Add download cleaner and dry run (#58)

code/Common/Configuration/DownloadCleaner/Category.cs

@@ -0,0 +1,45 @@
+using Common.Exceptions;
+using Microsoft.Extensions.Configuration;
+
+namespace Common.Configuration.DownloadCleaner;
+
+public sealed record Category : IConfig
+{
+    public required string Name { get; init; }
+
+    /// <summary>
+    /// Max ratio before removing a download.
+    /// </summary>
+    [ConfigurationKeyName("MAX_RATIO")]
+    public required double MaxRatio { get; init; } = -1;
+
+    /// <summary>
+    /// Min number of hours to seed before removing a download, if the ratio has been met.
+    /// </summary>
+    [ConfigurationKeyName("MIN_SEED_TIME")]
+    public required double MinSeedTime { get; init; } = 0;
+
+    /// <summary>
+    /// Number of hours to seed before removing a download.
+    /// </summary>
+    [ConfigurationKeyName("MAX_SEED_TIME")]
+    public required double MaxSeedTime { get; init; } = -1;
+
+    public void Validate()
+    {
+        if (string.IsNullOrWhiteSpace(Name))
+        {
+            throw new ValidationException($"{nameof(Name)} can not be empty");
+        }
+
+        if (MaxRatio < 0 && MaxSeedTime < 0)
+        {
+            throw new ValidationException($"both {nameof(MaxRatio)} and {nameof(MaxSeedTime)} are disabled");
+        }
+
+        if (MinSeedTime < 0)
+        {
+            throw new ValidationException($"{nameof(MinSeedTime)} can not be negative");
+        }
+    }
+}

code/Common/Configuration/DownloadCleaner/DownloadCleanerConfig.cs

@@ -0,0 +1,36 @@
+using Common.Exceptions;
+using Microsoft.Extensions.Configuration;
+
+namespace Common.Configuration.DownloadCleaner;
+
+public sealed record DownloadCleanerConfig : IJobConfig
+{
+    public const string SectionName = "DownloadCleaner";
+    
+    public bool Enabled { get; init; }
+    
+    public List<Category>? Categories { get; init; }
+
+    [ConfigurationKeyName("DELETE_PRIVATE")]
+    public bool DeletePrivate { get; set; }
+
+    public void Validate()
+    {
+        if (!Enabled)
+        {
+            return;
+        }
+        
+        if (Categories?.Count is null or 0)
+        {
+            throw new ValidationException("no categories configured");
+        }
+
+        if (Categories?.GroupBy(x => x.Name).Any(x => x.Count() > 1) is true)
+        {
+            throw new ValidationException("duplicated categories found");
+        }
+        
+        Categories?.ForEach(x => x.Validate());
+    }
+}