#!/usr/bin/python3
#
# This file is part of turnkey-version
#
# turnkey-version is open source software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation; either version 3 of the
# License, or (at your option) any later version.

import sys
import argparse
import os
import json

import sysversion

_ROOTFS = '/'
_TKL_VER = 'etc/turnkey_version'
TurnkeyVersionError = sysversion.TurnkeyVersionError


def main():
    parser = argparse.ArgumentParser(
            description='TurnKey Linux Version information')
    file_or_str = parser.add_mutually_exclusive_group()
    # rootfs provides backwards compatability
    file_or_str.add_argument(
            'rootfs', type=str, nargs="?", default=_ROOTFS,
            help="Path to root filesystem, defaults to '/'. Will read file"
                 f" 'ROOTFS/{_TKL_VER}'.")
    file_or_str.add_argument(
            '-f', '--file', type=str, metavar="PATH_TO_FILE", default=None,
            help="Absolute (i.e. leading /) or relative (to current; i.e. no"
                 " leading /) path to file containing turnkey version string."
                 " NOTE: conflicts with -s|--string.")
    file_or_str.add_argument(
            '-s', '--string', type=str, metavar="TKL_VER_STR",
            help="Process a string, instead of reading from a file."
                 "('turnkey-' prefix optional). NOTE: Conflicts with"
                 " -f|--file.")
    output = parser.add_argument_group(
            'Output options',
            description="Return space separated values, or all values in json"
                        " format. NOTE: If multiple elements returned, the"
                        " order will always be: 'NAME VERSION CODENAME ARCH'"
                        " (regardless of switch order).")
    output.add_argument('-n', '--name', action="store_true",
                        help="Return TurnKey appliance name. E.g. core.")
    output.add_argument('-t', '--tklversion', action="store_true",
                        help="Return TurnKey version number. E.g. 16.0.")
    output.add_argument('-c', '--codename', action="store_true",
                        help="Return relevant Debian codename. E.g. buster.")
    output.add_argument('-r', '--arch', action="store_true",
                        help="Return relevant architechture. E.g. amd64")
    output.add_argument('-a', '--all', action="store_true",
                        help="Return space separated name, version, codename &"
                        " arch. (Same as -ntcr).")
    output.add_argument('-j', '--json', action="store_true",
                        help="Return all name info in json format (conflicts"
                        " with other output options).")
    additional_output = parser.add_argument_group(
            'Additional output options',
            description="Return additional values. If no other output options"
                        " specified, these will be the only output. Otherwise,"
                        " these values will be appended after any other"
                        " results returned, either space separated, or if"
                        " -j|--json, as additional key, value pairs.")
    additional_output.add_argument('-d', '--debian-codename',
                                   action="store_true",
                                   help="Return system's reported Debian"
                                        " codename (not TurnKey version"
                                        " codename). If rootfs set, then"
                                        " return codename of chroot.")

    args = parser.parse_args()
    if args.name or args.tklversion or args.codename or args.arch:
        output_values = True
    else:
        output_values = False
    if args.all and output_values:
        parser.error(
            "-a|--all and -n|--name / -t|--tklversion / -c|--codename"
            " / -r|--arch are mutually exclusive.")
    if args.json and (args.all or output_values):
        parser.error("-j|--json conflicts with other output values.")
    if args.string:
        turnkey_version = args.string
        rootfs = ''
    else:
        # ensure that args.file is relative to args.rooffs
        if args.file:
            rootfs = ''
            v_file = os.path.abspath(args.file)
        else:
            rootfs = args.rootfs
            v_file = _TKL_VER

        turnkey_version = sysversion.get_turnkey_version(rootfs, v_file)
    if not turnkey_version:
        raise TurnkeyVersionError(
                "can't detect turnkey version - missing or invalid file"
                f"'{os.path.join(rootfs, v_file)}'.")

    tkl_appver = []
    tkl_appver_cls = sysversion.AppVer(turnkey_version, rootfs=rootfs)
    if args.all:
        args.name = True
        args.tklversion = True
        args.codename = True
        args.arch = True
    if args.name:
        tkl_appver.append(tkl_appver_cls.appname)
    if args.tklversion:
        tkl_appver.append(tkl_appver_cls.tklver)
    if args.codename:
        tkl_appver.append(tkl_appver_cls.codename)
    if args.arch:
        tkl_appver.append(tkl_appver_cls.arch)
    if args.debian_codename:
        tkl_appver.append(tkl_appver_cls.deb_codename)
    if args.json:
        print(json.dumps(tkl_appver_cls.app_json(
              deb_ver=args.debian_codename), indent=2))
    elif tkl_appver:
        print(' '.join(tkl_appver))
    else:
        print(turnkey_version)


if __name__ == "__main__":
    main()