"""
Semantic MediaWiki API Client

Greift direkt auf die MediaWiki API zu (kein XML-Export).
Unterstützt Login, Kategorien-Abfragen und SMW Browse-API.
"""
import os
import logging
import httpx
from typing import Optional

logger = logging.getLogger(__name__)

MEDIAWIKI_API_URL = os.getenv("MEDIAWIKI_API_URL", "")
MEDIAWIKI_USER    = os.getenv("MEDIAWIKI_USER", "")
MEDIAWIKI_PASSWORD = os.getenv("MEDIAWIKI_PASSWORD", "")


class SmwClientError(Exception):
    pass


class SmwClient:
    """Stateless MediaWiki/SMW API Client mit Session-Login."""

    def __init__(self, api_url: str = None, user: str = None, password: str = None):
        self.api_url  = (api_url or MEDIAWIKI_API_URL).rstrip("/")
        self.user     = user or MEDIAWIKI_USER
        self.password = password or MEDIAWIKI_PASSWORD
        self._cookies: dict = {}
        self._logged_in = False

        if not self.api_url:
            raise SmwClientError("MEDIAWIKI_API_URL nicht konfiguriert")

    # ------------------------------------------------------------------ #
    # Authentication                                                        #
    # ------------------------------------------------------------------ #

    async def login(self) -> None:
        """MediaWiki Login (zwei Schritte: Token holen → Login ausführen)."""
        async with httpx.AsyncClient(timeout=15) as client:
            # Schritt 1: Login-Token holen
            r1 = await client.get(self.api_url, params={
                "action": "query",
                "meta":   "tokens",
                "type":   "login",
                "format": "json",
            })
            r1.raise_for_status()
            j = self._parse_mw_response(r1.json())
            tok = (((j.get("query") or {}).get("tokens") or {}).get("logintoken"))
            if not tok:
                raise SmwClientError("MediaWiki Login-Token fehlt in API-Antwort")

            cookies = dict(r1.cookies)

            # Schritt 2: Einloggen
            r2 = await client.post(self.api_url, params={"format": "json"}, data={
                "action":     "login",
                "lgname":     self.user,
                "lgpassword": self.password,
                "lgtoken":    tok,
            }, cookies=cookies)
            r2.raise_for_status()
            result = self._parse_mw_response(r2.json())

            if result.get("login", {}).get("result") != "Success":
                reason = result.get("login", {}).get("reason", "unbekannt")
                raise SmwClientError(f"MediaWiki Login fehlgeschlagen: {reason}")

            self._cookies = dict(r2.cookies)
            self._logged_in = True
            logger.info("SMW Login erfolgreich als '%s'", self.user)

    def _parse_mw_response(self, data: dict) -> dict:
        """MediaWiki liefert oft HTTP 200 mit {\"error\": {...}} — sonst KeyErrors in Client-Code."""
        if not isinstance(data, dict):
            raise SmwClientError("Ungültige API-Antwort (kein JSON-Objekt)")
        err = data.get("error")
        if isinstance(err, dict):
            code = err.get("code", "")
            info = err.get("info") or err.get("*") or err.get("message") or ""
            raise SmwClientError(f"MediaWiki API: {code}: {info}".strip())
        return data

    async def _get(self, params: dict) -> dict:
        """Authentifizierter GET-Request gegen die API."""
        if not self._logged_in:
            await self.login()
        params["format"] = "json"
        try:
            async with httpx.AsyncClient(timeout=30, cookies=self._cookies) as client:
                r = await client.get(self.api_url, params=params)
                r.raise_for_status()
                return self._parse_mw_response(r.json())
        except SmwClientError:
            raise
        except Exception as e:
            raise SmwClientError(str(e))

    # ------------------------------------------------------------------ #
    # Kategorien                                                            #
    # ------------------------------------------------------------------ #

    async def get_category_members(self, category: str, limit: int = 500, recursive: bool = True) -> list[dict]:
        """
        Gibt alle Seiten einer Kategorie zurück (optional rekursiv durch Unterkategorien).
        Gibt Liste von {"pageid": int, "title": str} zurück.
        """
        members = []
        cmcontinue = None

        while True:
            params = {
                "action":  "query",
                "list":    "categorymembers",
                "cmtitle": f"Kategorie:{category}",
                "cmlimit": min(limit, 500),
                "cmtype":  "page",  # Nur Seiten, keine Unterkategorien
                "cmprop":  "ids|title",
            }
            if cmcontinue:
                params["cmcontinue"] = cmcontinue

            data = await self._get(params)
            q = data.get("query") or {}
            members.extend(q.get("categorymembers") or [])

            if "continue" in data and len(members) < limit:
                cmcontinue = data["continue"].get("cmcontinue")
            else:
                break

        # Rekursiv durch Unterkategorien gehen
        if recursive:
            subcats = await self._get_subcategories(category)
            logger.info(f"Kategorie '{category}': {len(members)} direkte Seiten, {len(subcats)} Unterkategorien")

            for subcat in subcats:
                if len(members) >= limit:
                    break
                subcat_name = subcat["title"].replace("Kategorie:", "")
                subcat_members = await self.get_category_members(subcat_name, limit=limit - len(members), recursive=True)
                members.extend(subcat_members)

        return members[:limit]

    async def _get_subcategories(self, category: str) -> list[dict]:
        """Gibt alle Unterkategorien einer Kategorie zurück."""
        subcats = []
        cmcontinue = None

        while True:
            params = {
                "action":  "query",
                "list":    "categorymembers",
                "cmtitle": f"Kategorie:{category}",
                "cmlimit": 500,
                "cmtype":  "subcat",  # Nur Unterkategorien
                "cmprop":  "ids|title",
            }
            if cmcontinue:
                params["cmcontinue"] = cmcontinue

            data = await self._get(params)
            q = data.get("query") or {}
            subcats.extend(q.get("categorymembers") or [])

            if "continue" in data:
                cmcontinue = data["continue"].get("cmcontinue")
            else:
                break

        return subcats

    # ------------------------------------------------------------------ #
    # Seiteninhalte                                                         #
    # ------------------------------------------------------------------ #

    async def get_page_wikitext(self, title: str) -> str:
        """Rohen Wikitext einer Seite abrufen."""
        data = await self._get({
            "action":  "query",
            "titles":  title,
            "prop":    "revisions",
            "rvprop":  "content",
            "rvslots": "main",
        })
        pages = data["query"]["pages"]
        page  = next(iter(pages.values()))
        if "missing" in page:
            raise SmwClientError(f"Seite '{title}' nicht gefunden")
        return page["revisions"][0]["slots"]["main"]["*"]

    async def get_page_html(self, title: str) -> str:
        """Geparsten HTML-Inhalt einer Seite abrufen."""
        data = await self._get({
            "action": "parse",
            "page":   title,
            "prop":   "text",
        })
        return data["parse"]["text"]["*"]

    # ------------------------------------------------------------------ #
    # Semantic MediaWiki                                                    #
    # ------------------------------------------------------------------ #

    async def browse_subject(self, title: str) -> dict:
        """
        SMW Browse-API: Gibt alle Properties (Attribute) einer Seite zurück.
        Gibt dict {property_name: [value, ...]} zurück.
        """
        data = await self._get({
            "action":  "browsebysubject",
            "subject": title,
        })
        # Normalisiere: {property_label: [wert1, wert2]}
        result = {}
        for prop_data in (data.get("query") or {}).get("data") or []:
            prop_label = prop_data.get("property", "")
            if prop_label.startswith("_"):  # Interne SMW-Properties überspringen
                continue
            values = []
            for item in prop_data.get("dataitem", []):
                raw = item.get("item", "")
                # SMW codiert Werte manchmal als "Wert#0##" → bereinigen
                clean = raw.split("#")[0].strip() if "#" in raw else raw.strip()
                if clean:
                    values.append(clean)
            if values:
                result[prop_label] = values
        return result

    async def ask_query(self, query: str, limit: int = 100) -> list[dict]:
        """
        SMW Ask-API: Semantische Abfrage.
        Beispiel: query = "[[Kategorie:Übungen]]|?Fokusbereich|?Ziel"
        Gibt Liste von {title, properties} zurück.
        """
        data = await self._get({
            "action": "ask",
            "query":  f"{query}|limit={limit}",
        })

        results = []
        for title, props in data.get("query", {}).get("results", {}).items():
            entry = {"title": title, "properties": {}}
            for prop_name, prop_data in props.get("printouts", {}).items():
                values = []
                for item in prop_data:
                    if isinstance(item, dict):
                        values.append(item.get("fulltext") or item.get("raw") or str(item))
                    else:
                        values.append(str(item))
                entry["properties"][prop_name] = values
            results.append(entry)
        return results

    # ------------------------------------------------------------------ #
    # Schema-Discovery                                                      #
    # ------------------------------------------------------------------ #

    async def discover_properties(self, sample_title: str) -> dict:
        """
        Gibt alle SMW-Properties einer Beispielseite zurück.
        Nützlich um die Property-Namen zu ermitteln bevor der Mapper gebaut wird.
        """
        props = await self.browse_subject(sample_title)
        logger.info("Properties von '%s': %s", sample_title, list(props.keys()))
        return props