import csv
import os                                                                                                        
from datetime import datetime, timedelta
csv_file = 'data/calendar.csv'
ics_file = 'data/calendar.ics'
if not os.path.exists(csv_file):
    print(f"Error: {csv_file} not found. Please ensure your CSV is located at {csv_file}.")                      
    exit(1)                       
ics_lines = [                                                                                                    
    "BEGIN:VCALENDAR",                                                                                           
    "VERSION:2.0",                
    "PRODID:-//Hermes Agent//Calendar Exporter//DE",                                                             
    "CALSCALE:GREGORIAN",         
    "METHOD:PUBLISH"
]
days_map = {
    "montag": "MO", "dienstag": "TU", "mittwoch": "WE", "donnerstag": "TH",
    "freitag": "FR", "samstag": "SA", "sonntag": "SU"
}
with open(csv_file, mode='r', encoding='utf-8') as f:                                                            
    reader = csv.DictReader(f)                                                                                   
    for row in reader:            
        title = row.get("titel", "Termin")
        time_str = row.get("zeit", "09:00")                                                                      
        rhythm = row.get("wochentag", "").strip().lower()
        date_str = row.get("datum", "").strip()                                                                  
        desc = row.get("beschreibung", "")
        # Zeit parsen                                                                                            
        try:                                                                                                     
            hour, minute = map(int, time_str.split(":"))
        except:
            hour, minute = 9, 0
        uid = f"hermes-{abs(hash(title + time_str + rhythm + date_str))}@local"                                  
                                  
        if rhythm == "täglich":
            start_dt = datetime.now().replace(hour=hour, minute=minute, second=0, microsecond=0)                 
            start_str = start_dt.strftime("%Y%m%dT%H%M%S")
            end_str = (start_dt + timedelta(hours=1)).strftime("%Y%m%dT%H%M%S")
                                                                                                                 
            ics_lines.extend([                                                                                   
                "BEGIN:VEVENT",                                                                                  
                f"UID:{uid}",                                                                                    
                f"DTSTART:{start_str}",                                                                          
                f"DTEND:{end_str}",
                f"SUMMARY:{title}",
                f"DESCRIPTION:{desc}",
                "RRULE:FREQ=DAILY",
                "END:VEVENT"
            ])
        elif rhythm in days_map:
            start_dt = datetime.now().replace(hour=hour, minute=minute, second=0, microsecond=0)                 
            start_str = start_dt.strftime("%Y%m%dT%H%M%S")
            end_str = (start_dt + timedelta(hours=1)).strftime("%Y%m%dT%H%M%S")
            byday = days_map[rhythm]                                                                             
                                                                                                                 
            ics_lines.extend([                                                                                   
                "BEGIN:VEVENT",   
    f"UID:{uid}",
                f"DTSTART:{start_str}",                                                                          
                f"DTEND:{end_str}",
                f"SUMMARY:{title}",
                f"DESCRIPTION:{desc}",
                f"RRULE:FREQ=WEEKLY;BYDAY={byday}",
                "END:VEVENT"
            ])
        elif date_str:
            try:                                                                                                 
                dt = datetime.strptime(date_str, "%Y-%m-%d").replace(hour=hour, minute=minute)
                start_str = dt.strftime("%Y%m%dT%H%M%S")
                end_str = (dt + timedelta(hours=1)).strftime("%Y%m%dT%H%M%S")
                ics_lines.extend([                                                                               
                    "BEGIN:VEVENT",                                                                              
                    f"UID:{uid}",                                                                                
                    f"DTSTART:{start_str}",                                                                      
                    f"DTEND:{end_str}",
                    f"SUMMARY:{title}",
                    f"DESCRIPTION:{desc}",
                    "END:VEVENT"
                ])
            except Exception as e:
                print(f"Skipping row due to date parse error: {row} ({e})")
ics_lines.append("END:VCALENDAR")                                                                                
with open(ics_file, mode='w', encoding='utf-8') as f:
    f.write("\n".join(ics_lines))                                                                                
print(f"Erfolgreich generiert: {ics_file}")