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
   6 import os
   7 import shlex
   8 import subprocess
   9
  10 import yaml
  11
  12
  13 class PresetHandler:
  14     def __init__(self, path):
  15         self.path = path
  16         self._presets = {}
  17
  18     @property
  19     def presets(self):
  20         if not self._presets and os.path.isfile(self.path):
  21             with open(self.path) as fh:
  22                 self._presets = yaml.safe_load(fh) or {}
  23
  24         return self._presets
  25
  26     def __contains__(self, name):
  27         return name in self.presets
  28
  29     def __getitem__(self, name):
  30         return self.presets[name]
  31
  32     def __len__(self):
  33         return len(self.presets)
  34
  35     def __str__(self):
  36         if not self.presets:
  37             return ""
  38         return yaml.safe_dump(self.presets, default_flow_style=False)
  39
  40     def list(self):
  41         if not self.presets:
  42             print("no presets found")
  43         else:
  44             print(self)
  45
  46     def edit(self):
  47         if "EDITOR" not in os.environ:
  48             print(
  49                 "error: must set the $EDITOR environment variable to use --edit-presets"
  50             )
  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:
  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 for handler in self.handlers for k, v in handler.presets.items()
  82         }
  83         return yaml.safe_dump(all_presets, default_flow_style=False)
  84
  85     def list(self):
  86         if len(self) == 0:
  87             print("no presets found")
  88             return
  89
  90         for handler in self.handlers:
  91             val = str(handler)
  92             if val:
  93                 val = "\n  ".join(
  94                     [""] + val.splitlines() + [""]
  95                 )  # indent all lines by 2 spaces
  96                 print("Presets from {}:".format(handler.path))
  97                 print(val)