using NUnit.Framework;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using UnityEditor;
using UnityEngine;
using UnityEngine.SceneManagement;
using UnityEngine.TestTools;

/// <summary>
/// Test the SystemController class
/// </summary>
[TestFixture]
public class SystemControllerTests
{
    /// <summary>
    /// Wait time between scene transitions
    /// </summary>
    private const float WAIT_TIME = 0.2f;

    /// <summary>
    /// Reference to the SystemController instance
    /// </summary>
    private SystemController controller;

    /// <summary>
    /// Setting up the tests
    /// </summary>
    [UnitySetUp]
    public IEnumerator Setup_SystemController()
    {
        string path = $"{Application.persistentDataPath}/wesign_unit_test.json";
        string oneUser = "{\"version\":1537,\"users\":[{\"entries\":[],\"username\":\"Tester0\",\"avatarIndex\":0,\"playtime\":0.0,\"minigames\":[],\"courses\":[]}],\"currentUser\":0,\"currentMinigame\":0,\"currentCourse\":0,\"currentTheme\":0,\"useGPU\":false}";

        File.WriteAllText(path, oneUser);
        PersistentDataController.PATH = path;
        PersistentDataController.GetInstance().Load();
        AssetDatabase.LoadAssetAtPath<UserAvatarList>("Assets/Accounts/ScriptableObjects/UserAvatarList.asset").Awake();

        controller = SystemController.GetInstance();
        controller.LoadNextScene("Common/Scenes/MainMenuScreen");

        yield return new WaitForSeconds(WAIT_TIME);
    }

    /// <summary>
    /// Cleaning up the tests
    /// </summary>
    [TearDown]
    public void TearDown_SystemController()
    {
        controller.BackToScene(SceneManager.sceneCountInBuildSettings);
    }

    /// <summary>
    /// Test whether all scenes are correctly inserted to the build path
    /// </summary>
    [Test]
    public void Test_GetSceneIndex_ValidScene()
    {
        List<string> scenes = new List<string>()
        {
            "Common/Scenes/Boot",
            "Common/Scenes/MainMenuScreen",
            "Common/Scenes/CoursesMenuScreen",
            "Common/Scenes/ListCoursesScreen",
            "Common/Scenes/ListMinigamesScreen",
            "Common/Scenes/CourseActivityScreen",
            "Common/Scenes/MinigameActivityScreen",
            "Common/Scenes/ThemeSelectionScreen",
            "Common/Scenes/SettingsScreen",
            "Accounts/Scenes/UserCreationScreen",
            "Accounts/Scenes/ChangeUserScreen",
            "Accounts/Scenes/UserProgressScreen",
            "Courses/Scenes/CourseScreen",
            "SpellingBee/Scenes/SpellingBeeGame",
            "Hangman/Scenes/HangmanGame",
            "JustSign/Scenes/JustSignGame",
        };
        for (var i = 0; i < scenes.Count; i++)
            Assert.AreEqual(i, SystemController.GetSceneIndex(scenes[i]));
    }

    /// <summary>
    /// Test whether a next scene can be loaded
    /// </summary>
    [UnityTest]
    public IEnumerator Test_LoadNextScene_String()
    {
        int stackSize = controller.GetSceneStackSize();
        string previous = "Common/Scenes/MainMenuScreen";
        string next = "Common/Scenes/CoursesMenuScreen";
        Assert.AreEqual(SystemController.GetSceneIndex(previous), controller.currentScene);
        Assert.AreEqual(stackSize, controller.GetSceneStackSize());
        controller.LoadNextScene(next);
        yield return new WaitForSeconds(WAIT_TIME);

        Assert.AreEqual(SystemController.GetSceneIndex(previous), controller.previousScene);
        Assert.AreEqual(SystemController.GetSceneIndex(next), controller.currentScene);
        Assert.AreEqual(stackSize + 1, controller.GetSceneStackSize());
    }

