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// Take a look at the license at the top of the repository in the LICENSE file.
use std::path::PathBuf;
use crate::translate::*;
#[doc(alias = "g_win32_get_package_installation_directory_of_module")]
#[doc(alias = "get_package_installation_directory_of_module")]
pub fn package_installation_directory_of_module(
hmodule: std::os::windows::raw::HANDLE,
) -> Result<PathBuf, std::io::Error> {
// # Safety
// The underlying `GetModuleFilenameW` function has three possible
// outcomes when a raw pointer get passed to it:
// - When the pointer is a valid HINSTANCE of a DLL (e.g. acquired
// through the `GetModuleHandleW`), it sets a file path to the
// assigned "out" buffer and sets the return value to be the length
// of said path string
// - When the pointer is null, it sets the full path of the process'
// executable binary to the assigned buffer and sets the return value
// to be the length of said string
// - Whenever the provided buffer size is too small, it will set a
// truncated version of the path and return the length of said string
// while also setting the thread-local last-error code to
// `ERROR_INSUFFICIENT_BUFFER` (evaluates to 0x7A)
// - When the pointer is not a valid HINSTANCE that isn't NULL (e.g.
// a pointer to some GKeyFile), it will return 0 and set the last-error
// code to `ERROR_MOD_NOT_FOUND` (evaluates to 0x7E)
//
// The `g_win32_get_package_installation_directory_of_module` already
// handles all of the outcomes gracefully by:
// - Preallocating a MAX_PATH-long array of wchar_t for the out buffer,
// so that outcome #3 can be safely assumed to never happen
// - Returning NULL when outcome #4 happens
match unsafe {
from_glib_full::<_, Option<PathBuf>>(
ffi::g_win32_get_package_installation_directory_of_module(hmodule),
)
} {
Some(pb) => Ok(pb),
None => Err(std::io::Error::last_os_error()),
}
}