"""nemo_relay — optional Hermes plugin for NeMo Relay observability."""

from __future__ import annotations

import asyncio
import inspect
import json
import logging
import os
import threading
import tomllib
from dataclasses import dataclass, field
from pathlib import Path
from typing import Any, Optional

logger = logging.getLogger(__name__)

_INIT_FAILED = object()
_LOCK = threading.RLock()
_RUNTIME: "_Runtime | object | None" = None


@dataclass
class _SessionState:
    session_id: str
    handle: Any = None
    atif_exporter: Any = None
    atif_subscriber_name: str = ""
    is_embedded_subagent: bool = False
    parent_session_id: str = ""
    llm_spans: dict[str, Any] = field(default_factory=dict)
    tool_spans: dict[str, Any] = field(default_factory=dict)


@dataclass
class _SubagentParent:
    parent_session_id: str
    parent_handle: Any
    metadata: dict[str, Any]


@dataclass
class _Settings:
    plugins_toml_path: str = ""
    atof_enabled: bool = False
    atof_output_directory: str = ""
    atof_filename: str = "hermes-atof.jsonl"
    atof_mode: str = "append"
    atif_enabled: bool = False
    atif_output_directory: str = ""
    atif_filename_template: str = "hermes-atif-{session_id}.json"
    atif_subagent_export_mode: str = "embedded"
    atif_agent_name: str = "Hermes Agent"
    atif_agent_version: str = "unknown"
    atif_model_name: str = "unknown"


class _Runtime:
    def __init__(self, nemo_relay: Any, settings: _Settings) -> None:
        self.nemo_relay = nemo_relay
        self.settings = settings
        self.sessions: dict[str, _SessionState] = {}
        self.subagent_parents: dict[str, _SubagentParent] = {}
        self.atof_exporter: Any = None
        self._plugin_config_initialized = self._configure_plugins_toml()
        if not self._plugin_config_initialized:
            self._configure_atof()

    def _configure_plugins_toml(self) -> bool:
        if not self.settings.plugins_toml_path:
            return False
        plugin_mod = getattr(self.nemo_relay, "plugin", None)
        initialize = getattr(plugin_mod, "initialize", None)
        if not callable(initialize):
            return False
        config_path = Path(self.settings.plugins_toml_path)
        try:
            config = tomllib.loads(config_path.read_text(encoding="utf-8"))
            self._ensure_plugin_config_output_dirs(config)
            result = initialize(config)
            if inspect.isawaitable(result):
                asyncio.run(result)
            return True
        except RuntimeError:
            logger.debug("NeMo Relay plugins.toml init skipped inside a running event loop")
            return False
        except Exception as exc:
            logger.debug("NeMo Relay plugins.toml init failed: %s", exc, exc_info=True)
            return False

    def _ensure_plugin_config_output_dirs(self, config: dict[str, Any]) -> None:
        for component in config.get("components", []):
            if not isinstance(component, dict):
                continue
            if component.get("kind") != "observability":
                continue
            if component.get("enabled") is False:
                continue
            component_config = component.get("config")
            if not isinstance(component_config, dict):
                continue
            for exporter_name in ("atof", "atif"):
                exporter_config = component_config.get(exporter_name)
                if not isinstance(exporter_config, dict):
                    continue
                output_directory = exporter_config.get("output_directory")
                if isinstance(output_directory, str) and output_directory.strip():
                    Path(output_directory).mkdir(parents=True, exist_ok=True)

    def _configure_atof(self) -> None:
        if not self.settings.atof_enabled:
            return
        config = self.nemo_relay.AtofExporterConfig()
        if self.settings.atof_output_directory:
            Path(self.settings.atof_output_directory).mkdir(parents=True, exist_ok=True)
            config.output_directory = self.settings.atof_output_directory
        config.filename = self.settings.atof_filename
        if self.settings.atof_mode.lower() == "overwrite":
            config.mode = self.nemo_relay.AtofExporterMode.Overwrite
        else:
            config.mode = self.nemo_relay.AtofExporterMode.Append
        self.atof_exporter = self.nemo_relay.AtofExporter(config)
        self.atof_exporter.register("hermes.nemo_relay.atof")

