"""Database operations for detection pipeline — SQLModel."""

from __future__ import annotations

from typing import Optional
from uuid import UUID

from sqlmodel import select

from .connection import get_session
from .models import (
    DetectJob, StageCheckpoint, KnownBrand, SourceBrandSighting,
)


# ---------------------------------------------------------------------------
# DetectJob
# ---------------------------------------------------------------------------

def create_detect_job(**fields) -> DetectJob:
    job = DetectJob(**fields)
    with get_session() as session:
        session.add(job)
        session.commit()
        session.refresh(job)
        return job


def get_detect_job(id: UUID) -> DetectJob | None:
    with get_session() as session:
        return session.get(DetectJob, id)


def update_detect_job(job_id: UUID, **fields) -> None:
    with get_session() as session:
        job = session.get(DetectJob, job_id)
        if not job:
            return
        for k, v in fields.items():
            setattr(job, k, v)
        session.commit()


def list_detect_jobs(
    parent_job_id: Optional[UUID] = None,
    status: Optional[str] = None,
) -> list[DetectJob]:
    with get_session() as session:
        stmt = select(DetectJob)
        if parent_job_id:
            stmt = stmt.where(DetectJob.parent_job_id == parent_job_id)
        if status:
            stmt = stmt.where(DetectJob.status == status)
        return list(session.exec(stmt).all())


# ---------------------------------------------------------------------------
# StageCheckpoint
# ---------------------------------------------------------------------------

def save_stage_checkpoint(**fields) -> StageCheckpoint:
    with get_session() as session:
        # Upsert: replace if same job_id + stage
        job_id = fields.get("job_id")
        stage = fields.get("stage")
        if job_id and stage:
            stmt = select(StageCheckpoint).where(
                StageCheckpoint.job_id == job_id,
                StageCheckpoint.stage == stage,
            )
            existing = session.exec(stmt).first()
            if existing:
                for k, v in fields.items():
                    setattr(existing, k, v)
                session.commit()
                session.refresh(existing)
                return existing

        checkpoint = StageCheckpoint(**fields)
        session.add(checkpoint)
        session.commit()
        session.refresh(checkpoint)
        return checkpoint


def get_stage_checkpoint(job_id: UUID, stage: str) -> StageCheckpoint | None:
    with get_session() as session:
        stmt = select(StageCheckpoint).where(
            StageCheckpoint.job_id == job_id,
            StageCheckpoint.stage == stage,
        )
        return session.exec(stmt).first()


def list_stage_checkpoints(job_id: UUID) -> list[str]:
    with get_session() as session:
        stmt = (
            select(StageCheckpoint.stage)
            .where(StageCheckpoint.job_id == job_id)
            .order_by(StageCheckpoint.stage_index)
        )
        return list(session.exec(stmt).all())


def delete_stage_checkpoints(job_id: UUID) -> None:
    with get_session() as session:
        stmt = select(StageCheckpoint).where(StageCheckpoint.job_id == job_id)
        for cp in session.exec(stmt).all():
            session.delete(cp)
        session.commit()


# ---------------------------------------------------------------------------
# KnownBrand
# ---------------------------------------------------------------------------

def get_or_create_brand(canonical_name: str, aliases: Optional[list[str]] = None,
                        source: str = "ocr") -> tuple[KnownBrand, bool]:
    normalized = canonical_name.strip()
    with get_session() as session:
        stmt = select(KnownBrand).where(KnownBrand.canonical_name.ilike(normalized))
        brand = session.exec(stmt).first()
        if brand:
            return brand, False

        brand = KnownBrand(
            canonical_name=normalized,
            aliases=aliases or [],
            first_source=source,
        )
        session.add(brand)
        session.commit()
        session.refresh(brand)
        return brand, True


def find_brand_by_text(text: str) -> KnownBrand | None:
    normalized = text.strip().lower()
    with get_session() as session:
        stmt = select(KnownBrand).where(KnownBrand.canonical_name.ilike(normalized))
        brand = session.exec(stmt).first()
        if brand:
            return brand

        # Alias search — check if normalized is in any brand's aliases
        all_brands = session.exec(select(KnownBrand)).all()
        for b in all_brands:
            if normalized in [a.lower() for a in (b.aliases or [])]:
                return b
        return None


def list_all_brands() -> list[KnownBrand]:
    with get_session() as session:
        return list(session.exec(select(KnownBrand).order_by(KnownBrand.canonical_name)).all())


def update_brand(brand_id: UUID, **fields) -> None:
    with get_session() as session:
        brand = session.get(KnownBrand, brand_id)
        if not brand:
            return
        for k, v in fields.items():
            setattr(brand, k, v)
        session.commit()


# ---------------------------------------------------------------------------
# SourceBrandSighting
# ---------------------------------------------------------------------------

def get_source_sightings(source_asset_id: UUID) -> list[SourceBrandSighting]:
    with get_session() as session:
        stmt = (
            select(SourceBrandSighting)
            .where(SourceBrandSighting.source_asset_id == source_asset_id)
            .order_by(SourceBrandSighting.occurrences.desc())
        )
        return list(session.exec(stmt).all())


def record_sighting(source_asset_id: UUID, brand_id: UUID, brand_name: str,
                    timestamp: float, confidence: float, source: str = "ocr") -> SourceBrandSighting:
    with get_session() as session:
        stmt = select(SourceBrandSighting).where(
            SourceBrandSighting.source_asset_id == source_asset_id,
            SourceBrandSighting.brand_id == brand_id,
        )
        sighting = session.exec(stmt).first()

        if sighting:
            total_conf = sighting.avg_confidence * sighting.occurrences + confidence
            sighting.occurrences += 1
            sighting.last_seen_timestamp = timestamp
            sighting.avg_confidence = total_conf / sighting.occurrences
            session.commit()
            session.refresh(sighting)
            return sighting

        sighting = SourceBrandSighting(
            source_asset_id=source_asset_id,
            brand_id=brand_id,
            brand_name=brand_name,
            first_seen_timestamp=timestamp,
            last_seen_timestamp=timestamp,
            occurrences=1,
            detection_source=source,
            avg_confidence=confidence,
        )
        session.add(sighting)
        session.commit()
        session.refresh(sighting)
        return sighting