from sqlalchemy import Column, Integer, String, Float, DateTime, ForeignKey, JSON, Text
from sqlalchemy.sql import func
from app.core.database import Base


class PredictionTask(Base):
    """AI预测任务元数据"""
    __tablename__ = "prediction_tasks"

    id = Column(Integer, primary_key=True, autoincrement=True)
    device_id = Column(Integer, ForeignKey("devices.id"))
    prediction_type = Column(String(50), nullable=False)  # pv, load, heatpump, optimization
    horizon_hours = Column(Integer, default=24)
    status = Column(String(20), default="pending")  # pending, running, completed, failed
    parameters = Column(JSON)  # extra config for the prediction run
    error_message = Column(Text)
    created_at = Column(DateTime(timezone=True), server_default=func.now())
    completed_at = Column(DateTime(timezone=True))


class PredictionResult(Base):
    """AI预测结果时序数据"""
    __tablename__ = "prediction_results"

    id = Column(Integer, primary_key=True, autoincrement=True)
    task_id = Column(Integer, ForeignKey("prediction_tasks.id"), nullable=False, index=True)
    timestamp = Column(DateTime(timezone=True), nullable=False, index=True)
    predicted_value = Column(Float, nullable=False)
    confidence_lower = Column(Float)
    confidence_upper = Column(Float)
    actual_value = Column(Float)  # filled later for accuracy tracking
    unit = Column(String(20))


class OptimizationSchedule(Base):
    """AI优化调度建议"""
    __tablename__ = "optimization_schedules"

    id = Column(Integer, primary_key=True, autoincrement=True)
    device_id = Column(Integer, ForeignKey("devices.id"))
    date = Column(DateTime(timezone=True), nullable=False, index=True)
    schedule_data = Column(JSON)  # hourly on/off + setpoints
    expected_savings_kwh = Column(Float, default=0)
    expected_savings_yuan = Column(Float, default=0)
    status = Column(String(20), default="pending")  # pending, approved, executed, rejected
    approved_by = Column(Integer, ForeignKey("users.id"))
    approved_at = Column(DateTime(timezone=True))
    created_at = Column(DateTime(timezone=True), server_default=func.now())