"""SQLAlchemy 2.x ORM models,对应 DESIGN.md §7.4 schema。

4 张表:users / tasks / messages / usage_events。
- users 行在 web 入口按需 INSERT(`/v1/auth/login_password` 实际创行 / `/v1/auth/login`
  platform_key 入口 ensure_user_row);email UNIQUE(0005)给 login lookup 用,
  password_hash 是 bcrypt(`bcrypt.hashpw`),只在邮箱密码登录时有值
- messages.payload 用 jsonb,GIN 索引在 migration 里建;messages.model_profile
  (0006)只在 assistant 行有值,标注产生该条 message 的模型
- run 状态承载在 tasks.run_status / run_error 两列(0004 合并 runs 表);
  原 runs / 旧 usage_events 表 0004 删 — 详 DESIGN §7.4 取舍 / PROGRESS 05-18
- usage_events(0006 v2 形态):per-event 多态用量行,kind=chat/image/video/...,
  units 列 JSONB(chat 装 tokens_in/out,image 装 count/size 等)。用户级聚合
  走 (user_id, created_at) 复合索引,JOIN-free。详 DESIGN §7.4 / PROGRESS 05-19
"""
from __future__ import annotations

from datetime import datetime
from decimal import Decimal
from typing import Any, Optional
from uuid import UUID, uuid4

from sqlalchemy import (
    DateTime,
    ForeignKey,
    Integer,
    Numeric,
    Text,
    UniqueConstraint,
    func,
)
from sqlalchemy.dialects.postgresql import JSONB, UUID as PG_UUID
from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column


class Base(DeclarativeBase):
    pass


class User(Base):
    __tablename__ = "users"

    user_id: Mapped[UUID] = mapped_column(PG_UUID(as_uuid=True), primary_key=True, default=uuid4)
    email: Mapped[Optional[str]] = mapped_column(Text, nullable=True, unique=True)
    oidc_subject: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
    password_hash: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
    plan: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), server_default=func.now(), nullable=False
    )


class Task(Base):
    __tablename__ = "tasks"

    task_id: Mapped[UUID] = mapped_column(PG_UUID(as_uuid=True), primary_key=True, default=uuid4)
    user_id: Mapped[UUID] = mapped_column(
        PG_UUID(as_uuid=True), ForeignKey("users.user_id"), nullable=False
    )
    name: Mapped[str] = mapped_column(Text, nullable=False)
    working_dir: Mapped[str] = mapped_column(Text, nullable=False)
    skill: Mapped[str] = mapped_column(Text, nullable=False, default="")
    description: Mapped[str] = mapped_column(Text, nullable=False, default="")
    status: Mapped[str] = mapped_column(Text, nullable=False, default="active")
    model: Mapped[str] = mapped_column(Text, nullable=False, default="")
    model_profile: Mapped[str] = mapped_column(Text, nullable=False, default="")
    reasoning_effort: Mapped[str] = mapped_column(Text, nullable=False, default="")
    tokens_prompt: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    tokens_completion: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    cost_usd: Mapped[Decimal] = mapped_column(Numeric(12, 6), nullable=False, default=0)
    # 当前 in-flight 状态(原 runs 表合并入,DESIGN §7.4 简化 / 0004 migration):
    # idle / running / cancelling / error;ok / cancelled 收尾直接回 idle,
    # 只有 error 是持久终态(下次起新 run 时由 post_message 清掉)
    run_status: Mapped[str] = mapped_column(Text, nullable=False, default="idle")
    run_error: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), server_default=func.now(), nullable=False
    )
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), nullable=False
    )


class Message(Base):
    __tablename__ = "messages"
    __table_args__ = (UniqueConstraint("task_id", "idx", name="uq_messages_task_idx"),)

    message_id: Mapped[UUID] = mapped_column(PG_UUID(as_uuid=True), primary_key=True, default=uuid4)
    task_id: Mapped[UUID] = mapped_column(
        PG_UUID(as_uuid=True),
        ForeignKey("tasks.task_id", ondelete="CASCADE"),
        nullable=False,
    )
    idx: Mapped[int] = mapped_column(Integer, nullable=False)
    payload: Mapped[dict[str, Any]] = mapped_column(JSONB, nullable=False)
    tokens_in: Mapped[Optional[int]] = mapped_column(Integer, nullable=True)
    tokens_out: Mapped[Optional[int]] = mapped_column(Integer, nullable=True)
    # 0006:产生该 message 的模型(只在 assistant 行有值;user/tool/system 为 NULL)。
    # 跟 usage_events.model_profile 写入一致,JOIN-free 时按 message 直查也能拿到。
    model_profile: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), server_default=func.now(), nullable=False
    )


class UsageEvent(Base):
    """per-event 用量记账(0006 v2 形态)。

    一行 = 一次产生成本的调用。chat 类型由 loop 在 assistant message 入库后写入;
    未来的媒体工具(image/video/audio)在 tool execute 完后由 loop 顺手记账。
    units 列 polymorphic JSONB —— chat: {"tokens_in": N, "tokens_out": M};
    image: {"count": K, "size": "1024x1024"};按 kind 约定。

    按 user 聚合的统计 query 走 (user_id, created_at) 索引,不 JOIN tasks 表。
    """
    __tablename__ = "usage_events"

    event_id: Mapped[UUID] = mapped_column(PG_UUID(as_uuid=True), primary_key=True, default=uuid4)
    user_id: Mapped[UUID] = mapped_column(
        PG_UUID(as_uuid=True), ForeignKey("users.user_id"), nullable=False
    )
    task_id: Mapped[UUID] = mapped_column(
        PG_UUID(as_uuid=True),
        ForeignKey("tasks.task_id", ondelete="CASCADE"),
        nullable=False,
    )
    message_id: Mapped[Optional[UUID]] = mapped_column(
        PG_UUID(as_uuid=True),
        ForeignKey("messages.message_id", ondelete="SET NULL"),
        nullable=True,
    )
    kind: Mapped[str] = mapped_column(Text, nullable=False)            # chat / image / video / audio / ...
    model_profile: Mapped[str] = mapped_column(Text, nullable=False)   # deepseek_v4.pro / dall-e-3 / ...
    units: Mapped[dict[str, Any]] = mapped_column(JSONB, nullable=False)
    cost_usd: Mapped[Decimal] = mapped_column(Numeric(12, 6), nullable=False, default=0)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), server_default=func.now(), nullable=False
    )