fix(mega): use config file name for final merge (#78)

Based on feedback from Henky, updates mergekit-mega to require one of
the merges to omit the name key, that will then use the name of the
config file for the name.
Also fixes a bug I introduced when allowing the base model to be an
intermediate model where it wouldn't update the merge models to the
correct path
And removes some unnecessary print statements that I forgot to remove

mergekit/scripts/megamerge.py

@@ -53,7 +53,7 @@ def dfs(node, visited, stack):
     return None
 
 
-def merge(m, merge_options, force, out_path):
+def merge(m: str, merge_options: MergeOptions, force: bool, out_path: Path):
     """
     Merges a model and its dependencies
 
@@ -86,23 +86,23 @@ def merge(m, merge_options, force, out_path):
     del merges[m]
 
 
-def add_model_deps(model, name, out_path):
+def add_model_deps(model: str, name: str, out_path: Path):
     """
     Adds a model to `name`s dependencies if it is not already there and is a merge
     """
     model_lora = model.split("+")
     # name must not have a slash to avoid path traversal
     # therefore, we can use it to check if its a merge from the config
-    print(model_lora)
     if "/" not in model_lora[0]:
-        print(model_lora)
         # avoid duplicate deps
         if model_lora[0] not in merges[name]["deps"]:
             merges[name]["deps"].append(model_lora[0])
         model = str(out_path / model_lora[0])
         if len(model_lora) == 2:
             model += "+" + model_lora[1]
 
+    return model
+
 
 @click.command("mergekit-mega")
 @click.argument("config_file")
@@ -116,7 +116,15 @@ def add_model_deps(model, name, out_path):
     type=bool,
     default=False,
     is_flag=True,
-    help="overwrite existing merge results instead of skipping them",
+    help="Overwrite existing merge results instead of skipping them",
+)
+@click.option(
+    "--require-nameless",
+    "-R",
+    type=bool,
+    default=False,
+    is_flag=True,
+    help="Enforces exactly one unnamed merge in the YAML, which will inherit the input file's name.",
 )
 @add_merge_options
 def main(
@@ -125,6 +133,7 @@ def main(
     out_path: str,
     force: bool,
     verbose: bool,
+    require_nameless: bool,
 ):
     """
     Main entrypoint for mergekit-mega command see module docstring for more info
@@ -133,27 +142,39 @@ def main(
     logging.basicConfig(level=logging.INFO if verbose else logging.WARNING)
 
     out_path = Path(out_path)
+    final_found = False
+
     with open(config_file, "r", encoding="utf-8") as f:
         data = yaml.load_all(f, Loader=yaml.FullLoader)
 
         for d in data:
+            if "name" not in d:
+                if final_found:
+                    logging.error("Only one merge must not have a name")
+                    sys.exit(1)
+                # this sets the name of the final merge to the config file name without the extension
+                d["name"] = os.path.basename(config_file).rsplit(".", maxsplit=1)[0]
+                final_found = True
+
             if "/" in d["name"]:
                 logging.error("name must not contain a slash")
                 sys.exit(1)
 
             merges[d["name"]] = d
             merges[d["name"]]["deps"] = []
             if "base_model" in d:
-                add_model_deps(d["base_model"], d["name"], out_path)
-                if "/" not in d["base_model"]:
-                    d["base_model"] = str(out_path / d["base_model"])
+                d["base_model"] = add_model_deps(d["base_model"], d["name"], out_path)
             if "slices" in d:
                 for slc in d["slices"]:
                     for src in slc["sources"]:
-                        add_model_deps(src["model"], d["name"], out_path)
+                        src["model"] = add_model_deps(src["model"], d["name"], out_path)
             if "models" in d:
                 for mdl in d["models"]:
-                    add_model_deps(mdl["model"], d["name"], out_path)
+                    mdl["model"] = add_model_deps(mdl["model"], d["name"], out_path)
+
+    if require_nameless and not final_found:
+        logging.error("No final merge found")
+        sys.exit(1)
 
     logging.info("Merging: %s", ", ".join(merges))