refactor(resolver): port to reader factory

By that, we can remove a lot of boilerplate code and also support
explicitly passing the sbom type.

Signed-off-by: Felix Moessbauer <[email protected]>

Author: fmoessbauer

src/debsbom/resolver/resolver.py

@@ -6,6 +6,7 @@
 from pathlib import Path
 from io import IOBase
 
+from ..bomreader.bomreader import BomReader
 from ..util.sbom_processor import SbomProcessor
 from ..dpkg import package
 from ..sbom import SBOMType
@@ -31,37 +32,30 @@ def create(filename: Path, bomtype: SBOMType | None = None) -> "PackageResolver"
         """
         Factory to create a PackageResolver for the given SBOM type (based on the filename extension).
         """
-        if filename.name.endswith("spdx.json"):
-            SBOMType.SPDX.validate_dependency_availability()
+        reader = BomReader.create(filename, bomtype)
+        if reader.sbom_type() is SBOMType.SPDX:
             from .spdx import SpdxPackageResolver
-            from ..bomreader.spdxbomreader import SpdxBomFileReader
 
-            return SpdxPackageResolver(SpdxBomFileReader(filename).read())
-        elif filename.name.endswith("cdx.json"):
-            SBOMType.CycloneDX.validate_dependency_availability()
+            return SpdxPackageResolver(reader.read())
+        else:
             from .cdx import CdxPackageResolver
-            from ..bomreader.cdxbomreader import CdxBomFileReader
 
-            return CdxPackageResolver(CdxBomFileReader(filename).read())
-        else:
-            raise RuntimeError("Cannot determine file format")
+            return CdxPackageResolver(reader.read())
 
     @staticmethod
     def from_stream(stream: IOBase, bomtype=SBOMType) -> "PackageResolver":
         """
         Factory to create a PackageResolver for the given SBOM type that parses a stream.
         """
-        bomtype.validate_dependency_availability()
-        if bomtype == SBOMType.SPDX:
+        reader = BomReader.from_stream(stream, bomtype)
+        if reader.sbom_type() is SBOMType.SPDX:
             from .spdx import SpdxPackageResolver
-            from ..bomreader.spdxbomreader import SpdxBomReader
 
-            return SpdxPackageResolver(SpdxBomReader.read_stream(stream))
+            return SpdxPackageResolver(reader.read())
         else:
             from .cdx import CdxPackageResolver
-            from ..bomreader.cdxbomreader import CdxBomReader
 
-            return CdxPackageResolver(CdxBomReader.read_stream(stream))
+            return CdxPackageResolver(reader.read())
 
 
 class PackageStreamResolver(PackageResolver):