package mailkit

import (
	"strings"
	"testing"
)

// TestEnvelopeAddress covers the exact bug this fixes: a configured
// From address that includes a display name (a very natural thing to
// set ENKLY_SMTP_FROM to, e.g. "enkly <noreply@example.com>") must not
// be handed to MAIL FROM/RCPT TO as-is, or Gmail answers with "555
// 5.5.2 Syntax error, cannot decode response" because the envelope
// command only accepts a bare address (RFC 5321 §4.1.2).
func TestEnvelopeAddress(t *testing.T) {
	cases := []struct{ in, want string }{
		{"user@example.com", "user@example.com"},
		{"enkly <user@example.com>", "user@example.com"},
		{"  enkly  <user@example.com>  ", "user@example.com"},
		{"\"Enkly Notifications\" <user@example.com>", "user@example.com"},
		// Not parseable as an address at all: returned unchanged so the
		// SMTP server's own rejection explains the problem, rather than
		// this function silently swallowing it.
		{"not-an-address", "not-an-address"},
	}
	for _, c := range cases {
		if got := envelopeAddress(c.in); got != c.want {
			t.Errorf("envelopeAddress(%q) = %q, want %q", c.in, got, c.want)
		}
	}
}

// TestNewTrimsConfig guards against the same class of bug from a
// different angle: SMTP config values arriving from os.Getenv with
// stray whitespace or an embedded "\r" (e.g. a CRLF-saved .env or
// docker-compose.yml) must not reach the wire as part of an SMTP
// command line, or the server sees a corrupted command.
func TestNewTrimsConfig(t *testing.T) {
	m := New(Config{
		Host:     " smtp.gmail.com\r\n",
		Port:     " 587 ",
		Username: " user@example.com \r",
		Password: " app-password \r",
		From:     " enkly <user@example.com> \r",
	})
	if m.cfg.Host != "smtp.gmail.com" {
		t.Errorf("Host = %q", m.cfg.Host)
	}
	if m.cfg.Port != "587" {
		t.Errorf("Port = %q", m.cfg.Port)
	}
	if m.cfg.Username != "user@example.com" {
		t.Errorf("Username = %q", m.cfg.Username)
	}
	if m.cfg.Password != "app-password" {
		t.Errorf("Password = %q", m.cfg.Password)
	}
	if m.cfg.From != "enkly <user@example.com>" {
		t.Errorf("From = %q", m.cfg.From)
	}
}

// TestNewDefaults checks the Gmail host/port/from defaults still apply
// after adding trimming, so a minimal config keeps working out of the
// box.
func TestNewDefaults(t *testing.T) {
	m := New(Config{Username: "user@example.com", Password: "app-password"})
	if m.cfg.Host != "smtp.gmail.com" {
		t.Errorf("default Host = %q", m.cfg.Host)
	}
	if m.cfg.Port != "587" {
		t.Errorf("default Port = %q", m.cfg.Port)
	}
	if m.cfg.From != "user@example.com" {
		t.Errorf("default From = %q", m.cfg.From)
	}
}

func TestConfigured(t *testing.T) {
	if New(Config{}).Configured() {
		t.Fatal("empty config must not report Configured")
	}
	if !New(Config{Username: "u", Password: "p"}).Configured() {
		t.Fatal("username+password must report Configured")
	}
}

func TestBuildMessageShape(t *testing.T) {
	msg := buildMessage("enkly <from@example.com>", "to@example.com", "Subject line", "body text")
	for _, want := range []string{
		"From: enkly <from@example.com>\r\n",
		"To: to@example.com\r\n",
		"Subject: Subject line\r\n",
		"\r\nbody text\r\n",
	} {
		if !strings.Contains(msg, want) {
			t.Errorf("buildMessage output missing %q; got:\n%s", want, msg)
		}
	}
}