"""SQLAlchemy 2.0 ORM models.

Scope of this scaffold: only the tables needed to prove the vertical slice
(架构文档 §6.2 identity / billing / task / 观测与成本). All remaining domains
(pf_ / rp_ / kb_ / ag_ / tr_ / cp_) are intentionally absent — see
packages/*/README.md for what still has to be built.

Conventions enforced here (架构文档 §6.1):
  1. 表名带域前缀 (`id_` / `bl_` / `tk_` / `ob_`)，为将来拆库预留边界。
  2. 主键统一雪花 ID (bigint)，不用自增、不用 UUID。
  3. 涉及配额的表必须有幂等键与流水。
  4. JSONB 只用于「结构会演进且不需要索引全部字段」的场景。
"""

from __future__ import annotations

from datetime import datetime
from decimal import Decimal
from typing import Any

from sqlalchemy import (
    BigInteger,
    Boolean,
    DateTime,
    Index,
    Integer,
    Numeric,
    PrimaryKeyConstraint,
    SmallInteger,
    String,
    Text,
    UniqueConstraint,
    func,
)
from sqlalchemy.dialects.postgresql import JSONB
from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column


class Base(DeclarativeBase):
    """Declarative base; ``Base.metadata`` is Alembic's ``target_metadata``."""


# ---------------------------------------------------------------------------
# identity 域
# ---------------------------------------------------------------------------
class User(Base):
    __tablename__ = "id_user"

    user_id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=False)
    status: Mapped[str] = mapped_column(String(16), nullable=False, default="active")
    nickname: Mapped[str | None] = mapped_column(String(64))
    avatar_key: Mapped[str | None] = mapped_column(String(255))
    register_source: Mapped[str] = mapped_column(String(32), nullable=False, default="unknown")
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, server_default=func.now()
    )
    last_active_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
    deleted_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))

    __table_args__ = (Index("ix_id_user_status", "status"),)


class UserIdentity(Base):
    """External identity mapping. UNIQUE(provider, union_id) per 架构文档 §6.2."""

    __tablename__ = "id_user_identity"

    identity_id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=False)
    user_id: Mapped[int] = mapped_column(BigInteger, nullable=False)
    provider: Mapped[str] = mapped_column(String(32), nullable=False)
    union_id: Mapped[str] = mapped_column(String(128), nullable=False)
    open_id: Mapped[str | None] = mapped_column(String(128))
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, server_default=func.now()
    )

    __table_args__ = (
        UniqueConstraint("provider", "union_id", name="uq_id_user_identity_provider_union"),
        Index("ix_id_user_identity_user", "user_id"),
    )


class Consent(Base):
    """CR-01 留证：人脸的单独同意必须独立成行，不得混入总协议。"""

    __tablename__ = "id_consent"

    consent_id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=False)
    user_id: Mapped[int] = mapped_column(BigInteger, nullable=False)
    consent_type: Mapped[str] = mapped_column(String(32), nullable=False)
    doc_version: Mapped[str] = mapped_column(String(32), nullable=False)
    granted_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, server_default=func.now()
    )
    revoked_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
    client_ip: Mapped[str | None] = mapped_column(String(64))
    ua: Mapped[str | None] = mapped_column(String(512))

    __table_args__ = (Index("ix_id_consent_user_type", "user_id", "consent_type"),)


# ---------------------------------------------------------------------------
# billing 域（V1：配额与计量，无支付）
# ---------------------------------------------------------------------------
class QuotaRule(Base):
    """FR-BILL-04 配额规则配置化：改配置不发版。"""

    __tablename__ = "bl_quota_rule"

    quota_key: Mapped[str] = mapped_column(String(64), primary_key=True)
    period_type: Mapped[str] = mapped_column(String(16), nullable=False)  # day/month/lifetime
    base_limit: Mapped[int] = mapped_column(Integer, nullable=False)
    task_bonus_max: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    hard_cap: Mapped[int] = mapped_column(Integer, nullable=False)
    description: Mapped[str | None] = mapped_column(String(255))
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, server_default=func.now()
    )


class Quota(Base):
    """周期配额计量：按 ``period_key`` 自然重置，无需定时任务清零。"""

