from __future__ import annotations

import re
from typing import Any, Dict, List, Optional, Protocol

from .models import SearchQuery, SearchResult


class QueryEmbedder(Protocol):
    def embed_query(self, text: str) -> List[float]:
        ...


class SearchStore(Protocol):
    def search(self, vector: List[float], query: SearchQuery, limit: int) -> List[SearchResult]:
        ...

    def get_document(self, document_id: str) -> Optional[Dict[str, Any]]:
        ...


class HybridSearchService:
    def __init__(self, embedder: QueryEmbedder, store: SearchStore) -> None:
        self.embedder = embedder
        self.store = store

    def search(self, query: SearchQuery) -> List[SearchResult]:
        vector = self.embedder.embed_query(query.text)
        candidates = self.store.search(vector, query, limit=query.limit)
        rescored = [
            SearchResult(
                id=result.id,
                score=result.score + keyword_boost(query.text, result),
                text=result.text,
                payload=result.payload,
            )
            for result in candidates
        ]
        return sorted(rescored, key=lambda result: result.score, reverse=True)[: query.limit]

    def get_document(self, document_id: str) -> Optional[Dict[str, Any]]:
        return self.store.get_document(document_id)


def keyword_boost(query_text: str, result: SearchResult) -> float:
    haystack = " ".join([result.text, " ".join(str(value) for value in result.payload.values() if value is not None)]).lower()
    boost = 0.0
    for phrase in re.findall(r'"([^"]+)"', query_text):
        if phrase.lower() in haystack:
            boost += 0.35
    for email in re.findall(r"[\w.+-]+@[\w.-]+\.[A-Za-z]{2,}", query_text):
        if email.lower() in haystack:
            boost += 0.3
    for token in re.findall(r"\b(?:#?\d{2,}|[A-Z]{2,}[-_]\d{2,}|[A-Z0-9]{4,}-[A-Z0-9-]{2,})\b", query_text):
        normalized = token.lower().lstrip("#")
        if token.lower() in haystack or normalized in haystack:
            boost += 0.25
    for word in re.findall(r"\b[A-Za-z][\w.-]{2,}\b", query_text):
        if word.lower() in haystack:
            boost += 0.03
    return boost