    def ensure_session(self, kwargs: dict[str, Any]) -> _SessionState:
        session_id = _session_id(kwargs)
        state = self.sessions.get(session_id)
        if state is not None:
            return state

        state = _SessionState(session_id=session_id)
        if self.settings.atif_enabled:
            state.atif_exporter = self.nemo_relay.AtifExporter(
                session_id,
                self.settings.atif_agent_name,
                self.settings.atif_agent_version,
                model_name=str(kwargs.get("model") or self.settings.atif_model_name),
                extra={"source": "hermes-agent", "plugin": "observability/nemo_relay"},
            )
            state.atif_subscriber_name = f"hermes.nemo_relay.atif.{session_id}"
            state.atif_exporter.register(state.atif_subscriber_name)

        subagent_parent = self.subagent_parents.get(session_id)
        metadata = _metadata(kwargs)
        parent_handle = None
        if subagent_parent is not None:
            parent_handle = subagent_parent.parent_handle
            metadata = {**metadata, **subagent_parent.metadata}
            state.is_embedded_subagent = True
            state.parent_session_id = subagent_parent.parent_session_id

        state.handle = self.nemo_relay.scope.push(
            f"hermes-session-{session_id}",
            self.nemo_relay.ScopeType.Agent,
            handle=parent_handle,
            data={"session_id": session_id},
            metadata=metadata,
        )
        self.sessions[session_id] = state
        return state

    def export_atif(self, state: _SessionState) -> None:
        if not self.settings.atif_enabled or state.atif_exporter is None:
            return
        if state.is_embedded_subagent and self.settings.atif_subagent_export_mode != "all":
            return
        output_dir = self.settings.atif_output_directory
        if not output_dir:
            return
        Path(output_dir).mkdir(parents=True, exist_ok=True)
        filename = self.settings.atif_filename_template.format(session_id=state.session_id)
        Path(output_dir, filename).write_text(state.atif_exporter.export_json(), encoding="utf-8")

    def close_session(self, kwargs: dict[str, Any]) -> None:
        session_id = _session_id(kwargs)
        self.subagent_parents.pop(session_id, None)
        state = self.sessions.pop(session_id, None)
        if state is None:
            return
        if state.handle is not None:
            try:
                self.nemo_relay.scope.pop(state.handle, output=_jsonable(kwargs))
            except Exception:
                logger.debug("NeMo Relay session pop failed", exc_info=True)
        self.export_atif(state)
        if state.atif_exporter is not None and state.atif_subscriber_name:
            try:
                state.atif_exporter.deregister(state.atif_subscriber_name)
            except Exception:
                logger.debug("NeMo Relay ATIF deregister failed", exc_info=True)

    def mark(self, name: str, kwargs: dict[str, Any]) -> None:
        state = self.ensure_session(kwargs)
        self.nemo_relay.scope.event(
            name,
            handle=state.handle,
            data=_jsonable(kwargs),
            metadata=_metadata(kwargs),
        )

    def mark_subagent_start(self, kwargs: dict[str, Any]) -> None:
        parent_state = self.ensure_session(kwargs)
        metadata = _metadata(kwargs)
        child_session_id = _child_session_id(kwargs)
        if child_session_id:
            self.subagent_parents[child_session_id] = _SubagentParent(
                parent_session_id=parent_state.session_id,
                parent_handle=parent_state.handle,
                metadata=_subagent_child_metadata(kwargs, metadata),
            )
        self.nemo_relay.scope.event(
            "hermes.subagent.start",
            handle=parent_state.handle,
            data=_jsonable(kwargs),
            metadata=metadata,
        )

    def mark_subagent_stop(self, kwargs: dict[str, Any]) -> None:
        child_session_id = _child_session_id(kwargs)
        if child_session_id:
            self.subagent_parents.pop(child_session_id, None)
        self.mark("hermes.subagent.stop", kwargs)


