from datetime import datetime
from app.extensions import db


class SystemSetting(db.Model):
    __tablename__ = 'system_settings'

    id = db.Column(db.Integer, primary_key=True)
    key = db.Column(db.String(64), unique=True, nullable=False, index=True)
    value = db.Column(db.Text, nullable=True)
    value_type = db.Column(db.Enum('string', 'integer', 'boolean', 'json'),
                           default='string')
    description = db.Column(db.String(255), nullable=True)
    updated_at = db.Column(db.DateTime, default=datetime.utcnow,
                           onupdate=datetime.utcnow)

    def __repr__(self):
        return f'<SystemSetting {self.key}={self.value}>'

    @classmethod
    def get(cls, key, default=None):
        setting = cls.query.filter_by(key=key).first()
        if setting is None:
            return default
        return setting.value

    @classmethod
    def set(cls, key, value, description=None):
        setting = cls.query.filter_by(key=key).first()
        if setting:
            setting.value = str(value)
            setting.updated_at = datetime.utcnow()
        else:
            setting = cls(key=key, value=str(value), description=description)
            db.session.add(setting)
        db.session.commit()

    # 默认配置项
    DEFAULTS = {
        'site_name': ('个人资料库', '站点名称'),
        'site_description': ('我的个人多媒体资料管理系统', '站点描述'),
        'allow_register': ('true', '是否允许用户注册'),
        'max_upload_mb': ('500', '单次最大上传大小(MB)'),
        'allowed_types': ('text,image,audio,video', '允许的资源类型'),
        'enable_magnet': ('true', '是否启用磁力下载'),
        'enable_url_download': ('true', '是否启用 URL 下载'),
    }