"""Select literal evidence by opaque IDs; never repair a model's factual prose."""

from __future__ import annotations

from copy import deepcopy
import hashlib
import json
import re


class EvidenceSelectionError(ValueError):
    pass


def identify(row: dict, *, required: bool = False) -> dict:
    payload = {
        k: row.get(k)
        for k in [
            "source_id",
            "passage_id",
            "person",
            "work_type",
            "year",
            "work_label",
            "text",
            "kind",
            "phase",
        ]
    }
    digest = hashlib.sha256(
        json.dumps(payload, sort_keys=True, ensure_ascii=False).encode()
    ).hexdigest()[:24]
    return {**row, "evidence_id": "E" + digest, "required": required}


def overview_candidates(context: dict) -> list[dict]:
    """Keep every main assignment item; do not confuse a backlog with goals."""
    from tools.answers.content_selection import (
        evidence_units,
        administrative_only,
        unit_score,
        scope_groups,
        matches_scope,
    )

    rows = evidence_units(context)
    selected = []
    for person, label in scope_groups(context):
        own = [row for row in rows if matches_scope(row, person, label)]
        main = [row for row in own if row["kind"] == "assignment"]
        # Without an explicit assignment, retain a bounded descriptive sample.
        # A plan or meeting history cannot become the main assignment.
        fallback = [
            row
            for row in own
            if row["kind"] in {"other", "progress"} and not administrative_only(row["text"])
        ]
        fallback.sort(key=lambda row: -unit_score(row["text"], row["kind"]))
        for row in main or fallback[:2]:
            if len(row["text"]) > 2500:
                context["complete"] = False
                context["truncated"] = True
                context["truncation_reasons"] = list(
                    dict.fromkeys(
                        [*(context.get("truncation_reasons") or []), "evidence_unit_limit"]
                    )
                )
                continue
            selected.append(identify(row, required=bool(main)))
    return selected


def resolve_selection(answer: dict, context: dict) -> dict:
    """Expand only IDs from the actual budgeted model input, keeping raw data intact."""
    out = deepcopy(answer)
    ids = out.pop("evidence_ids", [])
    if not ids:
        return out
    if out.get("evidence_quotes"):
        raise EvidenceSelectionError("mixed_evidence_selection")
    choices = {
        row["evidence_id"]: row
        for row in context.get("content_candidates", [])
        if row.get("evidence_id")
    }
    if any(identifier not in choices for identifier in ids):
        raise EvidenceSelectionError("unknown_evidence_id")
    wanted = set(ids)
    chosen = [
        row for row in context.get("content_candidates", []) if row.get("evidence_id") in wanted
    ]
    out["evidence_quotes"] = [
        {k: row[k] for k in ["source_id", "passage_id"]} | {"quote": row["text"]} for row in chosen
    ]
    sources = {row["source_id"]: row for row in context.get("sources", [])}
    urls = [
        sources[row["source_id"]]["source_url"]
        for row in chosen
        if sources.get(row["source_id"], {}).get("source_url")
    ]
    # Extra model-supplied URLs remain visible to the citation guard.
    out["source_urls"] = list(dict.fromkeys([*out.get("source_urls", []), *urls]))
    return out


def missing_required_evidence(answer: dict, context: dict) -> list[str]:
    """A short overview must still cover the supplied main assignment items."""

    def plain(text):
        return " ".join(re.sub(r"^[ \t]*(?:\d+[.)]|[-+*])\s+", "", text, flags=re.M).split())

    quotes = answer.get("evidence_quotes", [])
    return [
        row["evidence_id"]
        for row in context.get("content_candidates", [])
        if row.get("required")
        and not any(
            q["source_id"] == row["source_id"]
            and (not q.get("passage_id") or q["passage_id"] == row["passage_id"])
            and plain(row["text"]) in plain(q["quote"])
            for q in quotes
        )
    ]


def overview_units(answer: dict, context: dict) -> list[dict]:
    """Render all checked assignment items and at most two fallback units per person."""
    from tools.answers.content_selection import evidence_units, scope_groups, matches_scope

    rows = evidence_units(context, answer.get("evidence_quotes", []))
    selected = []
    for person, label in scope_groups(context):
        own = [row for row in rows if matches_scope(row, person, label)]
        main = [row for row in own if row["kind"] == "assignment"]
        for row in main or own[:2]:
            quote = next(
                q
                for q in answer["evidence_quotes"]
                if q["source_id"] == row["source_id"]
                and " ".join(row["text"].split()) in " ".join(q["quote"].split())
                and (not q.get("passage_id") or q["passage_id"] == row["passage_id"])
            )
            selected.append({"evidence": quote, "text": row["text"]})
    return selected