# database/ai_models.py
from sqlalchemy import Column, Integer, String, DateTime, Text, Float, ForeignKey, Index
from sqlalchemy.orm import relationship
from database.models import Base
from datetime import datetime, timezone

# Helper for default timestamps
datetime_now = lambda: datetime.now(timezone.utc)


class AgentContext(Base):
    """
    共享上下文表（替代硬編碼鏈），支援多 Agent 存取與 TTL。
    索引：(session_id, agent_name, context_key) 以加速跨 Agent 查詢。
    """
    __tablename__ = 'agent_context'

    id = Column(Integer, primary_key=True, autoincrement=True)
    session_id = Column(String(64), nullable=False, index=True)
    agent_name = Column(String(50), nullable=False, index=True)
    context_key = Column(String(100), nullable=False)
    context_val = Column(Text)  # JSON 字串
    created_at = Column(DateTime, default=datetime_now)
    ttl_minutes = Column(Integer, default=60)

    __table_args__ = (
        Index('idx_agent_context_session_key', 'session_id', 'agent_name', 'context_key'),
        Index('idx_agent_context_session_ttl', 'session_id', 'created_at'),
    )


class ActionPlan(Base):
    """
    行動計畫表（NemoTron 輸出，等待審核與執行追蹤）。
    """
    __tablename__ = 'action_plans'

    id = Column(Integer, primary_key=True, autoincrement=True)
    session_id = Column(String(64), nullable=True)
    plan_type = Column(String(50), nullable=True)       # price_adjust / restock / campaign
    sku = Column(String(100), nullable=True, index=True)
    payload = Column(Text)                              # JSON 行動內容
    status = Column(String(20), default='pending')      # pending/approved/rejected/executed
    created_by = Column(String(50))                     # nemotron / openclaw
    approved_by = Column(String(100), nullable=True)    # Telegram user_id
    created_at = Column(DateTime, default=datetime_now)
    executed_at = Column(DateTime, nullable=True)

    __table_args__ = (
        Index('idx_action_plan_sku_status', 'sku', 'status'),
        Index('idx_action_plan_created', 'created_at'),
    )


class ActionOutcome(Base):
    """
    行動結果追蹤（閉環學習核心）。
    """
    __tablename__ = 'action_outcomes'

    id = Column(Integer, primary_key=True, autoincrement=True)
    plan_id = Column(Integer, ForeignKey('action_plans.id'), nullable=False)
    metric_type = Column(String(50), nullable=True)      # sales_7d / price_rank / conversion
    before_val = Column(Float)
    after_val = Column(Float)
    measured_at = Column(DateTime)
    verdict = Column(String(20))                         # effective / neutral / backfired
    created_at = Column(DateTime, default=datetime_now)

    plan = relationship("ActionPlan", backref="outcomes")


class AgentStrategyWeights(Base):
    """
    Agent 策略權重（OpenClaw 學習累積）。
    索引：strategy_key 以便快速更新與查詢。
    """
    __tablename__ = 'agent_strategy_weights'

    id = Column(Integer, primary_key=True, autoincrement=True)
    strategy_key = Column(String(100), unique=True, nullable=False)  # e.g. price_cut_when_gap_gt_5pct
    weight = Column(Float, default=1.0)
    success_cnt = Column(Integer, default=0)
    fail_cnt = Column(Integer, default=0)
    updated_at = Column(DateTime, default=datetime_now)

    __table_args__ = (
        Index('idx_strategy_key', 'strategy_key'),
    )