✨ Create new plugins library to reduce dependencies

build.cake

@@ -5,9 +5,11 @@ Task("Define-Project")
     .Does<BuildInfo>(info =>
 {
     info.CoverageTarget = 99; // can't be 100 due to platform-specific code paths
+    info.WarningsAsErrors = false; // TEMP
 
     info.AddLibraryProjects("Yarhl");
     info.AddLibraryProjects("Yarhl.Media.Text");
+    info.AddLibraryProjects("Yarhl.Plugins");
     info.AddTestProjects("Yarhl.UnitTests");
     info.AddTestProjects("Yarhl.IntegrationTests");
 

src/Yarhl.Plugins/AssemblyUtils.cs

@@ -0,0 +1,52 @@
+// Copyright (c) 2019 SceneGate
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+namespace Yarhl.Plugins
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Reflection;
+    using System.Runtime.Loader;
+
+    /// <summary>
+    /// Utilities to work with Assemblies.
+    /// </summary>
+    internal static class AssemblyUtils
+    {
+        /// <summary>
+        /// Load assemblies.
+        /// </summary>
+        /// <param name="paths">List of assemblies to load.</param>
+        /// <returns>The assemblies.</returns>
+        public static IEnumerable<Assembly> LoadAssemblies(this IEnumerable<string> paths)
+        {
+            List<Assembly> assemblies = new List<Assembly>();
+            foreach (string path in paths) {
+                try {
+                    Assembly assembly = AssemblyLoadContext.Default.LoadFromAssemblyPath(path);
+                    assemblies.Add(assembly);
+                } catch (BadImageFormatException) {
+                    // Bad IL. Skip.
+                }
+            }
+
+            return assemblies;
+        }
+    }
+}

src/Yarhl.Plugins/FileFormat/ConverterMetadata.cs

@@ -0,0 +1,145 @@
+// Copyright (c) 2019 SceneGate
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+namespace Yarhl.Plugins.FileFormat
+{
+    using System;
+
+    /// <summary>
+    /// Metadata associated to a IConverter interface.
+    /// </summary>
+    public class ConverterMetadata : IExportMetadata
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ConverterMetadata" /> class.
+        /// </summary>
+        public ConverterMetadata()
+        {
+            // MEF should always set these properties, so they won't be null.
+            // We set some initial values to ensure later they are not set to null.
+            Name = "<invalid>";
+            Type = typeof(ConverterMetadata);
+            InternalSources = Type.EmptyTypes;
+            InternalDestinations = Type.EmptyTypes;
+        }
+
+        /// <summary>
+        /// Gets or sets the full name of the type. Shortcut of Type.FullName.
+        /// </summary>
+        /// <value>The full name of the type.</value>
+        public string Name { get; set; }
+
+        /// <summary>
+        /// Gets or sets the type of class implementing the converter.
+        /// </summary>
+        /// <value>Type of the converter.</value>
+        public Type Type { get; set; }
+
+        /// <summary>
+        /// Gets or sets a single type or list of types that the converter
+        /// can convert from.
+        /// </summary>
+        /// <value>Single or list of types for conversion.</value>
+        public object InternalSources { get; set; }
+
+        /// <summary>
+        /// Gets or sets a single type or list of types the converter can
+        /// convert to.
+        /// </summary>
+        /// <value>Single or list of types the converter can convert to.</value>
+        public object InternalDestinations { get; set; }
+
+        /// <summary>
+        /// Gets a list of source types that can convert from.
+        /// </summary>
+        /// <returns>List of source types that can convert from.</returns>
+        public Type[] GetSources()
+        {
+            if (InternalSources is not Type[] sourceList) {
+                sourceList = new[] { (Type)InternalSources };
+            }
+
+            return sourceList;
+        }
+
+        /// <summary>
+        /// Gets a list of destination types it can convert to.
+        /// </summary>
+        /// <returns>Destination types it can convert to.</returns>
+        public Type[] GetDestinations()
+        {
+            if (InternalDestinations is not Type[] destList) {
+                destList = new[] { (Type)InternalDestinations };
+            }
+
+            return destList;
+        }
+
+        /// <summary>
+        /// Check if the associated converter can convert from a given type.
+        /// It checks applying covariance rules.
+        /// </summary>
+        /// <param name="source">Source type for conversion.</param>
+        /// <returns>If this converter can realize the operation.</returns>
+        public bool CanConvert(Type source)
+        {
+            if (source == null)
+                throw new ArgumentNullException(nameof(source));
+
+            Type[] sources = GetSources();
+            for (int i = 0; i < sources.Length; i++) {
+                if (sources[i].IsAssignableFrom(source)) {
+                    return true;
+                }
+            }
+
+            return false;
+        }
+
+        /// <summary>
+        /// Check if the associated converter can convert from a given type
+        /// into another. It checks applying covariance and contravariance
+        /// rules.
+        /// </summary>
+        /// <param name="source">Source type for conversion.</param>
+        /// <param name="dest">Destination type for conversion.</param>
+        /// <returns>If this converter can realize the operation.</returns>
+        public bool CanConvert(Type source, Type dest)
+        {
+            if (source == null)
+                throw new ArgumentNullException(nameof(source));
+
+            if (dest == null)
+                throw new ArgumentNullException(nameof(dest));
+
+            Type[] sources = GetSources();
+            Type[] destinations = GetDestinations();
+
+            for (int i = 0; i < sources.Length; i++) {
+                bool matchSource = sources[i].IsAssignableFrom(source);
+                bool matchDest = dest.IsAssignableFrom(destinations[i]);
+                if (matchSource && matchDest) {
+                    return true;
+                }
+            }
+
+            return false;
+        }
+    }
+}

src/Yarhl.Plugins/FileFormat/FormatMetadata.cs

@@ -0,0 +1,52 @@
+// Copyright (c) 2019 SceneGate
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+namespace Yarhl.Plugins.FileFormat
+{
+    using System;
+
+    /// <summary>
+    /// Metadata associated to a Format class.
+    /// </summary>
+    public class FormatMetadata : IExportMetadata
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="FormatMetadata" /> class.
+        /// </summary>
+        public FormatMetadata()
+        {
+            // MEF should always set these properties, so they won't be null.
+            // We set some initial values to ensure later they are not set to null.
+            Name = "<invalid>";
+            Type = typeof(FormatMetadata);
+        }
+
+        /// <summary>
+        /// Gets or sets the type full name. Shortcut of Type.FullName.
+        /// </summary>
+        /// <value>The full name of the type.</value>
+        public string Name { get; set; }
+
+        /// <summary>
+        /// Gets or sets the type of the format.
+        /// </summary>
+        /// <value>The type of the format.</value>
+        public Type Type { get; set; }
+    }
+}

src/Yarhl.Plugins/FileFormat/IExportMetadata.cs

@@ -0,0 +1,42 @@
+// Copyright (c) 2019 SceneGate
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+namespace Yarhl.Plugins.FileFormat
+{
+    using System;
+
+    /// <summary>
+    /// Base metadata associated to a exported type.
+    /// </summary>
+    public interface IExportMetadata
+    {
+        /// <summary>
+        /// Gets or sets the name of the extension.
+        /// Usually it's the FullName property of Type.
+        /// </summary>
+        /// <value>Name of the extension.</value>
+        string Name { get; set; }
+
+        /// <summary>
+        /// Gets or sets the type of the extension.
+        /// </summary>
+        /// <value>The type of the extension.</value>
+        Type Type { get; set; }
+    }
+}