Move CatalogKey, ColumnMetadata, ColumnMap, CatalogTable to dbt-common (

#147)

* Move CatalogKey, ColumnMetadata, ColumnMap, CatalogTable to dbt-common

* Add changie

.changes/unreleased/Under the Hood-20240603-123631.yaml

@@ -0,0 +1,6 @@
+kind: Under the Hood
+body: Move CatalogKey, ColumnMetadata, ColumnMap, CatalogTable to dbt-common
+time: 2024-06-03T12:36:31.542118+02:00
+custom:
+    Author: aranke
+    Issue: "147"

dbt_common/contracts/metadata.py

@@ -1,7 +1,8 @@
 from dataclasses import dataclass
-from typing import Dict, Optional, Union
+from typing import Dict, Optional, Union, NamedTuple
 
 from dbt_common.dataclass_schema import dbtClassMixin
+from dbt_common.utils.formatting import lowercase
 
 
 @dataclass
@@ -24,3 +25,35 @@ class TableMetadata(dbtClassMixin):
     database: Optional[str] = None
     comment: Optional[str] = None
     owner: Optional[str] = None
+
+
+CatalogKey = NamedTuple(
+    "CatalogKey", [("database", Optional[str]), ("schema", str), ("name", str)]
+)
+
+
+@dataclass
+class ColumnMetadata(dbtClassMixin):
+    type: str
+    index: int
+    name: str
+    comment: Optional[str] = None
+
+
+ColumnMap = Dict[str, ColumnMetadata]
+
+
+@dataclass
+class CatalogTable(dbtClassMixin):
+    metadata: TableMetadata
+    columns: ColumnMap
+    stats: StatsDict
+    # the same table with two unique IDs will just be listed two times
+    unique_id: Optional[str] = None
+
+    def key(self) -> CatalogKey:
+        return CatalogKey(
+            lowercase(self.metadata.database),
+            self.metadata.schema.lower(),
+            self.metadata.name.lower(),
+        )