    __tablename__ = "bl_quota"

    user_id: Mapped[int] = mapped_column(BigInteger, nullable=False)
    quota_key: Mapped[str] = mapped_column(String(64), nullable=False)
    period_key: Mapped[str] = mapped_column(String(32), nullable=False)
    used: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    # 本周期创建时从规则拷下的 base_limit。规则中途被改，本周期仍按快照判定。
    limit_value: Mapped[int] = mapped_column(Integer, nullable=False)
    bonus_granted: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, server_default=func.now()
    )

    __table_args__ = (
        PrimaryKeyConstraint("user_id", "quota_key", "period_key", name="pk_bl_quota"),
    )


class Ledger(Base):
    """流水是真相，余额是缓存 (架构文档 §6.1 原则 4 / §6.2 bl_ledger).

    ``tx_type`` 在 V1 只用 system_grant / consume / refund；V2 增加
    purchase / gift —— 这是 V1→V2 免数据迁移的关键，不要拆表。
    ``status`` 承载 §7.4 的预扣三段式：reserved → committed / refunded。
    """

    __tablename__ = "bl_ledger"

    tx_id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=False)
    user_id: Mapped[int] = mapped_column(BigInteger, nullable=False)
    delta: Mapped[int] = mapped_column(Integer, nullable=False)
    tx_type: Mapped[str] = mapped_column(String(24), nullable=False)
    status: Mapped[str] = mapped_column(String(16), nullable=False, default="committed")
    reason: Mapped[str | None] = mapped_column(String(128))
    ref_type: Mapped[str | None] = mapped_column(String(32))
    ref_id: Mapped[str | None] = mapped_column(String(64))
    quota_key: Mapped[str | None] = mapped_column(String(64))
    period_key: Mapped[str | None] = mapped_column(String(32))
    balance_after: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    idempotency_key: Mapped[str] = mapped_column(String(128), nullable=False)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, server_default=func.now()
    )

    __table_args__ = (
        UniqueConstraint("idempotency_key", name="uq_bl_ledger_idempotency_key"),
        Index("ix_bl_ledger_user_created", "user_id", "created_at"),
    )


# ---------------------------------------------------------------------------
# task 域（统一任务中心）
# ---------------------------------------------------------------------------
class Task(Base):
    """全系统唯一的长耗时任务视图，前端任务中心直接读它 (架构文档 §6.2)。"""

    __tablename__ = "tk_task"

    task_id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=False)
    user_id: Mapped[int] = mapped_column(BigInteger, nullable=False)
    task_type: Mapped[str] = mapped_column(String(32), nullable=False)
    status: Mapped[str] = mapped_column(String(16), nullable=False)
    progress: Mapped[int] = mapped_column(SmallInteger, nullable=False, default=0)
    stage_text: Mapped[str | None] = mapped_column(String(128))
    idempotency_key: Mapped[str] = mapped_column(String(128), nullable=False)
    payload: Mapped[dict[str, Any]] = mapped_column(JSONB, nullable=False, default=dict)
    result: Mapped[dict[str, Any] | None] = mapped_column(JSONB)
    error_code: Mapped[int | None] = mapped_column(Integer)
    error_message: Mapped[str | None] = mapped_column(String(512))
    retry_count: Mapped[int] = mapped_column(SmallInteger, nullable=False, default=0)
    quota_reserved: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    reserve_tx_id: Mapped[int | None] = mapped_column(BigInteger)
    submitted_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, server_default=func.now()
    )
    started_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
    finished_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
    eta_seconds: Mapped[int | None] = mapped_column(Integer)

    __table_args__ = (
        UniqueConstraint("idempotency_key", name="uq_tk_task_idempotency_key"),
        Index("ix_tk_task_user_status", "user_id", "status"),
    )


# ---------------------------------------------------------------------------
# 观测与成本
# ---------------------------------------------------------------------------
class AiCall(Base):
    """成本归因的唯一数据源 (架构文档 §13, FR-BILL-08).

