[#47] Billing: Add penalty per business share

Elwig/Helpers/AppDbContext.cs

@@ -354,6 +354,27 @@ namespace Elwig.Helpers {
             _memberUnderDelivery[year] = buckets;
         }
 
+        public async Task<Dictionary<int, long>> GetBusinessSharePenalties(int year) {
+            using var cnx = await ConnectAsync();
+            var dict = new Dictionary<int, long>();
+            using var cmd = cnx.CreateCommand();
+            cmd.CommandText = $"""
+                SELECT mgnr, ROUND((
+                      COALESCE(-s.penalty_amount, 0) +
+                      COALESCE(-s.penalty_per_bs_amount * CEIL(CAST(-u.diff AS REAL) / s.min_kg_per_bs), 0) +
+                      COALESCE(u.diff * s.penalty_per_kg, 0)
+                    ) / POW(10, s.precision - 2))
+                FROM v_total_under_delivery u
+                    JOIN season s ON s.year = u.year
+                WHERE s.year = {year} AND u.diff < 0
+                """;
+            using var reader = await cmd.ExecuteReaderAsync();
+            while (await reader.ReadAsync()) {
+                dict[reader.GetInt32(0)] = reader.GetInt64(1);
+            }
+            return dict;
+        }
+
         public async Task<Dictionary<string, AreaComBucket>> GetMemberAreaCommitmentBuckets(int year, int mgnr, SqliteConnection? cnx = null) {
             if (!_memberAreaCommitmentBuckets.ContainsKey(year))
                 await FetchMemberAreaCommitmentBuckets(year, cnx);