using System;
using System.Collections.Generic;
using System.Collections.Immutable;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using Microsoft.Extensions.Configuration;

namespace ChaosBot.ConfigHelpers
{
    public class Configuration
    {
        private readonly IConfiguration _appSettingsWrapper;
        
        private static readonly Dictionary<string, IConfigurationDetails> ConfigurationFlags = new Dictionary<string, IConfigurationDetails>
        {
            {"Bot:Name", new ConfigurationDetails<string>("Bot:Name", "ChaosBot", true)},
            {"Bot:Version", new ConfigurationDetails<string>("Bot:Version", "1.0.0", true)},

            {"WebServer:Port", new ConfigurationDetails<int>("WebServer:Port", 8080, true)},
            {"WebServer:Debug", new ConfigurationDetails<bool>("WebServer:Debug", false, true)},

            {"Discord:Prefix", new ConfigurationDetails<string>("Discord:Prefix", "!", true)},
            {"Discord:Token", new ConfigurationDetails<string>("Discord:Token", "SECRET_TOKEN", true)},
            {"Discord:BaseUri", new ConfigurationDetails<string>("Discord:BaseUri", "http://localhost:8080/", true)},
            {"Discord:ClientId", new ConfigurationDetails<string>("Discord:ClientId", "1234567890", true)},
            {"Discord:ClientSecret", new ConfigurationDetails<string>("Discord:ClientSecret", "1234567890_SECRET_TOKEN", true)},

            {"Lodestone:ChaosBotApi:ApiToken", new ConfigurationDetails<string>("Lodestone:ChaosBotApi:ApiToken", "SECRET_TOKEN", true)},
            {"Lodestone:ChaosBotApi:Url", new ConfigurationDetails<string>("Lodestone:ChaosBotApi:Url", "http://locahost:8000", true)},

            {"Database:Host", new ConfigurationDetails<string>("Database:Host", "localhost", true)},
            {"Database:Port", new ConfigurationDetails<int>("Database:Port", 3306, true)},
            {"Database:User", new ConfigurationDetails<string>("Database:User", "root", true)},
            {"Database:Pass", new ConfigurationDetails<string>("Database:Pass", "password", true)},
            {"Database:Name", new ConfigurationDetails<string>("Database:Name", "chaosbot", true)},
            
            {"Module:Experience:Enabled", new ConfigurationDetails<bool>("Module:Experience:Enabled", true, false)},
            {"LevelUp:Channel", new ConfigurationDetails<string>("LevelUp:Channel", null, false)},
            {"LevelUp:MentionUser", new ConfigurationDetails<bool>("LevelUp:MentionUser", true, false)},
        };

        public Configuration()
        {
            _appSettingsWrapper = GetAppSettingsWrapper();
        }

        public IConfigurationDetails GetByKey(string key)
        {
            if (ConfigurationFlags.TryGetValue(key, out IConfigurationDetails details))
            {
                return details;
            }

            throw new ArgumentException($"Configuration '{key}' is not available");
        }

        public IConfigurationDetails<T> GetByKey<T>(string key)
        {
            IConfigurationDetails configurationDetails = GetByKey(key);

            if (configurationDetails.Type != typeof(T))
                throw new ArgumentException($"Configuration flag '{key}' is not of type '{typeof(T)}'");

            return (IConfigurationDetails<T>) configurationDetails;
        }

        internal static IConfiguration GetAppSettingsWrapper()
        {
            if (Program.AppSettingsHandler == null)
                throw new NullReferenceException("Program.AppSettingsHandler is unset");

            return Program.AppSettingsHandler;
        }
        
        public ImmutableDictionary<string, IConfigurationDetails> GetConfigurationFlags()
        {
            return ConfigurationFlags.ToImmutableDictionary();
        }
        
        public IConfigurationSection GetSection(string key)
        {
            return _appSettingsWrapper.GetSection(key);
        }
    }

    public interface IConfigurationDetails
    {
        string Key { get; }
        bool Restricted { get; }
        Type Type { get; }
        object DefaultValue { get; }
        string GetStringValue(ulong guildId);
        void SetValueFromString(string value, ulong guildId);
        void DeleteValue(ulong guildId);
    }

    public interface IConfigurationDetails<T> : IConfigurationDetails
    {
        new T DefaultValue { get; }
        T GetValue(ulong? guildId = null, bool readRestricted = false);
        T GetValue(T defaultValue, ulong? guildId = null, bool readRestricted = false);
        void SetValue(T value, ulong guildId);
    }
    
    public class ConfigurationDetails<T> : IConfigurationDetails<T>
    {
        public string Key { get; }
        public bool Restricted { get; }
        public T DefaultValue { get; }

        object IConfigurationDetails.DefaultValue => DefaultValue;
        public Type Type => typeof(T);

        public ConfigurationDetails(string key, T defaultValue, bool restricted)
        {
            Key = key;
            DefaultValue = defaultValue;
            Restricted = restricted;
        }

        public T GetValue(ulong? guildId = null, bool readRestricted = false)
        {
            return GetValue(DefaultValue, guildId, readRestricted);
        }

        public T GetValue(T defaultValue, ulong? guildId = null, bool readRestricted = false)
        {
            if (!readRestricted && Restricted)
                throw new UnauthorizedAccessException($"Configuration key '{Key}' is restricted");

            if (guildId.HasValue)
            {
                return ConfigurationRepository.GetValue(Key, guildId.Value, defaultValue);
            }

            return Configuration.GetAppSettingsWrapper().GetValue(Key, defaultValue);
        }

        public string GetStringValue(ulong guildId)
        {
            return GetValue(guildId: guildId).ToString();
        }

        public void SetValue(T value, ulong guildId)
        {
            if (Restricted)
                throw new UnauthorizedAccessException($"Configuration key '{Key}' is restricted");
            ConfigurationRepository.SetValue(Key, value, guildId);
        }

        public void SetValueFromString(string value, ulong guildId)
        {
            SetValue((T)Convert.ChangeType(value, typeof(T)), guildId);
        }

        public void DeleteValue(ulong guildId)
        {
            if (Restricted)
                throw new UnauthorizedAccessException($"Configuration key '{Key}' is restricted");
            ConfigurationRepository.DeleteValue(Key, guildId);
        }
    }
}