from __future__ import annotations

import re
from dataclasses import dataclass
from pathlib import Path
from typing import Dict, Iterable, List, Optional, Sequence, Tuple

from build_enriched_lexicon import ENRICHED_LEXICON_OUTPUT_PATH, TOPIC_DOMAIN_RULES, load_json
from crossword_generator import HORIZONTAL, Placement


@dataclass(frozen=True)
class Clue:
    number: int
    word: str
    direction: str
    x: int
    y: int
    text: str
    source: str


@dataclass(frozen=True)
class ClueCandidate:
    text: str
    source: str
    family: str
    difficulty_hint: str
    topic_score: int
    strong_topic: bool


DIFFICULTY_ALIASES = {
    "1": "easy",
    "2": "medium",
    "3": "hard",
    "4": "expert",
    "5": "expert",
    "easy": "easy",
    "medium": "medium",
    "hard": "hard",
    "expert": "expert",
}

GENERIC_CLUE_PATTERNS = (
    "termine da ricavare dagli incroci",
    "termine lessicale collegato",
    "collegato a:",
)


def load_enriched_entries(path: Path = ENRICHED_LEXICON_OUTPUT_PATH) -> Dict[str, Dict[str, object]]:
    payload = load_json(path, {"entries": []})
    if not isinstance(payload, dict):
        return {}
    return {
        str(entry.get("form", "")).lower(): entry
        for entry in payload.get("entries", []) or []
        if isinstance(entry, dict) and entry.get("form")
    }


def normalize_difficulty(value: Optional[str]) -> str:
    return DIFFICULTY_ALIASES.get(str(value or "medium").strip().lower(), "medium")


def clean_definition(text: str, answer: str) -> str:
    clue = str(text or "")
    clue = re.sub(r"\[[^\]]*\]", " ", clue)
    clue = re.sub(r"\s+", " ", clue).strip(" .;:-")
    if not clue:
        return ""
    clue = re.sub(re.escape(answer), "questa parola", clue, flags=re.IGNORECASE)
    clue = re.sub(r"\(\s*\)", "", clue)
    clue = re.sub(r"\s+,", ",", clue)
    clue = re.sub(r"\s+;", ";", clue)
    if clue and clue[0].islower():
        clue = clue[0].upper() + clue[1:]
    return clue + "."


def synset_has_strong_topic_domain(synset: Dict[str, object], topic: Optional[str]) -> bool:
    if not topic or topic == "general":
        return True
    rules = TOPIC_DOMAIN_RULES.get(topic, {})
    strong_domains = {str(domain).upper() for domain in rules.get("strong", ())}
    if not strong_domains:
        return True
    domains = {str(domain).upper() for domain in synset.get("domains", []) or []}
    return bool(domains.intersection(strong_domains))


def text_contains_answer(text: str, answer: str) -> bool:
    return bool(re.search(re.escape(answer), text, flags=re.IGNORECASE))


def directness_score(text: str) -> int:
    lowered = text.lower()
    score = 0
    direct_keywords = (
        "strumento",
        "veicolo",
        "animale",
        "pianta",
        "titolo",
        "edificio",
        "persona",
        "luogo",
        "malattia",
        "farmaco",
        "mezzo",
        "parte di",
    )
    for keyword in direct_keywords:
        if keyword in lowered:
            score += 8
    if any(marker in lowered for marker in ("cioè", "ossia", "ovvero")):
        score += 4
    return score


def preferred_length_range(difficulty: str) -> Tuple[int, int]:
    if difficulty == "easy":
        return 24, 90
    if difficulty == "medium":
        return 20, 75
    if difficulty == "hard":
        return 16, 60
    return 14, 50


def score_candidate(candidate: ClueCandidate, answer: str, difficulty: str) -> int:
    text = candidate.text
    lowered = text.lower()
    score = 0

    if not text or len(text) < 12:
        return -10_000

    if any(pattern in lowered for pattern in GENERIC_CLUE_PATTERNS):
        score -= 120

    if text_contains_answer(text, answer):
        score -= 140
    else:
        score += 40

