#!/usr/bin/env python3

import subprocess
import argparse
import time
import sys
import os

from os.path import expanduser

#the term qube refers to a qubes vm

def is_program_installed_in_qube( program, qube_name ):
    is_installed = True

    try:
        command = 'command -v ' + program
        subprocess.check_call([ 'qvm-run', '--no-color-output', qube_name, command ], stdout = open( os.devnull, 'w' ) )

    except subprocess.CalledProcessError:
        is_installed = False

    return is_installed


#this function requires virsh
#domstate only works for Xen domU (guests)
def is_qube_running( qube_name ):
    runs = False

    out = subprocess.check_output([ "virsh", "-c", "xen:///", "domstate", qube_name ])
    out = out.decode('utf-8').replace('\n', '')

    if 'running' == out:
        runs = True

    return runs


def get_qube_packages( qube_name ):
    content = "## Qubes Packages\n\n"

    #a qube can have more than one package manager installed (only one is functional)
    pkg_cmd = { 'dpkg' : 'dpkg -l qubes-*', 'pacman' : 'pacman -Qs qubes', 'rpm' : 'rpm -qa qubes-*' }

    if is_qube_running( qube_name ):

        for package_manager in pkg_cmd.keys():
            if is_program_installed_in_qube( package_manager, qube_name ):
                pkg_list_cmd = pkg_cmd[package_manager]

                try:
                    out = subprocess.check_output([ 'qvm-run', qube_name, '--pass-io', '--no-color-output', pkg_list_cmd ], stderr = open( os.devnull, 'w' ) )
                    out = out.decode('utf-8')
                    content += create_heading( ( "Package Manager: " + package_manager ), 3 )
                    content += wrap_code( out )
                except subprocess.CalledProcessError:
                    pass #do nothing

    else:
        content += "**No packages listed, because Qube " + qube_name + " was not running**\n\n"

    return content


def get_dom0_packages():
    content = create_heading( "Dom0 Packages", 2 )
    out = subprocess.check_output([ "rpm", "-qa", "qubes-*" ])
    out = out.decode('utf-8')
    content += wrap_code( out )

    return content


def wrap_code( text ):
    code = "~~~\n" + text + "~~~\n\n"

    return code

def create_heading( heading, level ):
    heading = heading + "\n\n"

    if 1 == level:
        heading = "# " + heading
    elif 2 == level:
        heading = "## " + heading
    else:
        heading = "### " + heading

    return heading



def get_log_file_content( qube_name ):
    content = "## Log Files\n\n"
    qubes_os_log = "/var/log/qubes/"
    ext = ".log"

    log_prefix = [ "guid", "pacat", "qubesdb", "qrexec" ]

    #constructs for each log file prefix the full path and reads the log file
    for prefix in log_prefix:
        log_file = prefix + "." + qube_name + ext
        content += create_heading( ( "Log File: " + log_file ), 3 )
        content += wrap_code( get_log_file( qubes_os_log + log_file ) )

    return content


def get_qube_prefs( qube_name ):
    qube_prefs = subprocess.check_output([ "qvm-prefs", qube_name ])
    qube_prefs = qube_prefs.decode('utf-8')

    content = create_heading( "Qube Prefs", 2 )
    content += wrap_code( qube_prefs )

    return content


def report( qube_name ):
    template = '''{title}
{content}
'''

    title_text = create_heading( "Bug report: " + qube_name, 1 )

    content_text = get_qube_prefs( qube_name )
    content_text += get_dom0_packages()
    content_text += get_log_file_content( qube_name )
    content_text += get_qube_packages( qube_name )


    report = template.format( title=title_text, content=content_text )

    return report


def write_report( report_content, file_path ):
    with open( file_path, 'w' ) as report_file:
        report_file.write( report_content )


def send_report( dest_qube, file_path):
    #if dest_qube is not running -> start dest_qube
    if not is_qube_running( dest_qube ):
        try:
            subprocess.check_call([ "qvm-start", dest_qube ])
        except subprocess.CalledProcessError:
            print( "Error while starting: " + dest_qube, file = sys.stderr )

    try:
        subprocess.check_call([ "qvm-move-to-vm", dest_qube, file_path ])
    except subprocess.calledProcessError:
        print( "Moving file bug-report failed", file = sys.stderr )


def get_log_file( log_file ):
    data = ""

    #open and close the file
    with open( log_file ) as log:
        data = log.read()

    return data


def qube_exist( qube_name ):
    exists = True

    try:
        #calls: qvm-check --quiet vmanme
        subprocess.check_call([ "qvm-check", "--quiet", qube_name ])

    except subprocess.CalledProcessError:
        exists = False

    return exists


def get_report_file_path( qube_name ):
    #exapanduser -> works corss platform
    home_dir = expanduser("~")
    date = time.strftime("%H%M%S")
    file_path = home_dir + "/" + qube_name + "_bug-report_" + date + ".md"

    return file_path


def main():
    parser = argparse.ArgumentParser( description = 'Generates a bug report for a specific qube (Qubes VM)' )
    parser.add_argument( 'vmname', metavar = '<vmanme>', type = str )
    parser.add_argument( '-d', '--dest-vm', metavar = '<dest-vm>', dest = "destvm", type = str, default = 'dom0', help = "send the report to the destination VM" )
    parser.add_argument( '-p', '--print-report', action = 'store_const', const = "print_report", required = False, help = "prints the report without writing it or sending it to a destination VM" )
    args = parser.parse_args()

    if qube_exist( args.vmname ):

        if qube_exist( args.destvm ):
            #get the report
            report_content = report( args.vmname )

            #if -p or --print-report is an argument print the report
            if args.print_report:
                print( report_content )

            #write and send the report
            else:
                file_path = get_report_file_path( args.vmname )
                write_report( report_content, file_path )
                print( "Report written to: " + file_path )

                if 'dom0' != args.destvm:
                    send_report( args.destvm, file_path )
                    print( "Report send to VM: " + args.destvm )

            exit(0)

        else:
            print ( "Destination VM does not exist" )
            exit(1)

    else:
        print( "VM does not exist" )
        exit(1)


#calls the main function -> program start point
main()