"""Entity matching with Jev (TypeSafe) — phases 3-5 of the final plan.

Mechanics (final plan v5 §2):
- برون‌گروهی: ONE Jev request per FIELD that has mentions (requests run in
  parallel; latency ≈ one round-trip regardless of field count).
- درون‌گروهی: inside a field request, ONE `choice` question per mention; every
  question rides with the SAME full candidate list (+ a `_none` option).
- درون‌واریانسی: all STT spellings of one entity travel in ONE question, and
  the instructions ask the model to treat them as one name.

Routing (thresholds from env; calibrated in phase 6):
  conf >= JEV_CONF_EXACT          → exact  (bind id, no ambiguity sub-message)
  JEV_CONF_FLOOR..JEV_CONF_EXACT  → ambiguity (candidate buttons sub-message)
  below floor / _none             → new    (existing auto-create path)

Fail-soft: a failed field simply yields no results for its mentions; callers
fall back to the difflib path (`safe_resolve`). With JEV_ENABLED=false nothing
in this module runs (zero regression).
"""
import asyncio
import hashlib
import json
import logging

from app import observability as obs
from app.config import settings
from app.jev import ask as jev_ask
from app.nlu import normalize_text

logger = logging.getLogger("bot.matching")

FIELD_ORDER = ["project", "supplier", "material", "brand", "spec", "unit"]

FIELD_FA = {
    "project": "پروژه",
    "supplier": "تأمین‌کننده",
    "material": "متریال",
    "brand": "برند",
    "spec": "مشخصه",
    "unit": "واحد",
}


# ---------------------------------------------------------------------------
# candidate lists (full lists — no prefilter, per owner decision)
# ---------------------------------------------------------------------------

async def _candidates(resolver, field: str) -> list:
    if field == "project":
        return await resolver.projects()
    if field == "supplier":
        return await resolver.all_suppliers()
    if field == "material":
        return await resolver.all_materials()
    if field == "brand":
        return await resolver.brands()
    if field == "spec":
        return await resolver.specs()
    if field == "unit":
        return await resolver.units()
    return []


def _hint(field: str, cand) -> str:
    """Short, token-cheap description shown next to a candidate name."""
    if field == "supplier":
        extra = cand.extra or {}
        bits = [b for b in (extra.get("category_name"), extra.get("location")) if b]
        return "، ".join(str(b) for b in bits) if bits else "تأمین‌کننده"
    return ""


def _instructions(field: str, variants: list[str]) -> str:
    fa = FIELD_FA.get(field, field)
    vlist = "»، «".join(v for v in variants if v)
    if len(variants) > 1:
        return (
            f"کاربر در پیام (صوتی) خود این {fa} را ذکر کرده و مدل‌های مختلف STT آن را به شکل‌های "
            f"«{vlist}» پیاده کرده‌اند؛ این‌ها چند نگارش از یک نام واحدند. با توجه به بافت جمله و "
            f"تشابه آوایی میان این واریانت‌ها، مشخص کن به کدام گزینه از فهرست اشاره دارد. "
            f"اگر هیچ‌کدام منطبق نیست یا تردید جدی داری «_none» را انتخاب کن."
        )
    return (
        f"کاربر «{vlist}» را به‌عنوان {fa} ذکر کرده است. این عبارت به کدام گزینه از فهرست اشاره دارد؟ "
        f"اگر هیچ‌کدام منطبق نیست یا تردید جدی داری «_none» را انتخاب کن."
    )


# ---------------------------------------------------------------------------
from app.fallback_matcher import MatchingFailureError, match_with_deepseek

# ---------------------------------------------------------------------------
# the per-field fan-out
# ---------------------------------------------------------------------------

async def resolve_mentions(
    ctx,
    patch: dict,
    mentions: list[dict],
    trace_id: str | None = None,
    raw_input: object = None,
) -> dict:
    """Run Jev per field; on failure, trigger DeepSeek Crisis Fallback.

    Return a map keyed by normalized variant.
    Each value: {"field", "status": exact|ambiguity|new", "variants",
                 "id"?, "name"?, "extra"?, "confidence"?, "candidates": [...]}
    """
    by_field: dict[str, list[dict]] = {}
    for m in mentions or []:
        field = str((m or {}).get("field") or "").strip()
        variants = [str(v).strip() for v in ((m or {}).get("variants") or []) if str(v or "").strip()]
        if field in FIELD_ORDER and variants:
            by_field.setdefault(field, []).append({"field": field, "variants": variants[:6]})

    results: dict[str, dict] = {}
    if not by_field:
        return results

    unhandled_mentions: list[dict] = []
    unhandled_fields: set[str] = set()

