#项目架构重构（Blueprints）：把 5000 行面条代码捋成乐高积木

# app/main/__init__.py
from flask import Blueprint

# 创建蓝图实例，三个核心参数：
# ① "main"：蓝图的唯一标识，后续 url_for 需要使用它
# ② __name__：蓝图的根目录，用来定位模板/静态文件
# ③ url_prefix（可选）：统一为所有路由添加前缀
main_bp = Blueprint("main", __name__)

# 最后导入 routes，将路由绑定到蓝图
# 注意：必须放在定义蓝图之后，避免循环导入！
from . import routes

# app/main/routes.py
from flask import render_template
from app.main import main_bp

@main_bp.route("/")
def index():
    return render_template("main/index.html")

@main_bp.route("/about")
def about():
    return render_template("main/about.html")

# app/__init__.py
from flask import Flask
from app.extensions import db, login_manager  # 假定已写好 extensions.py

def create_app():
    # 创建核心 Flask 应用
    app = Flask(__name__)

    # 1. 加载配置（后面单独介绍，这里先留空）
    app.config.from_object("app.config.DevConfig")

    # 2. 初始化全局扩展（DB、LoginManager 等）
    db.init_app(app)
    login_manager.init_app(app)

    # 3. ✨ 关键：注册蓝图
    # 注意：导入蓝图必须放在函数内部！！！
    # 否则会出现“循环导入”的死循环
    # （例如 routes.py 导入 db，extensions.py 又导入 create_app）
    from app.main import main_bp
    from app.auth import auth_bp
    from app.articles import articles_bp

    app.register_blueprint(main_bp)      # 主蓝图没有前缀，直接挂载到根路径
    app.register_blueprint(auth_bp)      # 认证蓝图，在内部已设置 /auth 前缀
    app.register_blueprint(articles_bp)  # 文章蓝图，在内部已设置 /articles 前缀

    # 4. 注册 Flask-Login 的用户加载器（必须和 login_manager 在同一个 create_app 内）
    @login_manager.user_loader
    def load_user(user_id):
        return db.session.get(User, int(user_id))  # User 可从 models.py 导入

    return app

# run.py
from app import create_app

app = create_app()

if __name__ == "__main__":
    app.run(debug=True)

# app/auth/__init__.py
from flask import Blueprint

# url_prefix="/auth"：所有该蓝图下的路由都会自动加上 /auth
# 比如 @auth_bp.route("/login") 实际访问路径就是 /auth/login
auth_bp = Blueprint("auth", __name__, url_prefix="/auth")

from . import routes

# app/auth/routes.py
from flask import render_template, redirect, url_for, flash, request
from flask_login import login_user, logout_user, login_required, current_user
from werkzeug.security import generate_password_hash, check_password_hash
from app.auth import auth_bp
from app.extensions import db
from app.models import User
from app.forms import LoginForm, RegisterForm

@auth_bp.route("/login", methods=["GET", "POST"])
def login():
    if current_user.is_authenticated:
        # ⚠️ 注意：url_for 现在必须使用「蓝图标识.视图函数名」
        # 跳转主首页应写成 url_for("main.index")，而不是 url_for("index")
        return redirect(url_for("main.index"))
    form = LoginForm()
    if form.validate_on_submit():
        user = User.query.filter_by(email=form.email.data).first()
        if user and user.check_password(form.password.data):
            login_user(user, remember=form.remember_me.data)
            next_page = request.args.get("next")
            return redirect(next_page or url_for("main.index"))
        flash("邮箱或密码错误，请重试", "danger")
    return render_template("auth/login.html", form=form)

@auth_bp.route("/logout")
@login_required
def logout():
    logout_user()
    flash("已成功退出登录，欢迎下次再来～", "info")
    return redirect(url_for("auth.login"))

# app/articles/__init__.py
from flask import Blueprint

articles_bp = Blueprint("articles", __name__, url_prefix="/articles")

from . import routes

# app/articles/routes.py
from flask import render_template, redirect, url_for, flash, abort, request
from flask_login import login_required, current_user
from app.articles import articles_bp
from app.extensions import db
from app.models import Post, Category
from app.forms import ArticleForm

@articles_bp.route("/")
def index():
    """文章列表页（带分页）"""
    page = request.args.get("page", 1, type=int)
    # 只显示已发布的文章，按创建时间倒序
    pagination = Post.query.filter_by(is_published=True)\
        .order_by(Post.created_at.desc())\
        .paginate(page=page, per_page=10, error_out=False)
    return render_template("articles/index.html", pagination=pagination)

@articles_bp.route("/<int:post_id>")
def detail(post_id):
    """文章详情页（带浏览量统计）"""
    post = Post.query.get_or_404(post_id)
    # 只有已发布的文章普通用户才能看
    if not post.is_published and (not current_user.is_authenticated or post.author != current_user):
        abort(403)
    post.views += 1
    db.session.commit()
    return render_template("articles/detail.html", post=post)

@articles_bp.route("/create", methods=["GET", "POST"])
@login_required
def create():
    """创建文章"""
    form = ArticleForm()
    if form.validate_on_submit():
        post = Post(
            title=form.title.data,
            content=form.content.data,
            summary=form.summary.data,
            author=current_user,
        )
        if form.is_published.data:
            post.is_published = True
        db.session.add(post)
        db.session.commit()
        flash("文章创建成功！", "success")
        return redirect(url_for("articles.detail", post_id=post.id))
    return render_template("articles/create.html", form=form)