/* package input is a thing Go wrapper around the Linux kernel input event 
 * system. */
package input

import "gitlab.com/beoran/galago/os/linux"
import "os"
import "unsafe"
import "syscall"
import "fmt"
import "path/filepath"


// Device models an input device
type Device struct { 
    *os.File
}

const Directory = "/dev/input"

func Open(name string) (*Device, error) {
    f, err := os.OpenFile(filepath.Join(Directory, name), os.O_RDWR, 0666)
    if err != nil {
        return nil, err
    }
    return &Device{File: f}, nil
} 

func List() ([]string, error) {
    dir, err := os.Open(Directory)
    if err != nil {
        return nil, err
    }
    return dir.Readdirnames(-1)
}


// Icotl performs an ioctl on the given de
func (d * Device) Ioctl(code uint32, pointer unsafe.Pointer) error {
    fmt.Printf("ioctl: %d %d %d\n", uintptr(d.Fd()), uintptr(code), uintptr(pointer))
    _, _, errno := syscall.Syscall(
        syscall.SYS_IOCTL,
        uintptr(d.Fd()),
        uintptr(code),
        uintptr(pointer))
    if (errno != 0) {
        return errno
    }
    return nil
}


func (d * Device) DriverVersion() (int32, error) {
    res := int32(0) 
    data := unsafe.Pointer(&res)
    err := d.Ioctl(linux.EVIOCGVERSION, data)
    return res, err
}

func (d * Device) Name() (string, error) {
    buffer := [256]byte{}
    err := d.Ioctl(linux.EVIOCGNAME(uintptr(len(buffer))), unsafe.Pointer(&buffer))
    return string(buffer[0:len(buffer)]), err
}

func (d * Device) Id() (linux.INPUT_id, error) {
    var result linux.INPUT_id 
    err := d.Ioctl(linux.EVIOCGID, unsafe.Pointer(&result))
    return result, err
}