from flask import Blueprint, jsonify, send_file, request
from flask_jwt_extended import jwt_required, get_jwt_identity
from ..models import File, Download, User, SystemSettings, Category, CategoryPermission, db
from datetime import datetime, date, timedelta
import os

# user_bp = Blueprint('user', __name__)
user_bp = Blueprint('user', __name__, url_prefix='/api')  # 添加 url_prefix='/api'


@user_bp.route('/files', methods=['GET'])
@jwt_required()
def get_available_files():
    # 获取所有未被领取的文件
    page = request.args.get('page', 1, type=int)
    per_page = request.args.get('per_page', 12, type=int)
    # 限制每页数量只能是10, 20, 50
    if per_page not in [10, 20, 50]:
        per_page = 12
    category_id = request.args.get('category_id', type=int)
    user_id = get_jwt_identity()
    
    # 获取用户有权限的所有分类ID
    authorized_category_ids = set()
    
    # 获取用户直接拥有权限的分类
    direct_permissions = db.session.query(CategoryPermission.category_id)\
        .filter_by(user_id=user_id).all()
    direct_category_ids = [p[0] for p in direct_permissions]
    
    # 添加直接权限的分类ID
    authorized_category_ids.update(direct_category_ids)
    
    # 处理继承权限
    for cat_id in direct_category_ids:
        permission = CategoryPermission.query.filter_by(
            user_id=user_id, category_id=cat_id
        ).first()
        
        if permission and permission.inherit_to_children:
            # 获取该分类的所有子分类
            category = Category.query.get(cat_id)
            if category:
                # 递归获取子分类ID
                def get_children_ids(parent_id):
                    children = Category.query.filter_by(parent_id=parent_id).all()
                    for child in children:
                        authorized_category_ids.add(child.id)
                        get_children_ids(child.id)
                
                get_children_ids(cat_id)
    
    # 如果没有任何权限，返回空列表
    if not authorized_category_ids:
        return jsonify({
            'files': [],
            'has_more': False
        }), 200
    
    # 基于权限过滤文件查询
    query = File.query.filter_by(is_taken=False)\
        .filter(File.category_id.in_(authorized_category_ids))
    
    # 如果指定了分类ID，进一步过滤
    if category_id:
        # 检查分类是否存在
        category = Category.query.get(category_id)
        if not category:
            return jsonify({'message': '分类不存在'}), 404
        
        # 检查用户是否有权限访问该分类
        if category_id not in authorized_category_ids:
            return jsonify({'message': '无权访问该分类'}), 403
        
        # 获取该分类及其所有子分类的ID
        filtered_category_ids = [category_id]
        # 递归获取子分类ID
        def get_children_ids(cat_id):
            children = Category.query.filter_by(parent_id=cat_id).all()
            for child in children:
                # 只添加用户有权限的子分类
                if child.id in authorized_category_ids:
                    filtered_category_ids.append(child.id)
                    get_children_ids(child.id)
        
        get_children_ids(category_id)
        query = query.filter(File.category_id.in_(filtered_category_ids))

    pagination = query.paginate(page=page, per_page=per_page, error_out=False)
    files = pagination.items
    has_more = pagination.has_next
    return jsonify({
        'files': [file.to_dict() for file in files],
        'has_more': has_more
    }), 200


@user_bp.route('/files/<int:file_id>', methods=['GET'])
@jwt_required()
def get_file_details(file_id):
    file = File.query.get_or_404(file_id)
    return jsonify(file.to_dict()), 200


@user_bp.route('/files/<int:file_id>/take', methods=['POST'])
@jwt_required()
def take_file(file_id):
    user_id = get_jwt_identity()
    user = User.query.get_or_404(user_id)
    file = File.query.get_or_404(file_id)

