| import re
|
| from email_validator import validate_email, EmailNotValidError
|
| from ..models import SyntaxResult
|
|
|
|
|
| RFC_5321_REGEX = re.compile(
|
| r'^(?:[a-zA-Z0-9!#$%&\'*+/=?^_`{|}~-]+'
|
| r'(?:\.[a-zA-Z0-9!#$%&\'*+/=?^_`{|}~-]+)*'
|
| r'|"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]'
|
| r'|\\[\x01-\x09\x0b\x0c\x0e-\x7f])*")'
|
| r'@(?:(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]*[a-zA-Z0-9])?\.)'
|
| r'+[a-zA-Z0-9](?:[a-zA-Z0-9-]*[a-zA-Z0-9])?'
|
| r'|\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}'
|
| r'(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?'
|
| r'|[a-zA-Z0-9-]*[a-zA-Z0-9]:'
|
| r'(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]'
|
| r'|\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\])$'
|
| )
|
|
|
|
|
| def validate_syntax(email: str) -> SyntaxResult:
|
| """
|
| Layer 1: Multi-method syntax validation.
|
| Uses email-validator library (RFC 5321/5322) + regex fallback.
|
| """
|
|
|
| if not email or len(email) > 254:
|
| return SyntaxResult(
|
| passed=False,
|
| error=f"Email length invalid: {len(email)} chars (max 254)"
|
| )
|
|
|
| if '@' not in email:
|
| return SyntaxResult(passed=False, error="Missing @ symbol")
|
|
|
| local_part, _, domain_part = email.rpartition('@')
|
|
|
| if len(local_part) > 64:
|
| return SyntaxResult(
|
| passed=False,
|
| error="Local part exceeds 64 characters (RFC 5321)"
|
| )
|
|
|
|
|
| try:
|
| validated = validate_email(
|
| email,
|
| check_deliverability=False,
|
| allow_smtputf8=True,
|
| allow_empty_local=False
|
| )
|
| return SyntaxResult(
|
| passed=True,
|
| normalized_email=validated.normalized,
|
| local_part=validated.local_part,
|
| domain=validated.domain
|
| )
|
| except EmailNotValidError as e:
|
|
|
| if RFC_5321_REGEX.match(email):
|
| return SyntaxResult(
|
| passed=True,
|
| normalized_email=email,
|
| local_part=local_part,
|
| domain=domain_part
|
| )
|
| return SyntaxResult(
|
| passed=False,
|
| error=str(e)
|
| )
|
| except Exception as e:
|
| return SyntaxResult(
|
| passed=False,
|
| error=f"Unexpected syntax error: {str(e)}"
|
| )
|
|
|
