using System;
using System.Collections.Generic;
using System.Text;

namespace Quadarax.Foundation.Core.Exceptions
{
    public abstract class ExceptionCodes
    {

        private readonly IDictionary<int, CodeMessageMap> _exceptionCodesCache = new Dictionary<int, CodeMessageMap>();


        protected ExceptionCodes()
        {
            _exceptionCodesCache.Add(int.MaxValue, new CodeMessageMap(int.MaxValue, "Exception with code '{0}' not found. Cannot create."));
            OnSetupCodes();
        }

        protected abstract void OnSetupCodes();
        
        protected void AddCode(int code, string message)
        {
            if (ExistsCode(code))
                throw new InvalidOperationException($"Exception code '{code}' with message '{message}' already exists in cache.");

            _exceptionCodesCache.Add(code, new CodeMessageMap(code, message));
        }

        protected bool ExistsCode(int code)
        {
            return _exceptionCodesCache.ContainsKey(code);
        }

        protected string GetMessage(int code, params string[] messageParams)
        {
            return string.Format(_exceptionCodesCache[code].Message, messageParams);
        }

        public CodeException CreateException(int code, params string[] messageParams)
        {
            return CreateException(code, null, messageParams);
        }
        public CodeException CreateException(int code, Exception innerException, params string[] messageParams)
        {
            if (!ExistsCode(code)) return new CodeException(int.MaxValue, GetMessage(code, code.ToString()));

            return new CodeException(code, GetMessage(code, messageParams));
        }

        private class CodeMessageMap
        {
            public int Code { get;}
            public string Message { get; }

            public CodeMessageMap(int code, string message)
            {
                if (string.IsNullOrEmpty(message)) throw new ArgumentNullException(nameof(message));

                Code = code;
                Message = message;
            }

            public override string ToString()
            {
                var sb = new StringBuilder();
                sb.Append(Code).Append(";").Append(Message);
                return base.ToString();
            }
        }
    }
}