package classes

import "testing"

// TestHandle: generator charset is a subset of MentionParser, uniqueness
// uses the smallest free integer suffix, and short names fall back to user{id}.
func TestHandle(t *testing.T) {
	t.Parallel()
	g := HandleGenerator{}

	if got := g.Slug("Paweł"); got != "pawel" {
		t.Fatalf("slug Paweł = %q, want pawel", got)
	}
	if got := g.Slug("John Doe"); got != "johndoe" {
		t.Fatalf("slug John Doe = %q, want johndoe", got)
	}
	if got := g.Slug("Zoë"); got != "zoe" {
		t.Fatalf("slug Zoë = %q, want zoe", got)
	}

	handle := g.Generate("James", func(string) bool { return false }, nil)
	if handle != "james" {
		t.Fatalf("generate James = %q, want james", handle)
	}
	if !validHandle(handle) {
		t.Fatalf("generated %q is outside [a-z0-9._-]{2,255}", handle)
	}

	taken := map[string]struct{}{}
	isTaken := func(c string) bool {
		_, ok := taken[c]
		return ok
	}
	first := g.Generate("James", isTaken, nil)
	taken[first] = struct{}{}
	second := g.Generate("James", isTaken, nil)
	taken[second] = struct{}{}
	third := g.Generate("James", isTaken, nil)
	if first != "james" || second != "james1" || third != "james2" {
		t.Fatalf("suffixes = %q %q %q, want james james1 james2", first, second, third)
	}

	id := uint(42)
	if got := g.Generate("", func(string) bool { return false }, &id); got != "user42" {
		t.Fatalf("empty name = %q, want user42", got)
	}
	if got := g.Generate("x", func(string) bool { return false }, &id); got != "user42" {
		t.Fatalf("short name = %q, want user42", got)
	}
	if got := g.Generate("???", func(string) bool { return false }, &id); got != "user42" {
		t.Fatalf("punctuation name = %q, want user42", got)
	}
	if got := g.Generate("", func(string) bool { return false }, nil); got != "user" {
		t.Fatalf("no id = %q, want user", got)
	}

	names := []string{"James", "Paweł", "John Doe", "???", "a", "Zoë", "   ", "....", "O'Brien"}
	for _, name := range names {
		got := g.Generate(name, func(string) bool { return false }, &id)
		if !validHandle(got) {
			t.Errorf("generated %q for %q is outside the MentionParser subset", got, name)
		}
	}
}

func validHandle(s string) bool {
	if len(s) < 2 || len(s) > 255 {
		return false
	}
	for _, r := range s {
		switch {
		case r >= 'a' && r <= 'z', r >= '0' && r <= '9', r == '.', r == '_', r == '-':
		default:
			return false
		}
	}
	return true
}