import os
import time
import sys
import subprocess
import re

import config
import lcd


def _get_process_list():
    pids = [int(pid) for pid in os.listdir('/proc') if pid.isdigit()]
    processes = []
    for pid in pids:
        try:
            with open("/proc/%i/cmdline" % pid, "r") as f:
                processes.append(f.read())
        except:
            pass
    return zip(pids, processes)


def _start_pppd():
    print " ".join(config.PPPD)
    p = subprocess.Popen(config.PPPD, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    stdout, stderr = p.communicate()
    if p.returncode != 0:
        sys.stderr.write("Could not run pppd succesfully! Here is some debug data:\n")
        sys.stderr.write("  STDOUT: %s\n" % stdout)
        sys.stderr.write("  STDERR: %s\n" % stderr)
    else:
        sys.stdout.write("PPPd started succesfully.\n")


def _get_pppd_pid():
    for pid, process in _get_process_list():
        if process.startswith("/usr/sbin/pppd"):
            return pid


def _kill_pppd():
    pid = _get_pppd_pid()
    if pid:
        os.kill(pid, 9)
        sys.stdout.write("Killed PPPd.\n")


def _check_connectivity():
    p = subprocess.Popen(config.PING, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    p.communicate()
    if p.returncode != 0:
        sys.stderr.write("There seem to be some connectivity problems... Waiting 15 seconds, then giving it another shot...\n")
        time.sleep(15)

        p = subprocess.Popen(config.PING, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        p.communicate()
        if p.returncode != 0:
            sys.stderr.write("Connectivity problems persisting! :(\n")
            return False
        else:
            sys.stderr.write("Seems to be okay now.\n")
    return True


def _get_public_ip():
    p = subprocess.Popen(["ip", "a", "list", "dev", "ppp0"], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    stderr, stdout = p.communicate()
    if p.returncode != 0:
        return "UNKNOWN"
    else:
        for line in stderr.split("\n"):
            m = re.match("^inet ([\.0-9]*) peer", line.strip())
            if m:
                return m.group(1)
        return "UNKNOWN"


def loop():
    screen = lcd.LCDScreen()

    def log(text, text2=None, clear=True):
        if clear:
            screen.clear()
        text = text[:16]
        text = ' ' * ((16 - len(text))/2) + text
        screen.text_at(0, 0, text)
        if text2:
            text2 = text2[:16]
            text2 = ' ' * ((16 - len(text2))/2) + text2
            screen.text_at(0, 1, text2)

    while True:
        pppd_pid = _get_pppd_pid()
        if not pppd_pid:
            log("Starting PPPd...")
            _start_pppd()
            screen.clear()

            timeout = 30
            while timeout >= 0:
                log("PPPd started.", "Testing in %i s.   " % timeout, False)
                time.sleep(1)
                timeout -= 1

            log("PPPd started.", "Testing...")

        if not _check_connectivity():
            sys.stderr.write("Restarting PPPd.\n")
            log("ADSL down!", "Restarting PPPd...")
            _kill_pppd()
            _start_pppd()
            log("ADSL down!", "PPPd restarted!")
        else:
            log("ADSL up!", _get_public_ip())
        time.sleep(60)