from __future__ import annotations

import hashlib
import os
import logging
from dataclasses import dataclass
from typing import Any
import time
import uuid
import datetime
import math

from .atlas_model import Entity, Identifier
from .atlas_store import load_entity_by_subject, save_entity_minimal
from .wikidata import WikidataSearch


ATLAS = "http://world.eu.org/atlas_ontology#"
DEFAULT_ENDPOINT = os.getenv("ATLAS_VIRTUOSO_MCP_SSE_URL", "http://192.168.0.249:8501/mcp/sse")
DEFAULT_UPDATE_ENDPOINT = os.getenv("ATLAS_VIRTUOSO_MCP_SSE_URL", DEFAULT_ENDPOINT)
DEBUG_LOGS = os.getenv("ATLAS_DEBUG_LOGS", "false").lower() in {"1", "true", "yes", "on"}

logger = logging.getLogger(__name__)


def _hash_id(subject: str) -> str:
    return hashlib.sha1(subject.strip().lower().encode("utf-8")).hexdigest()[:16]


def _entity_iri(atlas_id: str) -> str:
    return f"atlas_data:entity_{atlas_id}"


async def _wikidata_lookup(subject: str, language: str = "en", limit: int = 1) -> list[dict[str, Any]]:
    search = WikidataSearch({"search": subject, "limit": limit, "language": language})
    result = await search.quick_resolve(subject, limit=limit)
    return result.get("results", []) or []


def _candidate_text(subject: str, wd: dict[str, Any], hints: dict[str, Any] | None = None) -> str:
    hints = hints or {}
    aliases = hints.get("aliases") or []
    parts = [subject, wd.get("label") or "", wd.get("description") or "", " ".join(str(a) for a in aliases)]
    return " | ".join(part for part in parts if part)


def _cosine_similarity(a: list[float] | None, b: list[float] | None) -> float:
    if not a or not b or len(a) != len(b):
        return 0.0
    dot = sum(x * y for x, y in zip(a, b))
    norm_a = math.sqrt(sum(x * x for x in a))
    norm_b = math.sqrt(sum(y * y for y in b))
    if not norm_a or not norm_b:
        return 0.0
    return dot / (norm_a * norm_b)


def _infer_atlas_type(label: str | None, description: str | None) -> str:
    text = f"{label or ''} {description or ''}".lower()
    if any(k in text for k in ["president", "person", "singer", "composer", "human", "actor", "writer"]):
        return "atlas:Person"
    if any(k in text for k in ["city", "town", "village", "country", "state", "location", "place"]):
        return "atlas:Location"
    if any(k in text for k in ["company", "organization", "organisation", "institution", "foundation", "band"]):
        return "atlas:Organization"
    return "atlas:Other"


def _score_wikidata_candidate(
    subject: str,
    wd: dict[str, Any],
    *,
    context: dict[str, Any] | None = None,
    hints: dict[str, Any] | None = None,
    use_embeddings: bool = False,
    subject_embedding: list[float] | None = None,
    candidate_embedding: list[float] | None = None,
) -> tuple[float, dict[str, float]]:
    context = context or {}
    hints = hints or {}

    score = 0.0
    breakdown: dict[str, float] = {}
    subject_norm = subject.strip().lower()
    label = (wd.get("label") or "").strip()
    description = (wd.get("description") or "").strip()
    label_norm = label.lower()
    description_norm = description.lower()

    if label_norm == subject_norm:
        score += 0.75
        breakdown["exact_label"] = 0.75
    elif subject_norm and subject_norm in label_norm:
        score += 0.45
        breakdown["partial_label"] = 0.45

    for alias in hints.get("aliases") or []:
        alias_norm = str(alias).strip().lower()
        if alias_norm and alias_norm == label_norm:
            score += 0.15
            breakdown["alias_match"] = 0.15
            break

    expected_type = (hints.get("expected_type") or "").strip().lower()
    inferred_type = _infer_atlas_type(label, description).lower()
    if expected_type and expected_type in inferred_type:
        score += 0.1
        breakdown["expected_type"] = 0.1

