using System;
using UnityEngine;

namespace Luneraria.UI
{
    /// <summary>
    /// Player preferences of the HUD and options (port of scripts/autoload/preferences.gd as far as
    /// the HUD uses it): UI size, reduced motion, volume, mute, full screen. Stored in PlayerPrefs.
    /// Tests can set values without touching the stored ones (Persist = false).
    /// </summary>
    public static class LunePreferences
    {
        public static event Action Changed;
        /// <summary>False in tests: values change for the session only.</summary>
        public static bool Persist = true;

        static float _uiScale = -1f;
        static int _reducedMotion = -1;
        static float _volume = -1f;
        static int _muted = -1;
        static int _fullscreen = -1;

        public static float UiScale
        {
            get
            {
                if (_uiScale < 0f)
                    _uiScale = PlayerPrefs.GetFloat("lune.ui_scale", 1f);
                return _uiScale;
            }
            set { _uiScale = value; Save("lune.ui_scale", value); }
        }

        public static bool ReducedMotion
        {
            get
            {
                if (_reducedMotion < 0)
                    _reducedMotion = PlayerPrefs.GetInt("lune.reduced_motion", 0);
                return _reducedMotion == 1;
            }
            set { _reducedMotion = value ? 1 : 0; Save("lune.reduced_motion", _reducedMotion); }
        }

        public static float Volume
        {
            get
            {
                if (_volume < 0f)
                    _volume = PlayerPrefs.GetFloat("lune.volume", .8f);
                return _volume;
            }
            set { _volume = Mathf.Clamp01(value); Save("lune.volume", _volume); }
        }

        public static bool Muted
        {
            get
            {
                if (_muted < 0)
                    _muted = PlayerPrefs.GetInt("lune.muted", 0);
                return _muted == 1;
            }
            set { _muted = value ? 1 : 0; Save("lune.muted", _muted); }
        }

        public static bool Fullscreen
        {
            get
            {
                if (_fullscreen < 0)
                    _fullscreen = PlayerPrefs.GetInt("lune.fullscreen", Screen.fullScreen ? 1 : 0);
                return _fullscreen == 1;
            }
            set { _fullscreen = value ? 1 : 0; Save("lune.fullscreen", _fullscreen); }
        }

        static void Save(string key, float value)
        {
            if (Persist)
                PlayerPrefs.SetFloat(key, value);
            Changed?.Invoke();
        }

        static void Save(string key, int value)
        {
            if (Persist)
                PlayerPrefs.SetInt(key, value);
            Changed?.Invoke();
        }

        /// <summary>Writes pending values (Godot Preferences.commit).</summary>
        public static void Commit()
        {
            if (Persist)
                PlayerPrefs.Save();
        }

        /// <summary>Session values back to defaults (tests).</summary>
        public static void ResetSession(float uiScale = 1f, bool reducedMotion = false)
        {
            Persist = false;
            _uiScale = uiScale;
            _reducedMotion = reducedMotion ? 1 : 0;
            Changed?.Invoke();
        }
    }
}