fix(db): fill-forward candles buckets

kustomize/base/initdb/001_init.sql

@@ -162,10 +162,12 @@ RETURNS SETOF public.drift_candles
 LANGUAGE sql
 STABLE
 AS $$
+  -- Zwraca zawsze "ciągłe" buckety (fill forward), nawet jeśli nie było ticków w danej sekundzie/minucie.
+  -- Dzięki temu frontend może rysować regularną oś czasu (np. 1px = 1s) bez dziwnych przeskoków.
   WITH src AS (
     SELECT COALESCE(p_source, '') AS source_key
   ),
-  cached AS (
+  raw_cached AS (
     SELECT
       c.bucket,
       c.open,
@@ -181,7 +183,7 @@ AS $$
     ORDER BY c.bucket DESC
     LIMIT p_limit
   ),
-  fallback AS (
+  raw_fallback AS (
     SELECT
       time_bucket(make_interval(secs => p_bucket_seconds), ts) AS bucket,
       ts,
@@ -201,13 +203,88 @@ AS $$
       (array_agg(px ORDER BY ts DESC))[1] AS close,
       (array_agg(oracle_px ORDER BY ts DESC))[1] AS oracle_close,
       count(*) AS ticks
-    FROM fallback
+    FROM raw_fallback
     GROUP BY bucket
-  )
-  SELECT * FROM cached
+  ),
+  data AS (
+    SELECT * FROM raw_cached
     UNION ALL
     SELECT * FROM computed
-  WHERE NOT EXISTS (SELECT 1 FROM cached)
+    WHERE NOT EXISTS (SELECT 1 FROM raw_cached)
+  ),
+  bounds AS (
+    SELECT max(bucket) AS end_bucket FROM data
+  ),
+  params AS (
+    SELECT
+      make_interval(secs => p_bucket_seconds) AS step,
+      make_interval(secs => (p_bucket_seconds * (p_limit - 1))) AS span
+  ),
+  series AS (
+    SELECT generate_series(
+      bounds.end_bucket - params.span,
+      bounds.end_bucket,
+      params.step
+    ) AS bucket
+    FROM bounds, params
+    WHERE bounds.end_bucket IS NOT NULL
+  ),
+  joined AS (
+    SELECT
+      s.bucket,
+      d.open,
+      d.high,
+      d.low,
+      d.close,
+      d.oracle_close,
+      d.ticks
+    FROM series s
+    LEFT JOIN data d USING (bucket)
+    ORDER BY s.bucket ASC
+  ),
+  grouped AS (
+    SELECT
+      *,
+      sum(CASE WHEN close IS NOT NULL THEN 1 ELSE 0 END) OVER (ORDER BY bucket ASC) AS grp_close,
+      sum(CASE WHEN oracle_close IS NOT NULL THEN 1 ELSE 0 END) OVER (ORDER BY bucket ASC) AS grp_oracle
+    FROM joined
+  ),
+  first_vals AS (
+    SELECT
+      (SELECT close FROM grouped WHERE close IS NOT NULL ORDER BY bucket ASC LIMIT 1) AS first_close,
+      (SELECT oracle_close FROM grouped WHERE oracle_close IS NOT NULL ORDER BY bucket ASC LIMIT 1) AS first_oracle
+  ),
+  ff AS (
+    SELECT
+      g.bucket,
+      g.open,
+      g.high,
+      g.low,
+      g.close,
+      g.oracle_close,
+      g.ticks,
+      COALESCE(
+        g.close,
+        max(g.close) OVER (PARTITION BY g.grp_close),
+        f.first_close
+      ) AS ff_close,
+      COALESCE(
+        g.oracle_close,
+        max(g.oracle_close) OVER (PARTITION BY g.grp_oracle),
+        f.first_oracle
+      ) AS ff_oracle
+    FROM grouped g
+    CROSS JOIN first_vals f
+  )
+  SELECT
+    bucket,
+    COALESCE(open, ff_close) AS open,
+    COALESCE(high, ff_close) AS high,
+    COALESCE(low, ff_close) AS low,
+    COALESCE(close, ff_close) AS close,
+    COALESCE(oracle_close, ff_oracle) AS oracle_close,
+    COALESCE(ticks, 0) AS ticks
+  FROM ff
   ORDER BY bucket DESC
   LIMIT p_limit;
 $$;