    realm = (context.get("realm") or "").strip().lower()
    if realm and realm in description_norm:
        score += 0.1
        breakdown["realm"] = 0.1

    if wd.get("id"):
        score += 0.05
        breakdown["has_qid"] = 0.05

    if use_embeddings:
        sim = _cosine_similarity(subject_embedding, candidate_embedding)
        if sim > 0:
            emb_score = max(0.0, min(0.25, sim * 0.25))
            score += emb_score
            breakdown["embedding_similarity"] = emb_score

    score = min(score, 0.99)
    return score, breakdown


def _entity_from_wikidata(subject: str, wd: dict[str, Any]) -> Entity:
    atlas_id = _hash_id(subject)
    label = wd.get("label") or subject
    description = wd.get("description")
    qid = wd.get("id")
    entity_type = _infer_atlas_type(label, description)

    ent = Entity(
        id=atlas_id,
        label=label,
        description=description,
        type=entity_type,
        aliases=[subject] if subject.lower() != label.lower() else [],
        identifiers=[Identifier(scheme="wikidata-qid", value=qid)] if qid else [],
        needs_curation=True,
    )
    return ent


def _flatten_exception_details(exc: BaseException) -> list[str]:
    parts = [f"{type(exc).__name__}: {exc}"]
    nested = getattr(exc, "exceptions", None)
    if nested:
        for sub in nested:
            parts.extend(_flatten_exception_details(sub))
    return parts


async def _persist_entity(entity: Entity) -> None:
    await save_entity_minimal(entity, DEFAULT_UPDATE_ENDPOINT)


async def _load_entity(subject: str) -> dict[str, Any] | None:
    return await load_entity_by_subject(subject, DEFAULT_ENDPOINT)


def _required_confidence(mode: str, constraints: dict[str, Any]) -> float:
    requested = constraints.get("min_confidence")
    if requested is not None:
        return float(requested)
    if mode == "quick":
        return 0.55
    if mode in {"ranked", "hybrid", "llm_select"}:
        return 0.85
    if mode == "interactive":
        return 0.0
    return 0.5


def _is_ambiguous_subject(subject: str, wd_candidates: list[dict[str, Any]]) -> bool:
    if len(wd_candidates) < 2:
        return False
    subject_norm = subject.strip().lower()
    labels = [(cand.get("label") or "").strip().lower() for cand in wd_candidates]
    exact_matches = sum(1 for label in labels if label == subject_norm)
    return exact_matches >= 2 or (exact_matches == 1 and any(label == subject_norm for label in labels[1:]))


def _cache_can_satisfy(stored: dict[str, Any], mode: str, constraints: dict[str, Any]) -> bool:
    stored_confidence = float(stored.get("confidence") or 0.0)
    return stored_confidence >= _required_confidence(mode, constraints)


def _debug_decision(
    *,
    mode: str,
    top_confidence: float,
    auto_accept_threshold: float,
    interactive_below_threshold: bool,
    required_confidence: float,
    used_cache: bool,
    cache_confidence: float | None = None,
) -> dict[str, Any]:
    return {
        "mode": mode,
        "top_confidence": top_confidence,
        "auto_accept_threshold": auto_accept_threshold,
        "interactive_below_threshold": interactive_below_threshold,
        "required_confidence": required_confidence,
        "used_cache": used_cache,
        "cache_confidence": cache_confidence,
        "decision": (
            "cache_hit"
            if used_cache
            else "resolved"
            if top_confidence >= auto_accept_threshold
            else "ambiguous_below_threshold"
        ),
    }


