using System.Collections.Generic;
using System.Linq;
using Microsoft.Extensions.Configuration;
using xCommons.Configurations;
using xCommons.Constants;

namespace xCommons.Extensions
{
    public static partial class IConfigurationExtensions
    {
        /// <summary>
        /// Retrieve AppConfiguration from Configurations
        /// </summary>
        /// <param name="source"></param>
        /// <returns></returns>
        public static XAppConfiguration GetXAppConfiguration(this IConfiguration source)
        {
            //
            var xMessageResourceTitlesConfigSection = source
                .GetSection(ConfigurationNodeNames.MESSAGE_RESOURCE_TITLES_NODE);

            //
            var result = new XAppConfiguration
            {
                Name = source[nameof(XAppConfiguration.Name)],
                Version = source[nameof(XAppConfiguration.Version)],
                XPoweredValue = source[nameof(XAppConfiguration.XPoweredValue)],
                WelcomeMessage = source[nameof(XAppConfiguration.WelcomeMessage)],
                AllowedOrigins = source
                .GetSection(nameof(XAppConfiguration.AllowedOrigins))
                .Get<IEnumerable<string>>(),
                DefaultLanguage = source[nameof(XAppConfiguration.DefaultLanguage)],
                MessageResourceTitles = xMessageResourceTitlesConfigSection
                .Get<XMessageResourceTitles>()
            };

            //
            return result;
        }

        /// <summary>
        /// Retrieve Swagger Configurations
        /// </summary>
        /// <param name="source"></param>
        /// <returns></returns>
        public static XSwaggerConfiguration GetXSwaggerConfiguration(this IConfiguration source)
        {
            //
            var xSwaggerConfigSection = source
                .GetSection(ConfigurationNodeNames.SWAGGER_NODE);
            return xSwaggerConfigSection.Get<XSwaggerConfiguration>();
        }
    
        /// <summary>
        /// Converts a ConfigurationSection to object Representation ...
        /// </summary>
        /// <param name="section"></param>
        /// <returns></returns>
        public static object ToObject(this IConfigurationSection section)
        {
            //
            // an Inner Function for Create Recursive Parsing ...
            object ConvertSection(IConfigurationSection sec)
            {
                //
                var children = sec
                    .GetChildren()
                    .ToList();
                if (!children.Any())
                {
                    return sec.Value ?? string.Empty;
                }

                //
                // Detect Array Like Sections ...
                bool isArray = children.All(ch => int.TryParse(ch.Key, out _));
                if (isArray)
                {
                    //
                    return children
                        .OrderBy(c => int.Parse(c.Key))
                        .Select(ConvertSection)
                        .ToList();
                }

                //
                // Otherwise ...
                return children
                    .ToDictionary(
                        c => c.Key,
                        c => ConvertSection(c)
                    );
            }

            //
            // Try to Parse using Inner Function ...
            var result = ConvertSection(section);

            //
            return result;
        }

        /// <summary>
        /// Converts a ConfigurationSection to Json Representation ... 
        /// </summary>
        /// <param name="section"></param>
        /// <returns></returns>
        public static string ToJSON(this IConfigurationSection section)
        {
            //
            // Try to Parse using Inner Function ...
            var obj = section.ToObject();

            //
            // Convert it to Json ...
            var result = obj.ToJSON();

            //
            return result;
        }

        /// <summary>
        /// Get a Configuration Section as Object ... 
        /// </summary>
        /// <param name="source"></param>
        /// <param name="section"></param>
        /// <returns></returns>
        public static object GetSectionAsObject(
            this IConfiguration source,
            string section
        )
        {
            //
            object result = null;

            //
            if (!section.IsNullOrEmpty())
            {
                //
                var sec = source.GetSection(section);
                if (!sec.IsNull())
                {
                    result = sec.ToObject();
                }
            }

            //
            return result;
        }

        /// <summary>
        /// Retrieve a Configuration Section as Json String ...
        /// </summary>
        /// <param name="source"></param>
        /// <param name="section"></param>
        /// <returns></returns>
        public static string GetSectionAsJson(
            this IConfiguration source,
            string section
        )
        {
            //
            var result = string.Empty;

            //
            // Retrieve Secion as Object ...
            var obj = source.GetSectionAsObject(section);
            if (!obj.IsNull())
            {
                //
                // Converts Section Object to Json ...
                result = obj.ToJSON();
            }

            //
            return result;
        }    
    }
}