"""Client fuer den Memory-Service (CT 117).

Stellt Session-Management und Memory-Zugriff bereit.
Kein Import von Bot- oder LLM-Logik — reiner HTTP-Client.
"""

import logging
import time
import uuid
from typing import Optional

import requests

from core import config

log = logging.getLogger("memory_client")

_cfg = None
_base_url = None
_token = None

SESSION_TIMEOUT = 1800  # 30 Minuten Inaktivitaet = neue Session
_active_sessions: dict[str, dict] = {}  # channel_key -> {id, last_activity}


def _ensure_config():
    global _cfg, _base_url, _token
    if _base_url:
        return
    _cfg = config.parse_config()
    _base_url = _cfg.raw.get("MEMORY_API_URL", "").rstrip("/")
    _token = _cfg.raw.get("MEMORY_API_TOKEN", "")
    if not _base_url or not _token:
        log.warning("MEMORY_API_URL oder MEMORY_API_TOKEN nicht in homelab.conf")


def _headers():
    return {"Authorization": f"Bearer {_token}", "Content-Type": "application/json"}


def _post(path: str, data: dict) -> Optional[dict]:
    _ensure_config()
    if not _base_url:
        return None
    try:
        r = requests.post(f"{_base_url}{path}", json=data, headers=_headers(), timeout=5)
        if r.ok:
            return r.json()
        log.warning("Memory API %s: %s %s", path, r.status_code, r.text[:200])
    except Exception as e:
        log.warning("Memory API %s: %s", path, e)
    return None


def _get(path: str, params: dict = None) -> Optional[dict]:
    _ensure_config()
    if not _base_url:
        return None
    try:
        r = requests.get(f"{_base_url}{path}", params=params, headers=_headers(), timeout=5)
        if r.ok:
            return r.json()
        log.warning("Memory API %s: %s %s", path, r.status_code, r.text[:200])
    except Exception as e:
        log.warning("Memory API %s: %s", path, e)
    return None


def get_or_create_session(channel_key: str, source: str = "telegram") -> Optional[str]:
    """Gibt eine aktive Session-ID zurueck oder erstellt eine neue."""
    now = time.time()
    cached = _active_sessions.get(channel_key)
    if cached and (now - cached["last_activity"]) < SESSION_TIMEOUT:
        cached["last_activity"] = now
        return cached["id"]

    result = _post("/sessions", {"source": source, "channel_key": channel_key})
    if result and "id" in result:
        _active_sessions[channel_key] = {"id": result["id"], "last_activity": now}
        return result["id"]
    return None


def log_message(session_id: str, role: str, content: str, source: str = None, meta: str = None):
    """Speichert eine Nachricht in der Session."""
    if not session_id or not content:
        return
    data = {"role": role, "content": content}
    if source:
        data["source"] = source
    if meta:
        data["meta_json"] = meta
    _post(f"/sessions/{session_id}/messages", data)


def get_active_memory() -> list[dict]:
    """Holt alle aktiven Memory-Items fuer den System-Prompt."""
    result = _get("/memory", {"status": "active", "limit": 100})
    if result and "items" in result:
        return result["items"]
    return []


def format_memory_for_prompt(items: list[dict]) -> str:
    """Formatiert Memory-Items als Text-Block fuer den System-Prompt."""
    if not items:
        return ""
    lines = ["", "=== GEDAECHTNIS (persistente Fakten) ==="]
    for item in items:
        prefix = f"[{item['scope']}/{item['kind']}]"
        lines.append(f"{prefix} {item['content']}")
    lines.append("=== ENDE GEDAECHTNIS ===")
    return "\n".join(lines)