    /// <summary>
    /// Test whether a next scene can be loaded
    /// </summary>
    [UnityTest]
    public IEnumerator Test_LoadNextScene_Int()
    {
        int stackSize = controller.GetSceneStackSize();
        int previous = 1;
        int next = 2;
        Assert.AreEqual(previous, controller.currentScene);
        Assert.AreEqual(stackSize, controller.GetSceneStackSize());
        controller.LoadNextScene(next);
        yield return new WaitForSeconds(WAIT_TIME);

        Assert.AreEqual(previous, controller.previousScene);
        Assert.AreEqual(next, controller.currentScene);
        Assert.AreEqual(stackSize + 1, controller.GetSceneStackSize());
    }

    /// <summary>
    /// Test whether a scene can be swapped with the current one
    /// </summary>
    [UnityTest]
    public IEnumerator Test_SwapScene_String()
    {
        int stackSize = controller.GetSceneStackSize();
        string previous = "Common/Scenes/MainMenuScreen";
        string next = "Common/Scenes/CoursesMenuScreen";
        Assert.AreEqual(SystemController.GetSceneIndex(previous), controller.currentScene);
        Assert.AreEqual(stackSize, controller.GetSceneStackSize());
        controller.SwapScene(next);
        yield return new WaitForSeconds(WAIT_TIME);

        Assert.AreEqual(SystemController.GetSceneIndex(previous), controller.previousScene);
        Assert.AreEqual(SystemController.GetSceneIndex(next), controller.currentScene);
        Assert.AreEqual(stackSize, controller.GetSceneStackSize());
    }

    /// <summary>
    /// Test whether a scene can be swapped with the current one
    /// </summary>
    [UnityTest]
    public IEnumerator Test_SwapScene_Int()
    {
        int stackSize = controller.GetSceneStackSize();
        int previous = 1;
        int next = 2;
        Assert.AreEqual(previous, controller.currentScene);
        Assert.AreEqual(stackSize, controller.GetSceneStackSize());
        controller.SwapScene(next);
        yield return new WaitForSeconds(WAIT_TIME);

        Assert.AreEqual(previous, controller.previousScene);
        Assert.AreEqual(next, controller.currentScene);
        Assert.AreEqual(stackSize, controller.GetSceneStackSize());
    }

    /// <summary>
    /// Test whether the previous scene can be loaded
    /// </summary>
    [UnityTest]
    public IEnumerator Test_BackToPreviousScene_LoadScene()
    {
        int stackSize = controller.GetSceneStackSize();
        string previous = "Common/Scenes/MainMenuScreen";
        string current = "Common/Scenes/CoursesMenuScreen";
        string next = "Common/Scenes/ListCoursesScreen";
        controller.LoadNextScene(current);
        yield return new WaitForSeconds(WAIT_TIME);
        controller.LoadNextScene(next);
        yield return new WaitForSeconds(WAIT_TIME);

        Assert.AreEqual(SystemController.GetSceneIndex(current), controller.previousScene);
        Assert.AreEqual(SystemController.GetSceneIndex(next), controller.currentScene);
        Assert.AreEqual(stackSize + 2, controller.GetSceneStackSize());
        controller.BackToPreviousScene();
        yield return new WaitForSeconds(WAIT_TIME);

        Assert.AreEqual(stackSize + 1, controller.GetSceneStackSize());
        controller.BackToPreviousScene();
        yield return new WaitForSeconds(WAIT_TIME);

        Assert.AreEqual(SystemController.GetSceneIndex(current), controller.previousScene);
        Assert.AreEqual(SystemController.GetSceneIndex(previous), controller.currentScene);
        Assert.AreEqual(stackSize, controller.GetSceneStackSize());
    }

    /// <summary>
    /// Test whether when requesting to go back on the ast scene, will close the application
    /// </summary>
    [UnityTest]
    public IEnumerator Test_BackToPreviousScene_QuitApplication()
    {
        int stackSize = controller.GetSceneStackSize();

        controller.BackToPreviousScene();
        yield return new WaitForSeconds(WAIT_TIME);
        Assert.AreEqual(stackSize - 1, controller.GetSceneStackSize());
    }

