"""
hermes-piper-plugin (piper)

Overrides Hermes' default TTS provider from Edge to Piper at plugin load
time. Uses runtime monkey-patching — zero modifications to the Hermes repo.
"""

from __future__ import annotations

import logging

logger = logging.getLogger(__name__)

_PATCHED = False


def _apply_piper_patch() -> None:
    """Replace Edge default with Piper in TTS tool's provider selection.

    Python module-level constants are mutable — ``DEFAULT_PROVIDER`` is a
    string that ``_get_provider()`` reads at call time (not import time).
    Changing it after import is safe and immediately effective.
    """
    global _PATCHED
    if _PATCHED:
        return

    try:
        import tools.tts_tool

        old_default = getattr(tools.tts_tool, "DEFAULT_PROVIDER", "edge")
        tools.tts_tool.DEFAULT_PROVIDER = "piper"

        logger.info("piper-plugin: DEFAULT_PROVIDER changed from '%s' → 'piper'", old_default)
        _PATCHED = True
    except ImportError:
        logger.warning("piper-plugin: tools.tts_tool not importable — patch deferred")
    except Exception as exc:
        logger.warning("piper-plugin: failed to patch DEFAULT_PROVIDER: %s", exc)


def _on_session_start(**kw):
    """Log Piper default status at session start (idempotent)."""
    if not _PATCHED:
        _apply_piper_patch()

    try:
        import tools.tts_tool
        current = getattr(tools.tts_tool, "DEFAULT_PROVIDER", "?")
        logger.info("piper-plugin: TTS default provider = %s (patched=%s)", current, _PATCHED)
    except Exception:
        pass


def register(ctx) -> None:
    """Register Piper default override."""
    _apply_piper_patch()
    ctx.register_hook("on_session_start", _on_session_start)
    logger.info("piper-plugin: registered ✓ (TTS default → piper)")