package smtpserver

import (
	"strings"
	"testing"
)

// TestParseMessageDecodesBase64Attachment guards against a bug where
// mime/multipart.Reader only auto-decodes quoted-printable (not base64), so a
// base64-encoded attachment part was stored/read back as raw base64 text instead of
// its actual decoded bytes.
func TestParseMessageDecodesBase64Attachment(t *testing.T) {
	raw := "" +
		"From: sender@example.com\r\n" +
		"To: rcpt@example.com\r\n" +
		"Subject: test\r\n" +
		"MIME-Version: 1.0\r\n" +
		"Content-Type: multipart/mixed; boundary=\"BOUND\"\r\n" +
		"\r\n" +
		"--BOUND\r\n" +
		"Content-Type: text/plain\r\n" +
		"\r\n" +
		"hello\r\n" +
		"--BOUND\r\n" +
		"Content-Type: application/octet-stream\r\n" +
		"Content-Disposition: attachment; filename=\"LICENSE\"\r\n" +
		"Content-Transfer-Encoding: BASE64\r\n" +
		"\r\n" +
		"SGVsbG8sIHdvcmxkIQ==\r\n" +
		"--BOUND--\r\n"

	parsed, err := parseMessage([]byte(raw))
	if err != nil {
		t.Fatalf("parseMessage: %v", err)
	}
	if len(parsed.Attachments) != 1 {
		t.Fatalf("got %d attachments, want 1", len(parsed.Attachments))
	}
	got := string(parsed.Attachments[0].Data)
	want := "Hello, world!"
	if got != want {
		t.Errorf("attachment data = %q, want %q (decoded from base64, not left as raw base64 text)", got, want)
	}
}

// TestParseMessageLeavesNonBase64EncodingsAlone confirms 7bit/8bit/absent
// Content-Transfer-Encoding parts pass through unmodified.
func TestParseMessageLeavesNonBase64EncodingsAlone(t *testing.T) {
	raw := "" +
		"From: sender@example.com\r\n" +
		"To: rcpt@example.com\r\n" +
		"Subject: test\r\n" +
		"MIME-Version: 1.0\r\n" +
		"Content-Type: multipart/mixed; boundary=\"BOUND\"\r\n" +
		"\r\n" +
		"--BOUND\r\n" +
		"Content-Type: text/plain\r\n" +
		"\r\n" +
		"hello\r\n" +
		"--BOUND\r\n" +
		"Content-Type: text/plain\r\n" +
		"Content-Disposition: attachment; filename=\"notes.txt\"\r\n" +
		"Content-Transfer-Encoding: 7bit\r\n" +
		"\r\n" +
		"plain text content\r\n" +
		"--BOUND--\r\n"

	parsed, err := parseMessage([]byte(raw))
	if err != nil {
		t.Fatalf("parseMessage: %v", err)
	}
	if len(parsed.Attachments) != 1 {
		t.Fatalf("got %d attachments, want 1", len(parsed.Attachments))
	}
	got := strings.TrimSpace(string(parsed.Attachments[0].Data))
	if got != "plain text content" {
		t.Errorf("attachment data = %q, want %q", got, "plain text content")
	}
}