__license__   = 'GPL v3'
__copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
'''
Device scanner that fetches list of devices on system ina  platform dependent
manner.
'''

import sys, os, re, subprocess
from threading import RLock

from calibre import iswindows, isosx, plugins, islinux, isfreebsd

osx_scanner = win_scanner = linux_scanner = None

if iswindows:
    try:
        win_scanner = plugins['winutil'][0].get_usb_devices
    except:
        raise RuntimeError('Failed to load the winutil plugin: %s'%plugins['winutil'][1])
elif isosx:
    try:
        osx_scanner = plugins['usbobserver'][0].get_usb_devices
    except:
        raise RuntimeError('Failed to load the usbobserver plugin: %s'%plugins['usbobserver'][1])

class Drive(str):

    def __new__(self, val, order=0):
        typ = str.__new__(self, val)
        typ.order = order
        return typ


class WinPNPScanner(object):

    def __init__(self):
        self.scanner = None
        if iswindows:
            self.scanner = plugins['winutil'][0].get_removable_drives
            self.lock = RLock()

    def drive_is_ok(self, letter, debug=False):
        import win32api, win32file
        with self.lock:
            oldError = win32api.SetErrorMode(1) #SEM_FAILCRITICALERRORS = 1
            try:
                ans = True
                try:
                    win32file.GetDiskFreeSpaceEx(letter+':\\')
                except:
                    ans = False
                return ans
            finally:
                win32api.SetErrorMode(oldError)

    def drive_order(self, pnp_id):
        order = 0
        match = re.search(r'REV_.*?&(\d+)#', pnp_id)
        if match is None:
            match = re.search(r'REV_.*?&(\d+)', pnp_id)
        if match is not None:
            order = int(match.group(1))
        return order

    def __call__(self, debug=False):
        if self.scanner is None:
            return {}
        try:
            drives = self.scanner(debug)
        except:
            drives = {}
            if debug:
                import traceback
                traceback.print_exc()
        remove = set([])
        for letter in drives:
            if not self.drive_is_ok(letter, debug=debug):
                remove.add(letter)
        for letter in remove:
            drives.pop(letter)
        ans = {}
        for key, val in drives.items():
            val = [x.upper() for x in val]
            val = [x for x in val if 'USBSTOR' in x]
            if val:
                ans[Drive(key+':\\', order=self.drive_order(val[-1]))] = val[-1]
        return ans

win_pnp_drives = WinPNPScanner()

class LinuxScanner(object):

    SYSFS_PATH = os.environ.get('SYSFS_PATH', '/sys')

    def __init__(self):
        self.base = os.path.join(self.SYSFS_PATH, 'subsystem', 'usb', 'devices')
        if not os.path.exists(self.base):
            self.base = os.path.join(self.SYSFS_PATH, 'bus', 'usb', 'devices')
        self.ok = os.path.exists(self.base)

    def __call__(self):
        ans = set([])
        if not self.ok:
            raise RuntimeError('DeviceScanner requires the /sys filesystem to work.')

        for x in os.listdir(self.base):
            base = os.path.join(self.base, x)
            ven = os.path.join(base, 'idVendor')
            prod = os.path.join(base, 'idProduct')
            bcd = os.path.join(base, 'bcdDevice')
            man = os.path.join(base, 'manufacturer')
            serial = os.path.join(base, 'serial')
            prod_string = os.path.join(base, 'product')
            dev = []
            try:
                dev.append(int('0x'+open(ven).read().strip(), 16))
            except:
                continue
            try:
                dev.append(int('0x'+open(prod).read().strip(), 16))
            except:
                continue
            try:
                dev.append(int('0x'+open(bcd).read().strip(), 16))
            except:
                continue
            try:
                dev.append(open(man).read().strip())
            except:
                dev.append('')
            try:
                dev.append(open(prod_string).read().strip())
            except:
                dev.append('')
            try:
                dev.append(open(serial).read().strip())
            except:
                dev.append('')

            ans.add(tuple(dev))
        return ans

class FreeBSDScanner(object):

    def __call__(self):
        ans = set([])

        try:
            out = subprocess.Popen("/usr/sbin/usbconfig dump_device_desc | /usr/bin/awk 'function get_str(s) { split(s, a, /<|>/); if (a[2] != \"no string\") { return a[2]; } else { return \"\";} } BEGIN {state=0;} /^[[:space:]]+idVendor/ {state = 1; vendor = $3; next;} /idProduct/ {productid = $3; next;} /bcdDevice/ {bcd = $3; next;} /iManufacturer/ { manufacturer = get_str($0); next; }  /iProduct/ { product = get_str($0); next;} /iSerialNumber/ { sn = get_str($0); next;} /^$/ {if (state == 1) { state = 0; printf(\"%s%%%%%s%%%%%s%%%%%s%%%%%s%%%%%s\\n\",vendor, productid, bcd, manufacturer, product, sn);} }'", shell=True, stdout=subprocess.PIPE).communicate()[0]
        except OSError, e:
	    print >>sys.stderr, "Execution failed:", e

        if out.strip() == "":
            return ans
        for line in out.strip().split("\n"):
            ven, prod, bcd, man, prod_string, serial = line.strip().split("%%", 6)
            dev = []
            try:
                dev.append(int(ven, 16))
            except:
                continue
            try:
                dev.append(int(prod, 16))
            except:
                continue
            try:
                dev.append(int(bcd, 16))
            except:
                continue
            try:
                dev.append(man)
            except:
                dev.append('')
            try:
                dev.append(prod_string)
            except:
                dev.append('')
            try:
                dev.append(serial)
            except:
                dev.append('')

            ans.add(tuple(dev))
        return ans

linux_scanner = None

if islinux:
    linux_scanner = LinuxScanner()

freebsd_scanner = None

if isfreebsd:
    freebsd_scanner = FreeBSDScanner()

class DeviceScanner(object):

    def __init__(self, *args):
        if isosx and osx_scanner is None:
            raise RuntimeError('The Python extension usbobserver must be available on OS X.')
        self.scanner = win_scanner if iswindows else osx_scanner if isosx else freebsd_scanner if isfreebsd else linux_scanner
        self.devices = []

    def scan(self):
        '''Fetch list of connected USB devices from operating system'''
        self.devices = self.scanner()

    def is_device_connected(self, device, debug=False, only_presence=False):
        ''' If only_presence is True don't perform any expensive checks (used
        only in windows)'''
        return device.is_usb_connected(self.devices, debug=debug,
                only_presence=only_presence)


def main(args=sys.argv):
    return 0

if __name__ == '__main__':
    sys.exit(main())
