update docs and prep for frontend

VigilCareClinicalAPI/Services/QsofaService.cs

@@ -0,0 +1,54 @@
+using Microsoft.EntityFrameworkCore;
+using StackExchange.Redis;
+
+public class QsofaService : IQsofaService
+{
+    private readonly AppDbContext _db;
+    private readonly IConnectionMultiplexer _redis;
+
+    public QsofaService(AppDbContext db, IConnectionMultiplexer redis)
+    {
+        _db = db;
+        _redis = redis;
+    }
+
+    public async Task<QsofaCurrentResponse> GetCurrentAsync(Guid encounterId)
+    {
+        await EnsureEncounterExistsAsync(encounterId);
+
+        var values = await ReadCriterionValuesAsync(encounterId);
+        return BuildResponse(values);
+    }
+
+    public async Task<int> GetActiveCriteriaCountAsync(Guid encounterId)
+    {
+        var values = await ReadCriterionValuesAsync(encounterId);
+        return QsofaCalculator.CountActiveCriteria(values);
+    }
+
+    private async Task EnsureEncounterExistsAsync(Guid encounterId)
+    {
+        var exists = await _db.Encounters.AnyAsync(e => e.Id == encounterId);
+        if (!exists)
+            throw new NotFoundException("Encounter not found.", "ENCOUNTER_NOT_FOUND");
+    }
+
+    private async Task<RedisValue[]> ReadCriterionValuesAsync(Guid encounterId)
+    {
+        var cache = _redis.GetDatabase();
+        return await cache.StringGetAsync(QsofaCalculator.AllCriterionKeys(encounterId));
+    }
+
+    private static QsofaCurrentResponse BuildResponse(RedisValue[] values)
+    {
+        return new QsofaCurrentResponse(
+            QsofaCalculator.CountActiveCriteria(values),
+            new QsofaCriteriaState(
+                ParseOptionalDecimal(values[0]),
+                ParseOptionalDecimal(values[1]),
+                ParseOptionalDecimal(values[2])));
+    }
+
+    private static decimal? ParseOptionalDecimal(RedisValue value) =>
+        value.HasValue ? decimal.Parse(value.ToString()) : null;
+}