from __future__ import annotations

from sqlalchemy import func, or_, select
from sqlalchemy.orm import Session

from .models import CatchReport, ExternalObservation, Fish, SourceType, Spot, Waterbody


def audit_catalog(db: Session) -> dict[str, int]:
    count = lambda model: db.scalar(select(func.count()).select_from(model)) or 0
    failures = {
        "invalid_weights": db.scalar(select(func.count()).select_from(CatchReport).where(or_(CatchReport.weight_g <= 0, CatchReport.weight_g > 3_000_000))) or 0,
        "invalid_coordinates": db.scalar(select(func.count()).select_from(Spot).where(or_(Spot.x < -10_000, Spot.x > 10_000, Spot.y < -10_000, Spot.y > 10_000))) or 0,
        "incomplete_official_records": db.scalar(select(func.count()).select_from(CatchReport).where(CatchReport.source_type == SourceType.official_record, or_(CatchReport.caught_at.is_(None), CatchReport.source_url.is_(None)))) or 0,
        "incomplete_published_staging": db.scalar(select(func.count()).select_from(ExternalObservation).where(ExternalObservation.status == "published", or_(ExternalObservation.fish_id.is_(None), ExternalObservation.waterbody_id.is_(None), ExternalObservation.x.is_(None), ExternalObservation.y.is_(None), ExternalObservation.weight_g.is_(None), ExternalObservation.catch_report_id.is_(None)))) or 0,
    }
    return {"fishes": count(Fish), "waterbodies": count(Waterbody), "reports": count(CatchReport), "staging": count(ExternalObservation), **failures, "failures": sum(failures.values())}


def audit_waterbody_catalog(db: Session, expected_ids: set[str]) -> dict:
    """Check a verified RF4DB snapshot without withdrawing legacy rows."""
    rows = list(db.scalars(select(Waterbody).where(Waterbody.source_system == "rf4db")))
    observed_ids = [str(row.source_external_id) for row in rows if row.source_external_id]
    observed = set(observed_ids)
    duplicate_ids = sorted({item for item in observed_ids if observed_ids.count(item) > 1})
    missing = sorted(expected_ids - observed)
    unexpected = sorted(observed - expected_ids)
    provenance_issues = sorted(
        str(row.source_external_id)
        for row in rows
        if not row.source_external_id or not row.source_url or not row.source_checked_at
    )
    failures = len(missing) + len(duplicate_ids) + len(provenance_issues)
    return {
        "expected": len(expected_ids),
        "observed": len(observed),
        "missing_source_external_ids": missing,
        "unexpected_source_external_ids": unexpected,
        "duplicate_source_external_ids": duplicate_ids,
        "provenance_issues": provenance_issues,
        "failures": failures,
    }