package mail

import (
	"bytes"
	"errors"
	"net/mail"
	"strings"
	"testing"
)

func sampleAnnouncement() Announcement {
	return Announcement{
		CategoryLabel:  "New features",
		Subject:        "New in Vantage: scheduled workflows",
		BodyMarkdown:   "Workflows can now run **on a schedule**.\n\n<script>alert(1)</script>\n\n- cron syntax\n- time zones",
		UnsubscribeURL: "https://api.example/email/unsubscribe?c=features&t=abc",
		PreferencesURL: "https://hq.example/email-preferences?t=abc",
		PostalAddress:  "Hostxtra Ltd, 1 High Street, Leeds",
	}
}

func TestRenderAnnouncement(t *testing.T) {
	subject, html, text, err := RenderAnnouncement(sampleAnnouncement(), "https://hq.example")
	if err != nil {
		t.Fatal(err)
	}
	if subject != "New in Vantage: scheduled workflows" {
		t.Errorf("subject = %q", subject)
	}
	if !strings.Contains(html, "<strong>on a schedule</strong>") {
		t.Error("markdown not rendered to html")
	}
	if strings.Contains(html, "<script>") {
		t.Error("raw html from markdown reached the email")
	}
	for label, body := range map[string]string{"html": html, "text": text} {
		for _, want := range []string{"email/unsubscribe?c=features", "email-preferences?t=abc", "New features", "Hostxtra Ltd"} {
			if !strings.Contains(body, want) {
				t.Errorf("%s body missing %q", label, want)
			}
		}
		if strings.Contains(body, "\u2014") {
			t.Errorf("%s body contains an em dash", label)
		}
	}
	if !strings.Contains(text, "**on a schedule**") {
		t.Error("text part should carry the markdown source")
	}
}

func TestRenderAnnouncementWithoutPostalAddress(t *testing.T) {
	a := sampleAnnouncement()
	a.PostalAddress = ""
	_, html, _, err := RenderAnnouncement(a, "")
	if err != nil {
		t.Fatal(err)
	}
	if strings.Contains(html, "<no value>") {
		t.Error("empty postal address rendered as <no value>")
	}
}

func TestSendAnnouncementRefusesListsAndMissingLink(t *testing.T) {
	s := Sender{Host: "smtp.invalid", From: "updates@example.com"}
	prepare := func(what string, err error) {
		t.Helper()
		var se *SendError
		if !errors.As(err, &se) || se.Phase != PhasePrepare {
			t.Errorf("%s: err = %v, want a *SendError at PhasePrepare", what, err)
		}
	}
	prepare("a comma-separated To", s.SendAnnouncement("a@example.com, b@example.com", sampleAnnouncement()))
	a := sampleAnnouncement()
	a.UnsubscribeURL = ""
	prepare("no unsubscribe URL", s.SendAnnouncement("a@example.com", a))
}

// Gmail and Yahoo require both headers of the RFC 8058 pair on bulk mail.
func TestSendAnnouncementPutsListUnsubscribeOnTheWire(t *testing.T) {
	port, got := fakeSMTPData(t, nil)
	s := Sender{Host: "127.0.0.1", Port: port, From: "updates@example.com"}
	a := sampleAnnouncement()
	if err := s.SendAnnouncement("a@example.com", a); err != nil {
		t.Fatal(err)
	}
	msg, err := mail.ReadMessage(bytes.NewReader(<-got))
	if err != nil {
		t.Fatal(err)
	}
	if h := msg.Header.Get("List-Unsubscribe"); h != "<"+a.UnsubscribeURL+">" {
		t.Errorf("List-Unsubscribe = %q", h)
	}
	if h := msg.Header.Get("List-Unsubscribe-Post"); h != "List-Unsubscribe=One-Click" {
		t.Errorf("List-Unsubscribe-Post = %q", h)
	}
}