1 files changed, 63 insertions, 0 deletions
diff --git a/pre_commit/hook.py b/pre_commit/hook.py
new file mode 100644
index 0000000..b65ac42
--- /dev/null
+++ b/pre_commit/hook.py
@@ -0,0 +1,63 @@
+import logging
+import shlex
+from typing import Any
+from typing import Dict
+from typing import NamedTuple
+from typing import Sequence
+from typing import Tuple
+
+from pre_commit.prefix import Prefix
+
+logger = logging.getLogger('pre_commit')
+
+
+class Hook(NamedTuple):
+    src: str
+    prefix: Prefix
+    id: str
+    name: str
+    entry: str
+    language: str
+    alias: str
+    files: str
+    exclude: str
+    types: Sequence[str]
+    exclude_types: Sequence[str]
+    additional_dependencies: Sequence[str]
+    args: Sequence[str]
+    always_run: bool
+    pass_filenames: bool
+    description: str
+    language_version: str
+    log_file: str
+    minimum_pre_commit_version: str
+    require_serial: bool
+    stages: Sequence[str]
+    verbose: bool
+
+    @property
+    def cmd(self) -> Tuple[str, ...]:
+        return (*shlex.split(self.entry), *self.args)
+
+    @property
+    def install_key(self) -> Tuple[Prefix, str, str, Tuple[str, ...]]:
+        return (
+            self.prefix,
+            self.language,
+            self.language_version,
+            tuple(self.additional_dependencies),
+        )
+
+    @classmethod
+    def create(cls, src: str, prefix: Prefix, dct: Dict[str, Any]) -> 'Hook':
+        # TODO: have cfgv do this (?)
+        extra_keys = set(dct) - _KEYS
+        if extra_keys:
+            logger.warning(
+                f'Unexpected key(s) present on {src} => {dct["id"]}: '
+                f'{", ".join(sorted(extra_keys))}',
+            )
+        return cls(src=src, prefix=prefix, **{k: dct[k] for k in _KEYS})
+
+
+_KEYS = frozenset(set(Hook._fields) - {'src', 'prefix'})