using System.ComponentModel.DataAnnotations;
using System.Threading.Tasks;

namespace ZymonicServices;

public class ZymonicSettings : IZymonicSettings
{
	private IZymonicDbContextFactory _contextFactory;
	private IZymonicLogger _logger;
	public ZymonicSettings(IZymonicDbContextFactory contextFactory, IZymonicLogger logger, string? baseUri = null, string? systemName = null)
	{

		_contextFactory = contextFactory;
		_logger = logger;

		if (baseUri != null)
		{
			Setting("BaseUri", baseUri);
		}
		if (systemName != null)
		{
			Setting("SystemName", systemName);
		}
	}
	public string BaseUri()
	{
		string? baseUri = Setting("BaseUri");
		if (baseUri is null)
		{
			throw new ZymonicBasicSettingNotFound("BaseUri");
		}
		return baseUri;
	}
	public Dictionary<string, ZymonicSetting> SettingCache { get; set; } = new Dictionary<string, ZymonicSetting>();

	public string? Setting(string key, string? value = null, bool noCache = false)
	{
		ZymonicSetting? setting;
		IZymonicDbContext _context;
		// This is most likely the first use of DbContext so try/catch here
		try
		{
			_context = _contextFactory.CreateDbContext();
		}
		catch (Exception ex)
		{
			_logger.LogError("Couldn't create Db Context - {Exception}", ex);
			throw;
		}

		if (noCache || !SettingCache.ContainsKey(key))
		{
			setting = _context.Set<ZymonicSetting>().Where(x => x.Key == key).SingleOrDefault();
			if (setting is not null)
			{
				SettingCache[key] = setting;
			}
		}
		else
		{
			setting = SettingCache[key];
		}
		if (value == null)
		{
			if (setting != null)
			{
				value = setting.Value;
			}
		}
		else if (setting != null)
		{
			setting.Value = value;
			SettingCache[key] = setting;
			_context.Set<ZymonicSetting>().Update(setting);
			_context.SaveChangesAsync();
		}
		else
		{
			setting = new ZymonicSetting
			{
				Key = key,
				Value = value
			};
			SettingCache[key] = setting;
			_context.Set<ZymonicSetting>().Add(setting);
			_context.SaveChangesAsync();
		}

		return value;
	}
	public void ClearSetting(string key)
	{
		IZymonicDbContext _context = _contextFactory.CreateDbContext();
		ZymonicSetting? setting = _context.Set<ZymonicSetting>().Where(x => x.Key == key).SingleOrDefault();
		if (setting != null)
		{
			setting.Value = null;
			_context.Set<ZymonicSetting>().Update(setting);
			_context.SaveChangesAsync();
		}
	}

	public string SystemName()
	{
		string? systemName = Setting("SystemName");
		if (systemName is null)
		{
			throw new ZymonicBasicSettingNotFound("systemName");
		}
		return systemName;
	}
}

[ZymonicLocalDbSet]
public class ZymonicSetting
{
	[Key]
	public required string Key { get; set; }
	public string? Value { get; set; }
}

public class ZymonicBasicSettingNotFound : Exception
{
	public ZymonicBasicSettingNotFound(string message) : base(message) { }
}