config: rename load.py to file.py (MR 2252)

It's weird to have a function with the same name as the module, rename
it to avoid confusion.

Signed-off-by: Caleb Connolly <caleb@postmarketos.org>

pmb/config/file.py

@@ -0,0 +1,111 @@
+# Copyright 2023 Oliver Smith
+# SPDX-License-Identifier: GPL-3.0-or-later
+from pathlib import Path, PosixPath
+from typing import List
+from pmb.helpers import logging
+import configparser
+import os
+from pmb.core import Config
+
+
+def load(path: Path) -> Config:
+    config = Config()
+
+    cfg = configparser.ConfigParser()
+    if os.path.isfile(path):
+        cfg.read(path)
+
+    if "pmbootstrap" not in cfg:
+        cfg["pmbootstrap"] = {}
+    if "providers" not in cfg:
+        cfg["providers"] = {}
+
+    for key in Config.__dict__.keys():
+        if key == "providers":
+            setattr(config, key, cfg["providers"])
+        if key == "mirrors" and key in cfg:
+            for subkey in Config.mirrors.keys():
+                if subkey in cfg["mirrors"]:
+                    setattr(config, f"mirrors.{subkey}", cfg["mirrors"][subkey])
+        # default values won't be set in the config file
+        if key not in cfg["pmbootstrap"]:
+            continue
+        elif key == "mirror_alpine":
+            # DEPRCATED
+            config.mirrors["alpine"] = cfg["pmbootstrap"]["mirror_alpine"]
+            continue
+        # Handle whacky type conversions
+        elif key == "mirrors_postmarketos":
+            mirrors = cfg["pmbootstrap"]["mirrors_postmarketos"].split(",")
+            if len(mirrors) > 1:
+                logging.warning("Multiple mirrors are not supported, using the last one")
+            config.mirrors["pmaports"] = mirrors[-1].strip("/master")
+        # Convert strings to paths
+        elif type(getattr(Config, key)) == PosixPath:
+            setattr(config, key, Path(cfg["pmbootstrap"][key]))
+        # Yeah this really sucks and there isn't a better way to do it without external
+        # libraries
+        elif isinstance(getattr(Config, key), List) and isinstance(getattr(Config, key)[0], PosixPath):
+            setattr(config, key, [Path(p.strip()) for p in cfg["pmbootstrap"][key].split(",")])
+        elif isinstance(getattr(Config, key), bool):
+            setattr(config, key, cfg["pmbootstrap"][key].lower() == "true")
+        elif key in cfg["pmbootstrap"]:
+            setattr(config, key, cfg["pmbootstrap"][key])
+
+    # One time migration "mirror_alpine" -> mirrors.alpine
+    if "mirror_alpine" in cfg["pmbootstrap"] or "mirrors_postmarketos" in cfg["pmbootstrap"]:
+        logging.info("Migrating config file to 3.0 format.")
+        save(path, config)
+
+    return config
+
+
+def serialize(config: Config, skip_defaults=True) -> configparser.ConfigParser:
+    """Serialize the config object into a ConfigParser to write it out
+    in the pmbootstrap.cfg INI format.
+    
+    :param config: The config object to serialize
+    :param skip_defaults: Skip writing out default values
+    """
+    cfg = configparser.ConfigParser()
+    cfg["pmbootstrap"] = {}
+    cfg["providers"] = {}
+    cfg["mirrors"] = {}
+
+    # .keys() flat maps dictionaries like config.mirrors with
+    # dotted notation
+    for key in Config.keys():
+        # If the default value hasn't changed then don't write out,
+        # this makes it possible to update the default, otherwise
+        # we wouldn't be able to tell if the user overwrote it.
+        if skip_defaults and Config.get_default(key) == getattr(config, key):
+            continue
+        if key == "mirror_alpine" or key == "mirrors_postmarketos":
+            # DEPRECATED: skip these
+            continue
+        if key == "providers":
+            cfg["providers"] = config.providers
+        elif key.startswith("mirrors."):
+            _key = key.split(".")[1]
+            cfg["mirrors"][_key] = getattr(config, key)
+        # Convert strings to paths
+        elif type(getattr(Config, key)) == PosixPath:
+            cfg["pmbootstrap"][key] = str(getattr(config, key))
+        elif isinstance(getattr(Config, key), List) and isinstance(getattr(Config, key)[0], PosixPath):
+            cfg["pmbootstrap"][key] = ",".join(os.fspath(p) for p in getattr(config, key))
+        elif isinstance(getattr(Config, key), bool):
+            cfg["pmbootstrap"][key] = str(getattr(config, key))
+        else:
+            cfg["pmbootstrap"][key] = str(getattr(config, key))
+
+    return cfg
+
+def save(output: Path, config: Config):
+    logging.debug(f"Save config: {output}")
+    output.parent.mkdir(parents=True, exist_ok=True)
+    output.touch(0o700, exist_ok=True)
+    
+    cfg = serialize(config)
+
+    with output.open("w") as handle:
+        cfg.write(handle)