feat: add the metadata interface to the reporter class

snakemake_interface_report_plugins/reporter.py

@@ -5,7 +5,7 @@
 
 
 from abc import ABC, abstractmethod
-from typing import List, Mapping
+from typing import List, Mapping, Dict, Optional, Union
 from snakemake_interface_report_plugins.interfaces import (
     CategoryInterface,
     ConfigFileRecordInterface,
@@ -28,6 +28,9 @@ def __init__(
         settings: ReportSettingsBase,
         workflow_description: str,
         dag: DAGReportInterface,
+        metadata: Optional[
+            Dict[str, Union[str, int, float, List[str], List[int], List[float]]]
+        ] = {},
     ):
         self.rules = rules
         self.jobs = jobs
@@ -37,10 +40,40 @@ def __init__(
         self.workflow_description = workflow_description
         self.dag = dag
 
+        # ensure that metadata is a key value dictionary
+        if not validate_flat_dict(metadata):
+            raise TypeError(
+                "Metadata must be single level dict[str, str | int | float | list[str] | list[int] | list[float]]]"
+            )
+
+        self.metadata = metadata
+
         self.__post_init__()
 
     def __post_init__(self):
         pass
 
     @abstractmethod
     def render(self): ...
+
+
+def is_valid_flat_value(value) -> bool:
+    if isinstance(value, (str, int, float)):
+        return True
+    elif isinstance(value, list):
+        return all(isinstance(item, (str, int, float)) for item in value)
+    else:
+        return False
+
+
+def validate_flat_dict(metadata: dict) -> bool:
+    if not isinstance(metadata, dict):
+        return False
+
+    for k, v in metadata.items():
+        if not isinstance(k, str):
+            return False
+        if not is_valid_flat_value(v):
+            return False
+
+    return True