import pandas as pd
import requests
import markdown
from io import StringIO
from datetime import datetime, timedelta
from .config_loader import config

_cache = {"events": None, "remarks": None, "timestamp": None}
HEADERS = {"User-Agent": "Mozilla/5.0"}

def invalidate_cache():
    global _cache
    _cache = {"events": None, "remarks": None, "timestamp": None}
    return "Cache gelöscht"

def _is_cache_valid():
    if _cache["timestamp"] is None:
        return False
    return (datetime.now() - _cache["timestamp"]) < timedelta(hours=1)

def get_upcoming_events(days_to_show=None, limit=None):
    # Sofort Standardwert aus Config setzen, falls None oder 0
    if not days_to_show:
        days_to_show = config['processing']['days_to_show']

    # 1. Daten laden (entweder aus Cache oder von Google)
    if not _is_cache_valid() or _cache["events"] is None:
        url = config['links']['times_csv']
        response = requests.get(url, headers=HEADERS)
        response.raise_for_status()
        response.encoding = 'utf-8'
        
        df = pd.read_csv(StringIO(response.text))
        
        # Typografie: Bindestrich durch En-Dash (–) ersetzen
        for col in ['Morgen', 'Nachmittag']:
            df[col] = df[col].fillna('').astype(str).str.replace('-', '–', regex=False)
            
        date_col = config['google_sheet']['date_column']
        df = df.dropna(subset=[date_col])
        df[date_col] = pd.to_datetime(df[date_col], dayfirst=True, errors='coerce')
        
        wt_map = {0: 'Mo', 1: 'Di', 2: 'Mi', 3: 'Do', 4: 'Fr', 5: 'Sa', 6: 'So'}
        df['Wochentag'] = df[date_col].dt.weekday.map(wt_map)
        
        _cache["events"] = df.sort_values(by=date_col).to_dict(orient='records')
        _cache["timestamp"] = datetime.now()

    heute = pd.Timestamp(datetime.now().date())
    date_col = config['google_sheet']['date_column']

    # PRIORITÄT 1: Zeilen-Limit (gewinnt immer)
    if limit and limit > 0:
        return [e for e in _cache["events"] if e[date_col] >= heute][:limit]
    
    # PRIORITÄT 2: Tage-Logik
    ende = heute + timedelta(days=int(days_to_show))
    return [e for e in _cache["events"] if heute <= e[date_col] < ende]

def get_remarks():
    if _is_cache_valid() and _cache["remarks"] is not None:
        return _cache["remarks"]
    
    url = config['links']['remarks_csv']
    response = requests.get(url, headers=HEADERS)
    response.raise_for_status()
    response.encoding = 'utf-8'
    
    df = pd.read_csv(StringIO(response.text), skiprows=2, header=None)
    
    if not df.empty:
        raw_remarks = df[0].dropna().astype(str).tolist()
        processed = []
        for r in raw_remarks:
            html = markdown.markdown(r.strip())
            if html.startswith("<p>") and html.endswith("</p>"):
                html = html[3:-4]
            processed.append(html)
        _cache["remarks"] = processed
        _cache["timestamp"] = datetime.now()
    else:
        _cache["remarks"] = []
        
    return _cache["remarks"]