module smtp

import encoding.base64

fn test_mail_message_data_with_attachment_has_valid_multipart_boundaries() {
    mail := Mail{
        from:        '[email protected]'
        to:          '[email protected]'
        subject:     'Multipart test'
        body:        'message body'
        boundary:    'test-boundary'
        attachments: [
            Attachment{
                filename: 'note.txt'
                bytes:    'attachment'.bytes()
            },
        ]
    }

    message := mail.message_data()

    assert message.contains('Content-Type: multipart/mixed; boundary="test-boundary"\r\n\r\n--test-boundary\r\n')
    assert message.contains('Content-Type: text/plain; charset=UTF-8\r\nContent-Transfer-Encoding: base64\r\n\r\nbWVzc2FnZSBib2R5\r\n--test-boundary\r\n')
    assert message.contains('Content-Disposition: attachment; filename="note.txt"\r\n\r\nYXR0YWNobWVudA==\r\n--test-boundary--\r\n.\r\n')
    assert !message.contains('Content-Type: multipart/mixed; boundary="test-boundary"\r\n--test-boundary\r\n')
    assert !message.contains('YXR0YWNobWVudA==\r\n--test-boundary\r\n.\r\n')
}

fn test_mail_message_data_with_text_and_html_uses_multipart_alternative() {
    mail := Mail{
        from:     '[email protected]'
        to:       '[email protected]'
        subject:  'Multipart alternative test'
        body:     'legacy body'
        boundary: 'test-boundary'
        text:     Message{
            body: 'text body'
        }
        html:     Message{
            body: '<h1>Hello</h1>'
        }
    }

    message := mail.message_data()

    assert message.contains('MIME-Version: 1.0\r\nContent-Type: multipart/alternative; boundary="test-boundary"\r\n\r\n--test-boundary\r\n')
    assert message.contains('Content-Type: text/plain; charset=UTF-8\r\nContent-Transfer-Encoding: base64\r\n\r\n${base64.encode_str('text body')}\r\n--test-boundary\r\n')
    assert message.contains('Content-Type: text/html; charset=UTF-8\r\nContent-Transfer-Encoding: base64\r\n\r\n${base64.encode_str('<h1>Hello</h1>')}\r\n--test-boundary--\r\n.\r\n')
    assert !message.contains(base64.encode_str('legacy body'))
    assert !message.contains('multipart/mixed')
}

fn test_mail_message_data_with_text_html_and_attachment_uses_nested_multipart() {
    mail := Mail{
        from:     '[email protected]'
        to:       '[email protected]'
        subject:  'Multipart mixed test'
        boundary: 'test-boundary'
        text:     Message{
            body: 'text body'
        }
        html:     Message{
            body:        '<p>Hello</p>'
            attachments: [
                Attachment{
                    filename: 'note.txt'
                    bytes:    'attachment'.bytes()
                },
            ]
        }
    }

    message := mail.message_data()

    assert message.contains('Content-Type: multipart/mixed; boundary="test-boundary"\r\n\r\n--test-boundary\r\nContent-Type: multipart/alternative; boundary="test-boundary-alternative"\r\n\r\n--test-boundary-alternative\r\n')
    assert message.contains('Content-Type: text/plain; charset=UTF-8\r\nContent-Transfer-Encoding: base64\r\n\r\n${base64.encode_str('text body')}\r\n--test-boundary-alternative\r\n')
    assert message.contains('Content-Type: text/html; charset=UTF-8\r\nContent-Transfer-Encoding: base64\r\n\r\n${base64.encode_str('<p>Hello</p>')}\r\n--test-boundary-alternative--\r\n')
    assert message.contains('--test-boundary\r\nContent-Type: application/octet-stream\r\nContent-Transfer-Encoding: base64\r\nContent-Disposition: attachment; filename="note.txt"\r\n\r\n${base64.encode_str('attachment')}\r\n--test-boundary--\r\n.\r\n')
}

fn test_fold_base64_wraps_long_lines() {
    lines := fold_base64(base64.encode_str('0123456789'.repeat(8))).split('\r\n')

    assert lines.len == 2
    assert lines[0].len == 76
    assert lines[1].len == 32
}

fn test_envelope_addr_strips_display_name() {
    assert envelope_addr('[email protected]') == '[email protected]'
    assert envelope_addr('  [email protected]  ') == '[email protected]'
    assert envelope_addr('<[email protected]>') == '[email protected]'
    assert envelope_addr('Ivan Petrov <[email protected]>') == '[email protected]'
    assert envelope_addr('"Petrov, Ivan" <[email protected]>') == '[email protected]'
    // Quoted local-parts may legitimately contain '<'. Without a trailing '>',
    // the input is not an angle-addr wrapper and must pass through unchanged.
    assert envelope_addr('"a<b"@example.com') == '"a<b"@example.com'
    // Quoted display name and quoted local-part both containing '<'/'>'.
    assert envelope_addr('"a<b" <"a<b"@example.com>') == '"a<b"@example.com'
    // Escaped quote inside a quoted display name must not end the quoted run.
    assert envelope_addr('"a\\"<b" <[email protected]>') == '[email protected]'
    // Malformed input (no closing '>') passes through; the server can reject.
    assert envelope_addr('Ivan <[email protected]') == 'Ivan <[email protected]'
}

fn test_mail_message_data_preserves_display_name_in_from_header() {
    mail := Mail{
        from:    'Ivan Petrov <[email protected]>'
        to:      '[email protected]'
        subject: 'Test'
        body:    'hi'
    }

    message := mail.message_data()

    assert message.contains('From: Ivan Petrov <[email protected]>\r\n')
}