using System.Collections.Concurrent;
using System.Diagnostics;
using System.Reflection;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;

namespace BangumiRenamer.Utils;

public class ConfigItemAttribute(string name) : Attribute
{
    public readonly string Name = name;
}

public interface IConfigItem
{
    public void BeforeSave()
    {
    }

    public void AfterLoad()
    {
    }
}

public interface IConfig
{
    public T Get<T>() where T : class, IConfigItem, new();

    public void Reset<T>() where T : class, IConfigItem, new();

    public bool Save();
}

public sealed class Config(string configPath) : IConfig
{
    public static IConfig G => _G;
    public static Config _G { private get; set; }
    
    private static readonly ConcurrentDictionary<Type, string> Cache = new();
    private readonly ConcurrentDictionary<string, IConfigItem> _configObjects = new();
    private readonly ConcurrentDictionary<string, JObject> _configs = new();

    private static string GetConfigItemName(Type type)
    {
        if (Cache.TryGetValue(type, out var name)) return name;
        name = type.Name;
        if(type.GetCustomAttribute(typeof(ConfigItemAttribute)) is ConfigItemAttribute info)
        {
            name = string.IsNullOrEmpty(info.Name) ? type.Name : info.Name;
        }
        Cache[type] = name;
        return name;
    }
    
    public T Get<T>() where T : class, IConfigItem, new()
    {
        var name = GetConfigItemName(typeof(T));
        if (_configObjects.TryGetValue(name, out var value))
        {
            return (T) value;
        }
        T result;
        if (_configs.TryGetValue(name, out var jObject))
        {
            result = jObject.ToObject<T>();
            result.AfterLoad();
        }
        else
        {
            result = new T();
        }
        _configObjects[name] = result;
        return result;
    }

    public void Reset<T>() where T : class, IConfigItem, new()
    {
        var name = GetConfigItemName(typeof(T));
        _configs.TryRemove(name, out _);
        _configObjects.Remove(name, out _);
    }

    public bool Load()
    {
        _configs.Clear();
        _configObjects.Clear();
        if (!File.Exists(configPath)) return false;
        try
        {
            var configJson = File.ReadAllText(configPath);
            var config = JObject.Parse(configJson);
            foreach (var kv in config)
            {
                _configs[kv.Key] = kv.Value.ToObject<JObject>();
            }
        }
        catch (Exception)
        {
            return false;
        }
        return true;
    }

    public bool Save()
    {
        if (string.IsNullOrEmpty(configPath)) return false;
        try
        {
            foreach (var config in _configObjects)
            {
                config.Value.BeforeSave();
                _configs[config.Key] = JObject.FromObject(config.Value);
            }

            File.WriteAllText(configPath, JsonConvert.SerializeObject(_configs, Formatting.Indented));
        }
        catch (Exception)
        {
            return false;
        }
        return true;
    }

    public static void CreateEmptyConfig()
    {
        var configItemTypes = AppDomain.CurrentDomain.GetAssemblies()
            .SelectMany(assembly =>
            {
                try
                {
                    return assembly.GetTypes();
                }
                catch (ReflectionTypeLoadException)
                {
                    return Array.Empty<Type>();
                }
            })
            .Where(type => type.IsClass && 
                           !type.IsAbstract && 
                           typeof(IConfigItem).IsAssignableFrom(type))
            .ToList();

        var filePath = "config.json";
        var config = new Config(filePath);
        foreach (var type in configItemTypes)
        {
            var name = GetConfigItemName(type);
            config._configObjects[name] = (IConfigItem) Activator.CreateInstance(type);
        }
        config.Save();

        if (File.Exists(filePath))
        {
            // 使用 explorer.exe 的 /select 命令行参数
            string argument = $"/select,\"{filePath}\"";
    
            // 启动 explorer.exe 进程
            Process.Start("explorer.exe", argument);
        }
    }
}