    min_len, max_len = preferred_length_range(difficulty)
    length = len(text)
    if min_len <= length <= max_len:
        score += 28
    else:
        score -= abs(length - max_len) if length > max_len else abs(min_len - length) // 2

    directness = directness_score(text)
    if difficulty == "easy":
        score += directness * 2
    elif difficulty == "medium":
        score += directness
    elif difficulty == "hard":
        score -= max(0, directness - 6)
    else:
        score -= directness

    family_bonus = {
        "semantic_definition": 56,
        "semantic_gloss": 34,
        "refined_sense": 30,
        "babelnet_best_gloss": 18,
        "babelnet_gloss": 10,
        "fallback": 0,
    }
    score += family_bonus.get(candidate.family, 0)

    difficulty_pref = {
        "easy": {"direct", "balanced"},
        "medium": {"balanced", "direct"},
        "hard": {"balanced", "oblique"},
        "expert": {"oblique", "balanced"},
    }
    if candidate.difficulty_hint in difficulty_pref.get(difficulty, {"balanced"}):
        score += 18

    if difficulty == "easy" and ";" in text:
        score += 8
    if difficulty in {"hard", "expert"} and ";" in text:
        score -= 8

    if candidate.topic_score >= 40:
        score += 18
    elif candidate.topic_score > 0:
        score += 8
    elif candidate.family in {"babelnet_best_gloss", "babelnet_gloss"}:
        score -= 140

    if candidate.strong_topic:
        score += 10

    if difficulty in {"easy", "medium"} and re.search(r"\((?:mil|fig|lett|fam)\.\)", lowered):
        score -= 28

    if length > 120:
        score -= 45
    if length > 180:
        score -= 90

    return score


def candidate_hint(text: str, family: str) -> str:
    lowered = text.lower()
    if family in {"semantic_definition", "semantic_gloss"} and len(text) <= 70:
        return "direct"
    if any(marker in lowered for marker in ("fig.", "figurato", "poetico", "letterario")):
        return "oblique"
    if len(text) > 85:
        return "direct"
    return "balanced"


def add_candidate(
    candidates: List[ClueCandidate],
    seen: set[Tuple[str, str]],
    *,
    text: str,
    answer: str,
    source: str,
    family: str,
    topic_score: int = 0,
    strong_topic: bool = False,
) -> None:
    cleaned = clean_definition(text, answer)
    if not cleaned:
        return
    key = (cleaned.lower(), family)
    if key in seen:
        return
    seen.add(key)
    candidates.append(
        ClueCandidate(
            text=cleaned,
            source=source,
            family=family,
            difficulty_hint=candidate_hint(cleaned, family),
            topic_score=topic_score,
            strong_topic=strong_topic,
        )
    )


def semantic_candidates(entry: Dict[str, object], answer: str) -> List[ClueCandidate]:
    semantic = entry.get("semantic", {})
    if not isinstance(semantic, dict):
        return []

    candidates: List[ClueCandidate] = []
    seen: set[Tuple[str, str]] = set()

    for synset in semantic.get("synsets", []) or []:
        if not isinstance(synset, dict):
            continue
        add_candidate(
            candidates,
            seen,
            text=str(synset.get("definition", "")),
            answer=answer,
            source="semantic",
            family="semantic_definition",
        )

    for gloss in semantic.get("glosses", []) or []:
        add_candidate(
            candidates,
            seen,
            text=str(gloss),
            answer=answer,
            source="semantic",
            family="semantic_gloss",
        )

    return candidates


def babelnet_candidates(entry: Dict[str, object], answer: str, topic: Optional[str]) -> List[ClueCandidate]:
    babelnet = entry.get("babelnet", {})
    if not isinstance(babelnet, dict) or babelnet.get("status") not in {"enriched", "ambiguous"}:
        return []

    candidates: List[ClueCandidate] = []
    seen: set[Tuple[str, str]] = set()

