using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using StardewModdingAPI.Toolkit.Framework.Clients.Wiki;

namespace StardewModdingAPI.Web.Framework.Caching.Wiki
{
    /// <summary>Manages cached wiki data in-memory.</summary>
    internal class WikiCacheMemoryRepository : BaseCacheRepository, IWikiCacheRepository
    {
        /*********
        ** Fields
        *********/
        /// <summary>The saved wiki metadata.</summary>
        private Cached<WikiMetadata>? Metadata;

        /// <summary>The cached wiki data.</summary>
        private Cached<WikiModEntry>[] Mods = Array.Empty<Cached<WikiModEntry>>();


        /*********
        ** Public methods
        *********/
        /// <summary>Get the cached wiki metadata.</summary>
        /// <param name="metadata">The fetched metadata.</param>
        public bool TryGetWikiMetadata([NotNullWhen(true)] out Cached<WikiMetadata>? metadata)
        {
            metadata = this.Metadata;
            return metadata != null;
        }

        /// <summary>Get the cached wiki mods.</summary>
        /// <param name="filter">A filter to apply, if any.</param>
        public IEnumerable<Cached<WikiModEntry>> GetWikiMods(Func<WikiModEntry, bool>? filter = null)
        {
            foreach (var mod in this.Mods)
            {
                if (filter == null || filter(mod.Data))
                    yield return mod;
            }
        }

        /// <summary>Save data fetched from the wiki compatibility list.</summary>
        /// <param name="stableVersion">The current stable Stardew Valley version.</param>
        /// <param name="betaVersion">The current beta Stardew Valley version.</param>
        /// <param name="mods">The mod data.</param>
        public void SaveWikiData(string? stableVersion, string? betaVersion, IEnumerable<WikiModEntry> mods)
        {
            this.Metadata = new Cached<WikiMetadata>(new WikiMetadata(stableVersion, betaVersion));
            this.Mods = mods.Select(mod => new Cached<WikiModEntry>(mod)).ToArray();
        }
    }
}