fs-uae-wrapper/fs_uae_wrapper/utils.py

"""
Misc utilities
"""
import configparser
import logging
import os
import pathlib
import shutil
import subprocess

from fs_uae_wrapper import file_archive, message


class CmdOption(dict):
    """
    Holder class for commandline switches.
    """

    def add(self, option):
        """parse and add option to the dictionary"""
        if not option.startswith('--'):
            raise AttributeError(f"Cannot add option {option} to the "
                                 f"dictionary")
        if '=' in option:
            key, val = option.split('=', 1)
            key = key[2:].strip()
            self[key] = val.strip()
        else:
            key = option[2:].strip()
            # parameters are always as options - parse them when need it later
            self[key] = '1'

    def list(self):
        """Return list of options as it was passed through the commandline"""
        ret_list = []
        for key, val in self.items():
            if val != '1':
                ret_list.append(f'--{key}={val}')
            else:
                ret_list.append(f'--{key}')
        return ret_list


def get_config_options(conf):
    """Read config file and return options as a dict"""
    parser = configparser.ConfigParser()
    try:
        parser.read(conf)
    except configparser.ParsingError:
        # Configuration syntax is wrong
        return None

    return {key: val for section in parser.sections()
            for key, val in parser.items(section)}


def operate_archive(arch_name, operation, text, params):
    """
    Create archive from contents of current directory
    """

    archiver = file_archive.get_archiver(arch_name)

    if archiver is None:
        return False

    msg = message.Message(text)
    if text:
        msg.show()

    res = False

    if operation == 'extract':
        res = archiver.extract(arch_name)

    if operation == 'create':
        res = archiver.create(arch_name, params)

    msg.close()

    return res


def create_archive(arch_name, title='', params=None):
    """
    Create archive from contents of current directory
    """
    msg = ''
    if title:
        msg = f"Creating archive for `{title}'. Please be patient"
    return operate_archive(arch_name, 'create', msg, params)


def extract_archive(arch_name, title='', params=None):
    """
    Extract provided archive to current directory
    """
    msg = ''
    if title:
        msg = f"Extracting files for `{title}'. Please be patient"
    return operate_archive(arch_name, 'extract', msg, params)


def run_command(cmd):
    """
    Run provided command. Return true if command execution returns zero exit
    code, false otherwise. If cmd is not a list, there would be an attempt to
    split it up for subprocess call method. May throw exception if cmd is not
    a list neither a string.
    """

    if not isinstance(cmd, list):
        cmd = cmd.split()

    logging.debug("Executing `%s'.", " ".join(cmd))
    code = subprocess.call(cmd)
    if code != 0:
        logging.error('Command `%s` returned non 0 exit code.', cmd[0])
        return False
    return True


def merge_all_options(configuration, commandline):
    """
    Merge dictionaries with wrapper options into one. Commandline options
    have precedence.
    """
    options = configuration.copy()
    options.update(commandline)
    return options


def interpolate_variables(string, config_path, base=None):
    """
    Interpolate variables used in fs-uae configuration files, like:
        - $CONFIG
        - $HOME
        - $EXE
        - $APP
        - $DOCUMENTS
        - $BASE
    """

    _string = string
    if '$CONFIG' in string:
        conf_path = pathlib.Path(config_path).resolve().parent
        string = str(pathlib.Path(string.replace('$CONFIG', str(conf_path)))
                     .resolve())

    if '$HOME' in string:
        string = string.replace('$HOME', os.path.expandvars('$HOME'))

    if '$EXE' in string:
        string = string.replace('$EXE', shutil.which('fs-uae'))

    if '$APP' in string:
        string = string.replace('$APP', shutil.which('fs-uae'))

    if '$DOCUMENTS' in string:
        xdg_docs = os.getenv('XDG_DOCUMENTS_DIR',
                             os.path.expanduser('~/Documents'))
        string = string.replace('$DOCUMENTS', xdg_docs)

    if base:
        if '$BASE' in string:
            string = string.replace('$BASE', base)

    if os.path.exists(string):
        return string
    return _string


def get_config(conf_file):
    """
    Try to find configuration files and collect data from it.
    Will search for paths described in https://fs-uae.net/paths
    - ~/Documents/FS-UAE/Configurations/Default.fs-uae
    - ~/Documents/FS-UAE/Configurations/Host.fs-uae
    - ~/FS-UAE/Configurations/Default.fs-uae
    - ~/FS-UAE/Configurations/Host.fs-uae
    - ~/.config/fs-uae/fs-uae.conf
    - ./fs-uae.conf
    - ./Config.fs-uae
    """

    xdg_conf = os.getenv('XDG_CONFIG_HOME', os.path.expanduser('~/.config'))
    user = os.path.expanduser('~/')
    paths = ((os.path.join(xdg_conf, 'fs-uae/fs-uae.conf'),
              os.path.join(xdg_conf, 'fs-uae/')),
             (os.path.join(user,
                           'Documents/FS-UAE/Configurations/Default.fs-uae'),
              os.path.join(user, 'Documents/FS-UAE')),
             (os.path.join(user, 'FS-UAE/Configurations/Default.fs-uae'),
              os.path.join(user, 'FS-UAE')))

    for path, conf_dir in paths:
        if os.path.exists(path):
            config = get_config_options(path)
            if config is None:
                continue
            conf = get_config_options(conf_file) or {}
            config.update(conf)
            break
    else:
        conf_dir = None
        config = get_config_options(conf_file) or {}

    if 'base_dir' in config:
        base_dir = interpolate_variables(config['base_dir'], conf_file)
        host = os.path.join(base_dir, 'Configurations/Host.fs-uae')

        if os.path.exists(host):
            host_conf = get_config_options(host) or {}
            config.update(host_conf)
            # overwrite host options again via provided custom/relative conf
            conf = get_config_options(conf_file) or {}
            config.update(conf)
    elif conf_dir:
        config['_base_dir'] = conf_dir

    return config


def get_arch_ext(archiver_name):
    """Return extension for the archiver"""
    return file_archive.Archivers.get_extension_by_name(archiver_name)