from __future__ import annotations

import logging
from collections.abc import Iterable
from typing import Any

from src.config import ALL_CATEGORIES_LABEL, ConfigurationError, Settings, load_settings


logger = logging.getLogger(__name__)


def build_category_filter(category: str | None) -> str | None:
    if not category or category == ALL_CATEGORIES_LABEL:
        return None
    escaped = category.replace("\\", "\\\\").replace("'", "\\'")
    return f"category = '{escaped}'"


class VectorStore:
    def __init__(self, settings: Settings | None = None) -> None:
        self.settings = settings or load_settings()
        self.settings.require_upstash()
        try:
            from upstash_vector import Index
        except ImportError as exc:
            raise ConfigurationError(
                "The upstash-vector package is not installed. Run `pip install -r requirements.txt`."
            ) from exc

        assert self.settings.upstash_url is not None
        assert self.settings.upstash_token is not None
        self.namespace = self.settings.upstash_namespace
        self.index = Index(url=self.settings.upstash_url, token=self.settings.upstash_token)
        logger.info("Connected to Upstash Vector namespace %s", self.namespace)

    def upsert_image_vector(self, id: str, vector: list[float], metadata: dict[str, Any]) -> None:
        self.upsert_many([{"id": id, "vector": vector, "metadata": metadata}])

    def upsert_many(self, items: Iterable[dict[str, Any]]) -> None:
        vectors = [
            {"id": item["id"], "vector": item["vector"], "metadata": item["metadata"]}
            for item in items
        ]
        if not vectors:
            return
        logger.info("Upserting %d vector(s) to namespace %s", len(vectors), self.namespace)
        self.index.upsert(vectors=vectors, namespace=self.namespace)

    def query_vector(
        self,
        vector: list[float],
        top_k: int,
        category: str | None = None,
    ) -> list[Any]:
        query_filter = build_category_filter(category)
        kwargs: dict[str, Any] = {
            "vector": vector,
            "top_k": int(top_k),
            "include_metadata": True,
            "include_vectors": False,
            "namespace": self.namespace,
        }
        if query_filter:
            kwargs["filter"] = query_filter
        logger.info(
            "Querying Upstash Vector with top_k=%s category=%s",
            top_k,
            category or ALL_CATEGORIES_LABEL,
        )
        return list(self.index.query(**kwargs))

    def clear_namespace(self) -> None:
        logger.warning("Clearing Upstash Vector namespace %s", self.namespace)
        self.index.reset(namespace=self.namespace)