using System;
using System.Linq;
using System.Text.RegularExpressions;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Options;
using StardewModdingAPI.Web.Framework.Caching;
using StardewModdingAPI.Web.Framework.Caching.Wiki;
using StardewModdingAPI.Web.Framework.ConfigModels;
using StardewModdingAPI.Web.ViewModels;

namespace StardewModdingAPI.Web.Controllers
{
    /// <summary>Provides user-friendly info about SMAPI mods.</summary>
    internal class ModsController : Controller
    {
        /*********
        ** Fields
        *********/
        /// <summary>The cache in which to store mod metadata.</summary>
        private readonly IWikiCacheRepository Cache;

        /// <summary>The number of minutes before which wiki data should be considered old.</summary>
        private readonly int StaleMinutes;


        /*********
        ** Public methods
        *********/
        /// <summary>Construct an instance.</summary>
        /// <param name="cache">The cache in which to store mod metadata.</param>
        /// <param name="configProvider">The config settings for mod update checks.</param>
        public ModsController(IWikiCacheRepository cache, IOptions<ModCompatibilityListConfig> configProvider)
        {
            ModCompatibilityListConfig config = configProvider.Value;

            this.Cache = cache;
            this.StaleMinutes = config.StaleMinutes;
        }

        /// <summary>Display information for all mods.</summary>
        [HttpGet]
        [Route("mods")]
        public ViewResult Index()
        {
            return this.View("Index", this.FetchData());
        }


        /*********
        ** Private methods
        *********/
        /// <summary>Asynchronously fetch mod metadata from the wiki.</summary>
        public ModListModel FetchData()
        {
            // fetch cached data
            if (!this.Cache.TryGetWikiMetadata(out Cached<WikiMetadata>? metadata))
                return new ModListModel(null, null, Array.Empty<ModModel>(), lastUpdated: DateTimeOffset.UtcNow, isStale: true);

            // build model
            return new ModListModel(
                stableVersion: metadata.Data.StableVersion,
                betaVersion: metadata.Data.BetaVersion,
                mods: this.Cache
                    .GetWikiMods()
                    .Select(mod => new ModModel(mod.Data))
                    .OrderBy(p => Regex.Replace((p.Name ?? "").ToLower(), "[^a-z0-9]", "")), // ignore case, spaces, and special characters when sorting
                lastUpdated: metadata.LastUpdated,
                isStale: this.Cache.IsStale(metadata.LastUpdated, this.StaleMinutes)
            );
        }
    }
}