from datetime import datetime, timezone
import json
from app import db


def format_datetime(dt: datetime) -> str:
    """Format datetime to ISO format with UTC timezone indicator"""
    if dt is None:
        return None
    # If datetime is naive (no timezone), assume it's UTC
    if dt.tzinfo is None:
        dt = dt.replace(tzinfo=timezone.utc)
    return dt.isoformat()


class Task(db.Model):
    """Task model for scan tasks"""
    __tablename__ = 'tasks'
    
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(200), nullable=False)
    status = db.Column(
        db.Enum('pending', 'running', 'completed', 'failed', name='task_status'), 
        default='pending',
        index=True
    )
    progress = db.Column(db.Integer, default=0)
    created_by = db.Column(db.Integer, db.ForeignKey('users.id'), nullable=False)
    created_at = db.Column(db.DateTime, default=datetime.utcnow, index=True)
    started_at = db.Column(db.DateTime)
    completed_at = db.Column(db.DateTime)
    celery_task_id = db.Column(db.String(100), index=True)
    
    # Task configuration (JSON)
    _credential_ids = db.Column('credential_ids', db.Text)
    _regions = db.Column('regions', db.Text)
    _project_metadata = db.Column('project_metadata', db.Text)
    
    # CloudShell Scanner fields
    source = db.Column(db.String(20), default='credential')  # 'credential' 或 'upload'
    scan_data_path = db.Column(db.String(500), nullable=True)  # 上传的 JSON 文件路径
    
    # Relationships
    created_by_user = db.relationship('User', back_populates='tasks')
    logs = db.relationship('TaskLog', back_populates='task', cascade='all, delete-orphan')
    report = db.relationship('Report', back_populates='task', uselist=False, cascade='all, delete-orphan')
    
    @property
    def credential_ids(self) -> list:
        """Get credential IDs as list"""
        if self._credential_ids:
            return json.loads(self._credential_ids)
        return []
    
    @credential_ids.setter
    def credential_ids(self, value: list):
        """Set credential IDs from list"""
        self._credential_ids = json.dumps(value)
    
    @property
    def regions(self) -> list:
        """Get regions as list"""
        if self._regions:
            return json.loads(self._regions)
        return []
    
    @regions.setter
    def regions(self, value: list):
        """Set regions from list"""
        self._regions = json.dumps(value)
    
    @property
    def project_metadata(self) -> dict:
        """Get project metadata as dict"""
        if self._project_metadata:
            return json.loads(self._project_metadata)
        return {}
    
    @project_metadata.setter
    def project_metadata(self, value: dict):
        """Set project metadata from dict"""
        self._project_metadata = json.dumps(value)
    
    def to_dict(self) -> dict:
        """Convert task to dictionary"""
        return {
            'id': self.id,
            'name': self.name,
            'status': self.status,
            'progress': self.progress,
            'created_by': self.created_by,
            'created_at': format_datetime(self.created_at),
            'started_at': format_datetime(self.started_at),
            'completed_at': format_datetime(self.completed_at),
            'credential_ids': self.credential_ids,
            'regions': self.regions,
            'project_metadata': self.project_metadata,
            'source': self.source,
            'scan_data_path': self.scan_data_path
        }
    
    def __repr__(self):
        return f'<Task {self.id} {self.name} ({self.status})>'


class TaskLog(db.Model):
    """Task log model for storing task execution logs"""
    __tablename__ = 'task_logs'
    
    id = db.Column(db.Integer, primary_key=True)
    task_id = db.Column(db.Integer, db.ForeignKey('tasks.id'), nullable=False, index=True)
    level = db.Column(db.Enum('info', 'warning', 'error', name='log_level'), default='info')
    message = db.Column(db.Text, nullable=False)
    details = db.Column(db.Text)  # JSON for stack trace, etc.
    created_at = db.Column(db.DateTime, default=datetime.utcnow, index=True)
    
    # Relationships
    task = db.relationship('Task', back_populates='logs')
    
    def to_dict(self) -> dict:
        """Convert log to dictionary"""
        result = {
            'id': self.id,
            'task_id': self.task_id,
            'level': self.level,
            'message': self.message,
            'created_at': format_datetime(self.created_at)
        }
        if self.details:
            result['details'] = json.loads(self.details)
        return result
    
    def __repr__(self):
        return f'<TaskLog {self.id} [{self.level}] {self.message[:50]}>'