tools/tryselect/preset.py

   1 # This Source Code Form is subject to the terms of the Mozilla Public
   2 # License, v. 2.0. If a copy of the MPL was not distributed with this
   3 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
   4
   5 from __future__ import absolute_import, print_function, unicode_literals
   6
   7 import os
   8 import shlex
   9 import subprocess
  10
  11 import yaml
  12
  13
  14 class PresetHandler(object):
  15
  16     def __init__(self, path):
  17         self.path = path
  18         self._presets = {}
  19
  20     @property
  21     def presets(self):
  22         if not self._presets and os.path.isfile(self.path):
  23             with open(self.path, 'r') as fh:
  24                 self._presets = yaml.safe_load(fh) or {}
  25
  26         return self._presets
  27
  28     def __contains__(self, name):
  29         return name in self.presets
  30
  31     def __getitem__(self, name):
  32         return self.presets[name]
  33
  34     def __len__(self):
  35         return len(self.presets)
  36
  37     def __str__(self):
  38         if not self.presets:
  39             return ''
  40         return yaml.safe_dump(self.presets, default_flow_style=False)
  41
  42     def list(self):
  43         if not self.presets:
  44             print("no presets found")
  45         else:
  46             print(self)
  47
  48     def edit(self):
  49         if 'EDITOR' not in os.environ:
  50             print("error: must set the $EDITOR environment variable to use --edit-presets")
  51             return
  52
  53         subprocess.call(shlex.split(os.environ['EDITOR']) + [self.path])
  54
  55     def save(self, name, **data):
  56         self.presets[name] = data
  57
  58         with open(self.path, "w") as fh:
  59             fh.write(str(self))
  60
  61
  62 class MergedHandler(object):
  63     def __init__(self, *paths):
  64         """Helper class for dealing with multiple preset files."""
  65         self.handlers = [PresetHandler(p) for p in paths]
  66
  67     def __contains__(self, name):
  68         return any(name in handler for handler in self.handlers)
  69
  70     def __getitem__(self, name):
  71         for handler in self.handlers:
  72             if name in handler:
  73                 return handler[name]
  74         raise KeyError(name)
  75
  76     def __len__(self):
  77         return sum(len(h) for h in self.handlers)
  78
  79     def __str__(self):
  80         all_presets = {
  81             k: v
  82             for handler in self.handlers
  83             for k, v in handler.presets.items()
  84         }
  85         return yaml.safe_dump(all_presets, default_flow_style=False)
  86
  87     def list(self):
  88         if len(self) == 0:
  89             print("no presets found")
  90             return
  91
  92         for handler in self.handlers:
  93             val = str(handler)
  94             if val:
  95                 val = '\n  '.join([''] + val.splitlines() + [''])  # indent all lines by 2 spaces
  96                 print("Presets from {}:".format(handler.path))
  97                 print(val)