    async def one_field(field: str, ms: list[dict]) -> None:
        try:
            cands = await _candidates(ctx.resolver, field)
        except Exception:
            logger.exception("matching: candidate fetch failed for %s", field)
            unhandled_mentions.extend(ms)
            unhandled_fields.add(field)
            return
        if not cands:
            unhandled_mentions.extend(ms)
            unhandled_fields.add(field)
            return

        by_name: dict[str, object] = {}
        criteria: dict[str, str] = {}
        for c in cands:
            if c.name in criteria:
                continue
            criteria[c.name] = _hint(field, c)
            by_name[c.name] = c
        criteria["_none"] = "هیچ‌کدام از موارد موجود نیست"

        capped = ms[: settings.JEV_MAX_QUESTIONS_PER_FIELD]
        questions = {
            f"mention_{i}": {
                "type": "choice",
                "instructions": _instructions(field, m["variants"]),
                "criteria": criteria,
            }
            for i, m in enumerate(capped)
        }
        state = {
            "field": field,
            "patch_context": json.dumps(patch, ensure_ascii=False, default=str)[:1500],
        }
        await obs.event(trace_id, "jev.request", field=field, payload={
            "n_mentions": len(capped), "n_candidates": len(cands),
        })
        resp = await jev_ask(state, questions)
        await obs.event(trace_id, "jev.result", field=field, ok=resp is not None,
                        model=(resp or {}).get("model"),
                        latency_ms=(resp or {}).get("latency_ms"),
                        payload={"answers": (resp or {}).get("answers"),
                                 "usage": (resp or {}).get("usage")})
        if resp is None:
            # Observability: log jev.failure event
            await obs.event(trace_id, "jev.failure", field=field, payload={
                "error": "jev_unavailable_or_error",
                "reason": "HTTP error or timeout or no response",
                "model": settings.JEV_MODEL,
                "n_mentions": len(capped),
            })
            unhandled_mentions.extend(capped)
            unhandled_fields.add(field)
            return
        answers = resp.get("answers") or {}

        decisions = []
        for i, m in enumerate(capped):
            ans = answers.get(f"mention_{i}") or {}
            if not ans:
                unhandled_mentions.append(m)
                unhandled_fields.add(field)
                continue
            choice = ans.get("choice")
            conf = float(ans.get("confidence") or 0.0)
            probs = ans.get("probabilities") or {}
            cand = by_name.get(choice) if choice else None
            ranked = sorted(
                ({"id": by_name[n].id, "name": n, "prob": float(p or 0.0)}
                 for n, p in probs.items() if n != "_none" and n in by_name),
                key=lambda x: -x["prob"],
            )[:6]

            base = {"field": field, "variants": m["variants"], "confidence": conf,
                    "choice": (cand.name if cand is not None else None),
                    "candidates": ranked}

            if cand is not None and conf >= settings.JEV_CONF_EXACT:
                res = {**base, "status": "exact", "id": cand.id, "name": cand.name,
                       "extra": cand.extra or {}}
            elif cand is not None and conf >= settings.JEV_CONF_FLOOR:
                res = {**base, "status": "ambiguity", "id": cand.id, "name": cand.name,
                       "extra": cand.extra or {},
                       "candidates": ranked or [{"id": cand.id, "name": cand.name, "prob": conf}]}
            elif cand is None:
                res = {**base, "status": "new"}
            else:
                # Below-floor pick: route to fallback matcher
                unhandled_mentions.append(m)
                unhandled_fields.add(field)
                continue
            for v in m["variants"]:
                results[normalize_text(v)] = res
            decisions.append({"variants": m["variants"], "status": res["status"],
                              "choice": res.get("name"), "confidence": conf,
                              "probs_top": [{k: round(v, 3)} for k, v in
                                            sorted(probs.items(), key=lambda kv: -kv[1])[:3]]})
        await obs.event(trace_id, "routing.decision", field=field,
                        payload={"source": "jev", "mentions": decisions})

    if settings.JEV_ENABLED:
        await asyncio.gather(*(one_field(f, ms) for f, ms in by_field.items()))
    else:
        # Jev disabled -> all mentions route to DeepSeek fallback
        for f, ms in by_field.items():
            unhandled_mentions.extend(ms)
            unhandled_fields.add(f)

    # If any mentions were unhandled / failed in Jev, run DeepSeek Crisis Fallback
    if unhandled_mentions:
        cands_by_field = {}
        for f in unhandled_fields:
            try:
                cands_by_field[f] = await _candidates(ctx.resolver, f)
            except Exception:
                cands_by_field[f] = []
        fallback_res = await match_with_deepseek(
            raw_input=raw_input,
            mentions=unhandled_mentions,
            candidates_by_field=cands_by_field,
            patch_context=patch,
            trace_id=trace_id,
        )
        results.update(fallback_res)

    return results


def lookup(jev_map: dict | None, name: str | None) -> dict | None:
    """Find the Jev result for a raw name (by normalized variant)."""
    if not jev_map or not name:
        return None
    return jev_map.get(normalize_text(name))


