#!/usr/bin/env python3
import re
import sys

# Read data from stdin
data = sys.stdin.read()

# Remove unwanted text
data = re.sub(r'\[-- Autoview.*--\]', '', data)
data = re.sub(r'\[-- Attachment #[0-9] --\]', '', data)
data = re.sub(r'\[cid\]', '', data)
data = re.sub(r'\[-- application.*unsupported.*--\]', '', data)
data = re.sub(r'\[-- image.*unsupported.*--\]', '', data)
data = re.sub(r'\[-- Type.*--\]', '', data)

# replace text for signed and encrypted email
data = re.sub(r'\[-- OpenSSL.*\nVerification successful\n.*',
               '[-- Signed Email: Verification successful --]', data)
data = re.sub(r'\[-- The following data is S/MIME encrypted --\]',
               '[-- Encrypted Email: S/MIME --]', data)
data = re.sub(r'\[-- The following data is signed --\]', '', data)
data = re.sub(r'\[-- End of signed data --\]', '', data)
data = re.sub(r'\[-- End of S/MIME encrypted data. --\]', '', data)

# Add line for quoted email
data = re.sub(r'(?<=\n)(From:.*)', '_'*80 + r'\n\1', data)

# clean up multiple blanks lines
data = re.sub(r'.*\n', '', data)
data = re.sub(r'\n\s*\n', r'\n\n', data)

# Output filtered text to stdout
sys.stdout.write(data)