    /// <summary>
    /// Test whether a previous scene can be loaded
    /// </summary>
    [UnityTest]
    public IEnumerator Test_BackToScene_String_LoadScene()
    {
        int stackSize = controller.GetSceneStackSize();
        string previous = "Common/Scenes/MainMenuScreen";
        string current = "Common/Scenes/CoursesMenuScreen";
        string next = "Common/Scenes/ListCoursesScreen";
        controller.LoadNextScene(current);
        yield return new WaitForSeconds(WAIT_TIME);
        controller.LoadNextScene(next);
        yield return new WaitForSeconds(WAIT_TIME);

        Assert.AreEqual(SystemController.GetSceneIndex(current), controller.previousScene);
        Assert.AreEqual(SystemController.GetSceneIndex(next), controller.currentScene);
        Assert.AreEqual(stackSize + 2, controller.GetSceneStackSize());
        controller.BackToScene(previous);
        yield return new WaitForSeconds(WAIT_TIME);

        Assert.AreEqual(SystemController.GetSceneIndex(next), controller.previousScene);
        Assert.AreEqual(SystemController.GetSceneIndex(previous), controller.currentScene);
        Assert.AreEqual(stackSize, controller.GetSceneStackSize());
    }

    /// <summary>
    /// Test whether when requesting to go back to scene that is no longer loaded, will close the application
    /// </summary>
    [UnityTest]
    public IEnumerator Test_BackToScene_String_QuitApplication()
    {
        int stackSize = controller.GetSceneStackSize();

        string previous = "Common/Scenes/MainMenuScreen";
        string current = "Common/Scenes/CoursesMenuScreen";
        string next = "Common/Scenes/ListCoursesScreen";
        controller.SwapScene(current);
        yield return new WaitForSeconds(WAIT_TIME);
        controller.LoadNextScene(next);
        yield return new WaitForSeconds(WAIT_TIME);

        Assert.AreEqual(SystemController.GetSceneIndex(current), controller.previousScene);
        Assert.AreEqual(SystemController.GetSceneIndex(next), controller.currentScene);
        Assert.AreEqual(stackSize + 1, controller.GetSceneStackSize());
        controller.BackToScene(previous);

        yield return new WaitForSeconds(WAIT_TIME);
        Assert.AreEqual(stackSize - 1, controller.GetSceneStackSize());
    }

    /// <summary>
    /// Test whether a previous scene can be loaded
    /// </summary>
    [UnityTest]
    public IEnumerator Test_BackToScene_Int_LoadScene()
    {
        int stackSize = controller.GetSceneStackSize();
        int previous = 1;
        int current = 2;
        int next = 3;
        controller.LoadNextScene(current);
        yield return new WaitForSeconds(WAIT_TIME);
        controller.LoadNextScene(next);
        yield return new WaitForSeconds(WAIT_TIME);

        Assert.AreEqual(current, controller.previousScene);
        Assert.AreEqual(next, controller.currentScene);
        Assert.AreEqual(stackSize + 2, controller.GetSceneStackSize());
        controller.BackToScene(previous);
        yield return new WaitForSeconds(WAIT_TIME);

        Assert.AreEqual(next, controller.previousScene);
        Assert.AreEqual(previous, controller.currentScene);
        Assert.AreEqual(stackSize, controller.GetSceneStackSize());
    }

    /// <summary>
    /// Test whether when requesting to go back to scene that is no longer loaded, will close the application
    /// </summary>
    [UnityTest]
    public IEnumerator Test_BackToScene_Int_QuitApplication()
    {
        int stackSize = controller.GetSceneStackSize();

        int previous = 1;
        int current = 2;
        int next = 3;
        controller.SwapScene(current);
        yield return new WaitForSeconds(WAIT_TIME);
        controller.LoadNextScene(next);
        yield return new WaitForSeconds(WAIT_TIME);

        Assert.AreEqual(current, controller.previousScene);
        Assert.AreEqual(next, controller.currentScene);
        Assert.AreEqual(stackSize + 1, controller.GetSceneStackSize());
        controller.BackToScene(previous);

        yield return new WaitForSeconds(WAIT_TIME);
        Assert.AreEqual(stackSize - 1, controller.GetSceneStackSize());
    }
}