gregExtractor/SnapshotStore.cs

using System.Text.Json;

namespace gregExtractor;

public sealed class SnapshotStore
{
    private readonly JsonSerializerOptions _jsonOptions = new()
    {
        WriteIndented = true,
    };

    public SnapshotStore(string stateDirectory)
    {
        StateDirectory = stateDirectory;
        Directory.CreateDirectory(StateDirectory);
        SnapshotPath = Path.Combine(StateDirectory, "source-snapshot.json");
        ReportPath = Path.Combine(StateDirectory, "last-change-report.json");
    }

    public string StateDirectory { get; }
    public string SnapshotPath { get; }
    public string ReportPath { get; }

    public SourceSnapshot? TryLoadSnapshot()
    {
        if (!File.Exists(SnapshotPath))
            return null;

        string json = File.ReadAllText(SnapshotPath);
        return JsonSerializer.Deserialize<SourceSnapshot>(json, _jsonOptions);
    }

    public void SaveSnapshot(SourceSnapshot snapshot)
    {
        string json = JsonSerializer.Serialize(snapshot, _jsonOptions);
        File.WriteAllText(SnapshotPath, json);
    }

    public void SaveReport(ChangeReport report)
    {
        string json = JsonSerializer.Serialize(report, _jsonOptions);
        File.WriteAllText(ReportPath, json);
    }
}