def register(ctx) -> None:
    ctx.register_hook("on_session_start", on_session_start)
    ctx.register_hook("on_session_end", on_session_end)
    ctx.register_hook("on_session_finalize", on_session_finalize)
    ctx.register_hook("on_session_reset", on_session_reset)
    ctx.register_hook("pre_llm_call", on_pre_llm_call)
    ctx.register_hook("post_llm_call", on_post_llm_call)
    ctx.register_hook("pre_api_request", on_pre_api_request)
    ctx.register_hook("post_api_request", on_post_api_request)
    ctx.register_hook("api_request_error", on_api_request_error)
    ctx.register_hook("pre_tool_call", on_pre_tool_call)
    ctx.register_hook("post_tool_call", on_post_tool_call)
    ctx.register_hook("pre_approval_request", on_pre_approval_request)
    ctx.register_hook("post_approval_response", on_post_approval_response)
    ctx.register_hook("subagent_start", on_subagent_start)
    ctx.register_hook("subagent_stop", on_subagent_stop)


def on_session_start(**kwargs: Any) -> None:
    runtime = _get_runtime()
    if runtime is not None:
        _safe(lambda: runtime.ensure_session(kwargs))


def on_session_end(**kwargs: Any) -> None:
    runtime = _get_runtime()
    if runtime is not None:
        _safe(lambda: (runtime.mark("hermes.session.end", kwargs), runtime.export_atif(runtime.ensure_session(kwargs))))


def on_session_finalize(**kwargs: Any) -> None:
    runtime = _get_runtime()
    if runtime is not None:
        _safe(lambda: runtime.close_session(kwargs))


def on_session_reset(**kwargs: Any) -> None:
    runtime = _get_runtime()
    if runtime is not None:
        _safe(lambda: runtime.close_session(kwargs))


def on_pre_llm_call(**kwargs: Any) -> None:
    runtime = _get_runtime()
    if runtime is not None:
        _safe(lambda: runtime.mark("hermes.turn.start", kwargs))


def on_post_llm_call(**kwargs: Any) -> None:
    runtime = _get_runtime()
    if runtime is not None:
        _safe(lambda: runtime.mark("hermes.turn.end", kwargs))


def on_pre_api_request(**kwargs: Any) -> None:
    runtime = _get_runtime()
    if runtime is None:
        return

    def _record() -> None:
        state = runtime.ensure_session(kwargs)
        request_payload = kwargs.get("request")
        request_body = request_payload.get("body") if isinstance(request_payload, dict) else {}
        request = runtime.nemo_relay.LLMRequest({}, _jsonable(request_body))
        span = runtime.nemo_relay.llm.call(
            str(kwargs.get("provider") or "llm"),
            request,
            handle=state.handle,
            data=_jsonable({"turn_id": kwargs.get("turn_id"), "api_request_id": kwargs.get("api_request_id")}),
            metadata=_metadata(kwargs),
            model_name=str(kwargs.get("model") or ""),
        )
        state.llm_spans[_api_key(kwargs)] = span

    _safe(_record)


def on_post_api_request(**kwargs: Any) -> None:
    runtime = _get_runtime()
    if runtime is None:
        return

    def _record() -> None:
        state = runtime.ensure_session(kwargs)
        span = state.llm_spans.pop(_api_key(kwargs), None)
        if span is None:
            runtime.mark("hermes.api.response.unmatched", kwargs)
            return
        runtime.nemo_relay.llm.call_end(
            span,
            _jsonable(kwargs.get("response") or {}),
            data=_jsonable({"usage": kwargs.get("usage"), "finish_reason": kwargs.get("finish_reason")}),
            metadata=_metadata(kwargs),
        )

    _safe(_record)


def on_api_request_error(**kwargs: Any) -> None:
    runtime = _get_runtime()
    if runtime is None:
        return

    def _record() -> None:
        state = runtime.ensure_session(kwargs)
        span = state.llm_spans.pop(_api_key(kwargs), None)
        if span is None:
            runtime.mark("hermes.api.error", kwargs)
            return
        runtime.nemo_relay.llm.call_end(
            span,
            {"error": _jsonable(kwargs.get("error") or {})},
            data=_jsonable(kwargs),
            metadata=_metadata(kwargs),
        )