    # 检查文件是否已被领取
    if file.is_taken:
        return jsonify({'message': '该文件已被领取'}), 400

    # 检查用户今日领取数量是否已达上限
    today = date.today()
    start_of_day = datetime.combine(today, datetime.min.time())
    end_of_day = datetime.combine(today, datetime.max.time())

    today_downloads = Download.query.filter(
        Download.user_id == user_id,
        Download.download_time >= start_of_day,
        Download.download_time <= end_of_day
    ).count()

    # 使用系统设置中的每日配额
    daily_quota = user.daily_quota
    if daily_quota <= 0:
        daily_quota = SystemSettings.get_value('daily_quota', 5)

    if today_downloads >= daily_quota:
        return jsonify({
            'message': f'今日领取数量已达上限({daily_quota}个)',
            'today_downloads': today_downloads,
            'daily_quota': daily_quota
        }), 400

    # 更新文件状态
    file.is_taken = True
    file.taken_by = user_id
    file.taken_at = datetime.utcnow()

    # 创建下载记录
    download = Download(
        user_id=user_id,
        file_id=file_id
    )

    db.session.add(download)
    db.session.commit()

    return jsonify({
        'message': '文件领取成功',
        'file': file.to_dict(),
        'download_id': download.id
    }), 200


@user_bp.route('/downloads/<int:download_id>', methods=['GET'])
@jwt_required()
def download_file(download_id):
    user_id = get_jwt_identity()
    download = Download.query.get_or_404(download_id)

    # 验证权限
    if download.user_id != user_id:
        return jsonify({'message': '无权下载此文件'}), 403

    file = download.file

    # 检查文件是否存在
    if not os.path.exists(file.file_path):
        return jsonify({'message': '文件不存在'}), 404

    # 发送文件
    return send_file(
        file.file_path,
        as_attachment=True,
        download_name=file.original_filename,
        mimetype='application/octet-stream' # 确保浏览器下载而不是预览
    )


@user_bp.route('/files/<int:file_id>/download', methods=['GET'])
@jwt_required()
def download_file_by_id(file_id):
    user_id = get_jwt_identity()
    
    # 检查用户是否有权限下载此文件
    download = Download.query.filter_by(
        user_id=user_id,
        file_id=file_id
    ).first()
    
    if not download:
        return jsonify({'message': '您没有下载此文件的权限'}), 403
    
    file = File.query.get_or_404(file_id)
    
    # 检查用户是否有权限访问该文件所属分类
    has_permission = False
    
    # 获取用户有权限的所有分类ID
    authorized_category_ids = set()
    
    # 获取用户直接拥有权限的分类
    direct_permissions = db.session.query(CategoryPermission.category_id)\
        .filter_by(user_id=user_id).all()
    direct_category_ids = [p[0] for p in direct_permissions]
    
    # 添加直接权限的分类ID
    authorized_category_ids.update(direct_category_ids)
    
    # 处理继承权限
    for cat_id in direct_category_ids:
        permission = CategoryPermission.query.filter_by(
            user_id=user_id, category_id=cat_id
        ).first()
        
        if permission and permission.inherit_to_children:
            # 获取该分类的所有子分类
            category = Category.query.get(cat_id)
            if category:
                # 递归获取子分类ID
                def get_children_ids(parent_id):
                    children = Category.query.filter_by(parent_id=parent_id).all()
                    for child in children:
                        authorized_category_ids.add(child.id)
                        get_children_ids(child.id)
                
                get_children_ids(cat_id)
    
    # 检查文件所属分类是否在授权列表中
    if file.category_id in authorized_category_ids:
        has_permission = True
    
    if not has_permission:
        return jsonify({'message': '您没有访问此文件所属分类的权限'}), 403
    
    # 检查文件是否存在
    if not os.path.exists(file.file_path):
        return jsonify({'message': '文件不存在'}), 404
    
    # 发送文件
    return send_file(
        file.file_path,
        as_attachment=True,
        download_name=file.original_filename,
        mimetype='application/octet-stream' # 确保浏览器下载而不是预览
    )


