using System;
using System.IO;
using UnityEngine;

/// Shared JSON-backed store for the player-facing game settings, written human-readable
/// to <persistentDataPath>/Settings.json. Replaces the former per-value PlayerPrefs storage.
/// Loaded lazily on first access and cached in memory (reads are plain field access, so the
/// per-frame Multiplier reads from the camera controllers never touch the disk). Each change is
/// written immediately (settings edits are rare user actions), so a hard-killed build keeps them.
///
/// The typed domain facades (MouseSensitivity, MasterVolume) own the ranges/clamping and read/write
/// through here; this class stays domain-agnostic and only persists the raw values.
public static class GameSettings
{
    private const string FileName = "Settings.json";
    private const int FileVersion = 1;

    [Serializable]
    private class Data
    {
        public int version = FileVersion;
        public float mouseSensitivity = global::MouseSensitivity.Default;
        public float masterVolume = global::MasterVolume.Default;
    }

    private static Data _data;
    private static Data Store => _data ??= Load();

    private static string SavePath() => Path.Combine(Application.persistentDataPath, FileName);

    public static float MouseSensitivity
    {
        get => Store.mouseSensitivity;
        set
        {
            if (Mathf.Approximately(Store.mouseSensitivity, value)) return;
            Store.mouseSensitivity = value;
            Save();
        }
    }

    public static float MasterVolume
    {
        get => Store.masterVolume;
        set
        {
            if (Mathf.Approximately(Store.masterVolume, value)) return;
            Store.masterVolume = value;
            Save();
        }
    }

    private static Data Load()
    {
        string path = SavePath();
        if (File.Exists(path))
        {
            try
            {
                var data = JsonUtility.FromJson<Data>(File.ReadAllText(path));
                if (data != null) return data;
            }
            catch (Exception e)
            {
                Debug.LogWarning($"[GameSettings] Loading {FileName} failed, using defaults: {e.Message}");
            }
        }
        return new Data();
    }

    private static void Save()
    {
        try
        {
            Directory.CreateDirectory(Application.persistentDataPath);
            File.WriteAllText(SavePath(), JsonUtility.ToJson(Store, true));
        }
        catch (Exception e)
        {
            Debug.LogWarning($"[GameSettings] Saving {FileName} failed: {e.Message}");
        }
    }
}