@dataclass
class ResolveService:
    load_entity_fn: Any = _load_entity
    wikidata_lookup_fn: Any = _wikidata_lookup
    persist_entity_fn: Any = _persist_entity

    async def resolve(self, *, subject: str, context: dict[str, Any] | None = None,
                      constraints: dict[str, Any] | None = None,
                      hints: dict[str, Any] | None = None,
                      debug: dict[str, Any] | None = None,
                      strategy: dict[str, Any] | None = None) -> dict[str, Any]:
        context = context or {}
        constraints = constraints or {}
        hints = hints or {}
        debug = debug or {}
        strategy = strategy or {}
        language = (context.get("language") or "en").strip() or "en"
        mode = (strategy.get("mode") or "quick").strip().lower() or "quick"
        use_embeddings = bool(strategy.get("use_embeddings", False))
        max_candidates = int(constraints.get("max_candidates") or 5)
        auto_accept_threshold = float(strategy.get("auto_accept_threshold") or 0.85)
        interactive_below_threshold = bool(strategy.get("interactive_below_threshold", True))
        required_confidence = _required_confidence(mode, constraints)
        try:
            request_id = str(uuid.uuid4())
            ts = datetime.datetime.now(datetime.timezone.utc).isoformat()
            start = time.time()
            subject = (subject or "").strip()
            if not subject:
                return {
                    "status": "not_found",
                    "entity": None,
                    "confidence": 0.0,
                    "candidates": [],
                    "ambiguity": None,
                    "resolution_path": [],
                    "meta": {"request_id": request_id, "timestamp": ts, "duration_ms": 0},
                    "error": None,
                }

            if DEBUG_LOGS:
                logger.info("resolve start subject=%s", subject)

            stored = await self.load_entity_fn(subject)
            if stored:
                if DEBUG_LOGS:
                    logger.info("store hit subject=%s atlas_id=%s", subject, stored.get("atlas_id"))
                stored_confidence = float(stored.get("confidence") or (0.9 if not stored.get("needs_curation", False) else 0.6))
                if _cache_can_satisfy(stored, mode, constraints):
                    return {
                        "status": "resolved",
                        "entity": {
                            "id": stored.get("atlas_id"),
                            "label": stored.get("label"),
                            "type": stored.get("type"),
                            "description": stored.get("description"),
                            "source": None,
                            "uri": None,
                            "attributes": {},
                        },
                        "confidence": stored_confidence,
                        "candidates": [],
                        "ambiguity": None,
                        "resolution_path": [
                            {"phase": "cache", "action": "store_hit", "source": "triple_store"}
                        ],
                        "meta": {
                            "request_id": request_id,
                            "timestamp": ts,
                            "duration_ms": int((time.time() - start) * 1000),
                            **({"debug": _debug_decision(mode=mode, top_confidence=stored_confidence, auto_accept_threshold=auto_accept_threshold, interactive_below_threshold=interactive_below_threshold, required_confidence=required_confidence, used_cache=True, cache_confidence=stored_confidence)} if debug.get("include_explanations") else {}),
                        },
                        "error": None,
                    }

                if DEBUG_LOGS:
                    logger.info("cache confidence too low subject=%s mode=%s confidence=%.3f required=%.3f", subject, mode, stored_confidence, required_confidence)

            wd_candidates = await self.wikidata_lookup_fn(
                subject,
                language,
                1 if mode == "quick" else max(1, min(max_candidates, 10)),
            )
            if not wd_candidates:
                if DEBUG_LOGS:
                    logger.info("wikidata miss subject=%s mode=%s", subject, mode)
                return {
                    "status": "not_found",
                    "entity": {
                        "id": None,
                        "label": None,
                        "type": None,
                        "description": None,
                        "source": None,
                        "uri": None,
                        "attributes": {},
                    },
                    "confidence": 0.0,
                    "candidates": [],
                    "ambiguity": None,
                    "resolution_path": [
                        {"phase": "query", "action": "wikidata_quick_resolve", "source": "remote"}
                    ],
                    "meta": {
                        "request_id": request_id,
                        "timestamp": ts,
                        "duration_ms": int((time.time() - start) * 1000),
                        **({"debug": _debug_decision(mode=mode, top_confidence=0.0, auto_accept_threshold=auto_accept_threshold, interactive_below_threshold=interactive_below_threshold, required_confidence=required_confidence, used_cache=False)} if debug.get("include_explanations") else {}),
                    },
                    "error": None,
                }

