Station records (#8720)

Co-authored-by: metalgearsloth <comedian_vs_clown@hotmail.com>

Content.Server/StationRecords/StationRecordSet.cs

@@ -0,0 +1,158 @@
+using System.Diagnostics.CodeAnalysis;
+using Content.Shared.StationRecords;
+
+namespace Content.Server.StationRecords;
+
+/// <summary>
+///     Set of station records. StationRecordsComponent stores these.
+///     Keyed by StationRecordKey, which should be obtained from
+///     an entity that stores a reference to it.
+/// </summary>
+public sealed class StationRecordSet
+{
+    private uint _currentRecordId;
+
+    private HashSet<StationRecordKey> _keys = new();
+
+    private HashSet<StationRecordKey> _recentlyAccessed = new();
+
+    [ViewVariables]
+    private Dictionary<Type, Dictionary<StationRecordKey, object>> _tables = new();
+
+    /// <summary>
+    ///     Gets all records of a specific type stored in the record set.
+    /// </summary>
+    /// <typeparam name="T">The type of record to fetch.</typeparam>
+    /// <returns>An enumerable object that contains a pair of both a station key, and the record associated with it.</returns>
+    public IEnumerable<(StationRecordKey, T)> GetRecordsOfType<T>()
+    {
+        if (!_tables.ContainsKey(typeof(T)))
+        {
+            yield break;
+        }
+
+        foreach (var (key, entry) in _tables[typeof(T)])
+        {
+            if (entry is not T cast)
+            {
+                continue;
+            }
+
+            _recentlyAccessed.Add(key);
+
+            yield return (key, cast);
+        }
+    }
+
+    /// <summary>
+    ///     Add a new record into this set of entries.
+    /// </summary>
+    /// <param name="station">Station that we're adding the record for.</param>
+    /// <returns>A key that represents the record in this set.</returns>
+    public StationRecordKey AddRecord(EntityUid station)
+    {
+        var key = new StationRecordKey(_currentRecordId++, station);
+
+        _keys.Add(key);
+
+        return key;
+    }
+
+    /// <summary>
+    ///     Add an entry into a record.
+    /// </summary>
+    /// <param name="key">Key for the record.</param>
+    /// <param name="entry">Entry to add.</param>
+    /// <typeparam name="T">Type of the entry that's being added.</typeparam>
+    public void AddRecordEntry<T>(StationRecordKey key, T entry)
+    {
+        if (!_keys.Contains(key) || entry == null)
+        {
+            return;
+        }
+
+        if (!_tables.TryGetValue(typeof(T), out var table))
+        {
+            table = new();
+            _tables.Add(typeof(T), table);
+        }
+
+        table.Add(key, entry);
+    }
+
+    /// <summary>
+    ///     Try to get an record entry by type, from this record key.
+    /// </summary>
+    /// <param name="key">The StationRecordKey to get the entries from.</param>
+    /// <param name="entry">The entry that is retrieved from the record set.</param>
+    /// <typeparam name="T">The type of entry to search for.</typeparam>
+    /// <returns>True if the record exists and was retrieved, false otherwise.</returns>
+    public bool TryGetRecordEntry<T>(StationRecordKey key, [NotNullWhen(true)] out T? entry)
+    {
+        entry = default;
+
+        if (!_keys.Contains(key)
+            || !_tables.TryGetValue(typeof(T), out var table)
+            || !table.TryGetValue(key, out var entryObject))
+        {
+            return false;
+        }
+
+        entry = (T) entryObject;
+        _recentlyAccessed.Add(key);
+
+        return true;
+    }
+
+    /// <summary>
+    ///     Checks if the record associated with this key has an entry of a certain type.
+    /// </summary>
+    /// <param name="key">The record key.</param>
+    /// <typeparam name="T">Type to check.</typeparam>
+    /// <returns>True if the entry exists, false otherwise.</returns>
+    public bool HasRecordEntry<T>(StationRecordKey key)
+    {
+        return _keys.Contains(key)
+               && _tables.TryGetValue(typeof(T), out var table)
+               && table.ContainsKey(key);
+    }
+
+    /// <summary>
+    ///     Get the recently accessed keys from this record set.
+    /// </summary>
+    /// <returns>All recently accessed keys from this record set.</returns>
+    public IEnumerable<StationRecordKey> GetRecentlyAccessed()
+    {
+        return _recentlyAccessed;
+    }
+
+    /// <summary>
+    ///     Clears the recently accessed keys from the set.
+    /// </summary>
+    public void ClearRecentlyAccessed()
+    {
+        _recentlyAccessed.Clear();
+    }
+
+    /// <summary>
+    ///     Removes all record entries related to this key from this set.
+    /// </summary>
+    /// <param name="key">The key to remove.</param>
+    /// <returns>True if successful, false otherwise.</returns>
+    public bool RemoveAllRecords(StationRecordKey key)
+    {
+        if (!_keys.Remove(key))
+        {
+            return false;
+        }
+
+        foreach (var table in _tables.Values)
+        {
+            table.Remove(key);
+        }
+
+        return true;
+    }
+}
+
+