Validate component usage (#23037)

* Update manifest validator

* Update circle

* Update text

* Typo

* fix link to codeowners

* Merge CODEOWNERS into hassfest

* Annotate errors with fixable

* Convert error to warning

* Lint

* Make abs path

* Python 3.5...

* Typo

* Fix tests

script/hassfest/__main__.py

@@ -0,0 +1,84 @@
+"""Validate manifests."""
+import pathlib
+import sys
+
+from .model import Integration, Config
+from . import dependencies, manifest, codeowners
+
+PLUGINS = [
+    manifest,
+    dependencies,
+    codeowners,
+]
+
+
+def get_config() -> Config:
+    """Return config."""
+    if not pathlib.Path('requirements_all.txt').is_file():
+        raise RuntimeError("Run from project root")
+
+    return Config(
+        root=pathlib.Path('.').absolute(),
+        action='validate' if sys.argv[-1] == 'validate' else 'generate',
+    )
+
+
+def main():
+    """Validate manifests."""
+    try:
+        config = get_config()
+    except RuntimeError as err:
+        print(err)
+        return 1
+
+    integrations = Integration.load_dir(
+        pathlib.Path('homeassistant/components')
+    )
+    manifest.validate(integrations, config)
+    dependencies.validate(integrations, config)
+    codeowners.validate(integrations, config)
+
+    # When we generate, all errors that are fixable will be ignored,
+    # as generating them will be fixed.
+    if config.action == 'generate':
+        general_errors = [err for err in config.errors if not err.fixable]
+        invalid_itg = [
+            itg for itg in integrations.values()
+            if any(
+                not error.fixable for error in itg.errors
+            )
+        ]
+    else:
+        # action == validate
+        general_errors = config.errors
+        invalid_itg = [itg for itg in integrations.values() if itg.errors]
+
+    print("Integrations:", len(integrations))
+    print("Invalid integrations:", len(invalid_itg))
+
+    if not invalid_itg and not general_errors:
+        codeowners.generate(integrations, config)
+        return 0
+
+    print()
+    if config.action == 'generate':
+        print("Found errors. Generating files canceled.")
+        print()
+
+    if general_errors:
+        print("General errors:")
+        for error in general_errors:
+            print("*", error)
+        print()
+
+    for integration in sorted(invalid_itg, key=lambda itg: itg.domain):
+        print("Integration {}:".format(integration.domain))
+        for error in integration.errors:
+            print("*", error)
+        print()
+
+    return 1
+
+
+if __name__ == "__main__":
+    sys.exit(main())