from datetime import datetime
from enum import Enum
from typing import TYPE_CHECKING

from sqlalchemy import DateTime, Enum as SAEnum, ForeignKey, String, Text, UniqueConstraint, func
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.database.base import Base

if TYPE_CHECKING:
    from app.chats.models import Chat
    from app.media.models import Attachment
    from app.users.models import User


class MessageType(str, Enum):
    TEXT = "text"
    IMAGE = "image"
    VIDEO = "video"
    AUDIO = "audio"
    VOICE = "voice"
    FILE = "file"
    CIRCLE_VIDEO = "circle_video"


class Message(Base):
    __tablename__ = "messages"

    id: Mapped[int] = mapped_column(primary_key=True, index=True)
    chat_id: Mapped[int] = mapped_column(ForeignKey("chats.id", ondelete="CASCADE"), nullable=False, index=True)
    sender_id: Mapped[int] = mapped_column(ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True)
    reply_to_message_id: Mapped[int | None] = mapped_column(
        ForeignKey("messages.id", ondelete="SET NULL"),
        nullable=True,
        index=True,
    )
    forwarded_from_message_id: Mapped[int | None] = mapped_column(
        ForeignKey("messages.id", ondelete="SET NULL"),
        nullable=True,
        index=True,
    )
    type: Mapped[MessageType] = mapped_column(SAEnum(MessageType), nullable=False, default=MessageType.TEXT)
    text: Mapped[str | None] = 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,
    )

    chat: Mapped["Chat"] = relationship(back_populates="messages", foreign_keys=[chat_id])
    sender: Mapped["User"] = relationship(back_populates="sent_messages")
    attachments: Mapped[list["Attachment"]] = relationship(back_populates="message", cascade="all, delete-orphan")


class MessageIdempotencyKey(Base):
    __tablename__ = "message_idempotency_keys"
    __table_args__ = (
        UniqueConstraint("chat_id", "sender_id", "client_message_id", name="uq_msg_idem_chat_sender_client"),
    )

    id: Mapped[int] = mapped_column(primary_key=True, index=True)
    chat_id: Mapped[int] = mapped_column(ForeignKey("chats.id", ondelete="CASCADE"), nullable=False, index=True)
    sender_id: Mapped[int] = mapped_column(ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True)
    client_message_id: Mapped[str] = mapped_column(String(64), nullable=False)
    message_id: Mapped[int] = mapped_column(ForeignKey("messages.id", ondelete="CASCADE"), nullable=False, index=True)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now(), nullable=False)


class MessageReceipt(Base):
    __tablename__ = "message_receipts"
    __table_args__ = (UniqueConstraint("chat_id", "user_id", name="uq_msg_receipts_chat_user"),)

    id: Mapped[int] = mapped_column(primary_key=True, index=True)
    chat_id: Mapped[int] = mapped_column(ForeignKey("chats.id", ondelete="CASCADE"), nullable=False, index=True)
    user_id: Mapped[int] = mapped_column(ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True)
    last_delivered_message_id: Mapped[int | None] = mapped_column(nullable=True)
    last_read_message_id: Mapped[int | None] = mapped_column(nullable=True)
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        server_default=func.now(),
        onupdate=func.now(),
        nullable=False,
    )


class MessageHidden(Base):
    __tablename__ = "message_hidden"
    __table_args__ = (UniqueConstraint("message_id", "user_id", name="uq_message_hidden_message_user"),)

    id: Mapped[int] = mapped_column(primary_key=True, index=True)
    message_id: Mapped[int] = mapped_column(ForeignKey("messages.id", ondelete="CASCADE"), nullable=False, index=True)
    user_id: Mapped[int] = mapped_column(ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now(), nullable=False)