package linguistics

import "testing"

func TestLanguageDetector_Detect_EN(t *testing.T) {
	d := NewLanguageDetector()
	lang, conf, err := d.Detect(Text{Body: " the and is in to of that for the "})
	if err != nil {
		t.Fatalf("Detect returned error: %v", err)
	}
	if lang != "en" {
		t.Fatalf("expected language 'en', got %q", lang)
	}
	if conf <= 0 {
		t.Errorf("expected positive confidence, got %f", conf)
	}
}

func TestLanguageDetector_Detect_ES(t *testing.T) {
	d := NewLanguageDetector()
	lang, _, _ := d.Detect(Text{Body: " el la es en de que por para el "})
	if lang != "es" {
		t.Fatalf("expected language 'es', got %q", lang)
	}
}

func TestLanguageDetector_Detect_FR(t *testing.T) {
	d := NewLanguageDetector()
	lang, _, _ := d.Detect(Text{Body: " le la est en de que pour dans le "})
	if lang != "fr" {
		t.Fatalf("expected language 'fr', got %q", lang)
	}
}

func TestLanguageDetector_Detect_DefaultEnglish(t *testing.T) {
	d := NewLanguageDetector()
	// Balanced/unknown should default to English per implementation
	lang, conf, err := d.Detect(Text{Body: " lorem ipsum dolor sit amet "})
	if err != nil {
		t.Fatalf("Detect returned error: %v", err)
	}
	if lang != "en" {
		t.Fatalf("expected default language 'en', got %q", lang)
	}
	if conf != 0.5 {
		t.Errorf("expected default confidence 0.5, got %f", conf)
	}
}