package dictionary

import (
	"testing"
)

func assertStrings(t testing.TB, got, want, given string) {
	t.Helper()

	if got != want {
		t.Errorf("got %q want %q given %q", got, want, given)
	}
}

func assertError(t testing.TB, got, want error) {
	t.Helper()

	if got != want {
		t.Errorf("got %q want %q", got, want)
	}
}

func TestSearch(t *testing.T) {
	dictionary := Dictionary{"test": "this is just a test"}

	t.Run("known word", func(t *testing.T) {
		got, _ := dictionary.Search("test")
		want := "this is just a test"

		assertStrings(t, got, want, "test")
	})

	t.Run("unknown word", func(t *testing.T) {
		_, err := dictionary.Search("undefined")
		if err == nil {
			t.Fatal("expected to get an error")
		}
		assertError(t, err, ErrNotFound)
	})
}

func assertDefinition(t testing.TB, dict Dictionary, word, def string) {
	t.Helper()

	got, err := dict.Search(word)
	if err != nil {
		t.Fatal("Should find added word:", err)
	}
	assertStrings(t, got, def, word)
}

func TestAdd(t *testing.T) {
	t.Run("new word", func(t *testing.T) {
		dict := Dictionary{}

		word := "test"
		def := "this is just a test"

		dict.Add(word, def)
		assertDefinition(t, dict, word, def)
	})

	t.Run("existing word", func(t *testing.T) {
		word := "test"
		def := "this is just a test"
		dict := Dictionary{word: def}

		err := dict.Add(word, def)
		assertError(t, err, ErrWordExists)
		assertDefinition(t, dict, word, def)
	})
}

func TestUpdate(t *testing.T) {
	t.Run("update an existing word", func(t *testing.T) {
		word := "test"
		def := "this is just a test"
		updated := "updated definition"
		dict := Dictionary{word: def}

		dict.Update(word, updated)
		assertDefinition(t, dict, word, updated)
	})

	t.Run("update an non-existing word", func(t *testing.T) {
		word := "test"
		updated := "updated definition"
		dict := Dictionary{}

		err := dict.Update(word, updated)
		assertError(t, err, ErrWordDoesNotExist)
	})
}

func TestDelete(t *testing.T) {
	t.Run("delete a word", func(t *testing.T) {
		word := "test"
		def := "this is just a test"
		dict := Dictionary{word: def}

		dict.Delete(word)
		_, err := dict.Search(word)
		if err == nil {
			t.Fatal("expected to get an error")
		}
		assertError(t, err, ErrNotFound)
	})
}