    best_synset = babelnet.get("best_synset", {})
    if isinstance(best_synset, dict):
        topic_score = int(best_synset.get("topic_score", 0) or 0)
        strong_topic = bool(best_synset.get("strong_topic")) or synset_has_strong_topic_domain(best_synset, topic)
        for gloss in best_synset.get("glosses", []) or []:
            add_candidate(
                candidates,
                seen,
                text=str(gloss),
                answer=answer,
                source="babelnet",
                family="babelnet_best_gloss",
                topic_score=topic_score,
                strong_topic=strong_topic,
            )

    for synset in babelnet.get("synsets", []) or []:
        if not isinstance(synset, dict):
            continue
        if topic and topic != "general" and not synset_has_strong_topic_domain(synset, topic):
            continue
        topic_score = 40 if topic and topic != "general" and synset_has_strong_topic_domain(synset, topic) else 0
        for gloss in synset.get("glosses", []) or []:
            add_candidate(
                candidates,
                seen,
                text=str(gloss),
                answer=answer,
                source="babelnet",
                family="babelnet_gloss",
                topic_score=topic_score,
                strong_topic=topic_score >= 40,
            )

    return candidates


def refined_sense_candidates(entry: Dict[str, object], answer: str) -> List[ClueCandidate]:
    senses = entry.get("senses", [])
    if not isinstance(senses, list):
        return []

    candidates: List[ClueCandidate] = []
    seen: set[Tuple[str, str]] = set()
    for sense in senses:
        if not isinstance(sense, dict):
            continue
        confidence = float(sense.get("confidence", 0.0) or 0.0)
        add_candidate(
            candidates,
            seen,
            text=str(sense.get("definition", "")),
            answer=answer,
            source=str(sense.get("source", "refined")),
            family="refined_sense",
            topic_score=int(confidence * 100),
            strong_topic=confidence >= 0.75,
        )
    return candidates


def fallback_definition(entry: Dict[str, object], answer: str) -> str:
    pos = str(entry.get("pos", "")).lower()
    topics = ", ".join(str(topic) for topic in entry.get("topics", []) if topic and str(topic).lower() != "general")
    if topics:
        return f"Termine {pos or 'lessicale'} collegato all'ambito: {topics}."
    return "Termine da ricavare dagli incroci."


def all_candidates(entry: Dict[str, object], answer: str, topic: Optional[str]) -> List[ClueCandidate]:
    candidates: List[ClueCandidate] = []
    candidates.extend(semantic_candidates(entry, answer))
    candidates.extend(refined_sense_candidates(entry, answer))
    candidates.extend(babelnet_candidates(entry, answer, topic))
    return candidates


def choose_candidate(candidates: Sequence[ClueCandidate], answer: str, difficulty: str) -> Optional[ClueCandidate]:
    ranked = sorted(
        candidates,
        key=lambda candidate: (
            score_candidate(candidate, answer, difficulty),
            candidate.topic_score,
            len(candidate.text),
        ),
        reverse=True,
    )
    return ranked[0] if ranked else None


def definition_for_word(
    word: str,
    entries: Dict[str, Dict[str, object]],
    topic: Optional[str] = None,
    difficulty: Optional[str] = None,
) -> tuple[str, str]:
    answer = word.lower()
    entry = entries.get(answer, {})
    if not entry:
        return "Termine da ricavare dagli incroci.", "fallback"

    normalized_difficulty = normalize_difficulty(difficulty)
    candidates = all_candidates(entry, answer, topic)
    best = choose_candidate(candidates, answer, normalized_difficulty)
    if best:
        return best.text, best.source

    return fallback_definition(entry, answer), "fallback"


def generate_clues(
    placements: Iterable[Placement],
    entries: Dict[str, Dict[str, object]],
    topic: Optional[str] = None,
    difficulty: Optional[str] = None,
) -> List[Clue]:
    clues = []
    for number, placement in enumerate(placements, start=1):
        text, source = definition_for_word(placement.word, entries, topic, difficulty)
        direction = "orizzontale" if placement.direction == HORIZONTAL else "verticale"
        clues.append(
            Clue(
                number=number,
                word=placement.word,
                direction=direction,
                x=placement.x,
                y=placement.y,
                text=text,
                source=source,
            )
        )
    return clues