#User avatar and personal information: Gravatar + customized upload combination plan

import hashlib

def get_gravatar_url(email, size=80):
    """生成带默认几何回退的 Gravatar URL"""
    # 邮箱预处理：严格去前后空格+转小写（Gravatar 只认这个规则！）
    cleaned_email = email.strip().lower()
    # 生成 32 位小写 MD5 哈希
    email_hash = hashlib.md5(cleaned_email.encode()).hexdigest()
    # 拼接完整 URL：默认尺寸 80px，无头像返回几何图案 identicon
    return f"https://www.gravatar.com/avatar/{email_hash}?s={size}&d=identicon"

# 测试调用
print(get_gravatar_url("alice@example.com"))
# → 输出类似：https://www.gravatar.com/avatar/5aba7...d1?s=80&d=identicon

def get_gravatar(
    email,
    size=80,
    rating="g",
    default="identicon"
):
    """支持多参数配置的 Gravatar URL 生成器"""
    cleaned_email = email.strip().lower()
    email_hash = hashlib.md5(cleaned_email.encode()).hexdigest()
    return f"https://www.gravatar.com/avatar/{email_hash}?s={size}&d={default}&r={rating}"

# app/extensions.py
import hashlib

def get_gravatar(
    email,
    size=80,
    rating="g",
    default="identicon"
):
    cleaned_email = email.strip().lower()
    email_hash = hashlib.md5(cleaned_email.encode()).hexdigest()
    return f"https://www.gravatar.com/avatar/{email_hash}?s={size}&d={default}&r={rating}"

# 这里可以放其他扩展工具，比如密码加密、日期格式化等

# app/__init__.py
from flask import Flask
from .extensions import get_gravatar

def create_app(config_class=Config):
    app = Flask(__name__)
    app.config.from_object(config_class)

    # ... 注册数据库、蓝图等其他扩展 ...

    # 注册 Jinja2 全局函数
    app.jinja_env.globals["get_gravatar"] = get_gravatar

    return app

# app/models/user.py
from datetime import datetime
from flask_login import UserMixin
from app.extensions import db, get_gravatar  # 注意从 extensions 导入 Gravatar 工具

class User(UserMixin, db.Model):
    __tablename__ = "users"

    id = db.Column(db.Integer, primary_key=True)
    email = db.Column(db.String(120), unique=True, nullable=False)
    username = db.Column(db.String(50), unique=True, nullable=False)
    password_hash = db.Column(db.String(256), nullable=False)
    # 新增：自定义头像的相对路径，默认空字符串
    avatar = db.Column(db.String(200), default="")
    # 顺便加个 bio 字段，完善个人资料
    bio = db.Column(db.String(500), default="")
    created_at = db.Column(db.DateTime, default=datetime.utcnow)

    def get_avatar(self, size=80):
        """组合优先：先看有没有自定义头像，没有用 Gravatar，最后用本地默认"""
        if self.avatar:
            return self.avatar
        if self.email:
            return get_gravatar(self.email, size=size)
        # 兜底：本地全年龄段友好的默认头像
        return "/static/img/default-avatar.png"

# app/routes/profile.py
import os
import uuid
from flask import Blueprint, request, redirect, url_for, flash, current_app, render_template
from flask_login import login_required, current_user
from werkzeug.utils import secure_filename
from PIL import Image
from app.extensions import db

profile_bp = Blueprint("profile", __name__, url_prefix="/profile")

# 允许的图片格式
ALLOWED_EXTENSIONS = {"png", "jpg", "jpeg", "gif", "webp"}

def allowed_file(filename):
    """检查文件后缀是否合法"""
    return "." in filename and filename.rsplit(".", 1)[1].lower() in ALLOWED_EXTENSIONS

@profile_bp.route("/edit", methods=["GET", "POST"])
@login_required
def edit_profile():
    """基础的个人资料编辑页（下一节完善表单）"""
    return render_template("profile/edit.html")

@profile_bp.route("/avatar", methods=["POST"])
@login_required
def upload_avatar():
    """处理自定义头像上传"""
    # 1. 检查有没有上传文件
    if "avatar" not in request.files:
        flash("没有检测到上传的头像文件！", "danger")
        return redirect(url_for("profile.edit_profile"))
    
    file = request.files["avatar"]
    # 2. 检查文件名是否为空
    if file.filename == "":
        flash("请选择一张图片后再提交！", "warning")
        return redirect(url_for("profile.edit_profile"))
    
    # 3. 检查文件格式
    if file and allowed_file(file.filename):
        # 4. 生成安全的文件名，提取后缀
        secure_name = secure_filename(file.filename)
        ext = secure_name.rsplit(".", 1)[1].lower()
        new_filename = f"{uuid.uuid4().hex}.{ext}"

        # 5. 创建上传目录（如果不存在）
        upload_dir = os.path.join(
            current_app.root_path, "static", "uploads", "avatars"
        )
        os.makedirs(upload_dir, exist_ok=True)
        local_path = os.path.join(upload_dir, new_filename)

        # 6. 压缩 / 裁剪图片：统一缩放到 200x200 以内的正方形
        try:
            with Image.open(file) as img:
                # 统一转 RGB 格式，避免 PNG 透明背景存成 JPEG 出错
                if img.mode in ("RGBA", "P"):
                    img = img.convert("RGB")
                # 用 LANCZOS 算法，压缩质量最高
                img.thumbnail((200, 200), Image.LANCZOS)
                # 保存为 JPEG 格式，质量 85
                img.save(local_path, "JPEG", quality=85, optimize=True)
        except Exception as e:
            flash(f"图片处理失败：{str(e)}", "danger")
            return redirect(url_for("profile.edit_profile"))

        # 7. 删除旧的自定义头像（避免浪费空间）
        if current_user.avatar:
            old_local_path = os.path.join(
                current_app.root_path, current_user.avatar.lstrip("/")
            )
            # 确保路径存在且是文件再删除
            if os.path.exists(old_local_path) and os.path.isfile(old_local_path):
                try:
                    os.remove(old_local_path)
                except Exception:
                    # 忽略删除失败的错误（比如权限问题）
                    pass

        # 8. 保存新头像的相对路径到数据库
        current_user.avatar = f"/static/uploads/avatars/{new_filename}"
        db.session.commit()
        flash("头像更新成功！", "success")

    else:
        flash("不支持的图片格式！请上传 png / jpg / jpeg / gif / webp 格式的图片。", "danger")

    return redirect(url_for("profile.edit_profile"))