//@ts-check
import { dlopen, FFIType } from 'bun:ffi';
import errno from './errno.js'
import * as fs from 'fs'
import * as path from 'path'

const {
	symbols: {
		syscall,
	},
} = dlopen('/usr/lib/libc.so.6', {
	syscall: {
		args: [ FFIType.int, FFIType.int, FFIType.cstring, FFIType.int ],
		returns: FFIType.int,
	},
});

// TBD
const SYSCALL_INIT_MODULE = 105
const SYSCALL_FINIT_MODULE = 273

export const doProcExists = () => fs.existsSync('/proc')

/**
 *
 * @param {string} path
 * @param {string} params
 * @param {number} flags
 * @deprecated untested very dangerous
 */
export function finit_module(path, params = "", flags = 0) {
    const fileDescriptor = fs.openSync(path, 'r')
    const result = syscall(SYSCALL_FINIT_MODULE, fileDescriptor, params, flags)
    if(result > 0) {
        throw new Error(errno[result])
    } else {
        if(result == -1) {
            throw new Error('non number or string argument recived')
        }else if(result == -2) {
            throw new Error('unsuported argument length (1-5)')
        }
    }
}

export function uname() {
    if(!doProcExists()) {
        throw "Proc don't exists exception"
    }
    const linuxVersionString = fs.readFileSync('/proc/version').toString()
    return linuxVersionString.split(' ')[2]
}

/**
 * @param {string} modulename
 * @deprecated untested very dangerous
 */
export function modprobe(modulename) {
    const name = uname()
    if(fs.existsSync(path.join('/lib/modules', name, 'kernel', modulename))) {
        finit_module(path.join('/lib/modules', name, 'kernel', modulename))
    } else {
        throw new Error("file not found " + path.join('/lib/modules', name, 'kernel', modulename))
    }
}


export function lsmod() {
    if(!doProcExists()) {
        throw "Proc don't exists exception"
    }
    return fs.readFileSync('/proc/modules').toString('utf-8').split('\n')
}