# ---------------------------------------------------------------------------
# writing results into drafts
# ---------------------------------------------------------------------------

def apply_choice(payload: dict, field: str, cand: dict, variants: list[str]) -> None:
    """Bind one chosen candidate (exact match or a user pick) into the payload."""
    name, cid = cand.get("name"), cand.get("id")
    extra = cand.get("extra") or {}
    variants_norm = {normalize_text(v) for v in (variants or []) if v}

    if field == "supplier":
        payload["supplier_id"] = cid
        payload["supplier_name"] = name
        for k in ("location", "phone", "contact_person", "category_name"):
            if extra.get(k):
                payload[f"supplier_{k}"] = extra[k]
    elif field == "project":
        resolved = payload.setdefault("resolved_projects", {})
        for v in (variants or []):
            resolved[v] = cid
        resolved[name] = cid
        if cid not in payload.get("project_ids", []):
            payload.setdefault("project_ids", []).append(cid)
        if not payload.get("project_id"):
            payload["project_id"] = cid
    elif field == "material":
        for item in payload.get("items") or []:
            if normalize_text(item.get("material_name") or "") in variants_norm:
                item["material_name"] = name
                item["material_id"] = cid
                item["material_row"] = {"id": cid,
                                        "canonical_unit_id": extra.get("canonical_unit_id")}
    elif field == "unit":
        for item in payload.get("items") or []:
            if normalize_text(item.get("unit_name") or "") in variants_norm:
                item["unit_id"] = cid
                item["unit_explicit"] = True
                item["unit_name"] = name
        if not payload.get("items"):
            payload["canonical_unit_id"] = cid
            payload["unit_name"] = name
    elif field == "brand":
        for item in payload.get("items") or []:
            if normalize_text(item.get("brand_name") or "") in variants_norm:
                item["brand_name"] = name
    elif field == "spec":
        for item in payload.get("items") or []:
            specs = item.get("specs") or []
            for i, s in enumerate(specs):
                if normalize_text(s) in variants_norm:
                    specs[i] = name


def apply_exact(payload: dict, res: dict) -> None:
    """Bind one exact Jev match into a draft payload."""
    apply_choice(payload, res.get("field"), {"id": res.get("id"), "name": res.get("name"),
                                             "extra": res.get("extra") or {}},
                 res.get("variants") or [])


def normalize_brand_spec(payload: dict, jev_map: dict | None) -> None:
    """Canonicalize brand/spec strings via exact matches (spec effect per owner:
    spelling normalization only)."""
    if not jev_map:
        return
    for item in payload.get("items") or []:
        brand = item.get("brand_name")
        if brand:
            hit = lookup(jev_map, brand)
            if hit and hit.get("status") == "exact":
                item["brand_name"] = hit["name"]
        specs = item.get("specs") or []
        for i, s in enumerate(specs):
            hit = lookup(jev_map, s)
            if hit and hit.get("status") == "exact":
                specs[i] = hit["name"]


# ---------------------------------------------------------------------------
# phase 4 — ambiguity sub-messages with candidate buttons
# ---------------------------------------------------------------------------

def _amb_id(field: str, variants: list[str]) -> str:
    digest = hashlib.sha1("|".join(sorted(variants)).encode()).hexdigest()[:4]
    return f"em_{field[:4]}_{digest}"


def _fa_num(n: int) -> str:
    return str(n).translate(str.maketrans("0123456789", "۰۱۲۳۴۵۶۷۸۹"))


def create_ambiguities(payload: dict, jev_map: dict | None) -> None:
    """One `entity_match` ambiguity entry per ambiguous mention (deduped)."""
    if not jev_map:
        return
    ambs = payload.setdefault("ambiguities", [])
    seen = {a.get("id") for a in ambs}
    unique: dict[int, dict] = {}
    for res in jev_map.values():
        unique[id(res)] = res  # dedupe identical result objects
    for res in unique.values():
        if res.get("status") != "ambiguity" or not res.get("candidates"):
            continue
        amb_id = _amb_id(res["field"], res.get("variants") or [])
        if amb_id in seen:
            continue
        cands = res["candidates"][:6]
        lines = [f"• {c['name']} — {_fa_num(int(round(c['prob'] * 100)))}٪" for c in cands]
        ambs.append({
            "id": amb_id,
            "kind": "entity_match",
            "field": res["field"],
            "variants": res.get("variants") or [],
            "candidates": [{"id": c["id"], "name": c["name"]} for c in cands],
            "title": f"تطبیق {FIELD_FA.get(res['field'], res['field'])}: «{' / '.join(res.get('variants') or [])}»",
            "details": "\n".join(lines),
            "status": "pending",
        })
        seen.add(amb_id)