from sqlalchemy import Column, Integer, Float, String
from sqlalchemy import ForeignKey, ForeignKeyConstraint
from geoalchemy2 import Geometry
from app.database import Base


class MSMInputData(Base):
    """
    络合模型输入数据模型

    存储络合模型(MSM)计算所需的所有输入参数
    模型逻辑：
      1. 每个记录对应农田样点(Farmland_data)的特定样本
      2. 大部分数值通过Soil_data和Parameters表数据计算得来
      3. Var字段标识数据类型来源(如：实测值/普查值)
    """
    __tablename__ = 'MSM_input_data'

    # 主键
    id = Column('ID', Integer, primary_key=True, autoincrement=True)

    # 外键参考Farmland_data表 (复合主键)
    farmland_id = Column('Farmland_ID', Integer, nullable=False)
    sample_id = Column('Sample_ID', Integer, nullable=False)

    # 外键约束定义
    __table_args__ = (
        ForeignKeyConstraint(
            ['Farmland_ID', 'Sample_ID'],
            ['Farmland_data.Farmland_ID', 'Farmland_data.Sample_ID']
        ),
        {'comment': '络合模型输入数据模型'}
    )

    # 过程模型数据索引符 - 标识数据来源（如：PC2013实测、XC2018普查、SP2023三普）
    var = Column('Var', String(20), nullable=False, comment='过程模型数据索引符')

    # 化学参数字段（带默认值的列）
    co2_tot = Column('CO2_g_tot', Float, default=1e-5, nullable=False,
                     comment='二氧化碳全量值')
    water_volume = Column('watervolume', Float, nullable=True,
                          comment='土壤水体积[cm³/cm³] = Soil_data.POR_Layer')
    sl_ratio = Column('SL', Float, nullable=True,
                      comment='固液比 = (1-POR_Layer)*bd020_90/(POR_Layer*1)')
    ph_value = Column('pH', Float, nullable=True,
                      comment='pH值(实测或Soil_data中IDW_*_pH三者之一)')

    # 金属离子浓度 (mol/L)
    ca_tot = Column('Ca_plus2_tot', Float, nullable=True,
                    comment='总游离钙 = ExCa_IDW*0.005/(POR_Layer/bd020_90)')
    mg_tot = Column('Mg_plus2_tot', Float, nullable=True,
                    comment='总游离镁 = ExMg_IDW*0.005/(POR_Layer/bd020_90)')
    k_tot = Column('K_plus_tot', Float, nullable=True,
                   comment='总游离钾 = ExK_IDW*0.005/(POR_Layer/bd020_90)')
    na_tot = Column('Na_plus_tot', Float, nullable=True,
                    comment='总游离钠 = ExNa_IDW*0.005/(POR_Layer/bd020_90)')
    cl_tot = Column('Cl_minus_tot', Float, nullable=True,
                    comment='总游离氯 = (Ca_tot+Mg_tot)*2 + K_tot + Na_tot')
    cd_tot = Column('Cd_tot', Float, nullable=True,
                    comment='总游离镉 = Cd/112000/(POR_Layer/bd020_90)')

    # 土壤成分 (kg/kg)
    hfo_kgkg = Column('HFO_kgkg', Float, nullable=True,
                      comment='不定型铁 = Fed_IDW/1000 + ExAl_IDW*0.00009')
    clay_kgkg = Column('CLAY_kgkg', Float, nullable=True,
                       comment='粘土矿物 = Soil_data.0002IDW')
    ha_kgkg = Column('HA_kgkg', Float, nullable=True,
                     comment='活性胡敏酸 = SOM_IDW/1724*F1*F2')
    fa_kgkg = Column('FA_kgkg', Float, nullable=True,
                     comment='活性富里酸 = SOM_IDW/1724*F1*(1-F2)')