import re

import os.path

from pathlib import Path
from typing import Optional


# load utility functions
def load_sshconfig_server_list(sshconfig: Path,
                               hostfilter: Optional[re.Pattern] = None,
                               lineSkip: Optional[re.Pattern] = None) -> set:
    """
    Load a list of servers from an ssh configuration file.
    """

    output = set()
    with sshconfig.open() as inconfig:
        for line in [l.strip() for l in inconfig]:
            if line.startswith("Host "):
                if lineSkip and lineSkip.match(line):
                    continue
                hostinfo = line.split('#', 2)[0]
                hostname = hostinfo.split()[-1]
                if hostfilter and not hostfilter.match(hostname):
                    continue
                output.add(hostname)
    return output


def load_bare_server_list(serverlist: Path,
                          hostfilter: Optional[re.Pattern] = None,
                          lineSkip: Optional[re.Pattern] = None) -> set:
    """
    Load a list of servers from a simple text file.
    """
    output = set()
    with sshconfig.open() as inconfig:
        for line in [l.strip() for l in inconfig]:
            if not line:
                continue
            if lineSkip and lineSkip.match(line):
                continue

            hostinfo = line.split('#', 2)[0]
            hostname = hostinfo.split()[-1]
            if hostfilter and not hostfilter.match(hostname):
                continue
            output.add(hostname)
    return output


def load_config(config_path: Path):
    output = dict()
    with config_path.open() as inconfig:
        section = 'global'
        cmd = False
        lineno = 0
        for rline in inconfig:
            lineno += 1

            line = rline.strip()

            if not line:
                continue
            if line.startswith('#'):
                continue

            if line.startswith('['):
                section = line[1:-1]
                if section.startswith("cmd") or section == 'startup':
                    cmd = True
                    output.setdefault(section, list())
                else:
                    cmd = False
                    output.setdefault(section, dict())
                continue

            if cmd:
                output[section].append(line)
            else:
                if not '=' in line:
                    print(f"config parse error, line {lineno}: {line}")
                    continue
                kv = line.split('=', 2)
                if len(kv) == 1:
                    value = ''
                else:
                    value = kv[1]
                output[section][kv[0]] = value
        return output