"""
数据库模型定义
"""

from datetime import datetime
from flask_sqlalchemy import SQLAlchemy
from werkzeug.security import generate_password_hash, check_password_hash
import hashlib

db = SQLAlchemy()

# ==================== 用户模型 ====================
class User(db.Model):
    """用户表"""
    __tablename__ = 'users'
    
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True, nullable=False)
    email = db.Column(db.String(120), unique=True, nullable=False)
    password_hash = db.Column(db.String(256), nullable=False)
    
    # 用户类型: guest, free, vip_basic, vip_pro, vip_enterprise, admin
    user_type = db.Column(db.String(20), default='free')
    
    # 会员信息
    membership_expire = db.Column(db.DateTime, nullable=True)  # 会员到期时间
    
    # 使用统计
    daily_count = db.Column(db.Integer, default=0)      # 今日翻译次数
    total_count = db.Column(db.Integer, default=0)      # 总翻译次数
    last_translate_date = db.Column(db.Date, nullable=True)  # 最后翻译日期
    
    # 时间戳
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    updated_at = db.Column(db.DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
    
    # 状态
    is_active = db.Column(db.Boolean, default=True)     # 是否启用
    is_admin = db.Column(db.Boolean, default=False)     # 是否管理员
    
    # 关系
    translations = db.relationship('Translation', backref='user', lazy=True)
    
    def set_password(self, password):
        self.password_hash = generate_password_hash(password)
    
    def check_password(self, password):
        return check_password_hash(self.password_hash, password)
    
    def is_vip(self):
        """检查是否为付费会员"""
        if self.user_type.startswith('vip'):
            if self.membership_expire and self.membership_expire > datetime.utcnow():
                return True
            # 过期则降级为免费用户
            self.user_type = 'free'
            self.membership_expire = None
            db.session.commit()
        return False
    
    def can_translate(self, pages, config):
        """检查是否可以翻译（次数、页数限制）"""
        limits = config['USER_LIMITS'].get(self.user_type, config['USER_LIMITS']['free'])
        
        # 检查页数限制
        max_pages = limits['max_pages']
        if max_pages > 0 and pages > max_pages:
            return False, f"PDF页数超出限制（最大{max_pages}页）"
        
        # 检查每日次数限制
        today = datetime.utcnow().date()
        if self.last_translate_date != today:
            self.daily_count = 0
            self.last_translate_date = today
        
        daily_limit = limits['daily_translations']
        if daily_limit > 0 and self.daily_count >= daily_limit:
            return False, f"今日翻译次数已达上限（{daily_limit}次）"
        
        return True, "OK"
    
    def increment_count(self):
        """增加翻译计数"""
        today = datetime.utcnow().date()
        if self.last_translate_date != today:
            self.daily_count = 0
            self.last_translate_date = today
        self.daily_count += 1
        self.total_count += 1
        db.session.commit()
    
    def to_dict(self):
        return {
            'id': self.id,
            'username': self.username,
            'email': self.email,
            'user_type': self.user_type,
            'is_vip': self.is_vip(),
            'is_admin': self.is_admin,
            'is_active': self.is_active,
            'daily_count': self.daily_count,
            'total_count': self.total_count,
            'created_at': self.created_at.isoformat() if self.created_at else None,
            'membership_expire': self.membership_expire.isoformat() if self.membership_expire else None,
        }


# ==================== 翻译记录模型 ====================
class Translation(db.Model):
    """翻译记录表"""
    __tablename__ = 'translations'
    
    id = db.Column(db.Integer, primary_key=True)
    
    # 用户关联
    user_id = db.Column(db.Integer, db.ForeignKey('users.id'), nullable=True)  # guest可为null
    
    # 文件信息
    file_hash = db.Column(db.String(64), nullable=False)  # 文件MD5哈希
    original_filename = db.Column(db.String(255), nullable=False)
    file_size = db.Column(db.Integer, nullable=False)
    page_count = db.Column(db.Integer, nullable=False)
    
    # 翻译信息
    source_language = db.Column(db.String(10), default='en')
    target_language = db.Column(db.String(10), default='zh')
    translate_params = db.Column(db.Text, nullable=True)  # JSON格式的翻译参数
    
    # 状态
    status = db.Column(db.String(20), default='pending')  # pending, processing, completed, failed
    progress = db.Column(db.Integer, default=0)           # 翻译进度 0-100
    error_message = db.Column(db.Text, nullable=True)
    
