fix: hacky fix for files with subloops (#193)

* fix: small hack for strange file

* update comment

* style(pre-commit.ci): auto fixes [...]

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

src/nd2/_parse/_parse.py

@@ -187,7 +187,7 @@ def _parse_ne_time_loop(item: NETimeLoopPars) -> strct.NETimeLoop:
 
 
 def load_experiment(
-    level: int, src: RawExperimentDict, dest: list[ExpLoop] | None = None
+    src: RawExperimentDict, level: int = 0, dest: list[ExpLoop] | None = None
 ) -> list[ExpLoop]:
     """Parse the "ImageMetadata[LV]!" section of an nd2 file."""
     dest = dest or []
@@ -208,10 +208,24 @@ def load_experiment(
             if prev.count < loop.count:
                 dest[-1] = loop
 
+    # FIXME:
+    # hack for file in https://github.com/tlambert03/nd2/issues/190
+    # there is a better fix, but this is a very rare case
+    loop_params = src.get("uLoopPars", {})
+    if "pSubLoops" in loop_params:
+        loop_params = cast("NETimeLoopPars", loop_params)
+        subloops = loop_params["pSubLoops"]
+        i0 = "i0000000000"
+        if i0 in subloops:
+            subnext = subloops[i0]["ppNextLevelEx"]
+            if i0 in subnext:
+                experiment = subnext[i0]["SLxExperiment"]
+                dest.extend(load_experiment(experiment))
+
     next_level_src = src.get("ppNextLevelEx")
     if next_level_src:
         for item in next_level_src.values():
-            dest = load_experiment(level + 1, item, dest)
+            dest = load_experiment(item, level + 1, dest)
 
     return dest
 

src/nd2/_sdk_types.py

@@ -157,6 +157,14 @@ class SpectLoopPars(TypedDict):
         pPlanes: PicturePlanesDict
         uiCount: NotRequired[int]
 
+    class SLxExperimentDict(TypedDict):
+        SLxExperiment: RawExperimentDict
+
+    class SubLoopDict(TypedDict):
+        uiNextLevelCount: int
+        # this is a dict of keys 'i0000000000', 'i0000000001', etc.
+        ppNextLevelEx: dict[str, SLxExperimentDict]
+
     class NETimeLoopPars(TypedDict):
         # keys are '_00' or 'i0000000000' ...
         pPeriod: dict[str, PeriodDict]
@@ -167,6 +175,8 @@ class NETimeLoopPars(TypedDict):
         uiPeriodCount: int
         wsCommandAfterPeriod: str
         wsCommandBeforePeriod: str
+        # this is a dict of keys 'i0000000000', 'i0000000001', etc.
+        pSubLoops: NotRequired[dict[str, SubLoopDict]]
 
     LoopParsDict: TypeAlias = Union[
         TimeLoopPars, XYPosLoopPars, ZStackLoopPars, SpectLoopPars, NETimeLoopPars

src/nd2/readers/_modern/modern_reader.py

@@ -219,7 +219,7 @@ def experiment(self) -> list[structures.ExpLoop]:
                 exp = self._decode_chunk(k, strip_prefix=False)
                 exp = exp.get("SLxExperiment", exp)  # for v3 only
                 self._raw_experiment = cast("RawExperimentDict", exp)
-                self._experiment = load_experiment(0, self._raw_experiment)
+                self._experiment = load_experiment(self._raw_experiment)
         return self._experiment
 
     def loop_indices(self) -> list[dict[str, int]]: