import shlex
from urllib.parse import urlparse

import paramiko


class SSHControlError(RuntimeError):
    pass



def _derive_host_from_url(rpc_url: str) -> str:
    try:
        parsed = urlparse(rpc_url)
        return parsed.hostname or ""
    except ValueError:
        return ""



def run_remote_command(settings: dict, command: str) -> dict:
    ssh_host = (settings.get("ssh_host") or "").strip() or _derive_host_from_url(settings.get("rpc_url", ""))
    ssh_username = (settings.get("ssh_username") or "").strip()
    ssh_password = settings.get("ssh_password") or ""
    ssh_key_path = (settings.get("ssh_key_path") or "").strip()
    ssh_port = int(settings.get("ssh_port") or 22)

    if not ssh_host:
        raise SSHControlError("SSH host is required to run start/restart commands")
    if not ssh_username:
        raise SSHControlError("SSH username is required to run start/restart commands")

    client = paramiko.SSHClient()
    client.set_missing_host_key_policy(paramiko.AutoAddPolicy())

    connect_args = {
        "hostname": ssh_host,
        "port": ssh_port,
        "username": ssh_username,
        "timeout": 10,
        "look_for_keys": False,
        "allow_agent": False,
    }

    if ssh_key_path:
        connect_args["key_filename"] = ssh_key_path
        if ssh_password:
            connect_args["passphrase"] = ssh_password
    elif ssh_password:
        connect_args["password"] = ssh_password
    else:
        connect_args["look_for_keys"] = True
        connect_args["allow_agent"] = True

    try:
        client.connect(**connect_args)
        _, stdout, stderr = client.exec_command(command, timeout=20)
        exit_code = stdout.channel.recv_exit_status()
        out = stdout.read().decode("utf-8", errors="replace").strip()
        err = stderr.read().decode("utf-8", errors="replace").strip()
    except Exception as exc:  # noqa: BLE001
        raise SSHControlError(f"SSH command failed: {exc}") from exc
    finally:
        client.close()

    return {
        "exit_code": exit_code,
        "stdout": out,
        "stderr": err,
        "host": ssh_host,
    }



def build_start_command(settings: dict) -> str:
    config_path = (settings.get("config_path") or "").strip()
    bitcoin_binary = (settings.get("bitcoin_binary") or "bitcoind").strip() or "bitcoind"

    if not config_path:
        raise SSHControlError("Config file path is required to start bitcoind")

    return f"{shlex.quote(bitcoin_binary)} -daemon -conf={shlex.quote(config_path)}"