using Microsoft.EntityFrameworkCore;
using System.Linq;
using System.Collections.Generic;
using System.IO;
using System.Runtime.CompilerServices;
using System.Text.Json;
using SZUAbsolventenverein.Module.AdminModules.Models;
using Oqtane.Modules;

namespace SZUAbsolventenverein.Module.AdminModules.Repository
{
    /// <summary>
    /// Repository to manage admin settings in the database.
    /// </summary>
    public interface IAdminSettingsRepository
    {
        /// <summary>
        /// Retrieves the administrative settings entry from the Database.
        /// </summary>
        /// <returns>An <see cref="Models.AdminSetting"/> object containing the settings for the specified module. Returns <see
        /// langword="null"/> if the module is not found.</returns>
        Models.AdminSetting GetAdminSetting();

        /// <summary>
        /// Updates the administrative settings with the specified values.
        /// </summary>
        /// <param name="adminSetting">The new administrative settings to apply. Cannot be null.</param>
        /// <returns>The updated <see cref="Models.AdminSetting"/> object reflecting the applied changes.</returns>
        Models.AdminSetting SetAdminSettings(Models.AdminSetting adminSetting);
    }

    /// <summary>
    /// Implementation of the <see cref="IAdminSettingsRepository"/> interface for managing admin settings in the database.
    /// </summary>
    public class AdminSettingsRepository : IAdminSettingsRepository, ITransientService
    {
        public AdminSettingsRepository()
        {
        }

        public AdminSetting GetAdminSetting()
        {
            return AdminSettingsExtensions.LoadSettings();
        }

        public AdminSetting SetAdminSettings(AdminSetting adminSetting)
        {
            return adminSetting.SaveChanges();
        }
    }
    
    /// <summary>
    /// Extension methods for saving and loading admin settings to/from a JSON file.
    /// </summary>
    public static class AdminSettingsExtensions
    {
        /// <summary>
        /// Path to the JSON file where admin settings are stored.
        /// </summary>
        private static string path = "AdminSettings.json";
        
        /// <summary>
        /// Saves the adminSettingsObject to a JSON file.
        /// </summary>
        /// <param name="adminSetting">Settings to save</param>
        /// <returns>The same AdminSettings object for chaining of Operations</returns>
        public static AdminSetting SaveChanges(this AdminSetting adminSetting)
        {
            string res = JsonSerializer.Serialize(adminSetting);

            File.WriteAllText(path, res);
            
            return adminSetting;
        }
        
        /// <summary>
        /// Loads the admin settings from the JSON file. If the file does not exist, returns a new AdminSetting object with default (0) values.
        /// </summary>
        /// <returns></returns>
        public static AdminSetting LoadSettings()
        {
            if (File.Exists(path))
            {
                string json = File.ReadAllText(path);
                return JsonSerializer.Deserialize<AdminSetting>(json);
            }
            
            return new AdminSetting();
        }
    }
}