package mail

import (
	"net/smtp"
	"strings"
	"testing"
)

func TestSMTPMailerSendBuildsHeadersForValidInput(t *testing.T) {
	mailer := &smtpMailer{cfg: Config{
		Host: "smtp.example.com",
		Port: "587",
		From: "sender@example.com",
	}}

	var captured string
	called := false
	prev := smtpSendMail
	smtpSendMail = func(addr string, auth smtp.Auth, from string, to []string, msg []byte) error {
		called = true
		if addr != "smtp.example.com:587" {
			t.Fatalf("addr=%q", addr)
		}
		if from != "sender@example.com" {
			t.Fatalf("from=%q", from)
		}
		if len(to) != 1 || to[0] != "recipient@example.com" {
			t.Fatalf("to=%v", to)
		}
		captured = string(msg)
		return nil
	}
	t.Cleanup(func() { smtpSendMail = prev })

	err := mailer.Send(Message{
		To:      "recipient@example.com",
		Subject: "Hello there",
		Text:    "plain body",
		HTML:    "<p>html body</p>",
	})
	if err != nil {
		t.Fatal(err)
	}
	if !called {
		t.Fatal("expected smtpSendMail to be called")
	}
	for _, want := range []string{
		"From: sender@example.com",
		"To: recipient@example.com",
		"Subject: Hello there",
	} {
		if !strings.Contains(captured, want) {
			t.Fatalf("message missing %q:\n%s", want, captured)
		}
	}
}

func TestSMTPMailerSendRejectsHeaderInjection(t *testing.T) {
	cases := []Message{
		{To: "recipient@example.com", Subject: "ok\r\nBcc:evil@example.com", Text: "body"},
		{To: "recipient@example.com\r\nBcc:evil@example.com", Subject: "ok", Text: "body"},
	}

	for _, tc := range cases {
		mailer := &smtpMailer{cfg: Config{
			Host: "smtp.example.com",
			Port: "587",
			From: "sender@example.com",
		}}

		called := false
		prev := smtpSendMail
		smtpSendMail = func(addr string, auth smtp.Auth, from string, to []string, msg []byte) error {
			called = true
			return nil
		}

		err := mailer.Send(tc)
		smtpSendMail = prev

		if err == nil {
			t.Fatalf("expected error for %#v", tc)
		}
		if called {
			t.Fatalf("smtpSendMail should not be called for %#v", tc)
		}
	}
}

func TestNewNoopWhenDisabledOrHostEmpty(t *testing.T) {
	if New(Config{Enabled: false, Host: "smtp.example.com"}).Enabled() {
		t.Fatal("disabled mailer must report Enabled=false")
	}
	if New(Config{Enabled: true, Host: ""}).Enabled() {
		t.Fatal("empty host must be noop")
	}
	if !New(Config{Enabled: true, Host: "smtp.example.com", From: "a@b.c"}).Enabled() {
		t.Fatal("enabled+host must be live SMTP mailer")
	}
}

func TestNewDynamicResolvesPerCall(t *testing.T) {
	calls := 0
	host := "smtp-a.example.com"
	m := NewDynamic(func() (Config, error) {
		calls++
		return ConfigFromParts(true, host, "587", "u", "p", "from@example.com"), nil
	})
	if !m.Enabled() {
		t.Fatal("expected enabled")
	}
	host = "smtp-b.example.com"
	if !m.Enabled() {
		t.Fatal("expected still enabled after host change")
	}
	if calls < 2 {
		t.Fatalf("expected resolve per Enabled call, got %d", calls)
	}
}

func TestSetPasswordURL(t *testing.T) {
	got := SetPasswordURL("http://localhost:5174/", "tok123")
	want := "http://localhost:5174/accept-invite?token=tok123&mode=set-password"
	if got != want {
		t.Fatalf("SetPasswordURL=%q want %q", got, want)
	}
	msg := SetPasswordMessage("http://localhost:5174", "u@example.com", "tok123")
	if !strings.Contains(msg.Text, want) && !strings.Contains(msg.Text, "token=tok123&mode=set-password") {
		t.Fatalf("SetPasswordMessage text missing link: %q", msg.Text)
	}
}