"""Plugin-registered TTS providers for ``tools.tts_tool``: routes ``tts.provider: <name>`` values
that are neither built-in nor ``type: command`` to a plugin :class:`agent.tts_provider.TTSProvider`.
Discovery goes through ``hermes_cli.plugins._ensure_plugins_discovered`` (imported lazily so the
tool module stays importable without the plugin machinery).
"""

from __future__ import annotations

import logging
import math
from typing import Any, Dict, Optional, Tuple

from tools.tts_command_provider import (
    BUILTIN_TTS_PROVIDERS, DEFAULT_COMMAND_TTS_OUTPUT_FORMAT, _get_named_provider_config,
    _is_command_provider_config)
from tools.tool_backend_helpers import NOUS_MANAGED_PROVIDER

logger = logging.getLogger("tools.tts_tool")


def _lookup_plugin_provider(key: str, *, discover: bool = True, retry: bool = False):
    """The registered ``TTSProvider`` named *key*, or None. ``discover`` runs plugin discovery first;
    ``retry`` re-discovers with ``force=True`` on a miss (a long-lived session may predate the
    plugin's install). Raises on registry/discovery failure — callers decide if fatal."""
    from agent.tts_registry import get_provider
    if discover:
        from hermes_cli.plugins import _ensure_plugins_discovered
        _ensure_plugins_discovered()
    plugin_provider = get_provider(key)
    if plugin_provider is None and retry:
        _ensure_plugins_discovered(force=True)
        plugin_provider = get_provider(key)
    return plugin_provider


def _plugin_route_key(provider: str, tts_config: dict[str, Any]) -> Optional[str]:
    """Normalized *provider* when a plugin may service it, else None: built-in names never reach the
    registry and a same-named ``type: command`` provider wins (config is more local than a plugin)."""
    key = (provider or "").lower().strip()
    if not key or key in BUILTIN_TTS_PROVIDERS or key == NOUS_MANAGED_PROVIDER:  # nous = the openai path
        return None
    if _is_command_provider_config(_get_named_provider_config(tts_config, key)):
        return None
    return key


def _plugin_voice_kwargs(tts_config: dict[str, Any]) -> dict[str, Any]:
    """``voice`` / ``model`` / ``speed`` for a plugin call (None = provider default). Shared by
    ``synthesize`` and the streaming path so a streamed reply keeps the configured voice."""
    cfg = tts_config if isinstance(tts_config, dict) else {}
    voice, model, speed = cfg.get("voice"), cfg.get("model"), cfg.get("speed")
    return {"voice": voice if isinstance(voice, str) and voice else None,
            "model": model if isinstance(model, str) and model else None,
            "speed": float(speed) if isinstance(speed, (int, float)) else None}


def _plugin_pcm_streaming_provider(provider: str, tts_config: dict[str, Any]) -> Optional[tuple[Any, int]]:
    """``(plugin, sample_rate)`` when the plugin servicing *provider* opted into raw-PCM streaming.

    Opt-in = ``streams_pcm`` truthy AND ``stream_sample_rate`` a finite number >= 1 Hz AND
    ``is_available()`` — read once per resolve, so per-profile state (key present, user opted out)
    belongs there. A bad rate is refused loudly: PCM played at a guessed rate garbles speech.
    """
    key = _plugin_route_key(provider, tts_config)
    if key is None:
        return None
    try:
        plugin = _lookup_plugin_provider(key)
        if plugin is None or not plugin.streams_pcm or not plugin.is_available():
            return None
        rate = plugin.stream_sample_rate
    except Exception:  # third-party plugin code: a broken plugin falls back to per-sentence synthesis
        logger.debug("plugin TTS streaming lookup failed for '%s'", key, exc_info=True)
        return None
    if isinstance(rate, bool) or not isinstance(rate, (int, float)) or not math.isfinite(rate) or rate < 1:
        logger.warning("TTS provider '%s' sets streams_pcm without a valid stream_sample_rate (%r); "
                       "using per-sentence synthesis instead", key, rate)
        return None
    return plugin, int(rate)


def _dispatch_to_plugin_provider(text: str, output_path: str, provider: str, tts_config: dict[str, Any]) -> Optional[str]:
    """Route to a plugin-registered TTS provider; None means "fall through".

    Invariants re-checked here so a caller refactor can't break them: built-in names never reach
    the registry; a same-named ``type: command`` provider wins; only an exact registered name
    dispatches. Plugin exceptions propagate to ``text_to_speech_tool``'s error envelope.

    Resolution invariants enforced here (matches issue #30398):
    1. The caller is responsible for the elif chain that handles ``edge``/``openai``/etc.; this function
    explicitly rejects those names defensively. 2. 3. Plugin dispatch fires only when ``provider`` matches a
    registered :class:`TTSProvider` whose ``name`` equals the configured value. Unknown names return None
    (caller falls through to Edge default). See #17843.
    """
    key = _plugin_route_key(provider, tts_config)
    if key is None:
        return None
    try:
        plugin_provider = _lookup_plugin_provider(key, retry=True)
    except Exception as exc:
        logger.debug("tts plugin dispatch skipped (discovery failed): %s", exc)
        return None
    if plugin_provider is None:
        return None
    fmt = (tts_config if isinstance(tts_config, dict) else {}).get(
        "output_format", DEFAULT_COMMAND_TTS_OUTPUT_FORMAT)
    logger.info("Generating speech with plugin TTS provider '%s'...", key)
    written = plugin_provider.synthesize(
        text, output_path, format=str(fmt).lower() if fmt else "mp3", **_plugin_voice_kwargs(tts_config))
    return written if isinstance(written, str) and written else output_path


def _plugin_provider_is_voice_compatible(provider: str) -> bool:
    """True when the registered plugin provider opts into voice-bubble delivery (any failure -> False)."""
    key = (provider or "").lower().strip()
    if not key or key in BUILTIN_TTS_PROVIDERS:
        return False
    try:
        plugin_provider = _lookup_plugin_provider(key, discover=False)
        return plugin_provider is not None and bool(plugin_provider.voice_compatible)
    except Exception as exc:
        logger.debug("tts plugin voice_compatible check failed for '%s': %s", key, exc)
        return False


def _plugin_provider_is_available(provider: str) -> bool:
    """``check_fn`` leg for plugin names: discovered provider reports ``is_available()``; any failure is False."""
    try:
        plugin = _lookup_plugin_provider(provider)
        return bool(plugin and plugin.is_available())
    except Exception:
        return False