import secrets
import datetime
from flask import Flask, render_template, request, jsonify, send_file
from weasyprint import HTML
import io

app = Flask(__name__)

def generate_secure_password():
    # Length: randomly between 12 and 16 characters
    length = secrets.choice(range(12, 17))
    
    # Allowed Characters
    upper = "ABCDEFGHJKMNPQRSTUVWXYZ" # without I, L, O
    lower = "abcdefghjkmnpqrstuvwxyz" # without i, l, o
    digits = "23456789" # without 0, 1
    special = "!§$%&/()=?\\+#*-_,;.:@€"
    
    while True:
        password = ''.join(secrets.choice(upper + lower + digits + special) for _ in range(length))
        
        # Minimum 2 characters from each category
        if (sum(c in upper for c in password) >= 2 and
            sum(c in lower for c in password) >= 2 and
            sum(c in digits for c in password) >= 2 and
            sum(c in special for c in password) >= 2):
            
            # Double check that no forbidden characters somehow made it in
            forbidden = "ILOilo01ÄÖÜäöü<>|~´`'^°\""
            if not any(c in forbidden for c in password):
                return password

@app.route('/')
def index():
    return render_template('index.html')

@app.route('/api/generate_password', methods=['GET'])
def api_generate_password():
    password = generate_secure_password()
    return jsonify({"password": password})

@app.route('/download_pdf', methods=['POST'])
def download_pdf():
    vorname = request.form.get('vorname', '')
    nachname = request.form.get('nachname', '')
    benutzername = request.form.get('benutzername', '')
    passwort = request.form.get('passwort', '')
    
    datum = datetime.datetime.now().strftime("%d.%m.%Y")
    
    # Render template
    html_out = render_template(
        'benutzer_template.html',
        VORNAME=vorname,
        NACHNAME=nachname,
        BENUTZERNAME=benutzername,
        PASSWORT=passwort,
        DATUM=datum
    )
    
    # Generate PDF
    pdf_file = io.BytesIO()
    HTML(string=html_out).write_pdf(pdf_file)
    pdf_file.seek(0)
    
    # Format filename safely
    safe_vorname = vorname.replace(' ', '_')
    safe_nachname = nachname.replace(' ', '_')
    filename = f"Benutzerantrag_{safe_vorname}_{safe_nachname}.pdf"
    
    return send_file(
        pdf_file,
        download_name=filename,
        as_attachment=True,
        mimetype='application/pdf'
    )

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=5000, debug=True)