import base64
import re
from tools.c64_data import SPECIAL_KEYS
def decode_base64_data(data: str) -> bytes:
"""Decode base64 data, handling both pure base64 and data URL formats."""
# Strip data URL prefix if present (e.g., "data:application/octet-stream;base64,...")
if data.startswith("data:"):
data = data.split(",", 1)[1]
return base64.b64decode(data)
def ascii_to_petscii(text: str) -> bytes:
"""Convert ASCII/Unicode text to PETSCII keyboard codes.
Supports special key placeholders like {RETURN}, {HOME}, {CLR}, etc.
"""
result = []
# Find all special keys and regular text segments
pattern = r'(\{[A-Z0-9_]+\})'
parts = re.split(pattern, text)
for part in parts:
if part.startswith('{') and part.endswith('}'):
# Special key placeholder
upper_part = part.upper()
if upper_part in SPECIAL_KEYS:
result.append(SPECIAL_KEYS[upper_part])
# Skip unknown placeholders
else:
# Regular text
for char in part:
code = ord(char)
if char == ' ':
result.append(32) # Space
elif 'A' <= char <= 'Z':
result.append(code)
elif 'a' <= char <= 'z':
# Lowercase -> uppercase PETSCII
result.append(code - 32)
elif '0' <= char <= '9':
result.append(code)
elif char in '!"#$%&\'()*+,-./:;<=>?@[]^':
result.append(code)
# Skip other unmapped characters
return bytes(result)