    **不允许「先上线后补埋点」** —— V1 不收费，成本是唯一财务变量，且这张表
    是 V2 定价的唯一数据来源。每一次 provider 调用（含失败与结构化重试）都写
    一行。生产环境按月分区。
    """

    __tablename__ = "ob_ai_call"

    call_id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=False)
    user_id: Mapped[int | None] = mapped_column(BigInteger)
    scene: Mapped[str] = mapped_column(String(48), nullable=False)
    provider: Mapped[str] = mapped_column(String(32), nullable=False)
    model: Mapped[str] = mapped_column(String(64), nullable=False)
    # Prompt 版本：架构文档 §8.1「可复现」要求记录，§6.2 的列清单漏了，这里补上。
    prompt_id: Mapped[str | None] = mapped_column(String(64))
    prompt_version: Mapped[str | None] = mapped_column(String(16))
    tokens_in: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    tokens_out: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    tokens_cached: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    # 思考模式 token 单独记，不并入 tokens_out：它按输出价计费，混在一起就看不出
    # 开关思考模式的成本差异，而这正是 T-P1-24a 要长期盯的数。
    tokens_reasoning: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    latency_ms: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    cost_cents: Mapped[Decimal] = mapped_column(
        Numeric(14, 6), nullable=False, default=Decimal("0")
    )
    # 该次调用适用的峰谷档位。没有它就无法事后复核 cost_cents ——
    # 单价随时刻变化，事后按「当前价」回算会得出不同结果 (T-P1-25c)。
    rate_tier: Mapped[str | None] = mapped_column(String(16))
    success: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False)
    error_code: Mapped[str | None] = mapped_column(String(64))
    error_message: Mapped[str | None] = mapped_column(Text)
    ref_type: Mapped[str | None] = mapped_column(String(32))
    ref_id: Mapped[str | None] = mapped_column(String(64))
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, server_default=func.now()
    )

    __table_args__ = (
        Index("ix_ob_ai_call_created", "created_at"),
        Index("ix_ob_ai_call_scene_created", "scene", "created_at"),
        Index("ix_ob_ai_call_user_created", "user_id", "created_at"),
    )


class UserSession(Base):
    """refresh token 的服务端会话（架构文档 §6.2 id_session，FR-ACC-05）.

    刻意叫 UserSession 而不是 Session：避免与 SQLAlchemy 的 AsyncSession 混淆。
    refresh token 本体是 opaque 随机串（不出现在任何存储里），库里只存 sha256
    哈希 —— 泄漏数据库不等于泄漏令牌。轮换 = 旧行 revoked + 新行，同一事务。
    """

    __tablename__ = "id_session"

    session_id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=False)
    user_id: Mapped[int] = mapped_column(BigInteger, nullable=False)
    refresh_token_hash: Mapped[str] = mapped_column(String(64), nullable=False)
    expire_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
    revoked: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False)
    revoked_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, server_default=func.now()
    )

    __table_args__ = (
        UniqueConstraint("refresh_token_hash", name="uq_id_session_token_hash"),
        Index("ix_id_session_user", "user_id"),
    )


class ObEvent(Base):
    """客户端埋点事件（架构文档 §6.2 ob_event，FR-SYS-06）.

    架构原文「按月分区」—— V1 先普通表（与 ob_ai_call 同样处理），
    数据量上来后再分区，先不预支复杂度。
    """

    __tablename__ = "ob_event"

    event_id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=False)
    user_id: Mapped[int] = mapped_column(BigInteger, nullable=False)
    event_name: Mapped[str] = mapped_column(String(64), nullable=False)
    props: Mapped[dict[str, Any]] = mapped_column(JSONB, nullable=False, default=dict)
    client_ts: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
    server_ts: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, server_default=func.now()
    )

    __table_args__ = (
        Index("ix_ob_event_name_ts", "event_name", "server_ts"),
        Index("ix_ob_event_user_ts", "user_id", "server_ts"),
    )