1 files changed, 167 insertions, 0 deletions
diff --git a/pre_commit/commands/install_uninstall.py b/pre_commit/commands/install_uninstall.py
new file mode 100644
index 0000000..d19e0d4
--- /dev/null
+++ b/pre_commit/commands/install_uninstall.py
@@ -0,0 +1,167 @@
+from __future__ import annotations
+
+import logging
+import os.path
+import shlex
+import shutil
+import sys
+
+from pre_commit import git
+from pre_commit import output
+from pre_commit.clientlib import InvalidConfigError
+from pre_commit.clientlib import load_config
+from pre_commit.repository import all_hooks
+from pre_commit.repository import install_hook_envs
+from pre_commit.store import Store
+from pre_commit.util import make_executable
+from pre_commit.util import resource_text
+
+
+logger = logging.getLogger(__name__)
+
+# This is used to identify the hook file we install
+PRIOR_HASHES = (
+    b'4d9958c90bc262f47553e2c073f14cfe',
+    b'd8ee923c46731b42cd95cc869add4062',
+    b'49fd668cb42069aa1b6048464be5d395',
+    b'79f09a650522a87b0da915d0d983b2de',
+    b'e358c9dae00eac5d06b38dfdb1e33a8c',
+)
+CURRENT_HASH = b'138fd403232d2ddd5efb44317e38bf03'
+TEMPLATE_START = '# start templated\n'
+TEMPLATE_END = '# end templated\n'
+
+
+def _hook_types(cfg_filename: str, hook_types: list[str] | None) -> list[str]:
+    if hook_types is not None:
+        return hook_types
+    else:
+        try:
+            cfg = load_config(cfg_filename)
+        except InvalidConfigError:
+            return ['pre-commit']
+        else:
+            return cfg['default_install_hook_types']
+
+
+def _hook_paths(
+        hook_type: str,
+        git_dir: str | None = None,
+) -> tuple[str, str]:
+    git_dir = git_dir if git_dir is not None else git.get_git_common_dir()
+    pth = os.path.join(git_dir, 'hooks', hook_type)
+    return pth, f'{pth}.legacy'
+
+
+def is_our_script(filename: str) -> bool:
+    if not os.path.exists(filename):  # pragma: win32 no cover (symlink)
+        return False
+    with open(filename, 'rb') as f:
+        contents = f.read()
+    return any(h in contents for h in (CURRENT_HASH,) + PRIOR_HASHES)
+
+
+def _install_hook_script(
+        config_file: str,
+        hook_type: str,
+        overwrite: bool = False,
+        skip_on_missing_config: bool = False,
+        git_dir: str | None = None,
+) -> None:
+    hook_path, legacy_path = _hook_paths(hook_type, git_dir=git_dir)
+
+    os.makedirs(os.path.dirname(hook_path), exist_ok=True)
+
+    # If we have an existing hook, move it to pre-commit.legacy
+    if os.path.lexists(hook_path) and not is_our_script(hook_path):
+        shutil.move(hook_path, legacy_path)
+
+    # If we specify overwrite, we simply delete the legacy file
+    if overwrite and os.path.exists(legacy_path):
+        os.remove(legacy_path)
+    elif os.path.exists(legacy_path):
+        output.write_line(
+            f'Running in migration mode with existing hooks at {legacy_path}\n'
+            f'Use -f to use only pre-commit.',
+        )
+
+    args = ['hook-impl', f'--config={config_file}', f'--hook-type={hook_type}']
+    if skip_on_missing_config:
+        args.append('--skip-on-missing-config')
+
+    with open(hook_path, 'w') as hook_file:
+        contents = resource_text('hook-tmpl')
+        before, rest = contents.split(TEMPLATE_START)
+        _, after = rest.split(TEMPLATE_END)
+
+        # on windows always use `/bin/sh` since `bash` might not be on PATH
+        # though we use bash-specific features `sh` on windows is actually
+        # bash in "POSIXLY_CORRECT" mode which still supports the features we
+        # use: subshells / arrays
+        if sys.platform == 'win32':  # pragma: win32 cover
+            hook_file.write('#!/bin/sh\n')
+
+        hook_file.write(before + TEMPLATE_START)
+        hook_file.write(f'INSTALL_PYTHON={shlex.quote(sys.executable)}\n')
+        args_s = shlex.join(args)
+        hook_file.write(f'ARGS=({args_s})\n')
+        hook_file.write(TEMPLATE_END + after)
+    make_executable(hook_path)
+
+    output.write_line(f'pre-commit installed at {hook_path}')
+
+
+def install(
+        config_file: str,
+        store: Store,
+        hook_types: list[str] | None,
+        overwrite: bool = False,
+        hooks: bool = False,
+        skip_on_missing_config: bool = False,
+        git_dir: str | None = None,
+) -> int:
+    if git_dir is None and git.has_core_hookpaths_set():
+        logger.error(
+            'Cowardly refusing to install hooks with `core.hooksPath` set.\n'
+            'hint: `git config --unset-all core.hooksPath`',
+        )
+        return 1
+
+    for hook_type in _hook_types(config_file, hook_types):
+        _install_hook_script(
+            config_file, hook_type,
+            overwrite=overwrite,
+            skip_on_missing_config=skip_on_missing_config,
+            git_dir=git_dir,
+        )
+
+    if hooks:
+        install_hooks(config_file, store)
+
+    return 0
+
+
+def install_hooks(config_file: str, store: Store) -> int:
+    install_hook_envs(all_hooks(load_config(config_file), store), store)
+    return 0
+
+
+def _uninstall_hook_script(hook_type: str) -> None:
+    hook_path, legacy_path = _hook_paths(hook_type)
+
+    # If our file doesn't exist or it isn't ours, gtfo.
+    if not os.path.exists(hook_path) or not is_our_script(hook_path):
+        return
+
+    os.remove(hook_path)
+    output.write_line(f'{hook_type} uninstalled')
+
+    if os.path.exists(legacy_path):
+        os.replace(legacy_path, hook_path)
+        output.write_line(f'Restored previous hooks to {hook_path}')
+
+
+def uninstall(config_file: str, hook_types: list[str] | None) -> int:
+    for hook_type in _hook_types(config_file, hook_types):
+        _uninstall_hook_script(hook_type)
+    return 0