            ranked_candidates = []
            subject_embedding = None
            embedder = None
            if use_embeddings:
                embedder = WikidataSearch()
                subject_embedding = await embedder.embed_text(_candidate_text(subject, {"label": subject, "description": "", "aliases": []}, hints))
            for wd in wd_candidates:
                candidate_embedding = None
                if use_embeddings and embedder is not None:
                    candidate_embedding = await embedder.embed_text(_candidate_text(subject, wd, hints))
                confidence, breakdown = _score_wikidata_candidate(
                    subject,
                    wd,
                    context=context,
                    hints=hints,
                    use_embeddings=use_embeddings,
                    subject_embedding=subject_embedding,
                    candidate_embedding=candidate_embedding,
                )
                ranked_candidates.append({**wd, "confidence": confidence, "score_breakdown": breakdown})
            ranked_candidates.sort(key=lambda item: ((item.get("confidence") or 0.0), item.get("label") or ""), reverse=True)

            wd = ranked_candidates[0]
            entity = _entity_from_wikidata(subject, wd)
            if mode == "quick":
                wd["confidence"] = min(wd.get("confidence", 0.0), 0.6)
            if DEBUG_LOGS:
                logger.info(
                    "wikidata hit subject=%s qid=%s atlas_id=%s type=%s",
                    subject,
                    wd.get("id"),
                    entity.id,
                    entity.type,
                )
            await self.persist_entity_fn(entity)

            resolution_path = [
                {"phase": "query", "action": "wikidata_quick_resolve", "source": "remote"},
                {"phase": "ranking", "action": f"mode_{mode}", "source": "resolver"},
            ]
            if use_embeddings:
                resolution_path.append(
                    {
                        "phase": "ranking",
                        "action": "embedding_similarity",
                        "source": "ollama",
                        "note": "embedding similarity used to score candidate order",
                    }
                )

            status = "ambiguous"
            ambiguity = {"reason": "pre-maintenance", "dimension": 0.5}
            if mode == "quick":
                status = "ambiguous"
            elif (wd.get("confidence") or 0.0) >= auto_accept_threshold:
                status = "resolved"
                ambiguity = None
            elif interactive_below_threshold:
                status = "ambiguous"

            return {
                "status": status,
                "entity": {
                    "id": entity.id,
                    "label": entity.label,
                    "type": entity.type,
                    "description": entity.description,
                    "source": "wikidata",
                    "uri": None,
                    "attributes": {
                        "wikidata_id": wd.get("id"),
                        "alias": subject,
                    },
                },
                "confidence": wd.get("confidence", 0.6),
                "candidates": [
                    {
                        "id": cand.get("id"),
                        "label": cand.get("label"),
                        "type": cand.get("type"),
                        "source": "wikidata",
                        "confidence": cand.get("confidence", 0.0),
                        "score_breakdown": cand.get("score_breakdown", {}) if debug.get("include_explanations") else {},
                    }
                    for cand in ranked_candidates
                ] if mode in {"ranked", "interactive", "hybrid", "llm_select"} else [],
                "ambiguity": ambiguity,
                "resolution_path": resolution_path + [{"phase": "persistence", "action": "store_save_minimal", "source": "triple_store"}],
                "meta": {
                    "request_id": request_id,
                    "timestamp": ts,
                    "duration_ms": int((time.time() - start) * 1000),
                    **({"debug": _debug_decision(mode=mode, top_confidence=wd.get("confidence", 0.0), auto_accept_threshold=auto_accept_threshold, interactive_below_threshold=interactive_below_threshold, required_confidence=required_confidence, used_cache=False)} if debug.get("include_explanations") else {}),
                },
                "error": None,
            }
        except Exception as exc:
            detail = " | ".join(_flatten_exception_details(exc))
            return {
                "status": "error",
                "entity": None,
                "confidence": 0.0,
                "candidates": [],
                "ambiguity": None,
                "resolution_path": [],
                "meta": {
                    "request_id": str(uuid.uuid4()),
                    "timestamp": datetime.datetime.now(datetime.timezone.utc).isoformat(),
                    "duration_ms": 0,
                },
                "error": {"code": "RESOLVE_FAILED", "message": detail},
            }