page
_page_size = 5  # article sizes per page
adminService = Blueprint("admin_service", __name__)

def check_is_admin():
    '''
    判断是否是管理员登录
    ：return：不同页面和结果
    '''
    # 未登录，跳转到未登录界面
    if not session.get("logged_in"):
        return render_template("not_login.html")

    # 用户名不是admin_name
    if session.get("username") != ADMIN_NAME:
        return "You are not admin!"

    return "pass"


@adminService.route("/admin", methods=["GET"])
def admin():
    '''
    判断是否是管理员登录
    ：return：不同页面
    '''
    is_admin = check_is_admin()
    if is_admin != "pass":
        return is_admin

    return render_template(
        "admin_index.html", yml=yml, username=session.get("username")
    )


@adminService.route("/admin/article", methods=["GET", "POST"])
def article():
    '''
    管理文章
    可添加文章、删除文章
    return:不同页面
    '''
    global _cur_page, _page_size

    is_admin = check_is_admin()
    if is_admin != "pass":
        return is_admin

    _article_number = get_number_of_articles()
    try:
        _page_size = min(
            max(1, int(request.args.get("size", 5))), _article_number
        )  # 最小的size是1
        _cur_page = min(
            max(1, int(request.args.get("page", 1))),
            _article_number // _page_size + (_article_number % _page_size > 0)
        )  # 最小的page是1
    except ValueError:
        return "page parmas must be int!"
    _articles = get_page_articles(_cur_page, _page_size)
    for _article in _articles:   # 获取每篇文章的title
        _article.title = _article.text.split("\n")[0]
        _article.content = '<br/>'.join(_article.text.split("\n")[1:])
    context = {
        "article_number": _article_number,
        "text_list": _articles,
        "page_size": _page_size,
        "cur_page": _cur_page,
        "username": session.get("username"),
    }

    def _update_context():
        article_len = get_number_of_articles()
        context["article_number"] = article_len
        context["text_list"] = get_page_articles(_cur_page, _page_size)
        _articles = get_page_articles(_cur_page, _page_size)
        for _article in _articles:   # 获取每篇文章的title
            _article.title = _article.text.split("\n")[0]
        context["text_list"] = _articles

    if request.method == "GET":
        try:
            delete_id = int(request.args.get("delete_id", 0))
        except ValueError:
            return "Delete article ID must be int!"
        if delete_id:  # delete article
            delete_article_by_id(delete_id)
            _update_context()
    else:
        data = request.form
        content = data.get("content", "")
        source = data.get("source", "")
        question = data.get("question", "")
        level = data.get("level", "4")
        if content:
            if level not in ['1', '2', '3', '4']:
                return "Level must be between 1 and 4."
            add_article(content, source, level, question)
            _update_context()
            title = content.split('\n')[0]
            flash(f'Article added. Title: {title}')
    return render_template("admin_manage_article.html", **context)


@adminService.route("/admin/user", methods=["GET", "POST"])
def user():
    '''
    用户管理
    可修改用户密码，过期日期
    return：不同页面
    '''
    is_admin = check_is_admin()
    if is_admin != "pass":
        return is_admin
    context = {
        "user_list": get_users(),
        "username": session.get("username"),
    }
    if request.method == "POST":
        data = request.form
        username = data.get("username", "")
        new_password = data.get("new_password", "")
        expiry_time = data.get("expiry_time", "")
        if username:
            if new_password:
                update_password_by_username(username, new_password)
                flash(f'Password updated to {new_password}')
            if expiry_time:
                update_expiry_time_by_username(username, "".join(expiry_time.split("-")))
                flash(f'Expiry date updated to {expiry_time}.')
    return render_template("admin_manage_user.html", **context)


@adminService.route("/admin/expiry", methods=["GET"])
def user_expiry_time():
    '''
    返回用户的过期日期
    '''
    is_admin = check_is_admin()
    if is_admin != "pass":
        return is_admin

    username = request.args.get("username", "")
    if not username:
        return "Username can't be empty."

    existed_user = get_user_by_username(username)
    if not existed_user:
        return "User does not exist."
    return existed_user.expiry_date