package main

import "testing"

func TestFindYouTubeURL(t *testing.T) {
	tests := []struct {
		name    string
		content string
		want    string
	}{
		{"watch", "みてみて https://www.youtube.com/watch?v=dQw4w9WgXcQ おもしろい", "https://www.youtube.com/watch?v=dQw4w9WgXcQ"},
		{"short host", "https://youtu.be/dQw4w9WgXcQ?t=42", "https://youtu.be/dQw4w9WgXcQ?t=42"},
		{"shorts", "https://www.youtube.com/shorts/abc_123", "https://www.youtube.com/shorts/abc_123"},
		{"live", "https://youtube.com/live/abc-123", "https://youtube.com/live/abc-123"},
		{"mobile", "https://m.youtube.com/watch?v=abc&feature=share", "https://m.youtube.com/watch?v=abc&feature=share"},
		{"trailing punctuation", "これ→https://youtu.be/abc123。", "https://youtu.be/abc123"},
		{"first of several", "https://youtu.be/one https://youtu.be/two", "https://youtu.be/one"},
		{"skips other links", "https://example.com/watch?v=x https://youtu.be/abc", "https://youtu.be/abc"},
		{"no url", "ただのつぶやき", ""},
		{"other site", "https://example.com/", ""},
		{"youtube without video", "https://www.youtube.com/", ""},
		{"watch without v", "https://www.youtube.com/watch?list=PL123", ""},
		{"lookalike host", "https://youtube.com.evil.example/watch?v=abc", ""},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if got := findYouTubeURL(tt.content); got != tt.want {
				t.Errorf("findYouTubeURL(%q) = %q, want %q", tt.content, got, tt.want)
			}
		})
	}
}