#!/usr/bin/env python3
"""
rcon-cli — interactive and one-shot remote console for Plutainer.

Usage:
  docker exec -i <container> rcon-cli          # interactive
  docker exec <container> rcon-cli <command>   # one-shot

"RCON" is the name people search for, so the command keeps it, but the protocol
underneath depends on the game: Quake3 RCON over UDP for the Call of Duty
families, Valve's RCON over TCP for Source games, a telnet console for 7 Days to
Die. The shell library decides which; this script only speaks them.
"""

import os
import subprocess
import sys

# Resolve symlinks so SCRIPT_DIR points at the real location rather than the
# symlink's directory (this is linked into /usr/local/bin).
SCRIPT_DIR = os.path.dirname(os.path.realpath(__file__))
sys.path.insert(0, SCRIPT_DIR)


def resolve_endpoint():
    """Ask the shell library how to reach this game's console."""
    script = f"""
        source "{SCRIPT_DIR}/lib/core.sh"
        detect_game_type || exit 1
        resolve_admin_endpoint || exit 1
        echo "$GAME_NAME"
        echo "$GAME_TYPE"
        echo "$ADMIN_PROTOCOL"
        echo "$ADMIN_PORT"
        echo "$ADMIN_PASSWORD"
        echo "${{ADMIN_DISABLED_HINT:-}}"
        echo "$ADMIN_HOSTS"
    """
    result = subprocess.run(["bash", "-c", script], capture_output=True, text=True)
    if result.returncode != 0:
        print(result.stderr.strip(), file=sys.stderr)
        sys.exit(1)

    lines = result.stdout.split("\n")
    if len(lines) < 7:
        print("Error: failed to resolve the server's console endpoint.", file=sys.stderr)
        if result.stderr.strip():
            print(result.stderr.strip(), file=sys.stderr)
        sys.exit(1)

    return {
        "game_name": lines[0].strip(),
        "game_type": lines[1].strip(),
        "protocol": lines[2].strip(),
        "port": lines[3].strip(),
        "password": lines[4],
        "hint": lines[5].strip(),
        # Source servers answer only on the container's own address; everything
        # else answers on loopback. Try in order rather than encoding which.
        "hosts": lines[6].split() or ["127.0.0.1"],
    }


# --- one class per protocol, same three methods -----------------------------


class Quake3Client:
    """CoD families. Connectionless UDP; every command is its own packet."""

    def __init__(self, cfg):
        from protocols import quake3

        if not cfg["password"]:
            raise SystemExit(
                "No rcon_password is set in this server's config, so RCON is disabled.\n"
                "Set PLUTAINER_RCON_PASSWORD and restart, or add the line yourself."
            )
        self.server = quake3.Quake3Server(
            "127.0.0.1:%s" % cfg["port"], rcon_password=cfg["password"]
        )

    def open(self):
        pass

    def send(self, cmd):
        _kind, response = self.server.rcon(cmd)
        return response.strip()

    def close(self):
        pass


class SourceRconClient:
    """Source games. Stateful TCP session, so the connection is held open."""

    def __init__(self, cfg):
        from protocols import source_rcon

        self.hosts = cfg["hosts"]
        self.port = cfg["port"]
        self.password = cfg["password"]
        self.module = source_rcon
        self.conn = None

    def open(self):
        self.conn = _first_reachable(
            self.hosts,
            lambda host: self.module.SourceRcon(host, self.port, self.password),
        )

    def send(self, cmd):
        return self.conn.command(cmd).strip()

    def close(self):
        if self.conn is not None:
            self.conn.close()


class TelnetClient:
    """7 Days to Die. Console stream; a reply is whatever arrives next."""

    def __init__(self, cfg):
        from protocols import telnet_admin

        self.hosts = cfg["hosts"]
        self.port = cfg["port"]
        self.password = cfg["password"]
        self.module = telnet_admin
        self.conn = None

    def open(self):
        self.conn = _first_reachable(
            self.hosts,
            lambda host: self.module.TelnetAdmin(host, self.port, self.password),
        )

    def send(self, cmd):
        return self.conn.command(cmd).strip()

    def close(self):
        if self.conn is not None:
            self.conn.close()


def _first_reachable(hosts, build):
    """Connect to the first host that answers, else raise the last error."""
    last = None
    for host in hosts:
        conn = build(host)
        try:
            conn.connect()
            return conn
        except Exception as err:
            last = err
    raise last or OSError("no address answered")


CLIENTS = {
    "quake3": Quake3Client,
    "source-rcon": SourceRconClient,
    "telnet": TelnetClient,
}


def build_client(cfg):
    protocol = cfg["protocol"]

    if protocol == "disabled":
        raise SystemExit(
            "%s has a remote console, but it is turned off in this server's config.\n%s"
            % (cfg["game_name"], cfg["hint"] or "")
        )
    if protocol == "none" or protocol not in CLIENTS:
        raise SystemExit(
            "%s has no remote console that Plutainer can talk to." % cfg["game_name"]
        )
    return CLIENTS[protocol](cfg)


def main():
    cfg = resolve_endpoint()
    client = build_client(cfg)

    try:
        client.open()
    except Exception as err:
        raise SystemExit("Could not open the console: %s" % err)

    try:
        # One-shot: everything after the program name is the command.
        if len(sys.argv) > 1:
            print(client.send(" ".join(sys.argv[1:])))
            return

        print(
            "Connected to %s (%s, %s) on port %s"
            % (cfg["game_name"], cfg["game_type"], cfg["protocol"], cfg["port"])
        )
        print("Type 'quit' or 'exit' to close. Ctrl+C also works.")
        print()
        while True:
            try:
                cmd = input("> ").strip()
            except (EOFError, KeyboardInterrupt):
                print()
                break
            if not cmd:
                continue
            if cmd.lower() in ("quit", "exit"):
                break
            try:
                print(client.send(cmd))
            except Exception as err:
                print("Console error: %s" % err, file=sys.stderr)
    finally:
        client.close()


if __name__ == "__main__":
    main()