Implement an internal generator for FiggleFonts class

Figgle.Fonts.Generator/Figgle.Fonts.Generator.csproj

@@ -0,0 +1,21 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netstandard2.0</TargetFramework>
+    <IsRoslynComponent>true</IsRoslynComponent>
+    <EnforceExtendedAnalyzerRules>true</EnforceExtendedAnalyzerRules>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.CodeAnalysis.Analyzers">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" PrivateAssets="all" />
+    <PackageReference Include="IsExternalInit" PrivateAssets="all" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\Figgle\Figgle.csproj" />
+  </ItemGroup>
+</Project>

Figgle.Fonts.Generator/FiggleFontGenerator.cs

@@ -0,0 +1,167 @@
+// Copyright Drew Noakes. Licensed under the Apache-2.0 license. See the LICENSE file for more details.
+
+using System;
+using System.Collections.Immutable;
+using System.IO;
+using System.Linq;
+using System.Security;
+using System.Text;
+using Microsoft.CodeAnalysis;
+
+namespace Figgle.Fonts.Generator;
+
+/// <summary>
+/// This is an internal source generator that populates the FiggleFonts class with properties for each bundled font.
+/// It is not intended for public use, but rather to automate the generation of the FiggleFonts class
+/// </summary>
+[Generator(LanguageNames.CSharp)]
+internal sealed class FiggleFontGenerator : IIncrementalGenerator
+{
+    private static readonly string[] _newLineCharacters = ["\r\n", "\n"];
+
+    private static readonly DiagnosticDescriptor _errorParsingFontFileDiagnostic = new(
+        "FIGGLE_IMPL001",
+        "Font Parsing Error",
+        "Failed to parse font '{0}'. Ensure it is a valid FIGlet font file.",
+        "FiggleFonts",
+        DiagnosticSeverity.Error,
+        isEnabledByDefault: true);
+
+    private const string Header =
+        """
+        // Copyright Drew Noakes. Licensed under the Apache-2.0 license. See the LICENSE file for more details.
+
+        // <auto-generated>
+        //     This code was generated by Figgle.Fonts.Generator.
+        //
+        //     Changes to this file may cause incorrect behavior and will be lost if
+        //     the code is regenerated.
+        // </auto-generated>
+
+        """;
+
+    public void Initialize(IncrementalGeneratorInitializationContext context)
+    {
+        var fontMemberNamesProvider = context.AdditionalTextsProvider
+            .Where(file => Path.GetFileName(file.Path).Equals("Aliases.csv", StringComparison.OrdinalIgnoreCase))
+            .Select(static (file, cancellationToken) =>
+            {
+                var csvFileContent = file.GetText(cancellationToken)?.ToString();
+                if (csvFileContent is null)
+                {
+                    return [];
+                }
+
+                var fontInfos = ImmutableArray.CreateBuilder<FontInfo>();
+                var entries = csvFileContent.Split(_newLineCharacters, StringSplitOptions.RemoveEmptyEntries);
+                foreach (var entry in entries)
+                {
+                    var components = entry.Split(',');
+                    if (components.Length == 2)
+                    {
+                        var fontName = components[0].Trim();
+                        var memberName = components[1].Trim();
+                        fontInfos.Add(new FontInfo(fontName, memberName));
+                    }
+                }
+
+                return fontInfos.ToImmutable();
+            });
+
+        var parsedFontsProvider = context.AdditionalTextsProvider
+            .Where(file => file.Path.EndsWith(".flf", StringComparison.OrdinalIgnoreCase))
+            .Select(static (file, cancellationToken) =>
+            {
+                var fontContent = file.GetText(cancellationToken)?.ToString();
