from __future__ import annotations

import sys
from threading import Event, Thread
from typing import Optional

from agent_runtime import run_agent
from agents import Agent, build_agent
from goal_loader import load_goal_instructions
from mud_env import load_env_file, read_connection_settings, read_tool_settings
from mud_session import (
    SessionState,
    graceful_shutdown,
    interactive_session,
    login,
    run_tool_loop,
)
from mud_tools import TOOL_DESCRIPTIONS, build_tool
from telnetclient import TelnetClient
from tools import Tool


DEFAULT_SEND_INTERVAL = 1.0
AUTO_STOP_IDLE_SECONDS = 2.0


def _start_tool_thread(
    client: TelnetClient,
    state: SessionState,
    tool: Tool,
    stop_event: Event,
    *,
    auto_stop: bool = False,
    auto_stop_idle: float = AUTO_STOP_IDLE_SECONDS,
) -> Thread:
    thread = Thread(
        target=run_tool_loop,
        args=(client, state, tool, stop_event),
        kwargs={
            "min_send_interval": DEFAULT_SEND_INTERVAL,
            "auto_stop": auto_stop,
            "auto_stop_idle": auto_stop_idle,
        },
        daemon=True,
    )
    thread.start()
    return thread


def _build_sideload_tools(specs: list[str]) -> list[tuple[str, Tool]]:
    sideload_tools: list[tuple[str, Tool]] = []
    seen_sideloads: set[str] = set()
    for spec in specs:
        lowered = spec.lower()
        if lowered in seen_sideloads:
            continue
        seen_sideloads.add(lowered)
        try:
            tool_instance = build_tool(spec)
        except RuntimeError as exc:
            print(f"[Tool] Failed to load sideload '{spec}': {exc}", file=sys.stderr)
            continue
        sideload_tools.append((spec, tool_instance))
    return sideload_tools


def _prime_agent(agent: Agent, output: str) -> None:
    if not output:
        return
    observe = getattr(agent, "observe", None)
    if callable(observe):
        try:
            observe(output)
        except Exception as exc:  # pragma: no cover - defensive
            print(f"[Agent] observe failed: {exc}", file=sys.stderr)


def _join_threads(threads: list[Thread], *, timeout: float = 1.0) -> None:
    for thread in threads:
        thread.join(timeout=timeout)


def main() -> int:
    load_env_file()

    connection = read_connection_settings()
    tool_settings = read_tool_settings()

    sideload_tools = _build_sideload_tools(tool_settings.sideload_specs)

    state = SessionState()
    stop_event = Event()
    tool_thread: Optional[Thread] = None
    tool: Optional[Tool] = None
    ephemeral_tools: list[Thread] = []
    sidecar_threads: list[Thread] = []
    agent_threads: list[Thread] = []

    with TelnetClient(host=connection.host, port=connection.port, timeout=10.0) as client:
        login(
            client,
            user=connection.user,
            password=connection.password,
            login_prompt=connection.login_prompt,
            state=state,
        )

        if tool_settings.tool_mode:
            tool = build_tool(tool_settings.tool_spec)
            tool_thread = _start_tool_thread(client, state, tool, stop_event)

        if sideload_tools:
            for sidecar_spec, sidecar_tool in sideload_tools:
                thread = _start_tool_thread(client, state, sidecar_tool, stop_event)
                sidecar_threads.append(thread)
                print(
                    f"[Tool] Sideloading '{sidecar_spec}' ({sidecar_tool.__class__.__name__})"
                )

        def run_ephemeral_tool(spec: str) -> None:
            spec = spec.strip()
            if not spec:
                print("[Tool] Usage: #execute <tool_spec>")
                return
            try:
                temp_tool = build_tool(spec)
            except RuntimeError as exc:
                print(f"[Tool] Failed to load '{spec}': {exc}", file=sys.stderr)
                return
            thread = _start_tool_thread(
                client,
                state,
                temp_tool,
                stop_event,
                auto_stop=True,
                auto_stop_idle=AUTO_STOP_IDLE_SECONDS,
            )
            ephemeral_tools.append(thread)
            print(f"[Tool] Executing {spec!r} once")

        def run_ephemeral_agent(spec: str) -> None:
            spec = spec.strip()
            if not spec:
                print("[Agent] Usage: #agent <agent_spec>")
                return
            try:
                temp_agent = build_agent(spec, allowed_tools=TOOL_DESCRIPTIONS)
            except RuntimeError as exc:
                print(f"[Agent] Failed to configure '{spec}': {exc}", file=sys.stderr)
                return

            _start_agent_thread(temp_agent, label=spec)

        def _start_agent_thread(agent: Agent, *, label: str) -> None:
            _prime_agent(agent, state.snapshot_output())

            def run_tool_instance(tool: Tool) -> bool:
                run_tool_loop(
                    client,
                    state,
                    tool,
                    stop_event,
                    min_send_interval=DEFAULT_SEND_INTERVAL,
                    auto_stop=True,
                    auto_stop_idle=AUTO_STOP_IDLE_SECONDS,
                )
                _prime_agent(agent, state.snapshot_output())
                return True

            thread = Thread(
                target=run_agent,
                args=(agent,),
                kwargs={
                    "build_tool": build_tool,
                    "run_tool": run_tool_instance,
                    "send_command": lambda cmd: state.send(client, cmd),
                    "stop_event": stop_event,
                },
                daemon=True,
            )
            agent_threads.append(thread)
            print(f"[Agent] Executing {label!r}")
            thread.start()

        if tool_settings.autoplay:
            try:
                autoplay_agent = build_agent("intelligent", allowed_tools=TOOL_DESCRIPTIONS)
            except RuntimeError as exc:
                print(f"[Autoplay] Failed to configure intelligent agent: {exc}", file=sys.stderr)
            else:
                goal = load_goal_instructions()
                if goal:
                    setattr(autoplay_agent, "instruction", goal)
                    print("[Autoplay] Loaded instructions from GOAL.md")
                else:
                    print(
                        "[Autoplay] GOAL.md missing or empty; starting without extra instructions",
                        file=sys.stderr,
                    )
                _start_agent_thread(autoplay_agent, label="intelligent (autoplay)")

        interrupted = False
        try:
            interactive_session(
                client,
                state=state,
                stop_event=stop_event,
                exit_command=connection.exit_command,
                tool_command=None if tool_settings.tool_mode else run_ephemeral_tool,
                agent_command=run_ephemeral_agent,
            )
        except KeyboardInterrupt:
            print()
            interrupted = True
        finally:
            stop_event.set()
            if tool_thread:
                tool_thread.join(timeout=1.0)
            _join_threads(sidecar_threads)
            _join_threads(ephemeral_tools)
            _join_threads(agent_threads)

        if interrupted:
            graceful_shutdown(client, connection.exit_command, state=state)

    return 0


if __name__ == "__main__":
    raise SystemExit(main())