"""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 re
import time
import uuid
from datetime import datetime, timedelta
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}

TOPIC_ALIASES = {
    "container": ["containers", "lxc", "lxc-container", "lxc container", "ct"],
    "server": ["servers", "proxmox", "pve", "host", "hosts"],
    "backup": ["backups", "pbs", "snapshot", "snapshots"],
    "projekt": ["projekte", "project", "projects"],
    "mail": ["mails", "email", "e-mail"],
}


def _normalize(text: str) -> str:
    """Normalisiert Text fuer robustes Matching."""
    t = text.lower().strip()
    for old, new in [("ä", "ae"), ("ö", "oe"), ("ü", "ue"), ("ß", "ss")]:
        t = t.replace(old, new)
    t = t.replace("-", " ").replace("_", " ")
    return t


def _topic_matches(text: str, topic: str) -> bool:
    """Prueft ob ein Topic im normalisierten Text vorkommt (inkl. Aliase)."""
    norm_text = _normalize(text)
    norm_topic = _normalize(topic)
    if norm_topic in norm_text:
        return True
    aliases = TOPIC_ALIASES.get(norm_topic, [])
    for alias in aliases:
        if _normalize(alias) in norm_text:
            return True
    for base, alias_list in TOPIC_ALIASES.items():
        if norm_topic in [_normalize(a) for a in alias_list] or norm_topic == base:
            if base in norm_text:
                return True
            for a in alias_list:
                if _normalize(a) in norm_text:
                    return True
    return False


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 _patch(path: str, data: dict) -> Optional[dict]:
    _ensure_config()
    if not _base_url:
        return None
    try:
        r = requests.patch(f"{_base_url}{path}", json=data, headers=_headers(), timeout=5)
        if r.ok:
            return r.json()
        log.warning("Memory API PATCH %s: %s %s", path, r.status_code, r.text[:200])
    except Exception as e:
        log.warning("Memory API PATCH %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.
    Ueberlebt Bot-Restarts durch API-Lookup der letzten Session."""
    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"]

    # Nach Restart: letzte Session vom API holen
    latest = _get("/sessions/latest", {"channel_key": channel_key})
    if latest and latest.get("id"):
        last_at = latest.get("last_activity_at", 0)
        if (now - last_at) < SESSION_TIMEOUT:
            _active_sessions[channel_key] = {"id": latest["id"], "last_activity": now}
            _patch(f"/sessions/{latest['id']}", {})
            log.info("Session wiederhergestellt nach Restart: %s", latest["id"][:12])
            return latest["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)


DEFAULT_TEMP_DAYS = 14
_WEEKDAYS_DE = {
    "montag": 0, "dienstag": 1, "mittwoch": 2, "donnerstag": 3,
    "freitag": 4, "samstag": 5, "sonntag": 6,
}


def parse_expires_from_text(text: str) -> Optional[int]:
    """Versucht aus deutschem Text ein absolutes Ablaufdatum (epoch) zu extrahieren.
    Gibt None zurueck wenn keine belastbare Zeit erkannt wird."""
    t = text.lower().strip()
    now = datetime.now()

    if "morgen" in t and "uebermorgen" not in t and "übermorgen" not in t:
        dt = now + timedelta(days=1)
        return int(dt.replace(hour=23, minute=59, second=59).timestamp())
    if "uebermorgen" in t or "übermorgen" in t:
        dt = now + timedelta(days=2)
        return int(dt.replace(hour=23, minute=59, second=59).timestamp())

    for day_name, day_num in _WEEKDAYS_DE.items():
        if day_name in t:
            days_ahead = (day_num - now.weekday()) % 7
            if days_ahead == 0:
                days_ahead = 7
            dt = now + timedelta(days=days_ahead)
            return int(dt.replace(hour=23, minute=59, second=59).timestamp())

    if "naechste woche" in t or "nächste woche" in t or "naechster woche" in t or "nächster woche" in t:
        dt = now + timedelta(days=7)
        return int(dt.replace(hour=23, minute=59, second=59).timestamp())
    if "naechsten monat" in t or "nächsten monat" in t:
        dt = now + timedelta(days=30)
        return int(dt.replace(hour=23, minute=59, second=59).timestamp())
    if "heute" in t:
        return int(now.replace(hour=23, minute=59, second=59).timestamp())

    m = re.search(r"(\d{1,2})\.(\d{1,2})\.(\d{4})", t)
    if m:
        try:
            dt = datetime(int(m.group(3)), int(m.group(2)), int(m.group(1)), 23, 59, 59)
            return int(dt.timestamp())
        except ValueError:
            pass

    m = re.search(r"(\d{4})-(\d{2})-(\d{2})", t)
    if m:
        try:
            dt = datetime(int(m.group(1)), int(m.group(2)), int(m.group(3)), 23, 59, 59)
            return int(dt.timestamp())
        except ValueError:
            pass

    return None


def default_expires() -> int:
    """Konservatives Default-Ablaufdatum fuer temporaere Items ohne erkannte Zeitangabe."""
    return int((datetime.now() + timedelta(days=DEFAULT_TEMP_DAYS)).timestamp())


def get_candidates() -> list[dict]:
    """Holt alle offenen Memory-Kandidaten."""
    result = _get("/memory", {"status": "candidate", "limit": 20})
    if result and "items" in result:
        return result["items"]
    return []


