import enum
import uuid
from datetime import datetime, timezone

from sqlalchemy import String, Text, Boolean, Integer, ForeignKey, JSON, Enum as SAEnum, text
from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column, relationship


class Base(DeclarativeBase):
    pass


class ConversationStatus(str, enum.Enum):
    active = "active"
    completed = "completed"
    abandoned = "abandoned"


class MessageRole(str, enum.Enum):
    user = "user"
    assistant = "assistant"
    system = "system"


class ConversationSource(str, enum.Enum):
    standalone = "standalone"
    embedded = "embedded"
    widget = "widget"
    app = "app"


class IntentLevel(str, enum.Enum):
    interested = "interested"
    not_interested = "not_interested"
    pending = "pending"


class Conversation(Base):
    __tablename__ = "conversations"

    id: Mapped[str] = mapped_column(
        String(36), primary_key=True, default=lambda: str(uuid.uuid4())
    )
    session_id: Mapped[str] = mapped_column(String(64), unique=True, index=True)
    page_token: Mapped[str | None] = mapped_column(String(64), nullable=True, index=True)
    status: Mapped[ConversationStatus] = mapped_column(
        SAEnum(ConversationStatus), default=ConversationStatus.active
    )
    source: Mapped[ConversationSource] = mapped_column(
        SAEnum(ConversationSource), default=ConversationSource.standalone
    )
    client_info: Mapped[dict | None] = mapped_column(JSON, nullable=True)
    created_at: Mapped[datetime] = mapped_column(
        default=lambda: datetime.now(timezone.utc)
    )
    updated_at: Mapped[datetime] = mapped_column(
        default=lambda: datetime.now(timezone.utc),
        onupdate=lambda: datetime.now(timezone.utc),
    )

    messages: Mapped[list["Message"]] = relationship(
        back_populates="conversation", order_by="Message.created_at"
    )
    profile: Mapped["CustomerProfile | None"] = relationship(
        back_populates="conversation", uselist=False
    )
    evaluation: Mapped["Evaluation | None"] = relationship(
        back_populates="conversation", uselist=False
    )


class Message(Base):
    __tablename__ = "messages"

    id: Mapped[str] = mapped_column(
        String(36), primary_key=True, default=lambda: str(uuid.uuid4())
    )
    conversation_id: Mapped[str] = mapped_column(
        ForeignKey("conversations.id", ondelete="CASCADE")
    )
    role: Mapped[MessageRole] = mapped_column(SAEnum(MessageRole))
    content: Mapped[str] = mapped_column(Text)
    created_at: Mapped[datetime] = mapped_column(
        default=lambda: datetime.now(timezone.utc)
    )

    conversation: Mapped["Conversation"] = relationship(back_populates="messages")


class CustomerProfile(Base):
    __tablename__ = "customer_profiles"

    id: Mapped[str] = mapped_column(
        String(36), primary_key=True, default=lambda: str(uuid.uuid4())
    )
    conversation_id: Mapped[str] = mapped_column(
        ForeignKey("conversations.id", ondelete="CASCADE"), unique=True
    )
    raw_info: Mapped[dict | None] = mapped_column(JSON, nullable=True, default=dict)
    summary: Mapped[str | None] = mapped_column(Text, nullable=True)
    updated_at: Mapped[datetime] = mapped_column(
        default=lambda: datetime.now(timezone.utc),
        onupdate=lambda: datetime.now(timezone.utc),
    )

    conversation: Mapped["Conversation"] = relationship(back_populates="profile")


class Evaluation(Base):
    __tablename__ = "evaluations"

    id: Mapped[str] = mapped_column(
        String(36), primary_key=True, default=lambda: str(uuid.uuid4())
    )
    conversation_id: Mapped[str] = mapped_column(
        ForeignKey("conversations.id", ondelete="CASCADE"), unique=True
    )
    intent_level: Mapped[IntentLevel] = mapped_column(SAEnum(IntentLevel))
    reasoning: Mapped[str | None] = mapped_column(Text, nullable=True)
    contact_info: Mapped[dict | None] = mapped_column(JSON, nullable=True)
    email_sent: Mapped[bool] = mapped_column(Boolean, default=False)
    correction_count: Mapped[int] = mapped_column(Integer, default=0)
    evaluated_at: Mapped[datetime] = mapped_column(
        default=lambda: datetime.now(timezone.utc)
    )

    conversation: Mapped["Conversation"] = relationship(back_populates="evaluation")


class LeadPushLog(Base):
    """询盘推送 UniService 日志(设计 2026-09-28-lead-push-to-uniservice)。

    status: pending → success/failed;skipped = contact 三选一(phone/whatsapp/
    email)不满足,对方必拒,预检后不发 HTTP 只留审计痕迹。
    outcome: 200 时对方逐条结论 accepted/duplicated(duplicated 不是错误)。
    """
    __tablename__ = "lead_push_logs"

    id: Mapped[str] = mapped_column(
        String(36), primary_key=True, default=lambda: str(uuid.uuid4())
    )
    evaluation_id: Mapped[str] = mapped_column(
        ForeignKey("evaluations.id", ondelete="CASCADE"), index=True
    )
    conversation_id: Mapped[str] = mapped_column(
        ForeignKey("conversations.id", ondelete="CASCADE"), index=True
    )
    push_type: Mapped[str] = mapped_column(String(16))  # lead/returning/correction
    status: Mapped[str] = mapped_column(String(16), default="pending", index=True)
    attempts: Mapped[int] = mapped_column(Integer, default=0)
    request_payload: Mapped[dict | None] = mapped_column(JSON, nullable=True)
    response_status: Mapped[int | None] = mapped_column(Integer, nullable=True)
    outcome: Mapped[str | None] = mapped_column(String(16), nullable=True)
    error_message: Mapped[str | None] = mapped_column(Text, nullable=True)
    created_at: Mapped[datetime] = mapped_column(
        default=lambda: datetime.now(timezone.utc)
    )
    updated_at: Mapped[datetime] = mapped_column(
        default=lambda: datetime.now(timezone.utc),
        onupdate=lambda: datetime.now(timezone.utc),
    )


async def ensure_schema(engine) -> None:
    """create_all + 旧库加列迁移(自 app/main.py lifespan/_migrate 提取,逻辑逐字等价)。

    jc 上线库(conversations 无 page_token / evaluations 无 correction_count)
    经此升级;新库 create_all 已含全部列,加列分支空跑。TenantRegistry 懒建
    每租户库时复用(Phase 1);生产装配见 app/main.py lifespan。
    """
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.create_all)
        result = await conn.execute(text("PRAGMA table_info(conversations)"))
        columns = {row[1] for row in result}
        if "page_token" not in columns:
            await conn.execute(text(
                "ALTER TABLE conversations ADD COLUMN page_token VARCHAR(64)"
            ))

        result = await conn.execute(text("PRAGMA table_info(evaluations)"))
        columns = {row[1] for row in result}
        if "correction_count" not in columns:
            await conn.execute(text(
                "ALTER TABLE evaluations ADD COLUMN correction_count INTEGER DEFAULT 0"
            ))