1 files changed, 99 insertions, 0 deletions
diff --git a/dhpython/_defaults.py b/dhpython/_defaults.py
new file mode 100755
index 0000000..cf7537b
--- /dev/null
+++ b/dhpython/_defaults.py
@@ -0,0 +1,99 @@
+#! /usr/bin/python3
+# Copyright © 2013 Piotr Ożarowski <piotr@debian.org>
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+
+import logging
+from configparser import ConfigParser
+from os import environ
+from os.path import exists
+from subprocess import Popen, PIPE
+
+SUPPORTED = {
+    'cpython2': [(2, 7)],
+    'cpython3': [(3, 8)],
+    'pypy': [(4, 0)]}
+DEFAULT = {
+    'cpython2': (2, 7),
+    'cpython3': (3, 8),
+    'pypy': (4, 0)}
+
+log = logging.getLogger('dhpython')
+
+
+def cpython_versions(major):
+    result = [None, None]
+    ver = '' if major == 2 else '3'
+    supported = environ.get("DEBPYTHON{}_SUPPORTED".format(ver))
+    default = environ.get("DEBPYTHON{}_DEFAULT".format(ver))
+    if not supported or not default:
+        config = ConfigParser()
+        config.read("/usr/share/python{}/debian_defaults".format(ver))
+        if not default:
+            default = config.get('DEFAULT', 'default-version', fallback='')[6:]
+        if not supported:
+            supported = config.get('DEFAULT', 'supported-versions', fallback='')\
+                .replace('python', '')
+    if default:
+        try:
+            result[0] = tuple(int(i) for i in default.split('.'))
+        except Exception as err:
+            log.warn('invalid debian_defaults file: %s', err)
+    if supported:
+        try:
+            result[1] = tuple(tuple(int(j) for j in i.strip().split('.'))
+                              for i in supported.split(','))
+        except Exception as err:
+            log.warn('invalid debian_defaults file: %s', err)
+    return result
+
+
+def from_file(fpath):
+    if not exists(fpath):
+        raise ValueError("missing interpreter: %s" % fpath)
+    command = "{} --version".format(fpath)
+    with Popen(command, shell=True, stdout=PIPE) as process:
+        stdout, stderr = process.communicate()
+        stdout = str(stdout, 'utf-8')
+
+    print(stdout)
+
+
+cpython2 = cpython_versions(2)
+cpython3 = cpython_versions(3)
+if cpython2[0]:
+    DEFAULT['cpython2'] = cpython2[0]
+if cpython3[0]:
+    DEFAULT['cpython3'] = cpython3[0]
+if cpython2[1]:
+    SUPPORTED['cpython2'] = cpython2[1]
+if cpython3[1]:
+    SUPPORTED['cpython3'] = cpython3[1]
+#from_file('/usr/bin/pypy')
+
+
+if __name__ == '__main__':
+    from sys import argv, stderr
+    if len(argv) != 3:
+        print('invalid number of arguments', file=stderr)
+        exit(1)
+    if argv[1] == 'default':
+        print('.'.join(str(i) for i in DEFAULT[argv[2]]))
+    elif argv[1] == 'supported':
+        print(','.join(('.'.join(str(i) for i in v) for v in SUPPORTED[argv[2]])))