package shared

import (
	"strings"
	"testing"
	"unicode/utf8"
)

func TestEscape(t *testing.T) {
	if got := Escape(`<b>Milk & eggs</b>`); got != "&lt;b&gt;Milk &amp; eggs&lt;/b&gt;" {
		t.Fatalf("Escape() = %q", got)
	}
}

func TestFitMessageLeavesShortText(t *testing.T) {
	text := "<b>Milk &amp; eggs</b>"
	if got := FitMessage(text); got != text {
		t.Fatalf("FitMessage() = %q, want unchanged", got)
	}
}

func TestFitMessageTruncatesPlainText(t *testing.T) {
	got := FitMessage(strings.Repeat("a", TelegramMessageLimit+100))
	if utf8.RuneCountInString(got) > TelegramMessageLimit {
		t.Fatalf("FitMessage() is %d runes, limit %d",
			utf8.RuneCountInString(got), TelegramMessageLimit)
	}
	if !strings.HasSuffix(got, "…") {
		t.Fatal("FitMessage() does not end with an ellipsis")
	}
}

func TestFitMessageClosesOpenTags(t *testing.T) {
	got := FitMessage("<b>" + strings.Repeat("a", TelegramMessageLimit))
	if utf8.RuneCountInString(got) > TelegramMessageLimit {
		t.Fatalf("FitMessage() is %d runes, limit %d",
			utf8.RuneCountInString(got), TelegramMessageLimit)
	}
	if !strings.HasSuffix(got, "</b>…") {
		t.Fatalf("FitMessage() does not close <b>: %q", got[len(got)-20:])
	}
}

func TestFitMessageDoesNotSplitEntity(t *testing.T) {
	got := FitMessage(strings.Repeat("a", TelegramMessageLimit-2) + "&amp;" + "tail")
	if utf8.RuneCountInString(got) > TelegramMessageLimit {
		t.Fatalf("FitMessage() is %d runes, limit %d",
			utf8.RuneCountInString(got), TelegramMessageLimit)
	}
	if strings.Contains(got, "&am…") || strings.HasSuffix(got, "&") {
		t.Fatalf("FitMessage() split an entity: %q", got[len(got)-10:])
	}
}

func TestFitMessageDoesNotSplitTag(t *testing.T) {
	got := FitMessage(strings.Repeat("a", TelegramMessageLimit-3) + "<b>tail</b>")
	if strings.HasSuffix(got, "<") || strings.HasSuffix(got, "<b") {
		t.Fatalf("FitMessage() split a tag: %q", got[len(got)-10:])
	}
	if utf8.RuneCountInString(got) > TelegramMessageLimit {
		t.Fatalf("FitMessage() is %d runes, limit %d",
			utf8.RuneCountInString(got), TelegramMessageLimit)
	}
}