"""SQLAlchemy models for conversations and leads."""

from __future__ import annotations

from datetime import datetime
from typing import Optional

from sqlalchemy import (
    Boolean,
    DateTime,
    ForeignKey,
    Integer,
    String,
    Text,
)
from sqlalchemy.orm import (
    DeclarativeBase,
    Mapped,
    mapped_column,
    relationship,
)


class Base(DeclarativeBase):
    """Declarative base."""


class Conversation(Base):
    """A chat session on web or WhatsApp."""

    __tablename__ = "conversations"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    channel: Mapped[str] = mapped_column(
        String(32), default="web"
    )
    language: Mapped[str] = mapped_column(
        String(8), default="en"
    )
    status: Mapped[str] = mapped_column(
        String(32), default="active"
    )
    external_id: Mapped[Optional[str]] = mapped_column(
        String(128), nullable=True
    )
    failure_streak: Mapped[int] = mapped_column(
        Integer, default=0
    )
    resolved_without_human: Mapped[bool] = mapped_column(
        Boolean, default=False
    )
    handed_off: Mapped[bool] = mapped_column(
        Boolean, default=False
    )
    appointment_booked: Mapped[bool] = mapped_column(
        Boolean, default=False
    )
    created_at: Mapped[datetime] = mapped_column(
        DateTime, default=datetime.utcnow
    )
    updated_at: Mapped[datetime] = mapped_column(
        DateTime,
        default=datetime.utcnow,
        onupdate=datetime.utcnow,
    )

    messages: Mapped[list["Message"]] = relationship(
        back_populates="conversation",
        cascade="all, delete-orphan",
        order_by="Message.created_at",
    )
    lead: Mapped[Optional["Lead"]] = relationship(
        back_populates="conversation",
        uselist=False,
        cascade="all, delete-orphan",
    )
    appointment: Mapped[Optional["Appointment"]] = (
        relationship(
            back_populates="conversation",
            uselist=False,
            cascade="all, delete-orphan",
        )
    )


class Message(Base):
    """Single message in a conversation."""

    __tablename__ = "messages"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    conversation_id: Mapped[int] = mapped_column(
        ForeignKey("conversations.id"), index=True
    )
    role: Mapped[str] = mapped_column(String(16))
    content: Mapped[str] = mapped_column(Text)
    language: Mapped[Optional[str]] = mapped_column(
        String(8), nullable=True
    )
    grounded: Mapped[Optional[bool]] = mapped_column(
        Boolean, nullable=True
    )
    created_at: Mapped[datetime] = mapped_column(
        DateTime, default=datetime.utcnow
    )

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


class Lead(Base):
    """Prospect qualification data collected in chat."""

    __tablename__ = "leads"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    conversation_id: Mapped[int] = mapped_column(
        ForeignKey("conversations.id"), unique=True
    )
    name: Mapped[Optional[str]] = mapped_column(
        String(128), nullable=True
    )
    need: Mapped[Optional[str]] = mapped_column(
        Text, nullable=True
    )
    budget: Mapped[Optional[str]] = mapped_column(
        String(64), nullable=True
    )
    contact_channel: Mapped[Optional[str]] = mapped_column(
        String(64), nullable=True
    )
    email: Mapped[Optional[str]] = mapped_column(
        String(256), nullable=True
    )
    phone: Mapped[Optional[str]] = mapped_column(
        String(64), nullable=True
    )
    complete: Mapped[bool] = mapped_column(
        Boolean, default=False
    )
    created_at: Mapped[datetime] = mapped_column(
        DateTime, default=datetime.utcnow
    )
    updated_at: Mapped[datetime] = mapped_column(
        DateTime,
        default=datetime.utcnow,
        onupdate=datetime.utcnow,
    )

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


class Appointment(Base):
    """Booked meeting slot."""

    __tablename__ = "appointments"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    conversation_id: Mapped[int] = mapped_column(
        ForeignKey("conversations.id"), unique=True
    )
    slot_start: Mapped[str] = mapped_column(String(64))
    slot_end: Mapped[str] = mapped_column(String(64))
    attendee_name: Mapped[Optional[str]] = mapped_column(
        String(128), nullable=True
    )
    attendee_email: Mapped[Optional[str]] = mapped_column(
        String(256), nullable=True
    )
    external_id: Mapped[Optional[str]] = mapped_column(
        String(128), nullable=True
    )
    status: Mapped[str] = mapped_column(
        String(32), default="confirmed"
    )
    created_at: Mapped[datetime] = mapped_column(
        DateTime, default=datetime.utcnow
    )

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


class UnansweredQuestion(Base):
    """Question the bot could not answer from KB."""

    __tablename__ = "unanswered_questions"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    conversation_id: Mapped[int] = mapped_column(
        ForeignKey("conversations.id"), index=True
    )
    question: Mapped[str] = mapped_column(Text)
    created_at: Mapped[datetime] = mapped_column(
        DateTime, default=datetime.utcnow
    )


class KnowledgeDoc(Base):
    """Ingested knowledge document metadata."""

    __tablename__ = "knowledge_docs"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    filename: Mapped[str] = mapped_column(String(256))
    source_type: Mapped[str] = mapped_column(String(32))
    chunk_count: Mapped[int] = mapped_column(Integer, default=0)
    created_at: Mapped[datetime] = mapped_column(
        DateTime, default=datetime.utcnow
    )