    _safe(_record)


def on_pre_tool_call(**kwargs: Any) -> None:
    runtime = _get_runtime()
    if runtime is None:
        return

    def _record() -> None:
        state = runtime.ensure_session(kwargs)
        span = runtime.nemo_relay.tools.call(
            str(kwargs.get("tool_name") or "tool"),
            _jsonable(kwargs.get("args") or {}),
            handle=state.handle,
            data=_jsonable({"turn_id": kwargs.get("turn_id"), "api_request_id": kwargs.get("api_request_id")}),
            metadata=_metadata(kwargs),
            tool_call_id=str(kwargs.get("tool_call_id") or ""),
        )
        state.tool_spans[_tool_key(kwargs)] = span

    _safe(_record)


def on_post_tool_call(**kwargs: Any) -> None:
    runtime = _get_runtime()
    if runtime is None:
        return

    def _record() -> None:
        state = runtime.ensure_session(kwargs)
        span = state.tool_spans.pop(_tool_key(kwargs), None)
        if span is None:
            runtime.mark("hermes.tool.response.unmatched", kwargs)
            return
        runtime.nemo_relay.tools.call_end(
            span,
            _jsonable(kwargs.get("result")),
            data=_jsonable({"status": kwargs.get("status"), "duration_ms": kwargs.get("duration_ms")}),
            metadata=_metadata(kwargs),
        )

    _safe(_record)


def on_pre_approval_request(**kwargs: Any) -> None:
    runtime = _get_runtime()
    if runtime is not None:
        _safe(lambda: runtime.mark("hermes.approval.request", kwargs))


def on_post_approval_response(**kwargs: Any) -> None:
    runtime = _get_runtime()
    if runtime is not None:
        _safe(lambda: runtime.mark("hermes.approval.response", kwargs))


def on_subagent_start(**kwargs: Any) -> None:
    runtime = _get_runtime()
    if runtime is not None:
        _safe(lambda: runtime.mark_subagent_start(kwargs))


def on_subagent_stop(**kwargs: Any) -> None:
    runtime = _get_runtime()
    if runtime is not None:
        _safe(lambda: runtime.mark_subagent_stop(kwargs))


def _get_runtime() -> Optional[_Runtime]:
    global _RUNTIME
    with _LOCK:
        if _RUNTIME is _INIT_FAILED:
            return None
        if isinstance(_RUNTIME, _Runtime):
            return _RUNTIME
        try:
            import nemo_relay as nemo_runtime
        except Exception as exc:
            logger.debug("NeMo Relay plugin disabled: import failed: %s", exc)
            _RUNTIME = _INIT_FAILED
            return None
        try:
            _RUNTIME = _Runtime(nemo_relay=nemo_runtime, settings=_load_settings())
        except Exception as exc:
            logger.debug("NeMo Relay plugin disabled: init failed: %s", exc, exc_info=True)
            _RUNTIME = _INIT_FAILED
            return None
        return _RUNTIME


def _load_settings() -> _Settings:
    return _Settings(
        plugins_toml_path=_env("HERMES_NEMO_RELAY_PLUGINS_TOML"),
        atof_enabled=_env_bool("HERMES_NEMO_RELAY_ATOF_ENABLED"),
        atof_output_directory=_env("HERMES_NEMO_RELAY_ATOF_OUTPUT_DIRECTORY"),
        atof_filename=_env("HERMES_NEMO_RELAY_ATOF_FILENAME") or "hermes-atof.jsonl",
        atof_mode=_env("HERMES_NEMO_RELAY_ATOF_MODE") or "append",
        atif_enabled=_env_bool("HERMES_NEMO_RELAY_ATIF_ENABLED"),
        atif_output_directory=_env("HERMES_NEMO_RELAY_ATIF_OUTPUT_DIRECTORY"),
        atif_filename_template=_env("HERMES_NEMO_RELAY_ATIF_FILENAME_TEMPLATE") or "hermes-atif-{session_id}.json",
        atif_subagent_export_mode=_atif_subagent_export_mode(),
        atif_agent_name=_env("HERMES_NEMO_RELAY_ATIF_AGENT_NAME") or "Hermes Agent",
        atif_agent_version=_env("HERMES_NEMO_RELAY_ATIF_AGENT_VERSION") or "unknown",
        atif_model_name=_env("HERMES_NEMO_RELAY_ATIF_MODEL_NAME") or "unknown",
    )