def activate_candidate(item_id: int, memory_type: str = "permanent", expires_at: int = None) -> bool:
    """Setzt einen Kandidaten auf aktiv mit Typ."""
    data = {"status": "active", "memory_type": memory_type}
    if expires_at:
        data["expires_at"] = expires_at
    result = _patch(f"/memory/{item_id}", data)
    return bool(result and result.get("ok"))


def delete_candidate(item_id: int) -> bool:
    """Loescht einen Kandidaten."""
    _ensure_config()
    if not _base_url:
        return False
    try:
        r = requests.delete(f"{_base_url}/memory/{item_id}", headers=_headers(), timeout=5)
        return r.ok
    except Exception:
        return False


def get_active_memory() -> list[dict]:
    """Holt alle aktiven Memory-Items (ohne abgelaufene). Fuer /memory-Befehl."""
    result = _get("/memory", {"status": "active", "limit": 100})
    if not result or "items" not in result:
        return []
    now_ts = int(time.time())
    items = []
    for item in result["items"]:
        exp = item.get("expires_at")
        if exp and exp < now_ts:
            _patch(f"/memory/{item['id']}", {"status": "archived"})
            continue
        items.append(item)
    return items


def get_relevant_memory(query: str, top_k: int = 10) -> list[dict]:
    """RAG-Suche: Holt die relevantesten Memory-Items per Vektor-Aehnlichkeit."""
    result = _get("/memory/search", {"q": query, "top_k": top_k, "status": "active"})
    if not result or "items" not in result:
        return get_active_memory()[:top_k]
    return result["items"]


def format_memory_for_prompt(items: list[dict]) -> str:
    """Formatiert Memory-Items als Text-Block fuer den System-Prompt."""
    if not items:
        return ""
    TYPE_ICON = {"fact": "📌", "preference": "⭐", "relationship": "👤", "plan": "📅", "temporary": "🕒", "uncertain": "❓"}
    lines = ["", "=== GEDAECHTNIS (relevante Fakten) ==="]
    for item in items:
        mtype = item.get("memory_type", "fact")
        icon = TYPE_ICON.get(mtype, "•")
        conf = item.get("confidence", "high")
        exp = item.get("expires_at")
        parts = [f"{icon} [{mtype}]"]
        if conf != "high":
            parts.append(f"({conf})")
        parts.append(item["content"])
        if exp:
            parts.append(f"(bis {datetime.fromtimestamp(exp).strftime('%d.%m.%Y')})")
        lines.append(" ".join(parts))
    lines.append("=== ENDE GEDAECHTNIS ===")
    return "\n".join(lines)


def get_session_messages(session_id: str, limit: int = 10) -> list[dict]:
    """Holt die letzten N Messages einer Session fuer den LLM-Kontext."""
    if not session_id:
        return []
    result = _get(f"/sessions/{session_id}/messages", {"limit": limit})
    if result and "messages" in result:
        return result["messages"]
    return []


def get_session_summary(session_id: str, limit: int = 20, topic: str = None) -> str:
    """Kompakte Zusammenfassung der aktuellen Session, optional nach Thema gefiltert."""
    if not session_id:
        return "Keine aktive Session."
    messages = get_session_messages(session_id, limit=limit)
    if not messages:
        return "Noch keine Nachrichten in dieser Session."

    exchanges = []
    current_q = None
    for msg in messages:
        role = msg.get("role", "")
        content = (msg.get("content") or "").strip()
        if not content:
            continue
        if role == "user":
            current_q = content[:200]
        elif role == "assistant" and current_q:
            exchanges.append((current_q, content[:200]))
            current_q = None
    if current_q:
        exchanges.append((current_q, None))

    if not exchanges:
        return "Keine Themen in dieser Session."

    if topic:
        matching_pairs = []
        matching_singles = []
        other_topics = []
        for q, a in exchanges:
            combined = q + " " + (a or "")
            if _topic_matches(combined, topic):
                matching_pairs.append((q, a))
            else:
                other_topics.append(q[:80])

        # Fallback: einzelne Messages pruefen (falls Pairing unvollstaendig)
        if not matching_pairs:
            for msg in messages:
                content = (msg.get("content") or "").strip()
                if content and _topic_matches(content, topic):
                    role = msg.get("role", "?")
                    matching_singles.append((role, content[:200]))

        lines = []
        if matching_pairs:
            lines.append("Zum Thema '" + topic + "' (" + str(len(matching_pairs)) + " Treffer):")
            for i, (q, a) in enumerate(matching_pairs, 1):
                line = str(i) + ". Frage: " + q
                if a:
                    line += "\n   Antwort: " + a
                lines.append(line)
        elif matching_singles:
            lines.append("Zum Thema '" + topic + "' (" + str(len(matching_singles)) + " relevante Messages):")
            for role, content in matching_singles:
                lines.append("  [" + role + "] " + content)
        else:
            lines.append("Zum Thema '" + topic + "' wurde in dieser Session nichts besprochen.")

        if other_topics:
            lines.append("\nSonstige Themen der Session: " + ", ".join(other_topics))
        return "\n".join(lines)

    lines = ["Session (" + str(len(exchanges)) + " Themen):"]
    for i, (q, a) in enumerate(exchanges, 1):
        line = str(i) + ". Frage: " + q
        if a:
            line += "\n   Antwort: " + a
        lines.append(line)
    return "\n".join(lines)