"""Stable, public fingerprint for persisted research-answer compatibility."""

from __future__ import annotations

import hashlib
import inspect
import json
from pathlib import Path
from typing import Any


def _hash(value: Any) -> str:
    if not isinstance(value, str):
        value = json.dumps(value, ensure_ascii=False, sort_keys=True, separators=(",", ":"))
    return hashlib.sha256(value.encode("utf-8")).hexdigest()[:20]


def _source(*values: Any) -> str:
    parts = []
    for value in values:
        if isinstance(value, str):
            parts.append(value)
            continue
        if inspect.ismodule(value):
            try:
                path = inspect.getsourcefile(value)
                parts.append(Path(path).read_text(encoding="utf-8") if path else repr(value))
            except (OSError, TypeError):
                parts.append(repr(value))
            continue
        try:
            parts.append(inspect.getsource(value))
        except (OSError, TypeError):
            parts.append(repr(value))
    return "\n\n".join(parts)


def build_research_release(corpus: Any, agent_module: Any) -> dict[str, Any]:
    """Fingerprint every input that can make a saved research answer stale.

    Prompt hashes are derived from their actual text and algorithm hashes from
    their function source, so ordinary prompt/retrieval edits invalidate saved
    answers without a developer remembering to bump a browser-session number.
    """
    coverage = corpus.coverage()
    manifest = getattr(corpus, "manifest", {}) or {}
    corpus_descriptor = {
        "release_version": coverage.get("release_version") or manifest.get("release_version") or "legacy",
        "accepted_judgments": coverage.get("accepted_judgments"),
        "units": coverage.get("units"),
        "paragraphs": coverage.get("paragraphs"),
        "artifacts": manifest.get("artifacts") or {},
        "model": manifest.get("model") or {},
    }
    corpus_type = type(corpus)
    # Full source digests deliberately over-invalidate rather than risk serving
    # an answer produced by changed ranking or verification helpers that were
    # not listed individually here.
    agent_source = _source(agent_module)
    corpus_source = _source(corpus_type)
    components = {
        "corpus": _hash(corpus_descriptor),
        "query_router": _hash(_source(
            getattr(agent_module, "QUERY_ROUTER_VERSION", ""),
            getattr(agent_module, "QUERY_BRIEF_SYS", ""),
            getattr(agent_module, "query_brief", None),
        )),
        "retrieval": _hash(_source(
            getattr(agent_module, "RETRIEVAL_VERSION", ""),
            agent_source,
            corpus_source,
            getattr(agent_module, "structured_search_stream", None),
            getattr(agent_module, "judge", None),
            getattr(corpus_type, "identity_hits", None),
            getattr(corpus_type, "search_lanes", None),
        )),
        "answer": _hash(_source(
            getattr(agent_module, "ANSWER_PROMPT_VERSION", ""),
            agent_source,
            getattr(agent_module, "_GROUND_SYS", ""),
            getattr(agent_module, "ground", None),
            getattr(agent_module, "verify_claims", None),
            getattr(agent_module, "_grounded_answer_text", None),
        )),
    }
    return {
        "fingerprint": _hash(components),
        "components": components,
        "corpus_release": corpus_descriptor["release_version"],
    }


__all__ = ["build_research_release"]