"""Detection d'une cible ssh (user/host/port) tapee a la main dans un terminal.

Sert a proposer le SFTP sur l'hote d'une commande `ssh ...` sans avoir a creer
un favori au prealable.
"""
from __future__ import annotations

import re

# Repere une commande ssh tapee a la main dans un terminal.
SSH_COMMAND_RE = re.compile(r"\bssh\s+(?P<args>[^\r\n|;&]+)")
# options ssh qui consomment la valeur suivante (a ne pas confondre avec l'hote)
SSH_VALUE_OPTIONS = {
    "-p", "-i", "-l", "-o", "-F", "-J", "-b", "-c", "-D", "-L", "-R", "-W", "-e", "-m", "-Q",
}
HOST_RE = re.compile(r"^[A-Za-z0-9][\w.\-]*$")


def _parse_ssh_args(args: str) -> dict | None:
    tokens = args.split()
    user, host, port = "", "", 22
    index = 0
    while index < len(tokens):
        token = tokens[index]
        if token.startswith("-"):
            if token in SSH_VALUE_OPTIONS:
                value = tokens[index + 1] if index + 1 < len(tokens) else ""
                if token == "-p" and value.isdigit():
                    port = int(value)
                if token == "-l" and value:
                    user = value
                index += 2
                continue
            if token.startswith("-p") and token[2:].isdigit():  # forme collee : -p2222
                port = int(token[2:])
            index += 1
            continue
        if not host:
            candidate = token
            if "@" in candidate:
                user, _, candidate = candidate.partition("@")
            if HOST_RE.match(candidate):
                host = candidate
        index += 1
    return {"user": user, "host": host, "port": port} if host else None


def detect_ssh_target(text: str) -> dict | None:
    """Renvoie la derniere cible ssh trouvee dans le texte d'un terminal."""
    result = None
    for match in SSH_COMMAND_RE.finditer(text):
        parsed = _parse_ssh_args(match.group("args"))
        if parsed:
            result = parsed
    return result