+                return new ParsedFont(
+                    Path.GetFileNameWithoutExtension(file.Path),
+                    fontContent is null ? null : FiggleFontParser.ParseString(fontContent));
+            })
+            .Collect();
+
+        context.RegisterSourceOutput(fontMemberNamesProvider.Combine(parsedFontsProvider), (context, pair) =>
+        {
+            var fontInfos = pair.Left;
+            var parsedFonts = pair.Right.ToImmutableDictionary(
+                keySelector: f => f.Name,
+                elementSelector: f => f.Font);
+
+            foreach (var kvp in parsedFonts)
+            {
+                if (kvp.Value is null)
+                {
+                    context.ReportDiagnostic(Diagnostic.Create(
+                        _errorParsingFontFileDiagnostic,
+                        Location.None,
+                        kvp.Key));
+                }
+            }
+
+            var source = $$"""
+                {{Header}}
+                namespace Figgle.Fonts;
+
+                partial class FiggleFonts
+                {{{RenderFiggleFontProperties(fontInfos, parsedFonts)}}
+                }
+                """;
+
+            // we expect only a single Alias.csv file, so we don't need to worry about making
+            // the source file name unique.
+            context.AddSource("FiggleFonts.g.cs", source);
+
+            static string RenderFiggleFontProperties(
+                ImmutableArray<FontInfo> fontInfos,
+                ImmutableDictionary<string, FiggleFont?> parsedFonts)
+            {
+                var builder = new StringBuilder(capacity: 4096);
+                var indentation = new string(' ', 4);
+                foreach (var fontInfo in fontInfos)
+                {
+                    builder.Append($$"""
+
+
+                        {{indentation}}/// <summary>
+                        {{indentation}}/// Obtains the <see cref="Figgle.FiggleFont" /> for the font name "{{fontInfo.FontName}}".
+                        {{indentation}}/// <example>
+                        {{indentation}}/// <code>
+                        {{indentation}}{{RenderSampleText(fontInfo.FontName, parsedFonts[fontInfo.FontName], indentation)}}
+                        {{indentation}}/// </code>
+                        {{indentation}}/// </example>
+                        {{indentation}}/// </summary>
+                        {{indentation}}public static FiggleFont {{fontInfo.MemberName}} => GetByName("{{fontInfo.FontName}}");
+                        """);
+                }
+
+                return builder.ToString();
+            }
+
+            static string RenderSampleText(string fontName, FiggleFont? font, string indentation)
+            {
+                if (font is null)
+                {
+                    return $"Failed to parse {fontName} into a {nameof(FiggleFont)}";
+                }
+
+                var renderedText = font.Render(fontName);
+
+                return string.Join(
+                    $"\r\n{indentation}",
+                    renderedText
+                        .Split(_newLineCharacters, StringSplitOptions.None)
+                        .Select(line => $"/// {EscapeXmlSpecialCharacters(line)}"));
+            }
+
+            static string EscapeXmlSpecialCharacters(string text)
+            {
+                // SecurityElement conveniently has Escape that escapes XML special
+                // characters, so we can just reuse it.
+                return SecurityElement.Escape(text);
+            }
+        });
+    }
+
+    private sealed record FontInfo(string FontName, string MemberName);
+
+    private sealed record ParsedFont(string Name, FiggleFont? Font);
+}

