1 files changed, 131 insertions, 0 deletions
diff --git a/nixpkgs/pkgs/servers/home-assistant/parse-requirements.py b/nixpkgs/pkgs/servers/home-assistant/parse-requirements.py
new file mode 100755
index 000000000000..63374b017956
--- /dev/null
+++ b/nixpkgs/pkgs/servers/home-assistant/parse-requirements.py
@@ -0,0 +1,131 @@
+#! /usr/bin/env nix-shell
+#! nix-shell -i python3 -p "python3.withPackages (ps: with ps; [ aiohttp astral async-timeout attrs certifi jinja2 pyjwt cryptography pip pytz pyyaml requests ruamel_yaml voluptuous ])"
+#
+# This script downloads Home Assistant's source tarball.
+# Inside the homeassistant/components directory, each component has an associated .py file,
+# specifying required packages and other components it depends on:
+#
+# REQUIREMENTS = [ 'package==1.2.3' ]
+# DEPENDENCIES = [ 'component' ]
+#
+# By parsing the files, a dictionary mapping component to requirements and dependencies is created.
+# For all of these requirements and the dependencies' requirements,
+# Nixpkgs' python3Packages are searched for appropriate names.
+# Then, a Nix attribute set mapping component name to dependencies is created.
+
+from urllib.request import urlopen
+import tempfile
+from io import BytesIO
+import tarfile
+import importlib
+import subprocess
+import os
+import sys
+import json
+import re
+
+COMPONENT_PREFIX = 'homeassistant.components'
+PKG_SET = 'python3Packages'
+
+# If some requirements are matched by multiple python packages,
+# the following can be used to choose one of them
+PKG_PREFERENCES = {
+    # Use python3Packages.youtube-dl-light instead of python3Packages.youtube-dl
+    'youtube-dl': 'youtube-dl-light'
+}
+
+def get_version():
+    with open(os.path.dirname(sys.argv[0]) + '/default.nix') as f:
+        m = re.search('hassVersion = "([\\d\\.]+)";', f.read())
+        return m.group(1)
+
+def parse_components(version='master'):
+    components = {}
+    with tempfile.TemporaryDirectory() as tmp:
+        with urlopen('https://github.com/home-assistant/home-assistant/archive/{}.tar.gz'.format(version)) as response:
+            tarfile.open(fileobj=BytesIO(response.read())).extractall(tmp)
+        # Use part of a script from the Home Assistant codebase
+        sys.path.append(tmp + '/home-assistant-{}'.format(version))
+        from script.gen_requirements_all import explore_module
+        for package in explore_module(COMPONENT_PREFIX, True):
+            # Remove 'homeassistant.components.' prefix
+            component = package[len(COMPONENT_PREFIX + '.'):]
+            try:
+                module = importlib.import_module(package)
+                components[component] = {}
+                components[component]['requirements'] = getattr(module, 'REQUIREMENTS', [])
+                components[component]['dependencies'] = getattr(module, 'DEPENDENCIES', [])
+            # If there is an ImportError, the imported file is not the main file of the component
+            except ImportError:
+                continue
+    return components
+
+# Recursively get the requirements of a component and its dependencies
+def get_reqs(components, component):
+    requirements = set(components[component]['requirements'])
+    for dependency in components[component]['dependencies']:
+        requirements.update(get_reqs(components, dependency))
+    return requirements
+
+# Store a JSON dump of Nixpkgs' python3Packages
+output = subprocess.check_output(['nix-env', '-f', os.path.dirname(sys.argv[0]) + '/../../..', '-qa', '-A', PKG_SET, '--json'])
+packages = json.loads(output)
+
+def name_to_attr_path(req):
+    attr_paths = set()
+    names = [req]
+    # E.g. python-mpd2 is actually called python3.6-mpd2
+    # instead of python-3.6-python-mpd2 inside Nixpkgs
+    if req.startswith('python-') or req.startswith('python_'):
+        names.append(req[len('python-'):])
+    for name in names:
+        # treat "-" and "_" equally
+        name = re.sub('[-_]', '[-_]', name)
+        pattern = re.compile('^python\\d\\.\\d-{}-\\d'.format(name), re.I)
+        for attr_path, package in packages.items():
+            if pattern.match(package['name']):
+                attr_paths.add(attr_path)
+    if len(attr_paths) > 1:
+        for to_replace, replacement in PKG_PREFERENCES.items():
+            try:
+                attr_paths.remove(PKG_SET + '.' + to_replace)
+                attr_paths.add(PKG_SET + '.' + replacement)
+            except KeyError:
+                pass
+    # Let's hope there's only one derivation with a matching name
+    assert len(attr_paths) <= 1, "{} matches more than one derivation: {}".format(req, attr_paths)
+    if len(attr_paths) == 1:
+        return attr_paths.pop()
+    else:
+        return None
+
+version = get_version()
+print('Generating component-packages.nix for version {}'.format(version))
+components = parse_components(version=version)
+build_inputs = {}
+for component in sorted(components.keys()):
+    attr_paths = []
+    for req in sorted(get_reqs(components, component)):
+        # Some requirements are specified by url, e.g. https://example.org/foobar#xyz==1.0.0
+        # Therefore, if there's a "#" in the line, only take the part after it
+        req = req[req.find('#') + 1:]
+        name = req.split('==')[0]
+        attr_path = name_to_attr_path(name)
+        if attr_path is not None:
+            # Add attribute path without "python3Packages." prefix
+            attr_paths.append(attr_path[len(PKG_SET + '.'):])
+    else:
+        build_inputs[component] = attr_paths
+
+with open(os.path.dirname(sys.argv[0]) + '/component-packages.nix', 'w') as f:
+    f.write('# Generated by parse-requirements.py\n')
+    f.write('# Do not edit!\n\n')
+    f.write('{\n')
+    f.write('  version = "{}";\n'.format(version))
+    f.write('  components = {\n')
+    for component, attr_paths in build_inputs.items():
+        f.write('    "{}" = ps: with ps; [ '.format(component))
+        f.write(' '.join(attr_paths))
+        f.write(' ];\n')
+    f.write('  };\n')
+    f.write('}\n')