from datetime import datetime

from sqlalchemy import BigInteger, DateTime, ForeignKey, Integer, JSON, String, Text, UniqueConstraint
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.db.base import Base
from app.models.mixins import TimestampMixin

BIGINT_PK = BigInteger().with_variant(Integer, "sqlite")


class TrainingSession(TimestampMixin, Base):
    """训练会话表：保存一次训练的运行状态、Django 用户隔离信息和短期 memory key。"""

    __tablename__ = "training_session"

    id: Mapped[int] = mapped_column(BIGINT_PK, primary_key=True, autoincrement=True, comment="训练会话ID")
    session_code: Mapped[str] = mapped_column(String(64), nullable=False, unique=True, index=True, comment="会话编码")
    user_id: Mapped[str] = mapped_column("external_user_id", String(128), nullable=False, index=True, comment="Django用户中心ID")
    tenant_id: Mapped[str | None] = mapped_column(String(128), comment="租户或项目ID")
    class_id: Mapped[str | None] = mapped_column(String(128), comment="班级或课程ID")
    entry_scene: Mapped[str | None] = mapped_column(String(64), comment="入口场景")
    case_id: Mapped[int] = mapped_column(ForeignKey("case_base.id"), nullable=False, index=True, comment="病例ID")
    training_type: Mapped[str] = mapped_column("case_type", String(30), nullable=False, comment="病例/训练类型")
    mode: Mapped[str] = mapped_column("training_mode", String(50), nullable=False, index=True, comment="训练模式")
    score_type: Mapped[str] = mapped_column(String(20), default="percentage", comment="分数输出类型")
    status: Mapped[str] = mapped_column(String(30), default="created", index=True, comment="会话状态")
    started_at: Mapped[datetime | None] = mapped_column(DateTime, comment="开始时间")
    inquiry_completed_at: Mapped[datetime | None] = mapped_column(DateTime, comment="问诊完成时间")
    completed_at: Mapped[datetime | None] = mapped_column(DateTime, comment="完成时间")
    memory_key: Mapped[str | None] = mapped_column(String(128), comment="短期memory key")
    metadata_: Mapped[dict | None] = mapped_column("metadata", JSON, comment="扩展数据")

    case = relationship("CaseBase")
    orders = relationship("SessionOrder", back_populates="session", cascade="all, delete-orphan")
    submission = relationship("SessionSubmission", back_populates="session", uselist=False, cascade="all, delete-orphan")

    __table_args__ = {"comment": "训练会话表"}


class SessionOrder(Base):
    """训练检查申请表：记录用户在一次训练中申请过的检查/检验项目和固定结果。"""

    __tablename__ = "training_order"

    id: Mapped[int] = mapped_column(BIGINT_PK, primary_key=True, autoincrement=True, comment="检查申请ID")
    session_id: Mapped[int] = mapped_column(ForeignKey("training_session.id"), nullable=False, index=True, comment="训练会话ID")
    user_id: Mapped[str] = mapped_column("external_user_id", String(128), nullable=False, index=True, comment="Django用户中心ID")
    case_id: Mapped[int] = mapped_column(ForeignKey("case_base.id"), nullable=False, index=True, comment="病例ID")
    case_exam_item_id: Mapped[int] = mapped_column("exam_item_id", ForeignKey("case_exam_item.id"), nullable=False, comment="检查项目ID")
    item_code: Mapped[str] = mapped_column(String(64), nullable=False, comment="项目编码")
    item_name: Mapped[str] = mapped_column(String(128), nullable=False, comment="项目名称")
    item_type: Mapped[str] = mapped_column(String(32), nullable=False, comment="项目类型")
    result_text: Mapped[str] = mapped_column(Text, nullable=False, comment="检查结果文本")
    result_structured: Mapped[dict | None] = mapped_column(JSON, comment="结构化检查结果")
    is_key: Mapped[bool] = mapped_column(default=False, comment="是否关键检查")
    is_abnormal: Mapped[bool] = mapped_column(default=False, comment="是否异常结果")
    ordered_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow, comment="申请时间")

    session = relationship("TrainingSession", back_populates="orders")
    case = relationship("CaseBase")
    exam_item = relationship("CaseExamItem")

    __table_args__ = (
        UniqueConstraint("session_id", "item_code", name="uk_training_order_session_item"),
        {"comment": "训练检查申请表"},
    )


class SessionSubmission(TimestampMixin, Base):
    """训练诊断治疗提交表：保存用户最终提交的诊断、治疗、沟通和随访内容。"""

    __tablename__ = "training_submission"

    id: Mapped[int] = mapped_column(BIGINT_PK, primary_key=True, autoincrement=True, comment="提交记录ID")
    session_id: Mapped[int] = mapped_column(ForeignKey("training_session.id"), nullable=False, unique=True, comment="训练会话ID")
    user_id: Mapped[str] = mapped_column("external_user_id", String(128), nullable=False, index=True, comment="Django用户中心ID")
    primary_diagnosis: Mapped[str | None] = mapped_column(Text, comment="主要诊断")
    differential_diagnoses: Mapped[list | None] = mapped_column(JSON, comment="鉴别诊断")
    diagnosis_basis: Mapped[str | None] = mapped_column(Text, comment="诊断依据")
    treatment_principle: Mapped[str | None] = mapped_column(Text, comment="治疗原则")
    treatment_measures: Mapped[str | None] = mapped_column(Text, comment="治疗措施")
    risk_plan: Mapped[str | None] = mapped_column(Text, comment="风险预案")
    communication: Mapped[str | None] = mapped_column(Text, comment="医患沟通")
    follow_up: Mapped[str | None] = mapped_column(Text, comment="随访安排")
    diagnosis_submitted_at: Mapped[datetime | None] = mapped_column(DateTime, comment="诊断提交时间")
    treatment_submitted_at: Mapped[datetime | None] = mapped_column(DateTime, comment="治疗提交时间")

    session = relationship("TrainingSession", back_populates="submission")

    __table_args__ = {"comment": "训练诊断治疗提交表"}