@user_bp.route('/user/downloads', methods=['GET'])
@jwt_required()
def get_user_downloads():
    user_id = get_jwt_identity()
    downloads = Download.query.filter_by(user_id=user_id).order_by(Download.download_time.desc()).all()
    return jsonify([download.to_dict() for download in downloads]), 200


@user_bp.route('/user/quota', methods=['GET'])
@jwt_required()
def get_user_quota():
    user_id = get_jwt_identity()
    user = User.query.get_or_404(user_id)

    today = date.today()
    start_of_day = datetime.combine(today, datetime.min.time())
    end_of_day = datetime.combine(today, datetime.max.time())

    today_downloads = Download.query.filter(
        Download.user_id == user_id,
        Download.download_time >= start_of_day,
        Download.download_time <= end_of_day
    ).count()

    return jsonify({
        'daily_quota': user.daily_quota,
        'today_used': today_downloads,
        'today_remaining': user.daily_quota - today_downloads
    }), 200


@user_bp.route('/user/categories', methods=['GET'])
@jwt_required()
def get_user_categories():
    user_id = get_jwt_identity()
    
    # 获取用户有权限的所有分类ID
    authorized_category_ids = set()
    
    # 获取用户直接拥有权限的分类
    direct_permissions = db.session.query(CategoryPermission.category_id)\
        .filter_by(user_id=user_id).all()
    direct_category_ids = [p[0] for p in direct_permissions]
    
    # 添加直接权限的分类ID
    authorized_category_ids.update(direct_category_ids)
    
    # 处理继承权限
    for cat_id in direct_category_ids:
        permission = CategoryPermission.query.filter_by(
            user_id=user_id, category_id=cat_id
        ).first()
        
        if permission and permission.inherit_to_children:
            # 获取该分类的所有子分类
            category = Category.query.get(cat_id)
            if category:
                # 递归获取子分类ID
                def get_children_ids(parent_id):
                    children = Category.query.filter_by(parent_id=parent_id).all()
                    for child in children:
                        authorized_category_ids.add(child.id)
                        get_children_ids(child.id)
                
                get_children_ids(cat_id)
    
    # 获取所有授权分类的详细信息
    categories = Category.query.filter(Category.id.in_(authorized_category_ids)).all()
    
    # 构建分类树结构
    category_dict = {}
    root_categories = []
    
    # 首先将所有分类添加到字典中
    for category in categories:
        category_dict[category.id] = {
            'id': category.id,
            'name': category.name,
            'parent_id': category.parent_id,
            'level': category.level,
            'path': category.path,
            'children': []
        }
    
    # 然后构建树结构
    for category_id, category_data in category_dict.items():
        if category_data['parent_id'] is None or category_data['parent_id'] not in category_dict:
            root_categories.append(category_data)
        else:
            parent = category_dict[category_data['parent_id']]
            parent['children'].append(category_data)
    
    return jsonify({
        'categories': root_categories
    }), 200


# 在 user.py 中添加
@user_bp.route('/user/profile', methods=['PUT'])
@jwt_required()
def update_profile():
    user_id = get_jwt_identity()
    user = User.query.get_or_404(user_id)
    data = request.get_json()

    if 'email' in data:
        # 检查邮箱是否已被其他用户使用
        if data['email'] != user.email:
            existing_user = User.query.filter_by(email=data['email']).first()
            if existing_user:
                return jsonify({'message': '邮箱已被注册'}), 400
        user.email = data['email']
    
    # 处理密码修改
    if 'current_password' in data and 'new_password' in data:
        if not user.check_password(data['current_password']):
            return jsonify({'message': '当前密码错误'}), 401
        
        if len(data['new_password']) < 6:
            return jsonify({'message': '新密码长度至少为6位'}), 400
            
        user.set_password(data['new_password'])

    db.session.commit()
    return jsonify({'message': '资料更新成功'}), 200