    # 输出
    output_path = db.Column(db.String(255), nullable=True)  # 翻译结果文件路径
    
    # 时间戳
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    completed_at = db.Column(db.DateTime, nullable=True)
    
    # 是否来自缓存
    from_cache = db.Column(db.Boolean, default=False)
    
    # 重译信息
    retranslate_request = db.Column(db.Text, nullable=True)  # 重译要求
    parent_id = db.Column(db.Integer, db.ForeignKey('translations.id'), nullable=True)  # 原翻译ID
    
    def to_dict(self):
        return {
            'id': self.id,
            'filename': self.original_filename,
            'pages': self.page_count,
            'status': self.status,
            'progress': self.progress,
            'from_cache': self.from_cache,
            'file_size': self.file_size,
            'created_at': self.created_at.isoformat() if self.created_at else None,
            'completed_at': self.completed_at.isoformat() if self.completed_at else None,
            'user_id': self.user_id,
        }


# ==================== 翻译缓存模型 ====================
class TranslationCache(db.Model):
    """翻译缓存表"""
    __tablename__ = 'translation_cache'
    
    id = db.Column(db.Integer, primary_key=True)
    
    # 文件哈希
    file_hash = db.Column(db.String(64), unique=True, nullable=False)
    
    # 缓存信息
    cache_path = db.Column(db.String(255), nullable=False)  # 缓存文件路径
    page_count = db.Column(db.Integer, nullable=False)
    file_size = db.Column(db.Integer, default=0)
    
    # 统计
    hit_count = db.Column(db.Integer, default=0)  # 缓存命中次数
    
    # 时间戳
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    expires_at = db.Column(db.DateTime, nullable=True)
    
    def increment_hit(self):
        self.hit_count += 1
        db.session.commit()
    
    @staticmethod
    def compute_hash(file_content):
        """计算文件哈希"""
        return hashlib.md5(file_content).hexdigest()


# ==================== 访客翻译记录 ====================
class GuestTranslation(db.Model):
    """访客翻译记录（基于IP或Session）"""
    __tablename__ = 'guest_translations'
    
    id = db.Column(db.Integer, primary_key=True)
    
    # 访客标识
    session_id = db.Column(db.String(64), nullable=False)  # Session ID
    ip_address = db.Column(db.String(45), nullable=True)
    
    # 统计
    daily_count = db.Column(db.Integer, default=0)
    total_count = db.Column(db.Integer, default=0)
    last_translate_date = db.Column(db.Date, nullable=True)
    
    created_at = db.Column(db.DateTime, default=datetime.utcnow)


# ==================== 系统配置模型 ====================
class SystemConfig(db.Model):
    """系统配置表"""
    __tablename__ = 'system_config'
    
    id = db.Column(db.Integer, primary_key=True)
    key = db.Column(db.String(100), unique=True, nullable=False)
    value = db.Column(db.Text, nullable=True)
    description = db.Column(db.String(255), nullable=True)
    updated_at = db.Column(db.DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
    
    @staticmethod
    def get(key, default=None):
        config = SystemConfig.query.filter_by(key=key).first()
        return config.value if config else default
    
    @staticmethod
    def set(key, value, description=None):
        config = SystemConfig.query.filter_by(key=key).first()
        if config:
            config.value = value
        else:
            config = SystemConfig(key=key, value=value, description=description)
            db.session.add(config)
        db.session.commit()


# ==================== 操作日志模型 ====================
class OperationLog(db.Model):
    """操作日志表"""
    __tablename__ = 'operation_logs'
    
    id = db.Column(db.Integer, primary_key=True)
    
    # 操作者
    user_id = db.Column(db.Integer, db.ForeignKey('users.id'), nullable=True)
    username = db.Column(db.String(80), nullable=True)
    
    # 操作信息
    action = db.Column(db.String(50), nullable=False)  # login, translate, register, etc.
    target = db.Column(db.String(100), nullable=True)  # 操作对象
    detail = db.Column(db.Text, nullable=True)         # 详细信息(JSON)
    
    # IP地址
    ip_address = db.Column(db.String(45), nullable=True)
    
    # 时间
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    
    def to_dict(self):
        return {
            'id': self.id,
            'username': self.username,
            'action': self.action,
            'target': self.target,
            'ip_address': self.ip_address,
            'created_at': self.created_at.isoformat() if self.created_at else None,
        }