# backend/voice/post_process.py
# §0.4 — JARVIS DSP Post-Processing Chain
# Shared by Kokoro and XTTS engines. Profile-driven via JARVIS_VOICE_PROFILE.
# Uses Spotify's pedalboard library (fast, lightweight, no FFmpeg dependency).

import numpy as np
import logging

logger = logging.getLogger(__name__)

def apply_jarvis_dsp_chain(audio: np.ndarray, sr: int) -> np.ndarray:
    """
    Full JARVIS DSP chain per JARVIS_VOICE_PROFILE["dsp_chain"]:
      noise_reduction → eq_low_mid_boost → compression → de_esser → limiter → subtle_room_reverb
    
    Input:  float32 numpy array, any sample rate
    Output: float32 numpy array, same sample rate, peak-limited to -1 dBFS
    """
    try:
        from pedalboard import Pedalboard, NoiseGate, LowShelfFilter, HighShelfFilter, \
                               PeakFilter, Compressor, Limiter, Reverb
        # Ensure float32
        audio = audio.astype(np.float32)
        
        # Reshape to (channels, samples) for pedalboard if 1D
        if audio.ndim == 1:
            audio = audio[np.newaxis, :]   # (1, N)

        board = Pedalboard([
            # Step 1: Noise reduction — light noise gate to suppress breath/hiss
            NoiseGate(threshold_db=-40, ratio=2.0, attack_ms=5.0, release_ms=100.0),

            # Step 2: EQ — boost 80–400 Hz body, cut harsh highs
            LowShelfFilter(cutoff_frequency_hz=200, gain_db=3.5, q=0.7),     # low + low-mid body
            PeakFilter(cutoff_frequency_hz=150, gain_db=2.0, q=1.0),          # chest resonance
            HighShelfFilter(cutoff_frequency_hz=5000, gain_db=-2.0, q=0.7),  # tame brightness

            # Step 3: De-esser — tame sibilance around 6 kHz
            PeakFilter(cutoff_frequency_hz=6000, gain_db=-4.0, q=3.0),

            # Step 4: Compression — 3:1, fast attack, medium release
            Compressor(threshold_db=-18.0, ratio=3.0, attack_ms=5.0, release_ms=80.0),

            # Step 5: Limiter — hard ceiling at -1 dBFS
            Limiter(threshold_db=-1.0, release_ms=100.0),

            # Step 6: Subtle room reverb — adds slight intimacy without muddying
            Reverb(room_size=0.08, wet_level=0.04, dry_level=0.96, damping=0.6),
        ])

        processed = board(audio, sr)

        # Return as 1D float32
        return processed[0].astype(np.float32)

    except ImportError:
        logger.warning("[DSP] pedalboard not installed — skipping DSP chain. Run: pip install pedalboard")
        # Graceful degradation: return audio as-is (flat float32)
        if audio.ndim > 1:
            audio = audio[0]
        return audio.astype(np.float32)
    except Exception as e:
        logger.error(f"[DSP] Chain failed: {e} — returning dry audio")
        if audio.ndim > 1:
            audio = audio[0]
        return audio.astype(np.float32)