Figgle.Fonts/Aliases.csv

@@ -0,0 +1,92 @@
+1row,OneRow
+3-d,ThreeD
+3d_diagonal,ThreeDDiagonal
+3x5,ThreeByFive
+4max,FourMax
+5lineoblique,FiveLineOblique
+amc3line,Amc3Line
+amc3liv1,Amc3Liv1
+amcaaa01,AmcAaa01
+amcneko,AmcNeko
+amcrazo2,AmcRazor2
+amcrazor,AmcRazor
+amcslash,AmcSlash
+amcslder,AmcSlder
+amcthin,AmcThin
+amctubes,AmcTubes
+amcun1,AmcUn1
+barbwire,BarbWire
+bigchief,BigChief
+bigfig,BigFig
+broadway_kb,BroadwayKB
+calgphy2,Caligraphy2
+catwalk,CatWalk
+cyberlarge,CyberLarge
+cybermedium,CyberMedium
+cybersmall,CyberSmall
+dancingfont,DancingFont
+defleppard,DefLeppard
+dietcola,DietCola
+dosrebel,DosRebel
+dotmatrix,DotMatrix
+doubleshorts,DoubleShorts
+drpepper,DRPepper
+dwhistled,DWhistled
+eftichess,EftiChess
+eftifont,EftiFont
+eftipiti,EftiPiti
+eftirobot,EftiRobot
+eftitalic,EftiItalic
+eftiwall,EftiWall
+eftiwater,EftiWater
+flowerpower,FlowerPower
+fourtops,FourTops
+funface,FunFace
+funfaces,FunFaces
+georgi16,Georgia16
+Georgia11,Georgia11
+graffiti,Graffiti
+henry3d,Henry3d
+horizontalleft,HorizontalLeft
+horizontalright,HorizontalRight
+impossible,Impossible
+kontoslant,KontoSlant
+larry3d,Larry3d
+lildevil,LilDevil
+lineblocks,LineBlocks
+lockergnome,LockerGnome
+maxfour,MaxFour
+mshebrew210,Mshebrew210
+nancyj,NancyJ
+nancyj-fancy,NancyJFancy
+nancyj-improved,NancyJImproved
+nancyj-underlined,NancyJUnderlined
+nscript,NScript
+ntgreek,NTGreek
+nvscript,NVScript
+oldbanner,OldBanner
+os2,OS2
+ogre,Ogre
+peaksslant,PeaksSlant
+rectangles,Rectangles
+rowancap,RowanCap
+santaclara,SantaClara
+sblood,SBlood
+slant,Slant
+slscript,ScriptSlant
+serifcap,SerifCap
+smallcaps,SmallCaps
+smisome1,IsometricSmall
+smkeyboard,KeyboardSmall
+smpoison,PoisonSmall
+smscript,ScriptSmall
+smshadow,ShadowSmall
+smslant,SlantSmall
+smtengwar,TengwarSmall
+standard,Standard
+threepoint,ThreePoint
+ticksslant,TicksSlant
+tinker-toy,TinkerToy
+twopoint,TwoPoint
+usaflag,UsaFlag
+wetletter,WetLetter

Figgle.Fonts/Figgle.Fonts.csproj

@@ -24,6 +24,11 @@
     <EmbeddedResource Include="$(FontsZipFile)" LogicalName="Figgle.Fonts.zip" />
   </ItemGroup>
 
+  <ItemGroup Label="Internal source generator configurations">
+    <AdditionalFiles Include="Aliases.csv" />
+    <AdditionalFiles Include="@(FontFiles)" Visible="false" />
+  </ItemGroup>
+
   <ItemGroup>
     <InternalsVisibleTo Include="Figgle.Tests" />
     <InternalsVisibleTo Include="Figgle.Generator" />
@@ -33,6 +38,18 @@
     <ProjectReference Include="..\Figgle\Figgle.csproj" />
   </ItemGroup>
 
+  <ItemGroup>
+    <ProjectReference Include="..\Figgle.Fonts.Generator\Figgle.Fonts.Generator.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" />
+
+    <!-- 
+      Figgle.Fonts.Generator depends on Figgle to generate sample text documentation, so we must include it as an "analyzer" to make it available
+      to the generator.
+
+      Note that this project *also* has a runtime dependency to Figgle, which we set as a normal ProjectReference above.  The two do not conflict.
+    -->
+    <ProjectReference Include="..\Figgle\Figgle.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" />
+  </ItemGroup>
+
   <!-- Create the zip file before build -->
   <Target Name="CreateFontsZip" BeforeTargets="PrepareForBuild" Inputs="@(FontFiles)" Outputs="$(FontsZipFile)" Condition="'$(DesignTimeBuild)' != 'true' AND '$(BuildingProject)' == 'true'">