"""定价方案模型

管理项目定价方案，支持多种定价策略
"""

from typing import Optional, List, TYPE_CHECKING
from decimal import Decimal

from sqlalchemy import BigInteger, String, Boolean, Text, ForeignKey, DECIMAL
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.models.base import BaseModel

if TYPE_CHECKING:
    from app.models.project import Project
    from app.models.user import User
    from app.models.profit_simulation import ProfitSimulation


class PricingPlan(BaseModel):
    """定价方案表"""
    
    __tablename__ = "pricing_plans"
    
    project_id: Mapped[int] = mapped_column(
        BigInteger,
        ForeignKey("projects.id"),
        nullable=False,
        index=True,
        comment="项目ID"
    )
    plan_name: Mapped[str] = mapped_column(
        String(100),
        nullable=False,
        comment="方案名称"
    )
    strategy_type: Mapped[str] = mapped_column(
        String(20),
        nullable=False,
        index=True,
        comment="策略类型：traffic-引流款, profit-利润款, premium-高端款"
    )
    base_cost: Mapped[Decimal] = mapped_column(
        DECIMAL(12, 2),
        nullable=False,
        comment="基础成本"
    )
    target_margin: Mapped[Decimal] = mapped_column(
        DECIMAL(5, 2),
        nullable=False,
        comment="目标毛利率(%)"
    )
    suggested_price: Mapped[Decimal] = mapped_column(
        DECIMAL(12, 2),
        nullable=False,
        comment="建议价格"
    )
    final_price: Mapped[Optional[Decimal]] = mapped_column(
        DECIMAL(12, 2),
        nullable=True,
        comment="最终定价"
    )
    ai_advice: Mapped[Optional[str]] = mapped_column(
        Text,
        nullable=True,
        comment="AI建议内容"
    )
    is_active: Mapped[bool] = mapped_column(
        Boolean,
        nullable=False,
        default=True,
        comment="是否启用"
    )
    created_by: Mapped[Optional[int]] = mapped_column(
        BigInteger,
        ForeignKey("users.id"),
        nullable=True,
        comment="创建人ID"
    )
    
    # 关系
    project: Mapped["Project"] = relationship(
        "Project",
        back_populates="pricing_plans"
    )
    creator: Mapped[Optional["User"]] = relationship(
        "User",
        back_populates="created_pricing_plans"
    )
    profit_simulations: Mapped[List["ProfitSimulation"]] = relationship(
        "ProfitSimulation",
        back_populates="pricing_plan",
        cascade="all, delete-orphan"
    )