Expose a 'decky_plugin' module to decky plugins (#353)

* Expose a 'decky_plugin' module to decky plugins

* expose decky user home path
* support 'py_modules' python modules in plugins
* allow for a '_migration' method in plugins to have an explicit file
  moving step

* Expose the plugin python module as .pyi stub interface

* Expose system and user python paths to plugins

1 files changed, 173 insertions, 0 deletions

diff --git a/plugin/decky_plugin.pyi b/plugin/decky_plugin.pyi
new file mode 100644
index 00000000..b311a55a
--- /dev/null
+++ b/plugin/decky_plugin.pyi
@@ -0,0 +1,173 @@
+"""
+This module exposes various constants and helpers useful for decky plugins.
+
+* Plugin's settings and configurations should be stored under `DECKY_PLUGIN_SETTINGS_DIR`.
+* Plugin's runtime data should be stored under `DECKY_PLUGIN_RUNTIME_DIR`.
+* Plugin's persistent log files should be stored under `DECKY_PLUGIN_LOG_DIR`.
+
+Avoid writing outside of `DECKY_HOME`, storing under the suggested paths is strongly recommended.
+
+Some basic migration helpers are available: `migrate_any`, `migrate_settings`, `migrate_runtime`, `migrate_logs`.
+
+A logging facility `logger` is available which writes to the recommended location.
+"""
+
+__version__ = '0.1.0'
+
+import logging
+
+"""
+Constants
+"""
+
+HOME: str
+"""
+The home directory of the effective user running the process.
+Environment variable: `HOME`.
+If `root` was specified in the plugin's flags it will be `/root` otherwise the user whose home decky resides in.
+e.g.: `/home/deck`
+"""
+
+USER: str
+"""
+The effective username running the process.
+Environment variable: `USER`.
+It would be `root` if `root` was specified in the plugin's flags otherwise the user whose home decky resides in.
+e.g.: `deck`
+"""
+
+DECKY_VERSION: str
+"""
+The version of the decky loader.
+Environment variable: `DECKY_VERSION`.
+e.g.: `v2.5.0-pre1`
+"""
+
+DECKY_USER: str
+"""
+The user whose home decky resides in.
+Environment variable: `DECKY_USER`.
+e.g.: `deck`
+"""
+
+DECKY_USER_HOME: str
+"""
+The home of the user where decky resides in.
+Environment variable: `DECKY_USER_HOME`.
+e.g.: `/home/deck`
+"""
+
+DECKY_HOME: str
+"""
+The root of the decky folder.
+Environment variable: `DECKY_HOME`.
+e.g.: `/home/deck/homebrew`
+"""
+
+DECKY_PLUGIN_SETTINGS_DIR: str
+"""
+The recommended path in which to store configuration files (created automatically).
+Environment variable: `DECKY_PLUGIN_SETTINGS_DIR`.
+e.g.: `/home/deck/homebrew/settings/decky-plugin-template`
+"""
+
+DECKY_PLUGIN_RUNTIME_DIR: str
+"""
+The recommended path in which to store runtime data (created automatically).
+Environment variable: `DECKY_PLUGIN_RUNTIME_DIR`.
+e.g.: `/home/deck/homebrew/data/decky-plugin-template`
+"""
+
+DECKY_PLUGIN_LOG_DIR: str
+"""
+The recommended path in which to store persistent logs (created automatically).
+Environment variable: `DECKY_PLUGIN_LOG_DIR`.
+e.g.: `/home/deck/homebrew/logs/decky-plugin-template`
+"""
+
+DECKY_PLUGIN_DIR: str
+"""
+The root of the plugin's directory.
+Environment variable: `DECKY_PLUGIN_DIR`.
+e.g.: `/home/deck/homebrew/plugins/decky-plugin-template`
+"""
+
+DECKY_PLUGIN_NAME: str
+"""
+The name of the plugin as specified in the 'plugin.json'.
+Environment variable: `DECKY_PLUGIN_NAME`.
+e.g.: `Example Plugin`
+"""
+
+DECKY_PLUGIN_VERSION: str
+"""
+The version of the plugin as specified in the 'package.json'.
+Environment variable: `DECKY_PLUGIN_VERSION`.
+e.g.: `0.0.1`
+"""
+
+DECKY_PLUGIN_AUTHOR: str
+"""
+The author of the plugin as specified in the 'plugin.json'.
+Environment variable: `DECKY_PLUGIN_AUTHOR`.
+e.g.: `John Doe`
+"""
+
+DECKY_PLUGIN_LOG: str
+"""
+The path to the plugin's main logfile.
+Environment variable: `DECKY_PLUGIN_LOG`.
+e.g.: `/home/deck/homebrew/logs/decky-plugin-template/plugin.log`
+"""
+
+"""
+Migration helpers
+"""
+
+
+def migrate_any(target_dir: str, *files_or_directories: str) -> dict[str, str]:
+    """
+    Migrate files and directories to a new location and remove old locations.
+    Specified files will be migrated to `target_dir`.
+    Specified directories will have their contents recursively migrated to `target_dir`.
+
+    Returns the mapping of old -> new location.
+    """
+
+
+def migrate_settings(*files_or_directories: str) -> dict[str, str]:
+    """
+    Migrate files and directories relating to plugin settings to the recommended location and remove old locations.
+    Specified files will be migrated to `DECKY_PLUGIN_SETTINGS_DIR`.
+    Specified directories will have their contents recursively migrated to `DECKY_PLUGIN_SETTINGS_DIR`.
+
+    Returns the mapping of old -> new location.
+    """
+
+
+def migrate_runtime(*files_or_directories: str) -> dict[str, str]:
+    """
+    Migrate files and directories relating to plugin runtime data to the recommended location and remove old locations
+    Specified files will be migrated to `DECKY_PLUGIN_RUNTIME_DIR`.
+    Specified directories will have their contents recursively migrated to `DECKY_PLUGIN_RUNTIME_DIR`.
+
+    Returns the mapping of old -> new location.
+    """
+
+
+def migrate_logs(*files_or_directories: str) -> dict[str, str]:
+    """
+    Migrate files and directories relating to plugin logs to the recommended location and remove old locations.
+    Specified files will be migrated to `DECKY_PLUGIN_LOG_DIR`.
+    Specified directories will have their contents recursively migrated to `DECKY_PLUGIN_LOG_DIR`.
+
+    Returns the mapping of old -> new location.
+    """
+
+
+"""
+Logging
+"""
+
+logger: logging.Logger
+"""The main plugin logger writing to `DECKY_PLUGIN_LOG`."""