"""EPUB search models."""

from __future__ import annotations

from datetime import datetime

from pgvector.sqlalchemy import Vector
from sqlalchemy import BigInteger, Boolean, DateTime, ForeignKey, Index, String, UniqueConstraint
from sqlalchemy.orm import Mapped, mapped_column, relationship

from python.orm.richie.base import TableBase, TableBaseBig


class EbookSource(TableBase):
    """One indexed EPUB file."""

    __tablename__ = "ebook_source"
    __table_args__ = (
        UniqueConstraint("file_path"),
        UniqueConstraint("file_sha256"),
    )

    title: Mapped[str]
    author: Mapped[str | None]
    language: Mapped[str | None]
    publisher: Mapped[str | None]
    identifier: Mapped[str | None]
    file_path: Mapped[str]
    file_sha256: Mapped[str] = mapped_column(String(64))
    file_mtime: Mapped[datetime] = mapped_column(DateTime(timezone=True))
    file_size: Mapped[int] = mapped_column(BigInteger)

    chapters: Mapped[list[EbookChapter]] = relationship(
        "EbookChapter",
        back_populates="source",
        cascade="all, delete-orphan",
        passive_deletes=True,
    )
    chunks: Mapped[list[EbookChunk]] = relationship(
        "EbookChunk",
        back_populates="source",
        cascade="all, delete-orphan",
        passive_deletes=True,
    )


class EbookChapter(TableBase):
    """A chapter or spine document inside an EPUB."""

    __tablename__ = "ebook_chapter"
    __table_args__ = (UniqueConstraint("source_id", "spine_index"),)

    source_id: Mapped[int] = mapped_column(ForeignKey("main.ebook_source.id", ondelete="CASCADE"))
    spine_index: Mapped[int]
    title: Mapped[str | None]
    href: Mapped[str | None]

    source: Mapped[EbookSource] = relationship("EbookSource", back_populates="chapters")
    chunks: Mapped[list[EbookChunk]] = relationship(
        "EbookChunk",
        back_populates="chapter",
        cascade="all, delete-orphan",
        passive_deletes=True,
    )


class EbookChunk(TableBaseBig):
    """A searchable text chunk."""

    __tablename__ = "ebook_chunk"
    __table_args__ = (
        UniqueConstraint("source_id", "chunk_index", name="uq_ebook_chunk_source_id_chunk_index"),
        UniqueConstraint("source_id", "content_sha256", name="uq_ebook_chunk_source_id_content_sha256"),
    )

    source_id: Mapped[int] = mapped_column(ForeignKey("main.ebook_source.id", ondelete="CASCADE"))
    chapter_id: Mapped[int | None] = mapped_column(ForeignKey("main.ebook_chapter.id", ondelete="SET NULL"))
    chunk_index: Mapped[int]
    text: Mapped[str]
    token_start: Mapped[int]
    token_count: Mapped[int]
    page_label: Mapped[str | None]
    content_sha256: Mapped[str] = mapped_column(String(64))
    search_text: Mapped[str]

    source: Mapped[EbookSource] = relationship("EbookSource", back_populates="chunks")
    chapter: Mapped[EbookChapter | None] = relationship("EbookChapter", back_populates="chunks")


class EbookEmbeddingModel(TableBase):
    """A supported embedding model."""

    __tablename__ = "ebook_embedding_model"

    name: Mapped[str] = mapped_column(String, unique=True)
    dimension: Mapped[int]
    is_default: Mapped[bool] = mapped_column(Boolean, default=False)


class EbookChunkEmbedding1024(TableBaseBig):
    """1024-dimensional chunk embedding."""

    __tablename__ = "ebook_chunk_embedding_1024"
    __table_args__ = (
        UniqueConstraint("chunk_id", "model_id"),
        Index(
            "ix_ebook_chunk_embedding_1024_embedding_cosine",
            "embedding",
            postgresql_using="hnsw",
            postgresql_ops={"embedding": "vector_cosine_ops"},
        ),
    )

    chunk_id: Mapped[int] = mapped_column(ForeignKey("main.ebook_chunk.id", ondelete="CASCADE"))
    model_id: Mapped[int] = mapped_column(ForeignKey("main.ebook_embedding_model.id", ondelete="CASCADE"))
    embedding: Mapped[list[float]] = mapped_column(Vector(1024))


class EbookChunkEmbedding2560(TableBaseBig):
    """2560-dimensional chunk embedding."""

    __tablename__ = "ebook_chunk_embedding_2560"
    __table_args__ = (UniqueConstraint("chunk_id", "model_id"),)

    chunk_id: Mapped[int] = mapped_column(ForeignKey("main.ebook_chunk.id", ondelete="CASCADE"))
    model_id: Mapped[int] = mapped_column(ForeignKey("main.ebook_embedding_model.id", ondelete="CASCADE"))
    embedding: Mapped[list[float]] = mapped_column(Vector(2560))


class EbookChunkEmbedding4096(TableBaseBig):
    """4096-dimensional chunk embedding."""

    __tablename__ = "ebook_chunk_embedding_4096"
    __table_args__ = (UniqueConstraint("chunk_id", "model_id"),)

    chunk_id: Mapped[int] = mapped_column(ForeignKey("main.ebook_chunk.id", ondelete="CASCADE"))
    model_id: Mapped[int] = mapped_column(ForeignKey("main.ebook_embedding_model.id", ondelete="CASCADE"))
    embedding: Mapped[list[float]] = mapped_column(Vector(4096))