src/storage/models.py

"""Persistence utilities, ORM models, and repository implementations."""

from datetime import datetime, timezone

from pgvector.sqlalchemy import Vector
from sqlalchemy import (
    CheckConstraint,
    DateTime,
    Float,
    ForeignKey,
    ForeignKeyConstraint,
    Index,
    Integer,
    String,
    Text,
)
from sqlalchemy.dialects.postgresql import JSONB
from sqlalchemy.orm import Mapped, mapped_column, relationship

from src.storage.db import Base


class Candidate(Base):
    """Data model for candidate values."""

    __tablename__ = "candidates"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    external_id: Mapped[str | None] = mapped_column(String(128), index=True, nullable=True)
    name: Mapped[str | None] = mapped_column(String(255), nullable=True)
    email: Mapped[str | None] = mapped_column(String(255), nullable=True)
    phone: Mapped[str | None] = mapped_column(String(64), nullable=True)
    links: Mapped[list[str] | None] = mapped_column(JSONB, nullable=True)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc), nullable=False
    )

    resumes: Mapped[list["Resume"]] = relationship(back_populates="candidate")


class Resume(Base):
    """Data model for resume values."""

    __tablename__ = "resumes"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    candidate_id: Mapped[int] = mapped_column(ForeignKey("candidates.id"), nullable=False)
    source_file: Mapped[str] = mapped_column(String(512), nullable=False)
    content_hash: Mapped[str | None] = mapped_column(String(64), nullable=True, index=True)
    raw_text: Mapped[str] = mapped_column(Text, nullable=False)
    parsed_json: Mapped[dict | None] = mapped_column(JSONB, nullable=True)
    signals_json: Mapped[dict | None] = mapped_column(JSONB, nullable=True)
    language: Mapped[str | None] = mapped_column(String(16), nullable=True)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc), nullable=False
    )

    candidate: Mapped[Candidate] = relationship(back_populates="resumes")
    sections: Mapped[list["ResumeSection"]] = relationship(back_populates="resume")


class ResumeSection(Base):
    """Data model for resumesection values."""

    __tablename__ = "resume_sections"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    resume_id: Mapped[int] = mapped_column(ForeignKey("resumes.id"), nullable=False)
    section_type: Mapped[str] = mapped_column(String(64), nullable=False, index=True)
    content: Mapped[str] = mapped_column(Text, nullable=False)
    tokens: Mapped[int | None] = mapped_column(Integer, nullable=True)
    metadata_json: Mapped[dict | None] = mapped_column(JSONB, nullable=True)

    resume: Mapped[Resume] = relationship(back_populates="sections")


class JobPosting(Base):
    """Data model for jobposting values."""

    __tablename__ = "job_postings"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    title: Mapped[str] = mapped_column(String(255), nullable=False)
    description: Mapped[str] = mapped_column(Text, nullable=False)
    requirements_json: Mapped[dict | None] = mapped_column(JSONB, nullable=True)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc), nullable=False
    )


class Embedding(Base):
    """Data model for embedding values."""

    __tablename__ = "embeddings"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    owner_id: Mapped[int] = mapped_column(Integer, nullable=False, index=True)
    model: Mapped[str] = mapped_column(String(128), nullable=False)
    dimensions: Mapped[int] = mapped_column(Integer, nullable=False)
    vector: Mapped[list[float]] = mapped_column(Vector(), nullable=False)
    text_hash: Mapped[str] = mapped_column(String(64), nullable=False, index=True)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc), nullable=False
    )

    __table_args__ = (
        CheckConstraint("dimensions > 0", name="ck_embeddings_dimensions_positive"),
        CheckConstraint(
            "dimensions = vector_dims(vector)", name="ck_embeddings_dimensions_match_vector"
        ),
        ForeignKeyConstraint(
            ["model", "dimensions"],
            ["embedding_models.model", "embedding_models.dimensions"],
            name="fk_embeddings_model_dimensions",
        ),
        Index("ix_embeddings_owner", "owner_id"),
        Index("ix_embeddings_model_dimensions_owner", "model", "dimensions", "owner_id"),
    )


class EmbeddingModel(Base):
    """Data model for embeddingmodel values."""

    __tablename__ = "embedding_models"

    model: Mapped[str] = mapped_column(String(128), primary_key=True)
    dimensions: Mapped[int] = mapped_column(Integer, nullable=False)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc), nullable=False
    )

    __table_args__ = (
        CheckConstraint("dimensions > 0", name="ck_embedding_models_dimensions_positive"),
        Index("ux_embedding_models_model_dimensions", "model", "dimensions", unique=True),
    )


class Match(Base):
    """Data model for match values."""

    __tablename__ = "matches"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    job_id: Mapped[int] = mapped_column(ForeignKey("job_postings.id"), nullable=False)
    candidate_id: Mapped[int] = mapped_column(ForeignKey("candidates.id"), nullable=False)
    retrieval_score: Mapped[float | None] = mapped_column(Float, nullable=True)
    rerank_score: Mapped[float | None] = mapped_column(Float, nullable=True)
    final_score: Mapped[float | None] = mapped_column(Float, nullable=True)
    reasons_json: Mapped[dict | None] = mapped_column(JSONB, nullable=True)
    interview_pack_json: Mapped[dict | None] = mapped_column(JSONB, nullable=True)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc), nullable=False
    )

    candidate: Mapped["Candidate"] = relationship()


class AsyncTask(Base):
    """Data model for background task tracking."""

    __tablename__ = "async_tasks"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    task_type: Mapped[str] = mapped_column(String(128), nullable=False, index=True)
    status: Mapped[str] = mapped_column(String(64), nullable=False, default="PENDING", index=True)
    input_payload: Mapped[dict | None] = mapped_column(JSONB, nullable=True)
    output_payload: Mapped[dict | None] = mapped_column(JSONB, nullable=True)
    error_message: Mapped[str | None] = mapped_column(Text, nullable=True)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc), nullable=False
    )
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        default=lambda: datetime.now(timezone.utc),
        onupdate=lambda: datetime.now(timezone.utc),
        nullable=False,
    )