#!/usr/bin/python3
import os
import sys
import pathlib
import tempfile
import subprocess
from argparse import ArgumentParser
from lxml import etree


def parse_args():
    parser = ArgumentParser(description='Generate DocBook documentation from D-Bus IDL.')
    parser.add_argument(
        '--idl',
        action='store',
        help='IDL file',
        required=True,
        type=str,
        metavar='FILE',
    )
    parser.add_argument(
        '--output-directory',
        action='store',
        help='Output directory where DocBook files will be saved',
        required=True,
        type=str,
        metavar='DIR',
    )
    parser.add_argument(
        '--tmp',
        action='store',
        help='Temporary directory for intermediate files',
        required=True,
        type=str,
        metavar='DIR',
    )
    return parser.parse_args()


ARGS = parse_args()

pathlib.Path(ARGS.output_directory).mkdir(parents=True, exist_ok=True)

REF_ENTRY_INFO = '''\
  <refentryinfo>
    <title>stafctl</title>
    <productname>nvme-stas</productname>
    <author>
      <personname>
        <honorific>Mr</honorific>
        <firstname>Martin</firstname>
        <surname>Belanger</surname>
      </personname>
      <affiliation>
        <orgname>Dell, Inc.</orgname>
      </affiliation>
    </author>
  </refentryinfo>
'''

MANVOLNUM = '<manvolnum>5</manvolnum>'
PURPOSE = '<refpurpose>DBus interface</refpurpose>'

PARSER = etree.XMLParser(remove_blank_text=True)


def add_missing_info(fname, stem):
    xml = etree.parse(fname, PARSER)
    root = xml.getroot()
    if root.tag != 'refentry':
        return

    if xml.find('refentryinfo'):
        return

    root.insert(0, etree.fromstring(REF_ENTRY_INFO))

    refmeta = xml.find('refmeta')
    if refmeta is not None:
        if refmeta.find('refentrytitle') is None:
            refmeta.append(etree.fromstring(f'<refentrytitle>{stem}</refentrytitle>'))
        refmeta.append(etree.fromstring(MANVOLNUM))

    refnamediv = xml.find('refnamediv')
    if refnamediv is not None:
        refpurpose = refnamediv.find('refpurpose')
        if refpurpose is not None:
            refnamediv.remove(refpurpose)

        refnamediv.append(etree.fromstring(PURPOSE))

    et = etree.ElementTree(root)
    et.write(fname, pretty_print=True)


FILE_PREFIX = 'nvme-stas'
FINAL_PREFIX = FILE_PREFIX + '-'


pathlib.Path(ARGS.tmp).mkdir(parents=True, exist_ok=True)
with tempfile.TemporaryDirectory(dir=ARGS.tmp) as tmpdirname:
    try:
        subprocess.run(['gdbus-codegen', '--output-directory', tmpdirname, '--generate-docbook', FILE_PREFIX, ARGS.idl])
    except subprocess.CalledProcessError as ex:
        sys.exit(f'Failed to generate DocBook file. {ex}')

    stems = []
    with os.scandir(tmpdirname) as it:
        for entry in it:
            if entry.is_file() and entry.name.endswith('.xml') and entry.name.startswith(FINAL_PREFIX):
                fname = entry.name[len(FINAL_PREFIX) :]  # Strip prefix
                stem = fname[0:-4]  # Strip '.xml' suffix
                stems.append(stem)
                tmp_file = os.path.join(tmpdirname, entry.name)
                add_missing_info(tmp_file, stem)
                os.replace(tmp_file, os.path.join(ARGS.output_directory, fname))

    print(';'.join(stems))