def _env(name: str) -> str:
    return os.environ.get(name, "").strip()


def _atif_subagent_export_mode() -> str:
    mode = _env("HERMES_NEMO_RELAY_ATIF_SUBAGENT_EXPORT_MODE").lower()
    return "all" if mode == "all" else "embedded"


def _env_bool(name: str) -> bool:
    return _env(name).lower() in {"1", "true", "yes", "on"}


def _session_id(kwargs: dict[str, Any]) -> str:
    return str(kwargs.get("session_id") or kwargs.get("parent_session_id") or "default")


def _child_session_id(kwargs: dict[str, Any]) -> str:
    return str(kwargs.get("child_session_id") or "")


def _subagent_child_metadata(kwargs: dict[str, Any], parent_metadata: dict[str, Any]) -> dict[str, Any]:
    child_session_id = _child_session_id(kwargs)
    metadata = {
        "session_id": child_session_id,
        "trajectory_id": child_session_id,
        "nemo_relay_scope_role": "subagent",
    }
    for target, source in (
        ("subagent_id", "child_subagent_id"),
        ("child_session_id", "child_session_id"),
        ("child_subagent_id", "child_subagent_id"),
        ("child_role", "child_role"),
        ("parent_session_id", "parent_session_id"),
        ("parent_turn_id", "parent_turn_id"),
        ("parent_subagent_id", "parent_subagent_id"),
        ("parent_trajectory_id", "parent_trajectory_id"),
        ("telemetry_schema_version", "telemetry_schema_version"),
    ):
        value = parent_metadata.get(source)
        if value is not None:
            metadata[target] = value
    return metadata


def _api_key(kwargs: dict[str, Any]) -> str:
    return str(kwargs.get("api_request_id") or f"{_session_id(kwargs)}:{kwargs.get('api_call_count') or 'api'}")


def _tool_key(kwargs: dict[str, Any]) -> str:
    return str(
        kwargs.get("tool_call_id")
        or f"{_session_id(kwargs)}:{kwargs.get('turn_id') or ''}:{kwargs.get('tool_name') or 'tool'}"
    )


def _metadata(kwargs: dict[str, Any]) -> dict[str, Any]:
    keys = (
        "telemetry_schema_version",
        "session_id",
        "platform",
        "task_id",
        "turn_id",
        "api_request_id",
        "tool_call_id",
        "parent_session_id",
        "parent_turn_id",
        "parent_subagent_id",
        "child_session_id",
        "child_subagent_id",
        "child_role",
        "child_status",
        "provider",
        "model",
        "api_mode",
        "status",
        "reason",
    )
    metadata = {
        key: _jsonable(kwargs[key])
        for key in keys
        if key in kwargs and kwargs[key] is not None
    }
    if "session_id" in metadata:
        metadata.setdefault("trajectory_id", metadata["session_id"])
    if "parent_session_id" in metadata:
        metadata.setdefault("parent_trajectory_id", metadata["parent_session_id"])
    if "child_session_id" in metadata:
        metadata.setdefault("child_trajectory_id", metadata["child_session_id"])
    return metadata


def _jsonable(value: Any) -> Any:
    if value is None or isinstance(value, (str, int, float, bool)):
        return value
    if isinstance(value, dict):
        return {str(k): _jsonable(v) for k, v in value.items()}
    if isinstance(value, (list, tuple, set)):
        return [_jsonable(v) for v in value]
    try:
        if hasattr(value, "model_dump"):
            return _jsonable(value.model_dump(mode="json"))
    except Exception:
        pass
    try:
        return json.loads(json.dumps(value, default=str))
    except Exception:
        return str(value)


def _safe(fn) -> None:
    try:
        fn()
    except Exception as exc:
        logger.debug("NeMo Relay hook handling failed: %s", exc, exc_info=True)


def reset_for_tests() -> None:
    global _RUNTIME
    with _LOCK:
        _RUNTIME = None