"""Client for the external EverMemOS consolidation service."""
from __future__ import annotations

from typing import Any

import httpx

from .config import get_config
from .schemas import AccessContext, EpisodeRecord, MemoryRecord


class EverMemOSError(RuntimeError):
    """Raised when the external EverMemOS service cannot consolidate."""


class EverMemOSClient:
    """Small HTTP client with a tolerant response normalizer.

    The deployed EverMemOS API may evolve independently from Memory Gateway.
    Gateway sends a stable payload and accepts several common response shapes:
    `result`, `data`, or the raw top-level object with `candidates/promoted`.
    """

    def __init__(
        self,
        base_url: str | None = None,
        api_key: str | None = None,
        timeout: int | None = None,
        health_path: str | None = None,
        consolidate_path: str | None = None,
    ) -> None:
        config = get_config().evermemos
        self.base_url = (base_url or config.url).rstrip("/")
        self.api_key = api_key if api_key is not None else config.api_key
        self.timeout = timeout or config.timeout
        self.health_path = health_path or config.health_path
        self.consolidate_path = consolidate_path or config.consolidate_path

    def _headers(self) -> dict[str, str]:
        headers = {"Content-Type": "application/json"}
        if self.api_key:
            headers["X-API-Key"] = self.api_key
            headers["Authorization"] = f"Bearer {self.api_key}"
        return headers

    def health(self) -> dict[str, Any]:
        url = self.base_url + self.health_path
        try:
            with httpx.Client(timeout=self.timeout, headers=self._headers()) as client:
                response = client.get(url)
                response.raise_for_status()
                return {"status": "ok", "url": self.base_url, "response": response.json()}
        except Exception as exc:  # noqa: BLE001
            return {"status": "error", "url": self.base_url, "error": str(exc)}

    def consolidate_session(
        self,
        session_id: str,
        ctx: AccessContext,
        episodes: list[EpisodeRecord],
        existing_memories: list[MemoryRecord],
        min_importance: float,
        target_namespace: str | None,
    ) -> dict[str, Any]:
        payload = {
            "schema_version": "memory-gateway.evermemos.consolidate.v1",
            "session_id": session_id,
            "context": ctx.model_dump(mode="json"),
            "min_importance": min_importance,
            "target_namespace": target_namespace,
            "episodes": [episode.model_dump(mode="json") for episode in episodes],
            "existing_memories": [memory.model_dump(mode="json") for memory in existing_memories],
        }
        paths = [
            self.consolidate_path,
            "/v1/sessions/consolidate",
            "/v1/memory/consolidate",
            "/api/v1/sessions/consolidate",
            "/api/consolidate",
            "/consolidate",
        ]
        errors: list[str] = []
        for path in dict.fromkeys(paths):
            try:
                with httpx.Client(timeout=self.timeout, headers=self._headers()) as client:
                    response = client.post(self.base_url + path, json=payload)
                    if response.status_code == 404:
                        errors.append(f"{path}: 404")
                        continue
                    response.raise_for_status()
                    return self._normalize_response(response.json(), path)
            except Exception as exc:  # noqa: BLE001
                errors.append(f"{path}: {exc}")
                if "Connection refused" in str(exc) or "timed out" in str(exc):
                    break
        raise EverMemOSError("; ".join(errors) or "EverMemOS consolidation failed")

    def _normalize_response(self, payload: dict[str, Any], path: str) -> dict[str, Any]:
        data = payload.get("result") or payload.get("data") or payload
        return {
            "backend": "external",
            "service_url": self.base_url,
            "endpoint": path,
            "raw": payload,
            "session_id": data.get("session_id"),
            "episodes": data.get("episodes"),
            "candidates": data.get("candidates") or data.get("candidate_memories") or [],
            "promoted": data.get("promoted") or data.get("promoted_memories") or data.get("memories") or [],
            "duplicates": data.get("duplicates") or [],
            "conflicts": data.get("conflicts") or [],
            "review_drafts": data.get("review_drafts") or [],
        }