"""审计数据中台 ORM 模型。

涵盖：数据版本、本体实体、知识图谱关系边、双时态属性、时序事件。
对应需求 R2 / R3，建模决策见 ADR-0002。
"""

from __future__ import annotations

import datetime as dt
import uuid

from sqlalchemy import (
    DateTime,
    Float,
    ForeignKey,
    Index,
    Integer,
    String,
    Text,
    UniqueConstraint,
)
from sqlalchemy.dialects.postgresql import JSONB, UUID
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.db import Base


def _uuid() -> uuid.UUID:
    return uuid.uuid4()


class DataVersion(Base):
    """数据版本登记：每批接入数据的来源/批次/时间/行数，支撑结论可追溯（R3）。"""

    __tablename__ = "data_version"

    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=_uuid)
    source_system: Mapped[str] = mapped_column(String(64), nullable=False)
    batch_label: Mapped[str] = mapped_column(String(128), nullable=False)
    row_count: Mapped[int] = mapped_column(Integer, default=0)
    ingested_at: Mapped[dt.datetime] = mapped_column(
        DateTime(timezone=True), default=lambda: dt.datetime.now(dt.UTC)
    )
    note: Mapped[str | None] = mapped_column(Text, nullable=True)


class Entity(Base):
    """本体实体节点（知识图谱顶点）。

    business_key 是源系统中的业务主键，用于主数据对齐（同一实体跨系统归一）。
    """

    __tablename__ = "entity"
    __table_args__ = (
        UniqueConstraint("entity_type", "business_key", name="uq_entity_type_bizkey"),
        Index("ix_entity_type", "entity_type"),
    )

    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=_uuid)
    entity_type: Mapped[str] = mapped_column(String(32), nullable=False)
    business_key: Mapped[str] = mapped_column(String(128), nullable=False)
    display_name: Mapped[str | None] = mapped_column(String(256), nullable=True)
    attributes: Mapped[dict] = mapped_column(JSONB, default=dict)

    # 主数据对齐：被归并到的"金主"实体（同一实控人/同一主体）。NULL 表示自身即主实体。
    canonical_id: Mapped[uuid.UUID | None] = mapped_column(
        UUID(as_uuid=True), ForeignKey("entity.id"), nullable=True
    )

    data_version_id: Mapped[uuid.UUID | None] = mapped_column(
        UUID(as_uuid=True), ForeignKey("data_version.id"), nullable=True
    )


class EntityRelationship(Base):
    """知识图谱关系边（有向）。多跳穿透用递归 CTE 遍历本表。"""

    __tablename__ = "entity_relationship"
    __table_args__ = (
        Index("ix_rel_source", "source_id"),
        Index("ix_rel_target", "target_id"),
        Index("ix_rel_type", "rel_type"),
    )

    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=_uuid)
    rel_type: Mapped[str] = mapped_column(String(32), nullable=False)
    source_id: Mapped[uuid.UUID] = mapped_column(
        UUID(as_uuid=True), ForeignKey("entity.id"), nullable=False
    )
    target_id: Mapped[uuid.UUID] = mapped_column(
        UUID(as_uuid=True), ForeignKey("entity.id"), nullable=False
    )
    attributes: Mapped[dict] = mapped_column(JSONB, default=dict)

    data_version_id: Mapped[uuid.UUID | None] = mapped_column(
        UUID(as_uuid=True), ForeignKey("data_version.id"), nullable=True
    )

    source: Mapped[Entity] = relationship(foreign_keys=[source_id])
    target: Mapped[Entity] = relationship(foreign_keys=[target_id])


class BitemporalFact(Base):
    """双时态事实：实体的某个属性/状态随时间变化的记录。

    - 业务有效期 valid_from/valid_to（应用时间）
    - 系统记录期 system_from/system_to（事务时间）
    回放历史 = 给定 (as_of_valid, as_of_system) 过滤两条时间线（见 repository）。
    """

    __tablename__ = "bitemporal_fact"
    __table_args__ = (
        Index("ix_btf_entity_attr", "entity_id", "attr_name"),
    )

    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=_uuid)
    entity_id: Mapped[uuid.UUID] = mapped_column(
        UUID(as_uuid=True), ForeignKey("entity.id"), nullable=False
    )
    attr_name: Mapped[str] = mapped_column(String(64), nullable=False)
    attr_value: Mapped[dict] = mapped_column(JSONB, default=dict)

    valid_from: Mapped[dt.datetime] = mapped_column(DateTime(timezone=True), nullable=False)
    valid_to: Mapped[dt.datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    system_from: Mapped[dt.datetime] = mapped_column(
        DateTime(timezone=True), default=lambda: dt.datetime.now(dt.UTC)
    )
    system_to: Mapped[dt.datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)

    data_version_id: Mapped[uuid.UUID | None] = mapped_column(
        UUID(as_uuid=True), ForeignKey("data_version.id"), nullable=True
    )


class MetricEvent(Base):
    """时序事件：行为/指标类数据（用户生命周期、回款、话务、佣金、资源使用）。

    部署后通过 TimescaleDB create_hypertable('metric_event', 'event_time') 转为超表。
    """

    __tablename__ = "metric_event"
    __table_args__ = (
        Index("ix_metric_subject_time", "subject_type", "subject_key", "event_time"),
        Index("ix_metric_name_time", "metric_name", "event_time"),
    )

    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=_uuid)
    event_time: Mapped[dt.datetime] = mapped_column(DateTime(timezone=True), nullable=False)
    subject_type: Mapped[str] = mapped_column(String(32), nullable=False)  # 如 msisdn/channel
    subject_key: Mapped[str] = mapped_column(String(128), nullable=False)
    metric_name: Mapped[str] = mapped_column(String(64), nullable=False)  # 如 traffic_mb/commission
    metric_value: Mapped[float] = mapped_column(Float, default=0.0)
    attributes: Mapped[dict] = mapped_column(JSONB, default=dict)

    data_version_id: Mapped[uuid.UUID | None] = mapped_column(
        UUID(as_uuid=True), ForeignKey("data_version.id"), nullable=True
    )