"""
Entity resolution (docs/06): block, score, and link records across sources so the
same company from GLEIF + Brreg + CVR collapses to one record with corroborated
confidence. rapidfuzz only; deterministic; no external calls.
"""
from __future__ import annotations

from typing import Any

from rapidfuzz import fuzz


def block_key(rec: dict[str, Any]) -> tuple[str, str]:
    """Cheap blocking key — same market + first initial — to avoid O(n^2)."""
    return (rec.get("market") or "", (rec.get("name") or "")[:1].upper())


def resolve(records: list[dict[str, Any]], threshold: int = 92) -> list[dict[str, Any]]:
    out: list[dict[str, Any]] = []
    for r in records:
        match = None
        for o in out:
            if block_key(o) == block_key(r) and fuzz.token_sort_ratio(o.get("name", ""), r.get("name", "")) >= threshold:
                match = o
                break
        if match:
            # corroboration: independent source agreeing bumps confidence + level
            match["confidence"] = min(0.99, match.get("confidence", 0.0) + 0.1)
            match["agreed_sources"] = match.get("agreed_sources", 1) + 1
            match.setdefault("merged_from", []).append(r.get("source"))
        else:
            out.append({**r, "agreed_sources": 1})
    return out