ProjectQuint/Assets/ProjectQuint/Runtime/Unity/Bootstrap/ProfileRatingThumbnailCatalog.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using ProjectQuint.Core.Progression;
using ProjectQuint.Library;
using ProjectQuint.Persistence;

namespace ProjectQuint.Bootstrap
{
    internal sealed class ProfileRatingThumbnailCatalog
    {
        private long _sourceSignature = long.MinValue;
        public IReadOnlyList<SongLibraryEntry> Songs { get; private set; } = Array.Empty<SongLibraryEntry>();
        public int Revision { get; private set; }

        public void Refresh(IReadOnlyList<RatingSummary> contexts,
            IReadOnlyList<SongLibraryEntry> activeSongs, int songsRevision, BmsPackRegistry registry)
        {
            var requestedChartIds = new HashSet<string>(StringComparer.Ordinal);
            foreach (var context in contexts ?? Array.Empty<RatingSummary>())
            {
                foreach (var entry in context.BestPlays ?? Array.Empty<RatingChartEntry>())
                {
                    if (!string.IsNullOrWhiteSpace(entry.ChartId))
                        requestedChartIds.Add(entry.ChartId);
                }
            }

            var signature = 17L;
            unchecked
            {
                signature = signature * 31 + (songsRevision);
                foreach (var chartId in requestedChartIds.OrderBy(id => id, StringComparer.Ordinal))
                    signature = signature * 31 + StringComparer.Ordinal.GetHashCode(chartId);
                foreach (var pack in registry?.Packs ?? Array.Empty<BmsPackDefinition>())
                {
                    var cachePath = registry.CachePathFor(pack);
                    var cache = new FileInfo(cachePath);
                    signature = signature * 31 + StringComparer.OrdinalIgnoreCase.GetHashCode(pack.Id ?? string.Empty);
                    signature = signature * 31 + (cache.Exists ? cache.Length : 0L);
                    signature = signature * 31 + (cache.Exists ? cache.LastWriteTimeUtc.Ticks : 0L);
                }
            }
            if (signature == _sourceSignature)
                return;

            var songsByChartId = new Dictionary<string, SongLibraryEntry>(StringComparer.Ordinal);
            void AddSong(SongLibraryEntry song)
            {
                if (song == null)
                    return;
                var chartId = ChartIdentityResolver.Resolve(song).Value;
                if (requestedChartIds.Contains(chartId) && !songsByChartId.ContainsKey(chartId))
                    songsByChartId.Add(chartId, song);
            }

            foreach (var song in activeSongs ?? Array.Empty<SongLibraryEntry>())
                AddSong(song);
            foreach (var pack in registry?.Packs ?? Array.Empty<BmsPackDefinition>())
            {
                foreach (var song in SongLibraryScanner.LoadCachedThumbnailEntries(
                             registry.CachePathFor(pack),
                             pack.ContentRoot,
                             pack.Id,
                             requestedChartIds))
                    AddSong(song);
            }

            Songs = songsByChartId.Values.ToArray();
            _sourceSignature = signature;
            unchecked
            {
                Revision++;
            }
        }

    }
}