気象庁のコード表を自動で更新する

AreaEpicenter[100] // 石狩地方北部

(await parser.ParseDocumentAsync(new MemoryStream(pageContent), CancellationToken.None))
    .QuerySelectorAll("a").Where(a => a.TextContent.Contains("個別コード表")).Select(a => a.GetAttribute("href")).First()

using var zipStream = await zipResponse.Content.ReadAsStreamAsync();
using var zipArchive = new ZipArchive(zipStream, ZipArchiveMode.Read, false, Encoding.GetEncoding("Shift_JIS"));

foreach (var entry in zipArchive.Entries)
{
    Console.WriteLine(entry.FullName);
    if (!entry.FullName.EndsWith(".xls"))
        continue;

    // 直接 Zip から読み込むとエラーになるので一旦メモリに展開
    using var memStream = new MemoryStream();
    using (var cStream = entry.Open())
        cStream.CopyTo(memStream);
    memStream.Seek(0, SeekOrigin.Begin);
    try
    {
        using var workbook = WorkbookFactory.Create(memStream, true);

using Microsoft.CodeAnalysis.Text;
using Microsoft.CodeAnalysis;
using System.Text;

namespace KyoshinEewViewer.CsvSourceGenerator;

[Generator(LanguageNames.CSharp)]
public partial class CsvDictionaryGenerator : ISourceGenerator
{
    public static string GenerateClassFile(StringBuilder sb, string dictionaryName, string csvText, string keyType, string keyFormat, string valueType, string valueFormat)
    {
        using var reader = new StringReader(csvText);

        sb.AppendLine($"        public static System.Collections.Generic.IReadOnlyDictionary<{keyType}, {valueType}> {dictionaryName} {{ get; }} = new System.Collections.Generic.Dictionary<{keyType}, {valueType}>(){{");

        while (true)
        {
            var line = reader.ReadLine();
            if (line == null) break;
            var fields = line.Split(',');
            sb.AppendLine($"            {{ {string.Format(keyFormat, fields)}, {string.Format(valueFormat, fields)} }},");
        }

        sb.AppendLine("        };");

        return sb.ToString();
    }
    private static StringBuilder SourceFilesFromAdditionalFiles(IEnumerable<(AdditionalText file, string keyType, string keyFormat, string valueType, string valueFormat)> pathsData)
    {
        var sb = new StringBuilder();
        sb.AppendLine(@"
#nullable enable
namespace KyoshinEewViewer {
    public static class CsvDictionary {");
        foreach (var (file, keyType, keyFormat, valueType, valueFormat) in pathsData)
        {
            var className = Path.GetFileNameWithoutExtension(file.Path);
            var csvText = file.GetText()!.ToString();
            GenerateClassFile(sb, className, csvText, keyType, keyFormat, valueType, valueFormat);
        }
        sb.AppendLine("    }\r\n}");
        return sb;
    }

    private static IEnumerable<(AdditionalText, string, string, string, string)> GetLoadOptions(GeneratorExecutionContext context)
    {
        foreach (var file in context.AdditionalFiles)
        {
            if (!Path.GetExtension(file.Path).Equals(".csv", StringComparison.OrdinalIgnoreCase))
                continue;

            context.AnalyzerConfigOptions.GetOptions(file).TryGetValue("build_metadata.Additionalfiles.KeyType", out var keyType);
            context.AnalyzerConfigOptions.GetOptions(file).TryGetValue("build_metadata.Additionalfiles.KeyFormat", out var keyFormat);
            context.AnalyzerConfigOptions.GetOptions(file).TryGetValue("build_metadata.Additionalfiles.ValueType", out var valueType);
            context.AnalyzerConfigOptions.GetOptions(file).TryGetValue("build_metadata.Additionalfiles.ValueFormat", out var valueFormat);

            if (keyType == null)
                throw new Exception("KeyType is not defined.");
            if (keyFormat == null)
                throw new Exception("KeyFormat is not defined.");

            if (valueType == null)
                throw new Exception("ValueType is not defined.");
            if (valueFormat == null)
                throw new Exception("ValueFormat is not defined.");

            yield return (file, keyType, keyFormat, valueType, valueFormat);
        }
    }

    public void Execute(GeneratorExecutionContext context)
        => context.AddSource($"CsvDictionary.g.cs", SourceText.From(SourceFilesFromAdditionalFiles(GetLoadOptions(context)).ToString(), Encoding.UTF8));

    public void Initialize(GeneratorInitializationContext context)
    {
    }
}

public static System.Collections.Generic.IReadOnlyDictionary<int, string> AdditionalCommentEarthquake { get; } = new System.Collections.Generic.Dictionary<int, string>(){
    { 0101, "今後若干の海面変動があるかもしれません。" },
    { 0102, "今後若干の海面変動があるかもしれませんが、被害の心配はありません。" },
    { 0103, "今後もしばらく海面変動が続くと思われます。" },
    { 0104, "今後もしばらく海面変動が続くと思われますので、海水浴や磯釣り等を行う際は注意してください。" },
    { 0105, "今後もしばらく海面変動が続くと思われますので、磯釣り等を行う際は注意してください。" },
    以下略

public static System.Collections.Generic.IReadOnlyDictionary<int, (string Name, string NameKana)> AreaForecastLocalEEW { get; } = new System.Collections.Generic.Dictionary<int, (string Name, string NameKana)>(){
    { 9011, ("北海道道央", "ほっかいどうどうおう") },
    { 9012, ("北海道道南", "ほっかいどうどうなん") },
    { 9013, ("北海道道北", "ほっかいどうどうほく") },
    { 9014, ("北海道道東", "ほっかいどうどうとう") },
    以下略